Tom Van Flandern and Newtonian Gravity
Bill Hobba
believes gravity propagates at speeds greater than c and Steve Carlips
reply. It has not really been a priority because the lornentz
transformations prove casualty would be violated if you could do it.
But I have actually read Tom's view and am left scratching my head at what
the fuss is about. Tom wrote:
'Indeed, it is widely accepted, even if less widely known, that the speed of
gravity in Newton's Universal Law is unconditionally infinite. (e.g., Misner
et al., 1973, p.177) This is usually not mentioned in proximity to the
statement that GR reduces to Newtonian gravity in the low-velocity,
weak-field limit because of the obvious question it begs about how that can
be true if the propagation speed in one model is the speed of light, and in
the other model it is infinite.'
As Landau demonstrates the existence of a classical potential implies forces
modeled by classical mechanics must propagate instantaneously. This is
associated with the instantaneous propagation time required by the Galilean
transformation on which classical mechanics is built. And it is true that
in the non relativistic limit Newtonian gravity results and that requires
instantaneous propagation of forces. But what you have done in taking the
non relativistic limit is to say we are dealing with speeds much smaller
than light so we make the speed of light to be infinite ie we have
introduced the assumption the speed of interaction is infinite ie the
Galilean transformation now apply not the lorentz transformations. It is
hardly a surprise that a theory based on instantaneous interaction requires
the speed of gravity to act instantaneously. And is it also hardly a
surprise that it now violates the known problems of having instantaneous
transmission of information - you have specifically decided for the purpose
of having a theory that applies to velocities much less than c you want c to
be infinite and are willing to accept that it is now not a theory that is in
accord with other known principles of nature. You can't say I, for the sake
of simplicity, will assume c to be infinite then worry about c being finite.
It makes no sense AFAIKS.
Of course I read Steve Carlip response and naturally agree with it. But in
view of what I write above I am left with this feeling it is an overkill.
What do others think? - or am I missing something (quite possibly).
Thanks
Bill
Tom Roberts
> I have been meaning for a while to actually tread Tom's views on why he
> believes gravity propagates at speeds greater than c and Steve Carlips
> reply. It has not really been a priority because the lornentz
> transformations prove casualty would be violated if you could do it.
>
> But I have actually read Tom's view and am left scratching my head at what
> the fuss is about.
The basic "fuss" is that Tom Van Flandern keeps insisting that in GR the
"speed of gravity" is infinite, when in fact it is not. There would be
no fuss if he merely stated that in the Newtonian limit of GR the "speed
of gravity" acts as if it were infinite.
I put "speed of gravity" in quotes, because a secondary problem with his
writing is that what he discusses is not really any sort of speed of
propagation at all.
If instead of the gravity of a moving planet he were
discussing the planet's surface, he would be proclaiming
loudly that the "speed of propagation" of the surface is
infinite (meaning that the surface arrives at any given
location as if it propagated with infinite speed from
the location of the center of the planet) -- how silly
that would sound, because it is quite clear that the
surface of a planet does not "propagate" from its center;
neither does its gravity.
Tom Roberts tjro...@lucent.com
Bill Hobba
"Tom Roberts" <tjro...@lucent.com> wrote in message
news:ZsDkc.1299$eH1.7...@newssvr28.news.prodigy.com...
Bill Hobba
"Tom Roberts" <tjro...@lucent.com> wrote in message
news:ZsDkc.1299$eH1.7...@newssvr28.news.prodigy.com...
> > I have been meaning for a while to actually tread Tom's views on why he
> > believes gravity propagates at speeds greater than c and Steve Carlips
> > reply. It has not really been a priority because the lornentz
> > transformations prove casualty would be violated if you could do it.
> >
> > But I have actually read Tom's view and am left scratching my head at
what
> > the fuss is about.
>
> The basic "fuss" is that Tom Van Flandern keeps insisting that in GR the
> "speed of gravity" is infinite, when in fact it is not.
If that is what Tom was saying then I see what the fuss is about. But it
would be a silly position because one of the reasons GR was concocted it to
address the problem that SR requires a theory of gravity (at least in the
weak gravity limit where it can be considered to apply) to not propagate
instantaneously.
>There would be
> no fuss if he merely stated that in the Newtonian limit of GR the "speed
> of gravity" acts as if it were infinite.
>
> I put "speed of gravity" in quotes, because a secondary problem with his
> writing is that what he discusses is not really any sort of speed of
> propagation at all.
Actually your right - I didn't see that before. It puts Steve Carlips reply
in perspective. Thanks for clarifying it.
Thanks
Bill
Harry
May that be related to the electrical field retardation problem that I
posted on 29 April? The way you put it, it sounds to me that Van
Flandern denies that the gravitational field of a planet retards on
its movement (under certain conditions?), just like I now wonder -
since a few days ago - if, as text books claim, the electrical field
retards on the movement of a charged particle when it is moving
inertially. As that can really be said to be static, I can imagine
that there is no retardation.
Harald
Mike
Van Flandern's Meta Model is built around the concept of Le Sage's
material graviton flux. It turns out that for that model to work and
avoid issues like exploding planets due to the gravitons hitting
matter at high speeds, these particles must have an ultra small mass
and travel at about 10^20 c (!) if I recall correcly the number. Thus,
in that model of his, gravity propagates at FTL speeds and there is a
physical mechanism which is based on momentum exchange and shadowing.
Gravity is thus a push force.
Now, Van Flandern was upset when Kopeikin announced his measurement of
the light deflection from Jupiter and pronounced the vg = c. This is
because, if vg = c then the graviton, which is unobservable entity now
my its properties, cannot exist. Furthermore, Van Flandern attacked
the geometric interpretation of GR and has declared the field force
interpretation as the only appropriate. This is because, the geometric
is consistent with vg=c but the field one is probably not.
I think Van Flandern is the last of physicalists reamining on the
planet. He is to be respected for his intense effort to 'save the
phenomena' and his quasi-static universe model in that respect. But he
is subject to contradictions that arise in his model and the needd to
continuously rearrange it and add new hypothesis in order to keep it
up with empirical observations. But he worths respect. I wish Van
Flandern's world was real but unfortunately it seems it is not. One
think i definitevely agree with Dr. Al is that this wrold is strange
and Newtonian or Le Sage models too naive to explain it.
Mike
Bill Hobba
"Mike" <ele...@yahoo.gr> wrote in message
news:9c1b39be.04050...@posting.google.com...
Particles traveling faster than light?
Consider a superluminal speed U>c. Choose coordinates so these events both
occur on the x axis and let their time and distance separations be delta x >
0 and delta t > 0. Consider another frame moving at a velocity v c2/U < v <
c. Then in that frame delta t' = (1/sqrt (1-v2/c2))(delata t - v delta
x/c2) = (delta t/sqrt (1-v2/c2))(1 - vU/c2)). Thus delta t < 0 implying
causality volition.
Your refutation?
>
> Now, Van Flandern was upset when Kopeikin announced his measurement of
> the light deflection from Jupiter and pronounced the vg = c. This is
> because, if vg = c then the graviton, which is unobservable entity now
> my its properties, cannot exist. Furthermore, Van Flandern attacked
> the geometric interpretation of GR and has declared the field force
> interpretation as the only appropriate. This is because, the geometric
> is consistent with vg=c but the field one is probably not.
And was fully refuted here
http://xxx.lanl.gov/PS_cache/gr-qc/pdf/9909/9909087.pdf. The point I was
bringing up was I thought Steve Carlips refutation may have been an
overkill - not that I disagreed with it in any way. However it turned out I
misunderstood exactly what Tom was saying.
>
> I think Van Flandern is the last of physicalists reamining on the
> planet.
> He is to be respected for his intense effort to 'save the
> phenomena' and his quasi-static universe model in that respect. But he
> is subject to contradictions that arise in his model and the needd to
> continuously rearrange it and add new hypothesis in order to keep it
> up with empirical observations. But he worths respect. I wish Van
> Flandern's world was real but unfortunately it seems it is not. One
> think i definitevely agree with Dr. Al is that this wrold is strange
> and Newtonian or Le Sage models too naive to explain it.
>
> Mike
Thanks
Bill
Paul Stowe
[Snip...]
>> Van Flandern's Meta Model is built around the concept of Le Sage's
>> material graviton flux. It turns out that for that model to work and
>> avoid issues like exploding planets due to the gravitons hitting
>> matter at high speeds, these particles must have an ultra small mass
>> and travel at about 10^20 c (!) if I recall correcly the number. Thus,
>> in that model of his, gravity propagates at FTL speeds and there is a
>> physical mechanism which is based on momentum exchange and shadowing.
>> Gravity is thus a push force.
>
> Particles traveling faster than light?
>
> Consider a superluminal speed U > c.
OK...
> Choose coordinates so these events both occur on the x axis
OK...
> and let their time and distance separations be delta x > 0 and delta t > 0.
OK...
> Consider another frame moving at a velocity v ...
OK...
> c2/U < v < c.
OK, but irrelevant
> Then in that frame delta t' = (1/sqrt (1-v2/c2))(delata t - v delta
> x/c2) = (delta t/sqrt (1-v2/c2))(1 - vU/c2)). Thus delta t < 0
> implying causality violation.
>
> Your refutation?
It's like multiplying by zero. The Lorentz transform is invalid in this
case. It's assumptional basis is nullified by assuming U > c!
Hmmm, let's see, 'hypothetically' I create a FTL transmitter than can
send signals a 25c... and we have a base on Mars and will use this to
communicate with. Does this mean that both parties will receive
transmissions 'out of order' and 'before' they were physically sent?
Nope, just that the round trip 'delta t' is 25 times faster than normal
radio. Changing FORs won't change the phyical situation one iotta.
Duh!
Paul Stowe
Paul Stowe
wrote:
Clarification, faster means shorter delta t... All signals
remain in transmission order, no negative delta.
Bill Hobba
"Paul Stowe" <p...@acompletelyjunkaddress.net> wrote in message
news:fsjd909grladk24ag...@4ax.com...
So Paul is claiming that for signals > c the lorentz transforms can not be
used But space time events are things recorded by clocks at points in
space. The fact it was registered is what counts - not the thing that
caused it to be registered. SR makes no such distinction.
>
> Hmmm, let's see, 'hypothetically' I create a FTL transmitter than can
> send signals a 25c... and we have a base on Mars and will use this to
> communicate with. Does this mean that both parties will receive
> transmissions 'out of order' and 'before' they were physically sent?
> Nope, just that the round trip 'delta t' is 25 times faster than normal
> radio. Changing FORs won't change the phyical situation one iotta.
>
> Duh!
No Paul what it shows is that in some inertial frame we will have the event
'the signal arriving at the receiver' preceding the event 'it was
transmitted'. Now consider the following set up. A signal is sent and
received then sent back to switch off the transmitter so it can not send any
more signals. In one inertial frame no problem. In another the signal will
arrive switching off the transmitter before it can send the signal. These
types of paradoxes go under the general heading of the 'grandfather paradox'
(you now when a person goes back in time and kills his own grandfather) and
provides a powerful argument against time travel and causality violation.
The fact that delta t' is negative simply admits no other interpretation.
Thanks
Bill
Bill Hobba
But that does not get around the fact that an inertial frame exists where
the ordering is reversed. That was the relevance of c2/U < v < c that you
considered irrelevant.
Thanks
Bill
Mike
SR. However, Van Flandern has LET in place of SR in his model, where c
is constant but not a global limit and thus your causality violation
does not hold as the speed of light is source dependent.
Mike
Mike
It would also be profitable to specify that these paradoxes arise when
one postulates invariance of c along with FTL speeds. In alternatives
to SR, like LR, FTL speeds are allowed without any causality violation
since the speed of light is dependent on the speed of its source,
which can serve as a light carrying medium.
But leaving physics and going into philosophy of science, what is
exactly the meaning of 'causality violation' in SR? The theory is
acausal in the first place. It is a block universe with no direction
of time but only temporal order in a way that is not specified
explicitely. In this sense, you are talking about reversing temporal
order of events and any talk about causality is shaky unless you prove
that causality is strongly associated with temporal order. But past,
present and future in SR cannot be distinguished in principle by
different observers in different inertial reference frames. Therefore,
all this talk is senseless and a handicap of SR because it shows how
the theory leads to counter-intuitive conclusions. First it assumes a
universal speed limit and then determines that if this limit is
exceeded there is causality violation. From this, the conclusion that
FTL speeds are not allowed without causality violation is a non
sequitur. Of course, the conclusion that c must be the limit is a
plain petitio principii.
My personal belief is the c is indeed a universal limit and Einstein
was right about that. But there are other things he missed for a
complete story and he end up with an absurd world. Maybe he intended
this as a start up but people are stuck with it and every effort to
improve it is met with resistance from orthodox relativists.
Mike
Harry
"Mike" <ele...@yahoo.gr> wrote in message
news:9c1b39be.04050...@posting.google.com...
> "Bill Hobba" <bho...@hotmail.com> wrote in message
SNIP
I think that he does not use LET but his own version which he regretfully
named "Lorentzian Relativity".
In any case, in Lorentz' theories light was always source independent.
Harald
Mike
principii. Van Flandern also claims GR violates conservation laws.
A 'simpler' explanation may be grounded on the hypothesis that gravity
propagation in GR is facilitated by a substantive space-time that is
not restricted by c.
Just a hypothesis, I mean. There was a recent paper ny a grad student
from Princeton asserting the substantive property of GR space-time.
Mike
Bill Hobba
Sorry. OR still has the Lorentz transformations thus my proof is still
valid.
> But leaving physics and going into philosophy of science, what is
> exactly the meaning of 'causality violation' in SR?
Effects precede causes. In no frame will a person be seen to switch on a
light and the light come on prior to the switch being activated. Such
events are always time like.
> The theory is
> acausal in the first place. It is a block universe with no direction
> of time but only temporal order in a way that is not specified
> explicitely.
I beg to differ. The fact one arrives at paradoxes if effects can precede
causes is well known.
> In this sense, you are talking about reversing temporal
> order of events and any talk about causality is shaky unless you prove
> that causality is strongly associated with temporal order.
It is not necessary to show any such thing. Simply consider some physical
set up to creates the 'grandfather paradox' and you are in serious logical
problems.
> But past,
> present and future in SR cannot be distinguished in principle by
> different observers in different inertial reference frames.
In SR effects never precede causes. Your refutation of this would be very
enlightening.
> Therefore,
> all this talk is senseless and a handicap of SR because it shows how
> the theory leads to counter-intuitive conclusions.
Only if one does not think properly.
> First it assumes a
> universal speed limit and then determines that if this limit is
> exceeded there is causality violation.
Hmmmm. An experimentally observed phenomena is an assumption. You might
like to reconsider that. Induction can never prove an assumption but it
gives it greater weight than 'just an assumption's eg we have no evidence
against it but we do have evidence against light having different speeds in
different inertial frames.
> From this, the conclusion that
> FTL speeds are not allowed without causality violation is a non
> sequitur. Of course, the conclusion that c must be the limit is a
> plain petitio principii.
Not really because other effects that follow from the invariance of the
speed of light such as the equivalence of mass and energy and the apparent
mass increase of particles that allow the design of the monitor your
probably writing this on are firmly established.
>
> My personal belief is the c is indeed a universal limit and Einstein
> was right about that. But there are other things he missed for a
> complete story and he end up with an absurd world. Maybe he intended
> this as a start up but people are stuck with it and every effort to
> improve it is met with resistance from orthodox relativists.
That is fine Mike. Got any specific suggestions? By specific I do not mean
philosophical generalities I mean specific predictions at variance with SR
that can be confirmed by experiment.
Thanks
Bill
Bill Hobba
Let has the Lorentz transformations just as SR does, and they are assumed to
hold in inertial frames just as SR does, so my argument is just as valid in
SR or LET.
Thanks
Bill
Bill Hobba
"Harry" <harald.v...@epfl.ch> wrote in message
news:40978bf0$1...@epflnews.epfl.ch...
Indeed that may be the case. In discussions I had with Tom it soon became
apparent he was using something different. However I could never coax the
details out of him because he always confirmed he believed in the Lorentz
transformations. My argument accepts their validity in any inertial frame -
no other assumption is made.
Thanks
Bill
Paul Stowe
More fundamental than that, NOT APPLICABLE! If there were another
'fixed' upper speed limit for these imagined hyperluminal particles
there'd be another set of expressions governing this.
> But space time events are things recorded by clocks at points in
> space. The fact it was registered is what counts - not the thing that
> caused it to be registered. SR makes no such distinction.
So, with hperluminal particles you're outside of SR's domain, BY
DEFINITION!
>> Hmmm, let's see, 'hypothetically' I create a FTL transmitter than can
>> send signals a 25c... and we have a base on Mars and will use this to
>> communicate with. Does this mean that both parties will receive
>> transmissions 'out of order' and 'before' they were physically sent?
>> Nope, just that the round trip 'delta t' is 25 times faster than normal
>> radio. Changing FORs won't change the phyical situation one iotta.
>>
>> Duh!
>
> No Paul what it shows is that in some inertial frame we will have the
> event 'the signal arriving at the receiver' preceding the event 'it was
> transmitted'.
No, it won't... All delta times are possitive.
> Now consider the following set up. A signal is sent and received then
> sent back to switch off the transmitter so it can not send any more
> signals. In one inertial frame no problem. In another the signal will
> arrive switching off the transmitter before it can send the signal.
Really? We have a hypothetical system by which we can send AND receive
information at 25c. So, instead of using light signals to 'synch' up
clocks we use these. Want to guess what happens then??? NO IMAGINED
CHANGE IN COORDINATES CAN CHANGE A PHYSICAL PROCESS. Thus you simply
cannot, in any so-called frame stop a FTL transmitter using slower RT
signals OR its own by signaling backward in time!
> These types of paradoxes go under the general heading of the 'grandfather
> paradox' (you now when a person goes back in time and kills his own
> grandfather) and provides a powerful argument against time travel and
> causality violation.
But I'm NOT talking about ANY causality violations!
> The fact that delta t' is negative simply admits no other interpretation.
That delta t is negative means you screwed up! There is, NO nor will
there ever be negative delta t's.
Paul Stowe
Bill Hobba
The space-time events they cause are not however.
>
> >> Hmmm, let's see, 'hypothetically' I create a FTL transmitter than can
> >> send signals a 25c... and we have a base on Mars and will use this to
> >> communicate with. Does this mean that both parties will receive
> >> transmissions 'out of order' and 'before' they were physically sent?
> >> Nope, just that the round trip 'delta t' is 25 times faster than normal
> >> radio. Changing FORs won't change the phyical situation one iotta.
> >>
> >> Duh!
> >
> > No Paul what it shows is that in some inertial frame we will have the
> > event 'the signal arriving at the receiver' preceding the event 'it was
> > transmitted'.
>
> No, it won't... All delta times are possitive.
Unfortunately the existence of in inertial frame where it is negative shows
otherwise.
>
> > Now consider the following set up. A signal is sent and received then
> > sent back to switch off the transmitter so it can not send any more
> > signals. In one inertial frame no problem. In another the signal will
> > arrive switching off the transmitter before it can send the signal.
>
> Really? We have a hypothetical system by which we can send AND receive
> information at 25c. So, instead of using light signals to 'synch' up
> clocks we use these. Want to guess what happens then??? NO IMAGINED
> CHANGE IN COORDINATES CAN CHANGE A PHYSICAL PROCESS. Thus you simply
> cannot, in any so-called frame stop a FTL transmitter using slower RT
> signals OR its own by signaling backward in time!
Still does not address the logical consequences of the Lorentz
transformation.
>
> > These types of paradoxes go under the general heading of the
'grandfather
> > paradox' (you now when a person goes back in time and kills his own
> > grandfather) and provides a powerful argument against time travel and
> > causality violation.
>
> But I'm NOT talking about ANY causality violations!
No, because you do not like the implication you simply ignore the fact that
negative delta t' results in some inertial frame.
>
> > The fact that delta t' is negative simply admits no other
interpretation.
>
> That delta t is negative means you screwed up! There is, NO nor will
> there ever be negative delta t's.
It is a standard procedure in logic - you assume something then show it
leads to a contradiction. Thus what you assume can not be true.
Thanks
Bill
Tom Van Flandern
again, and Mike.
"Bill Hobba" <bho...@hotmail.com> writes:
> [Hobba]: I have been meaning for a while to actually read Tom's views
on why he believes gravity propagates at speeds greater than c and Steve
Carlips reply. It has not really been a priority because the lorentz
transformations prove casualty would be violated if you could do it.
Causality would be violated if special relativity (SR) were
valid. But Lorentzian relativity (LR) competes with SR, has never been
falsified, and allows FTL propagation and communication. And the six
experiments showing that gravitational force propagates faster than
light *in forward time* show that SR is now falsified in favor of LR.
See "Experimental Repeal of the Speed Limit for Gravitational,
Electrodynamic, and Quantum Field Interactions", T. Van Flandern and
J.P. Vigier, Found.Phys. 32(#7), 1031-1068 (2002), which would never
have been published if your assumption about causality being violated by
FTL propagation were true in physics.
As we show in that paper, it is actually the geometric
interpretation of GR that violates causality because it proposes that
gravity is not a force that propagates, but is rather *caused* by the
curvature of "spacetime". However, comparisons of theory and
observations must be done in 3-space plus time, and curvature cannot
initiate 3-space motion unless a force acts. For example, the rubber
sheet analogy fails unless gravity pre-exists as a force underneath the
rubber sheet to make objects roll downhill. The same criticism applies
to any form of curvature - it provides no cause to initiate motion.
Moreover, the new 3-space momentum imparted by a source mass to an
orbiting target body cannot be created ex nihilo in physics. It
therefore requires a force by definition: "force is the time rate of
change of momentum".
Finally, please take note that "spacetime" has no spatial
component. Time-like geodesics are really proper time intervals
multiplied by c to make them appear space-like. See
http://metaresearch.org/cosmology/gravity/spacetime.asp. So no
"curvature of space" is involved in spacetime curvature, as Misner,
Thorne and Wheeler acknowledge on p. 32 of "Gravitation".
For all these good and sufficient reasons, the geometric
interpretation of GR must now give way to the field interpretation,
which was anyway always favored by Einstein, Dirac, Feynman, and other
notables. For example, we read in [R.P. Feynman (1995), Feynman Lectures
on Gravitation, Addison-Wesley, New York, section 8.4, p. 113]:
"It is one of the peculiar aspects of the theory of gravitation, that it
has both a field interpretation and a geometrical interpretation. . the
fact is that a spin-two field has this geometrical interpretation: this
is not something readily explainable - it is just marvelous. The
geometrical interpretation is not really necessary or essential to
physics."
> [Hobba]: As Landau demonstrates the existence of a classical potential
implies forces modeled by classical mechanics must propagate
instantaneously. This is associated with the instantaneous propagation
time required by the Galilean transformation on which classical
mechanics is built.
Because it is easy to construct a counterexample, the
demonstration you cite can only apply to special cases such as
gravitation and electrodynamics. For example, light amplitude has the
attributes of a classical potential field and varies with 1/r (where r
is distance from source), yet its corresponding 1/r^2 force, radiation
pressure, clearly propagates at the speed of light, not instantaneously.
But in the case of gravitation, we now appreciate that
potential and force are physically separate phenomena, with force
inducing a gradient onto the potential field and not vice versa. So
there is no logical reason why the propagation speeds of gravitational
force and changes in gravitational potential fields should be the same.
That would be like insisting that the speed of an asteroid had to be the
same as the speed of the sonic wave it sets off in our atmosphere upon
impact. In reality, the two speeds are independent, even though causally
related.
> [Hobba]: And it is true that in the non relativistic limit Newtonian
gravity results and that requires instantaneous propagation of forces.
But what you have done in taking the non relativistic limit is to say we
are dealing with speeds much smaller than light so we make the speed of
light to be infinite ie we have introduced the assumption the speed of
interaction is infinite ie the Galilean transformation now apply not the
lorentz transformations.
However, that is not what astronomers do. To get correct
orbits in celestial mechanics, we are obliged to calculate forces
instantaneously for bodies of all masses and speeds, then to calculate
their observed positions using speed-of-light retardation between body
and observer because the speed-of-light propagation delays are large and
significant and obviously not shared by gravitational forces.
Take binary pulsars as an example. The masses are
relativistically significant, and the velocities are also because
classical GR effects (light-bending, redshift, pericenter advance,
Shapiro delay) are plainly evident. Yet we must still use instantaneous
forces to get correct orbits. Any force propagation delay produces an
outward spiral, contrary to observations. And it is not sufficient to
hypothesize that each star anticipates the linear motion of its
companion one light-time ahead. The acceleration of the stars during one
light-time is also significant. So light-speed delays are flat-out
impossible for the forces between components in a binary pulsar.
To handle such real-world cases and to compare with
observations (all made in 3-space), GR must convert solutions to its
field equations (such as the Schwarzschild solution) into 3-space
equations of motion that describe the dynamical system. See MTW p. 1095
for an example of these equations. There are two very important things
to note about the derivation of these equations of motion:
(1) The gravitational field is described by retarded potential
equations (similar to Lienard-Wiechert potentials). But when the
gradient of the potential is taken to derive an expression for force, GR
uses an *instantaneous* gradient, not a retarded one. This creates
forces acting between source masses and target bodies over any distance
instantaneously, and is what I mean when I use the words "GR has
instantaneous gravitational forces built in" side-by-side with its
retarded potentials.
(2) Light-speed propagation delay is r/c. No terms in the GR equations
of motion are factored by r/c, showing that indeed no force propagation
delays are considered. Wherever c appears, it is raised to the second or
higher powers, signifying that it is being used as energy, not as speed.
So it describes the permeability or permittivity of "spacetime", or the
index of refraction in the optical medium of the gravitational potential
field, depending on which physical interpretation of the equations one
prefers.
> [Hobba]: .it now violates the known problems of having instantaneous
transmission of information.
In LR, no such problem exists. Exceeding the speed of light
is no more problematic than exceeding the speed of sound, where similar
Lorentz transformations apply to describe the behavior of sound in an
atmosphere. That is because, in LR, nothing happens to time, but merely
to electromagnetic-based clocks, which naturally break down when
traveling at speeds > c. This is analogous to speed-of-sound-dependent
phenomena becoming unmeasurable when the measuring apparatus travels
faster than sound. But the essential difference between LR and SR is
that, in the latter, speed and potential affect time itself; whereas in
LR, they do not. So causality violations are impossible in LR.
It is pleasant to finally have some clarity arrive on the
scene, and to get rid of some bogeymen that have been inhibiting
progress. The best part is that these new ideas were joined by another
senior physicist, passed peer review, were published in a mainstream
journal, and have encountered no post-publication challenges in nearly
two years now. As for all ideas, it is appropriate to remain skeptical
and to continue to try to falsify them. But by having met these criteria
and in the absence of a specific challenge, these updated physical
interpretations of relativity are now entitled to a presumption of basic
viability, as is any unchallenged model that has met all the demands of
rigorous science.
and "Tom Roberts" <tjro...@lucent.com> writes:
> [Roberts]: The basic "fuss" is that Tom Van Flandern keeps insisting
that in GR the "speed of gravity" is infinite, when in fact it is not.
There would be no fuss if he merely stated that in the Newtonian limit
of GR the "speed of gravity" acts as if it were infinite.
This statement blurs two important distinctions, which makes
it nonsensical. I must presume that you have not read the paper (cited
above) that you are criticizing, or you would not be making this false
claim.
The important distinctions are these:
(1) Physically, the gravitational potential field is a static optical
medium surrounding any source mass. [See, e.g., Gen.Rel.&Grav. 2#4,
347-357 by Fernando de Felice, "On the gravitational field acting as an
optical medium" (1971). Einstein and eight other authors cited by FdF
had adopted this viewpoint earlier.] Changes to that field, for example
when the source mass accelerates, are called "gravitational waves" and
propagate outward at the speed of light. This medium is affected by
gravitational force, but does not cause it. Gravity makes the medium
denser near source masses, with density following an inverse linear law,
much like a planetary atmosphere. The GR effects of light-bending,
redshift, pericenter advance, and Shapiro delay are due to refraction in
this optical medium we call "gravitational potential".
(2) Gravitational force is required to propagate much faster than light
by every experiment bearing on the question. The best approximation we
can make to its speed at present is "instantaneous". The necessity of
near-instantaneous forces is recognized in both celestial mechanics and
in GR because simple computer experiments readily show the consequences
of any significant propagation delay in gravitational forces is
disastrous for the inferred orbit, which becomes an outward spiral. GR
recognizes the need for near-instantaneous forces by using instantaneous
gradients of the potential field, wherein changes clearly take place at
the speed of light. Correspondingly, it has no propagation delay terms
in its equations of motion. So force is treated differently than
potential in GR.
You could not say that "the speed of gravity is not infinite
in GR" unless you changed the meaning of my words so that "gravity"
applies to changes in the potential field, which it clearly does not. I
usually specify that I am speaking of the speed of propagation of
gravitational force. With that clarification of meaning, the speed of
gravity in GR is infinite, and your claim above is shown to be false.
> [Roberts]: I put "speed of gravity" in quotes, because a secondary
problem with his writing is that what he discusses is not really any
sort of speed of propagation at all. If instead of the gravity of a
moving planet he were discussing the planet's surface, he would be
proclaiming loudly that the "speed of propagation" of the surface is
infinite (meaning that the surface arrives at any given location as if
it propagated with infinite speed from the location of the center of the
planet) -- how silly that would sound, because it is quite clear that
the surface of a planet does not "propagate" from its center; neither
does its gravity.
In my reply to Bill Hobba above, I elaborated my meaning,
which is nothing like the meaning you attribute to me. And I gave an
example of my meaning with an asteroid impact and a corresponding sonic
wave, pointing out how absurd it would be to associate the wave speed
with the speed of the asteroid. Yet isn't that just what you are arguing
for?
and "Bill Hobba" bho...@hotmail.com replied:
> [Hobba]: If that is what Tom was saying then I see what the fuss is
about. But it would be a silly position.
Because my intended meaning was nothing like what Tom
Roberts guessed, I hope my actual message is now clearer.
> [Hobba]: one of the reasons GR was concocted is to address the problem
that SR requires a theory of gravity (at least in the weak gravity limit
where it can be considered to apply) to not propagate instantaneously.
However, LR has no such requirement. And SR has now been
experimentally falsified in favor of LR by the six experiments showing
that gravitational force does in fact propagate FTL in forward time.
That would be flat-out impossible if SR were a correct description of
nature.
However, this is not a big change to physics, even if it
does have many ramifications for our understanding of physics. LR uses
the same Lorentz transformations (LT) as SR, and makes the same
predictions for all eleven independent classical experiments that test
either theory. LR differs from SR mainly by having a preferred frame
(the local gravitational potential field), and by having the LT work
only one way (preferred frame to moving frame) instead of both ways as
in SR. This completely eliminates the need for a universal speed limit
of c or any other value. The speed of light is then no more a barrier
than was the speed of sound when we were trying to exceed it with
propeller-driven aircraft.
and "Mike" <ele...@yahoo.gr> writes:
> [Mike]: Van Flandern's Meta Model is built around the concept of Le
Sage's material graviton flux.
Not quite. The Meta Model (MM for short, a complete
cosmology) is derived deductively from first principles without
assumptions. When it gets to gravity, it produces a Le Sage-type gravity
model, but one that answers all the classic objections to such models,
explains all known properties of gravity, and predicts five new
properties. This is detailed in my chapter "Gravity" in "Pushing
Gravity: New Perspectives on Le Sage's Theory of Gravitation", M.
Edwards, ed., Apeiron Press, Montreal, 93-122 (2002). It is an outgrowth
of my article "Possible new properties of gravity", Astrophys.&SpaceSci.
244, 249-261 (1996); also available at
http://metaresearch.org/cosmology/gravity/possiblenewpropertiesofgravity.asp.
So MM is not built around a Le Sage-type gravity model, but deduces that
such a model is required by nature for forces on any scale.
> [Mike]: It turns out that for that model to work and avoid issues like
exploding planets due to the gravitons hitting matter at high speeds,
these particles must have an ultra small mass and travel at about 10^20
c (!) if I recall correctly the number. Thus, in that model of his,
gravity propagates at FTL speeds and there is a physical mechanism which
is based on momentum exchange and shadowing. Gravity is thus a push
force.
The lower limit to the speed of gravitons is 2x10^10 c. And
the model does lead to a natural mechanism for exploding planets over
the long term - a possibility about which there exists a considerable
body of supporting evidence, as detailed on our web site at
http://metaresearch.org/solar%20system/eph/eph2000.asp and in many
publications, as referenced therein. So this feature must be credited as
a strength of MM and a deficiency of the several standard models it
replaces.
> Now, Van Flandern was upset when Kopeikin announced his measurement of
the light deflection from Jupiter and pronounced the vg = c. This is
because, if vg = c then the graviton, which is unobservable entity now
by its properties, cannot exist.
I was "upset" because Kopeikin was advised before the
experimental results were in (see
http://metaresearch.org/home/viewpoint/Kopeikin.asp) that he was making
an error of interpretation of the physics, confusing the speed of
gravitational potential changes (c) with the speed of gravitational
force (>> c), yet chose to press ahead anyway with misleading and
erroneous press headlines. As it turned out, Kopeikin's paper was
rejected, and many mainstream relativists criticized his conclusions on
similar grounds. See a list of such published comments just before the
"Summary" in http://metaresearch.org/home/viewpoint/Kopeikin.asp. He was
eventually allowed to publish the experiment restyled as a measurement
of light-bending by a planet rather than as a measure of the "speed of
gravity". But the damage done by the original press release has still
not all been repaired.
> Furthermore, Van Flandern attacked the geometric interpretation of GR
and has declared the field force interpretation as the only appropriate.
This is because, the geometric is consistent with vg=c but the field one
is probably not.
No, the geometric interpretation is falsified (in our
"Foundations of Physics" paper cited above) because it has no cause to
initiate motion and no source for the new momentum of target bodies, as
described above. Similar views can be found in the article at
http://metaresearch.org/cosmology/gravity/speed_limit.asp. The geometric
interpretation has no "force of gravity", so it has no "speed of
gravity" either.
> [Mike]: I think Van Flandern is the last of physicalists remaining on
the planet. He is to be respected for his intense effort to 'save the
phenomena' and his quasi-static universe model in that respect. But he
is subject to contradictions that arise in his model and the need to
continuously rearrange it and add new hypothesis in order to keep it up
with empirical observations.
Those would be damning criticisms if true. But as is often
the case when no specifics can be cited, the claim is not true. All
contradictions to classic Le Sage-type models were resolved in MM,
without exception, as shown in the "Pushing Gravity" book. And one of
the chief strengths of the MM is that it has never needed a "new
hypothesis" to keep it viable. Indeed, it has never introduced any
hypothesis, new or old, to explain any observation. The explanations of
all relevant observations and experiments already flowed deductively
from first principles without need of further tweaking by me or anyone -
something the standard models cannot claim. This is the subject of the
first five chapters of my book "Dark Matter, Missing Planets and New
Comets", North Atlantic Books, Berkeley, 2nd edition 1999. -|Tom|-
Tom Van Flandern - Washington, DC - see our web site on replacement
astronomy research at http://metaresearch.org
Bilge
>It would also be profitable to specify that these paradoxes arise when
>one postulates invariance of c along with FTL speeds. In alternatives
>to SR, like LR, FTL speeds are allowed without any causality violation
>since the speed of light is dependent on the speed of its source,
>which can serve as a light carrying medium.
I think you are missing the point here regarding relativity. The `c' in
the lorentz transforms is just a quantity which is preserved under
transformations between inertial frames. It doesn't even need to be a
velocity (search on ``doubly special relativity'', for example), although
it does need to be tied to energy and momentum in some way. What `c' does
have to do, is apply to all phenomena. If gravity propagates faster than
light, then `c' is the speed of gravity and you have to light as a
material particle having a non-zero mass. However, since the photon mass
has an experimental upper limit of around 10^17 ev, `c' has to be awfully
close to any speed anyone has ever measured for the velocity of a
light signal.
In any case, the ``causality violation'' is not because light has
any (known) relationship with causality that is special. The ``causality
violation'' occurs because _no_ information can propagate at a greater
velocity and if gravity propagated faster than `c', that would constitue
propagating information faster than `c'.
Bilge
>again, and Mike.
>
>
>"Bill Hobba" <bho...@hotmail.com> writes:
>
>> [Hobba]: I have been meaning for a while to actually read Tom's views
>on why he believes gravity propagates at speeds greater than c and Steve
>Carlips reply. It has not really been a priority because the lorentz
>transformations prove casualty would be violated if you could do it.
>
> Causality would be violated if special relativity (SR) were
>valid. But Lorentzian relativity (LR) competes with SR, has never been
>falsified, and allows FTL propagation and communication.
You keep saying that, but you can't seem to explain how that
works.
[...]
> As we show in that paper, it is actually the geometric
>interpretation of GR that violates causality because it proposes that
>gravity is not a force that propagates, but is rather *caused* by the
>curvature of "spacetime". However, comparisons of theory and
>observations must be done in 3-space plus time, and curvature cannot
>initiate 3-space motion unless a force acts. For example, the rubber
>sheet analogy fails unless gravity pre-exists as a force underneath the
>rubber sheet to make objects roll downhill.
If that constitutes your understanding of general relativity, then
your paper is non-sense. The fact that you published it foundations
of physics rather than prl, indicates your paper was more of a hand-
waving philosophical rambling than a research article.
>The same criticism applies
>to any form of curvature - it provides no cause to initiate motion.
>Moreover, the new 3-space momentum imparted by a source mass to an
>orbiting target body cannot be created ex nihilo in physics. It
>therefore requires a force by definition: "force is the time rate of
>change of momentum".
In other words, nothing can move. A ``straight line'' cannot, in your
terminology, ``initiate motion''.
>
> Finally, please take note that "spacetime" has no spatial
>component. Time-like geodesics are really proper time intervals
>multiplied by c to make them appear space-like.
Did you really study any of this stuff, tom? The constant `c' is
there to make timelike intervals use units based upon earth con-
ventions. There is no physics in a unit conversion. Changing kg
to lbs, for example, changes units invented by people. It doesn't
alter any physics.
[...]
>
> For all these good and sufficient reasons, the geometric
>interpretation of GR must now give way to the field interpretation,
>which was anyway always favored by Einstein, Dirac, Feynman, and other
>notables.
That may be, but there are no field theories which agree with
anything you've said either, so what difference would it make?
[...]
>> [Hobba]: As Landau demonstrates the existence of a classical potential
>implies forces modeled by classical mechanics must propagate
>instantaneously. This is associated with the instantaneous propagation
>time required by the Galilean transformation on which classical
>mechanics is built.
>
> Because it is easy to construct a counterexample, the
>demonstration you cite can only apply to special cases such as
>gravitation and electrodynamics. For example, light amplitude has the
>attributes of a classical potential field and varies with 1/r (where r
>is distance from source), yet its corresponding 1/r^2 force, radiation
>pressure, clearly propagates at the speed of light, not instantaneously.
Yes, but do you understand why, tom?
> But in the case of gravitation, we now appreciate that
>potential and force are physically separate phenomena, with force
>inducing a gradient onto the potential field and not vice versa.
Please write down the equations for both the gravitational potential
and electromagnetic potential and explain the difference as it relates
to your point.
[...]
>> [Hobba]: .it now violates the known problems of having instantaneous
>transmission of information.
>
> In LR, no such problem exists. Exceeding the speed of light
>is no more problematic than exceeding the speed of sound, where similar
>Lorentz transformations apply to describe the behavior of sound in an
>atmosphere. That is because, in LR, nothing happens to time, but merely
>to electromagnetic-based clocks, which naturally break down when
>traveling at speeds > c.
I've already explained this to you tom. Your ``problem'' here is with
your ``LR'', not relativity. In relativity, any object moving at a
constant velocity is at rest, because there is NO PREFERRED FRAME
against which to measure an absolute velocity. Do you really think
relativity tells you that If someone observes a clock which exceeds
`c' that all of the clocks in both frames break? C'mon, you can't be
that dense. On the other hand, in your theory, you have an absolute
frame, so that an absolute velocity has some meaning. You should
be embarrassed to post arguments which are that ill-conceived.
Harry
to hear what doesn't seem to make sense.
"Tom Van Flandern" <to...@starpower.net> wrote in message
news:409b122b$0$2985$61fe...@news.rcn.com...
> This message replies to Bill Hobba, Tom Roberts, Bill Hobba
> again, and Mike.
SNIP
> For all these good and sufficient reasons, the geometric
> interpretation of GR must now give way to the field interpretation,
> which was anyway always favored by Einstein, Dirac, Feynman, and other
> notables. For example, we read in [R.P. Feynman (1995), Feynman Lectures
> on Gravitation, Addison-Wesley, New York, section 8.4, p. 113]:
> "It is one of the peculiar aspects of the theory of gravitation, that it
> has both a field interpretation and a geometrical interpretation. . the
> fact is that a spin-two field has this geometrical interpretation: this
> is not something readily explainable - it is just marvelous. The
> geometrical interpretation is not really necessary or essential to
> physics."
Interesting remark, I hope it is correct for fields are more to my taste.
;-)
SNIP
For example, light amplitude has the
> attributes of a classical potential field and varies with 1/r (where r
> is distance from source), yet its corresponding 1/r^2 force, radiation
> pressure, clearly propagates at the speed of light, not instantaneously.
I beg you pardon, but it's quite obvious that light propagates at the speed
of light!
But I don't swallow the connection you make between wave amplitude and
potential field: I don't consider a static field the same thing as a
propagating wave.
SNIP
> To get correct
> orbits in celestial mechanics, we are obliged to calculate forces
> instantaneously for bodies of all masses and speeds, then to calculate
> their observed positions using speed-of-light retardation between body
> and observer because the speed-of-light propagation delays are large and
> significant and obviously not shared by gravitational forces.
I guess that's what Tom Roberts meant was that the field is synchronized
with the mass - just as with electrodynamics.
Thus that isn't a real issue, at least not specifically a GRT issue.
> Take binary pulsars as an example. The masses are
> relativistically significant, and the velocities are also because
> classical GR effects (light-bending, redshift, pericenter advance,
> Shapiro delay) are plainly evident. Yet we must still use instantaneous
> forces to get correct orbits. Any force propagation delay produces an
> outward spiral, contrary to observations. And it is not sufficient to
> hypothesize that each star anticipates the linear motion of its
> companion one light-time ahead. The acceleration of the stars during one
> light-time is also significant. So light-speed delays are flat-out
> impossible for the forces between components in a binary pulsar.
Acceleration is more interesting, for that is where field retardation should
come into play.
Thus, I guess that that is where you have to concentrate on for any
arguments.
> To handle such real-world cases and to compare with
> observations (all made in 3-space), GR must convert solutions to its
> field equations (such as the Schwarzschild solution) into 3-space
> equations of motion that describe the dynamical system. See MTW p. 1095
> for an example of these equations. There are two very important things
> to note about the derivation of these equations of motion:
> (1) The gravitational field is described by retarded potential
> equations (similar to Lienard-Wiechert potentials). But when the
> gradient of the potential is taken to derive an expression for force, GR
> uses an *instantaneous* gradient, not a retarded one.
I guess that is the same generic field retardation issue that Tom Roberts
and Steve Carlip mentioned. Right?
> This creates
> forces acting between source masses and target bodies over any distance
> instantaneously, and is what I mean when I use the words "GR has
> instantaneous gravitational forces built in" side-by-side with its
> retarded potentials.
Instantaneous is indistinguishable from simultaneous...
SNIP
> > [Roberts]: I put "speed of gravity" in quotes, because a secondary
> problem with his writing is that what he discusses is not really any
> sort of speed of propagation at all. If instead of the gravity of a
> moving planet he were discussing the planet's surface, he would be
> proclaiming loudly that the "speed of propagation" of the surface is
> infinite (meaning that the surface arrives at any given location as if
> it propagated with infinite speed from the location of the center of the
> planet) -- how silly that would sound, because it is quite clear that
> the surface of a planet does not "propagate" from its center; neither
> does its gravity.
>
> In my reply to Bill Hobba above, I elaborated my meaning,
> which is nothing like the meaning you attribute to me.
To me it sounded quite to-the-point, and I liked it!
> And I gave an
> example of my meaning with an asteroid impact and a corresponding sonic
> wave, pointing out how absurd it would be to associate the wave speed
> with the speed of the asteroid. Yet isn't that just what you are arguing
> for?
No, I think that he distinguishes between two things:
- fields which are (for us!) synchronous at corresponding points relative to
moving matter
- waves that travel from one point to another.
The way I understood him, you can consider a gravitation field as an
invisible extension of the matter that causes it.
> and "Bill Hobba" bho...@hotmail.com replied:
>
> > [Hobba]: If that is what Tom was saying then I see what the fuss is
> about. But it would be a silly position.
>
> Because my intended meaning was nothing like what Tom
> Roberts guessed, I hope my actual message is now clearer.
For me just not clear enough...
Harald
Bill Hobba
"Bilge" <dub...@radioactivex.lebesque-al.net> wrote in message
news:slrnc9m9vq...@radioactivex.lebesque-al.net...
> Mike:
>
> >It would also be profitable to specify that these paradoxes arise when
> >one postulates invariance of c along with FTL speeds. In alternatives
> >to SR, like LR, FTL speeds are allowed without any causality violation
> >since the speed of light is dependent on the speed of its source,
> >which can serve as a light carrying medium.
>
> I think you are missing the point here regarding relativity. The `c' in
> the lorentz transforms is just a quantity which is preserved under
> transformations between inertial frames. It doesn't even need to be a
> velocity (search on ``doubly special relativity'', for example), although
> it does need to be tied to energy and momentum in some way.
Thanks for the info. Looks an interesting idea. That the plank length and
time would change under SR has occasionally crossed my mid as well - but I
did not think much of it. Looks like Giovanni Amelino-Camelia is a bit of a
rebel.
Thanks
Bill
Mike
> again, and Mike.
>
[snip]
>
>
>
> and "Mike" <ele...@yahoo.gr> writes:
>
> > [Mike]: Van Flandern's Meta Model is built around the concept of Le
> Sage's material graviton flux.
>
> Not quite. The Meta Model (MM for short, a complete
> cosmology) is derived deductively from first principles without
> assumptions.
There can be no such thing as a 'complete cosmology' derived
deductively from first principles, unless these principles are
empirically determined. Your use of the word 'deductive' and
'principles' is inappropriate in this context. Goedels incopletness
theorem leads to theconclusion that a theory based on a deductive
formal language can be either complete (but inconcistent) or
inconsistent (but not complete). Russell's antinomies are a proof of
that and any model incorporating infinity in any sense, whether
countable or uncountable is subject to incincistencies. Therefore, at
first, you should not be claiming a 'complete cosmology' but a model
based on some principles.
Regarding your principles stated in your article "Physics has its
Principles", the comments are obviously devastating. Your principles
are states to be:
1. Every effect has an antecedent, proximate cause
2. No time reversal
3. No true action at a distance
4. No creation ex nihilo
5. No demise ad nihil
6. The finite cannot become infinite
You justify these intuitive principles of yours bt stating that "The
principles of physics are inviolate rules because any contradiction
would be tantamount to magic, a miracle, or the supernatural..."
Your justification is a plain logical fallacy, a trivial one called
'affirmation of the consequent'. You try to affirm the truth of your
metaphyscal principles based on an affirmation of the assumption that
there are no miracles implied by them. Plain, trivial, basic logical
error of the first kind. I can give you many examples of hypitheses
that can be used to explain how your principles can be false and
still there are no miracles taking place. A simple hypothesis
regarding metaphysical principles No 2 of yours is that time reversal
is possible but the one who goes back to the past cannot succeed to
change i, any effort is met with failure. But as a general comment,
from the point of view of the fundamentals in physics, all your
principles are metaphysical statements. Question:
What makes you think that one can arrive from a list of metaphysical
hypotheses to a 'complete cosmology' or even to any cosmology?
The object of physics Dr. Van Flandern is to reduce the number of
principles necessary for a hopefully complete description of the
phenomena down to nill. In the respect, GR was a genuing attempt to
reduce the principles down to a few hypothesis and use as many
epistemological principles as possible rather than ontological ones
like you do. Th two basic principles SR and GR is based on are:
1. The principles of relativity which is based on the empirical fact
that the only well-defined quantities of motion are relative ones
2. The epistemological principles that all phenomena must have the
same explanation in all moving reference frames.
Starting from those two basics principles, statements about time and
space are arrived at in a deductive way and not in a priori way s
metaphysical principles as you do. In essence, your physics are just
like Newtonican, you postulate unobservable entities a priori based on
metaphysical principles. In GR, space-time is also absolute and
substantival but the huge difference is that it is constructed not a
priori but based on much fewer assumptions and hypotheses about the
nature of the world.
Your realist model based on unobservable entities filling space, like
gravitons, can be one of an infinite number of models that can be
constructed and are all consistent but cannot be complete. They are
called 'compensatory theories'.
Anti-realists, like the great Leibniz and afterwards Mach, demand
arrival at an explanation of physical phenomena based on observable
reality. You may know insist that the graviton may be detected one day
but one can easily understand that it cannot by its own atributed
pripories, i.e. mass and speed. The claim to arrive at the graviton
existence with such properties from a deduction should worry you
rather than be though of as an achievment of the theory.
All of your principles are not self-evident truths but postulated
ontology and in many cases come in direct conflict with Quantum
mechanics predictions and observations, like 3,4 and 5. Regarding 6,
it is devoid of any meaningful use. In mathematics, the finite cannot
become infinite by definition of the way number fields are
constructed. But in reality, finite systems can lead to infinite
supertasks and halting problems when attempting to complete them (ex.
Thompson's lamp). This can lead to a serious questioning of your No 1
principle as one also devoid of any useful content in the context of
physical reality. All we need to explain reality may be just temporal
order and any 'talk' about 'causality' leads to impossibilities,
especially the inevitable postulation of final causes, 'which may be
of a not mechanical nature', and seriously question that there is
contigency in your type of universe (see the eccelelt article recently
published by James. W. McAllister on the 'Absence of Contingency in
the Newtonian Universe'.
http://www.kluweronline.com/issn/1233-1821
The use of the term deduction in the context of cosmology means
nothing. Any false formula implies a true formula, that is any number
of false hypothesis can imply empirical facts. I like to point out
though that this holds true for all theories and cosmologies but it is
stronger for those like yourr that start from a large number of
metaphysical principles to arrive at deductions , and less for those
theories that start from less demanding ontology and arrive that new
prediction that are confirmed by observations, like SR and GR.
I also would like to state that I have great respect for your
incredible knowledge of Astronomy and Astronomical facts, the work you
have done on (which is even mentioned in Will's book) and
understanding of orbital mechanics and this is not a questioning of
you recognized internationally status as a leading astronomer but
against a specific model of physical reality you propose.
Mike
[snip]
Tom Van Flandern
"Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>> [tvf]: Lorentzian relativity (LR) competes with SR, has never been
falsified, and allows FTL propagation and communication.
> [Bilge]: You keep saying that, but you can't seem to explain how that
works.
The literature is now filled with articles about how LR
works and about SR-LR comparisons. I recommend my own exposition, "What
the Global Positioning System tells us about the twins paradox",
Episteme #6 pt. II,
http://www.dipmat.unipg.it/~bartocci/ep6/ep6-vanfl.htm (2002/12/21). You
simply need to read some of this literature. The essence of LR is that
the local gravity field serves as a preferred frame, the Lorentz
transformations work only one way (from the preferred frame to any
moving frame), and they apply only to time interval readings on
electromagnetic-based clocks rather than to the dimension of time. In
particular, gravity-based clocks would be unaffected by either speed or
potential. An example of a "gravity-based clock" would be gravitational
force pulses (*not* gravitational waves) from a binary pulsar or contact
binary as read on a distant gravimeter.
>> [tvf]: As we show in that paper, it is actually the geometric
interpretation of GR that violates causality because it proposes that
gravity is not a force that propagates, but is rather *caused* by the
curvature of "spacetime". However, comparisons of theory and
observations must be done in 3-space plus time, and curvature cannot
initiate 3-space motion unless a force acts. For example, the rubber
sheet analogy fails unless gravity pre-exists as a force underneath the
rubber sheet to make objects roll downhill.
> [Bilge]: If that constitutes your understanding of general relativity,
then your paper is non-sense. The fact that you published it foundations
of physics rather than prl, indicates your paper was more of a
hand-waving philosophical rambling than a research article.
The trademark of a frustrated person without a cogent
argument is that he/she makes unfounded assertions and attacks the
messenger without providing any explanation or justification (other than
the occasional appeal to authority) for his/her viewpoint. That seems to
apply here.
If you have an actual criticism or point to make, please
state it. In any case, the editor, thorough reviewers, and subsequent
readers of the article in question have expressed opinions that differ
from yours.
>> [tvf]: The same criticism applies to any form of curvature - it
provides no cause to initiate motion. Moreover, the new 3-space momentum
imparted by a source mass to an orbiting target body cannot be created
ex nihilo in physics. It therefore requires a force by definition:
"force is the time rate of change of momentum".
> [Bilge]: In other words, nothing can move. A ``straight line'' cannot,
in your terminology, ``initiate motion''.
I believe I was restating Newton's first law of motion,
which is still in effect as of the last time I checked. I don't know how
you leapt to your statement from mine. So to make mine simpler, consider
my phrase "initiate motion" to apply to a body at rest.
>> [tvf]: Finally, please take note that "spacetime" has no spatial
component. Time-like geodesics are really proper time intervals
multiplied by c to make them appear space-like.
> [Bilge]: Did you really study any of this stuff, tom? The constant `c'
is there to make timelike intervals use units based upon earth
conventions. There is no physics in a unit conversion. Changing kg to
lbs, for example, changes units invented by people. It doesn't alter any
physics.
That was my point, exactly. Time-like geodesics are proper
time intervals with no spatial component. Changing their units to be
space-like does not change their physical meaning, which is purely
time-like.
>> [tvf]: For all these good and sufficient reasons, the geometric
interpretation of GR must now give way to the field interpretation,
which was anyway always favored by Einstein, Dirac, Feynman, and other
notables.
> [Bilge]: That may be, but there are no field theories which agree with
anything you've said either, so what difference would it make?
The field interpretation of GR I described in my chapter
"Gravity" in the book "Pushing Gravity: New Perspectives on Le Sage's
Theory of Gravitation" [M. Edwards, ed., Apeiron Press, Montreal, 93-122
(2002)] is a counterexample to your claim.
>> [tvf]: But in the case of gravitation, we now appreciate that
potential and force are physically separate phenomena, with force
inducing a gradient onto the potential field and not vice versa.
> [Bilge]: Please write down the equations for both the gravitational
potential and electromagnetic potential and explain the difference as it
relates to your point.
Equations are oblivious to causality, constraints, and
principles of physics. One can learn nothing of relevance to my point
from the equations you ask for. My point was that the physical
interpretation of GR that works best is one in which gravitational force
imposes a gradient on the gravitational potential field (an optical or
light-carrying medium), much as it does with the atmosphere of a planet.
The old idea that a gradient of the potential field somehow causes
gravitational force is ruled out for the two reasons I gave: no cause
exists to change a body at rest to one in motion; and no source exists
for this new momentum because the potential field in GR is static.
> [Bilge]: Your ``problem'' here is with your ``LR'', not relativity. In
relativity, any object moving at a constant velocity is at rest, because
there is NO PREFERRED FRAME against which to measure an absolute
velocity.
There are no "absolute velocities" in LR. But each local
gravitational potential field does provide a preferred frame, and that
makes physics much easier to understand, as you will see from reading my
paper cited above.
> [Bilge]: Do you really think relativity tells you that if someone
observes a clock which exceeds `c' that all of the clocks in both frames
break?
Again, I have no idea where you get these strawmen from. I
said simply that any single electromagnetic-based clock, pushed to an
FTL speed relative to the gravitational potential field in which it is
immersed, would indeed break, just as a sonic clock pushed to a
faster-than-sound speed in an atmosphere would break. This is not a hard
concept to grasp.
> [Bilge]: C'mon, you can't be that dense. On the other hand, in your
theory, you have an absolute frame, so that an absolute velocity has
some meaning. You should be embarrassed to post arguments which are that
ill-conceived.
More frustration, I see. Why not consider the actual model,
which is much more interesting and worth discussing than the flawed
imitations you like to advance so you have something to beat up?
and "Harry" <harald.v...@epfl.ch> writes:
>> [tvf]: For example, light amplitude has the attributes of a classical
potential field and varies with 1/r (where r is distance from source),
yet its corresponding 1/r^2 force, radiation pressure, clearly
propagates at the speed of light, not instantaneously.
> [Harry]: I beg you pardon, but it's quite obvious that light
propagates at the speed of light! But I don't swallow the connection you
make between wave amplitude and potential field: I don't consider a
static field the same thing as a propagating wave.
In what sense is the gravitational potential field any more
"static" than other potential fields? Disturbances of the gravitational
potential field are gravitational waves. This is supposed to be the
analog of electromagnetic waves or lightwaves. I merely gave an example
of a potential-like field with retardation, showing that an
instantaneous character is not a required attribute of potential-like
fields.
>> [tvf]: To get correct orbits in celestial mechanics, we are obliged
to calculate forces instantaneously for bodies of all masses and speeds,
then to calculate their observed positions using speed-of-light
retardation between body and observer because the speed-of-light
propagation delays are large and significant and obviously not shared by
gravitational forces.
> [Harry]: I guess that's what Tom Roberts meant was that the field is
synchronized with the mass - just as with electrodynamics. Thus that
isn't a real issue, at least not specifically a GRT issue.
How does a field "synchronized with the (source) mass"
differ from one that "propagates instantaneously"? Neither is allowed in
physics, only in math. In physics, there are no "rigid bodies" except as
model approximations of reality. Physical reality is that any force
acting on one end of a rigid rod and propagating to the other end must
travel as a pressure wave at the speed of sound in that medium, and
cannot produce any response "instantaneously". The same must hold for
fields if they are material, tangible entities -- as they must be to be
capable of affecting material, tangible bodies.
>> [tvf]: Take binary pulsars as an example. The masses are
relativistically significant, and the velocities are also because
classical GR effects (light-bending, redshift, pericenter advance,
Shapiro delay) are plainly evident. Yet we must still use instantaneous
forces to get correct orbits. Any force propagation delay produces an
outward spiral, contrary to observations. And it is not sufficient to
hypothesize that each star anticipates the linear motion of its
companion one light-time ahead. The acceleration of the stars during one
light-time is also significant. So light-speed delays are flat-out
impossible for the forces between components in a binary pulsar.
> [Harry]: Acceleration is more interesting, for that is where field
retardation should come into play. Thus, I guess that that is where you
have to concentrate on for any arguments.
But that is already a done deal. When a source mass
accelerates, changes in its gravitational force register with a target
body much faster than light can travel between them. See "The speed of
gravity - What the experiments say", Phys.Lett.A, v. 250, #1-3, pp. 1-11
(1998/12/21), also available at
http://metaresearch.org/cosmology/speed_of_gravity.asp.
>> [tvf]: The gravitational field is described by retarded potential
equations (similar to Lienard-Wiechert potentials). But when the
gradient of the potential is taken to derive an expression for force, GR
uses an *instantaneous* gradient, not a retarded one.
> [Harry]: I guess that is the same generic field retardation issue that
Tom Roberts and Steve Carlip mentioned. Right?
Right.
>> [tvf]: This creates forces acting between source masses and target
bodies over any distance instantaneously, and is what I mean when I use
the words "GR has instantaneous gravitational forces built in"
side-by-side with its retarded potentials.
> [Harry]: Instantaneous is indistinguishable from simultaneous...
However, in SR, there is no remote simultaneity. To avoid
that ambiguity, I speak of "instantaneous" in coordinate time, which
always advances. This lack of the possibility of time-reversal is why no
SR-type causality violations (travel into the past) can arise in LR.
> [Harry]: I think that [Roberts] distinguishes between two things:
- fields which are (for us!) synchronous at corresponding points
relative to moving matter
- waves that travel from one point to another.
The way I understood him, you can consider a gravitation field as an
invisible extension of the matter that causes it.
Indeed, I agree that is what he meant. But such concepts are
pure math with no counterparts in physics, as I described above for a
rigid rod. Even "invisible extensions of matter" cannot move instantly
with that matter when it accelerates without hypothesizing a force
propagating through the "invisible extension" instantaneously. Or as
Newton put it, one body (or body part) cannot influence another at a
distance without the action of something passing between them.
This really is a common sense (basic logic) point, even if
we have not been taught to think in such a way because of the challenges
it would create to existing theories.
Thanks for raising some interesting questions.
and "Mike" <ele...@yahoo.gr> writes:
>> [tvf]: Not quite. The Meta Model (MM for short, a complete cosmology)
is derived deductively from first principles without assumptions.
> [Mike]: There can be no such thing as a 'complete cosmology' derived
deductively from first principles, unless these principles are
empirically determined. Your use of the word 'deductive' and
'principles' is inappropriate in this context. Goedel's incompleteness
theorem leads to the conclusion that a theory based on a deductive
formal language can be either complete (but inconsistent) or
inconsistent (but not complete). Russell's antinomies are a proof of
that and any model incorporating infinity in any sense, whether
countable or uncountable is subject to inconsistencies. Therefore, at
first, you should not be claiming a 'complete cosmology' but a model
based on some principles.
I prefer to speak in the language of physics, not
philosophy. True, in a philosophical sense, MM is incomplete because all
five dimensions (space, time, and scale) are infinite in extent, and we
can only observe what is local. However, we can deduce some general
properties of substance that apply to all dimensions, and in that sense
the cosmology is "complete" because the rest of the universe has similar
properties to the parts we see, differing only in the "details".
As for your interpretation of Russell, I disagree. MM
distinguishes concepts such as dimensions, which are infinite, from
material, tangible ("physical") entities made of "substance", which are
always and everywhere necessarily finite (in extent, duration, and
matter content). So that dichotomy is how MM answers Russell.
> [Mike]: Regarding your principles stated in your article "Physics has
its Principles", the comments are obviously devastating. Your principles
are stated to be:
1. Every effect has an antecedent, proximate cause
2. No time reversal
3. No true action at a distance
4. No creation ex nihilo
5. No demise ad nihil
6. The finite cannot become infinite
You justify these intuitive principles of yours by stating that "The
principles of physics are inviolate rules because any contradiction
would be tantamount to magic, a miracle, or the supernatural..." Your
justification is a plain logical fallacy, a trivial one called
'affirmation of the consequent'. You try to affirm the truth of your
metaphyscal principles based on an affirmation of the assumption that
there are no miracles implied by them.
You misrepresent the logic involved. There are no miracles
implied by the principles *and* miracles are required by their
converses. That eliminates the claimed logical fallacy.
> [Mike]: A simple hypothesis regarding metaphysical principles No 2 of
yours is that time reversal is possible but the one who goes back to the
past cannot succeed to change it, any effort is met with failure.
That is a self-contradictory premise. Sending matter back to
the past is itself a change in the matter and energy content of the
universe in both past and present, and must displace other matter to
make room for itself, which sets off an unbounded chain of causality
altering that timeline forever. The displacement of a single air
molecule changes the timing and even the existence of collisions by
neighboring air molecules, which changes their neighbors in a continuing
chain, which eventually makes the difference between whether a leaf
falls or doesn't fall, which determines whether a caterpillar lives or
dies, which determines whether a child chasing a butterfly falls off a
cliff or doesn't, etc. until the whole universe is changed. There is no
way to bring a universe with the slightest change into exact agreement
with a universe lacking that change once any difference has arisen.
> [Mike]: What makes you think that one can arrive from a list of
metaphysical hypotheses to a 'complete cosmology' or even to any
cosmology?
There is nothing quite as convincing of the philosophical
possibility of white crows as to discover one. MM is an existing example
of such a cosmology. See for yourself: "Dark Matter, Missing Planets and
New Comets", North Atlantic Books, Berkeley (1993; 2nd edition 1999),
also available at http://metaresearch.org/store/advanced/default.asp and
at many public libraries.
> [Mike]: The object of physics Dr. Van Flandern is to reduce the number
of principles necessary for a hopefully complete description of the
phenomena down to nill. In the respect, GR was a genuine attempt to
reduce the principles down to a few hypothesis and use as many
epistemological principles as possible rather than ontological ones like
you do.
Why shouldn't a cosmology be more concerned with the nature
of existence than with the nature of knowledge? Anyway, we are using
"principles" with different meanings. You equate them above with
hypotheses, which are a form of assumptions. OTOH, my use of
"principles" means constraints on the nature of reality deduced from
reasoning alone, involving no observation or experiment. This usage and
maintaining the requirement that no miracles are admitted into physics
breaks the seeming "circularity" in the reasoning.
> [Mike]: The two basic principles SR and GR is based on are . Starting
from those two basics principles, statements about time and space are
arrived at in a deductive way and not in a priori ways metaphysical
principles as you do.
You are mistaken, and need to read what I actually did as
opposed to what you assume I did. In fact, the nature of space, time,
and scale were deduced from physical principles in MM, and no
assumptions of any kind were allowed to contaminate that process. Surely
that is better than SR's two unjustified assumptions.
> [Mike]: In essence, your physics are just like Newtonian, you
postulate unobservable entities a priori based on metaphysical
principles. In GR, space-time is also absolute and substantive but the
huge difference is that it is constructed not a priori but based on much
fewer assumptions and hypotheses about the nature of the world.
You made some wrong assumptions here too. I made no
postulates or assumptions, but SR did. The concept of "space" in MM is
not in any sense "absolute", but is in fact even more "relative" than in
SR and GR because it is relative in scale too. You remind me of the
blind man describing an elephant based on feeling its trunk.
> [Mike]: Your realist model based on unobservable entities filling
space, like gravitons, can be one of an infinite number of models that
can be constructed and are all consistent but cannot be complete. They
are called 'compensatory theories'.
Gravitons are just as observable as air molecules were to
the ancient Greeks. Their properties can be deduced from their
macroscopic effects, with the knowledge that one day technology will
permit direct observation.
I already described the physical sense in which MM is
"complete".
> [Mike]: Anti-realists, like the great Leibniz and afterwards Mach,
demand arrival at an explanation of physical phenomena based on
observable reality. You may now insist that the graviton may be detected
one day but one can easily understand that it cannot by its own
attributed properties, i.e. mass and speed. The claim to arrive at the
graviton existence with such properties from a deduction should worry
you rather than be thought of as an achievement of the theory.
This philosophy is too contrary to common sense for my
tastes. Why does the mass and speed of gravitons provide any kind of
barrier to detecting them? Why does deducing the existence of something
unseen (photons? electrons? everything in quantum physics? black holes?)
give cause for any special worry? We always keep open the possibility of
error when our inferences are based on incomplete information.
Uncertainty is an ever-present component of reality, and therefore of
physics too, even if it is non-palatable in philosophy.
> [Mike]: All of your principles are not self-evident truths but
postulated ontology and in many cases come in direct conflict with
Quantum mechanics predictions and observations, like 3,4 and 5.
QM is no counterexample to MM because it accepts
contradictions as part of reality in its interpretations of experiments.
MM is at least free of contradictions. And where do you see any
postulates left as assumptions in my paper about the "principles"?
> [Mike] Regarding 6, it is devoid of any meaningful use. In
mathematics, the finite cannot become infinite by definition of the way
number fields are constructed.
This principle simply means that one cannot assemble any
number of finite entities, however great, to make an infinite set. It
does not exclude pure concepts or properties of physical bodies (such as
slope) from becoming infinite as long as the concepts or properties are
not themselves physical (material, tangible) entities.
> [Mike]: All we need to explain reality may be just temporal order and
any 'talk' about 'causality' leads to impossibilities .
Not in MM, it doesn't. But you must see to believe.
I appreciate the constructive spirit of your comments.
However, you have a long way to go to convince me that epistemology is
more important than ontology for cosmology. I also have some opinions
about the former. But those would be way off-topic in this thread, or
even in this newsgroup. For the discussion of gravity in this thread, I
prefer we stick to physics and its principles. -|Tom|-
car...@no-physics-spam.ucdavis.edu
[...]
> To handle such real-world cases and to compare with
> observations (all made in 3-space), GR must convert solutions to its
> field equations (such as the Schwarzschild solution) into 3-space
> equations of motion that describe the dynamical system. See MTW p. 1095
> for an example of these equations. There are two very important things
> to note about the derivation of these equations of motion:
> (1) The gravitational field is described by retarded potential
> equations (similar to Lienard-Wiechert potentials). But when the
> gradient of the potential is taken to derive an expression for force, GR
> uses an *instantaneous* gradient, not a retarded one.
Note that despite repeated requests, Tom has never provided a mathematical
definition -- an equation -- for the operation he calls a ``retarded
gradient.'' Nor has such a definition appeared in any paper that I am
aware of. The term seems to be a fantasy.
In general relativity, roughly speaking, a gravitational source produces
a set of potentials. Changes in the source cause changes in the potential
that propagate at light speed. To compute the effective force on an
object at position x at time t, one takes the gradient -- the detivative
-- of the potential at position x and time t. In other words, an object
``here'' and ``now'' responds to the change in the potential ``here''
and ``now,'' and not somewhere else at some other time.
> This creates forces acting between source masses and target bodies
> over any distance instantaneously
No, it doesn't. This is a fantasy that has nothing at all to do with
the way GR works.
Steve Carlip
Mike
> This replies to Bilge, Harry, and Mike.
>
>
> As for your interpretation of Russell, I disagree. MM
> distinguishes concepts such as dimensions, which are infinite, from
> material, tangible ("physical") entities made of "substance", which are
> always and everywhere necessarily finite (in extent, duration, and
> matter content). So that dichotomy is how MM answers Russell.
>
also infinite? Infinity x infinity is a perfectly valid operation
producing infinity. Your 'theory' then has another implicit hypothesis
that dimensions are infinite but 'substance' finite. But dimensions
are logical terms and substance pressumably physical entity. I cannot
understand the use of arbitrary assumptions in order to avoid
paradoxes of infinity. Those assumptions have a strong ontological
content and are thus metaphysics.
1. Are you proposing infinite physical dimensions with finite
substances or
2. Infinite logical dimensions with finite substances?
The question is in other words? Is your space logically infinite,
physically infinite or both? If it is just logically infinite but
substance cannot be, then you have no space but only substance in your
physical model. Then, you must tell me how in the world substance is
subjected to your causality principle. The combination of no physical
space, physical substance and causality leads to the need for an
active principle (See Leibniz). According to Spinoza, this principle
can only be God. Going to the physics side (to prevent your complain
that this is philodophy) you must tell me how to define acceleration
in physics in pure relational terms other than in relation to some
absolute space-time. As you may know, such attempt has been met with
failure in 3-D physics. You need 4-D physics to resolve it but then in
turns out space-time becomes substantival.
On the other hand, if your space is both logically and physically
infinite but you maintain your substance is not, you must unavoidably
postulate absolute existence for space indepedent of substance and the
additional postulate of substance finitude. In this view, adopted by
some Cartesians and Newton, space-time is not a well-founded
phenomenon because there are absolute points in space and time but all
observed motion is relative.
Additionally, is your substance physically finite and logically finite
or physically finite but logically infinite?
You can see from the above that any reference to 'substance' lead to
exercises in futility and the need for metaphysical postulations. That
was the purpose.
>
> You misrepresent the logic involved. There are no miracles
> implied by the principles *and* miracles are required by their
> converses. That eliminates the claimed logical fallacy.
No, that is a plain petitio principii. Anyway you do it you will get a
fallacy:
1. The principles imply no magic
Now, if you claim that our world is no magical and therefore the
principle are self evident this is a fallacy of the affirmation of the
consequent.
2. No magic implies the principles
If you now claim that the principles are self evident truths, this is
again a fallacy of the same kind.
You could just say that the 'principles of physics' equate that there
is no magic in the world. But again you have a problem. In one side
you have a claim about the world (principles) and in the other again a
claim about the world (no magic). This is neither a synthetic nor an
analytic statement. It's called a transcendental argument. Such
argument cannot serve as the basis of justification of any physical
theory but only perceptions of human nature.
In other words, you do not justify why the principles exclude an
independent existence of magic but only the claim that if the
principles hold, then those principles entail no magic. I could
insist, that the very fact of these principles holding true is magic.
Here is your antinomy. These are the type of problems you run into
with Kantian type synthetic a priori statements arrived at by
transcendental arguments.
>
> > [Mike]: A simple hypothesis regarding metaphysical principles No 2 of
> yours is that time reversal is possible but the one who goes back to the
> past cannot succeed to change it, any effort is met with failure.
>
> That is a self-contradictory premise. Sending matter back to
> the past is itself a change in the matter and energy content of the
> universe in both past and present, [snip]
Unles past, present and future are one and the same thing. There are
many possibilities,. I get the impression you claim nowism, a
direction of time and possibly absolute, universal time. All
metaphysical statements leading to many paradoxes.
> Why shouldn't a cosmology be more concerned with the nature
> of existence than with the nature of knowledge? Anyway, we are using
> "principles" with different meanings. You equate them above with
> hypotheses, which are a form of assumptions. OTOH, my use of
> "principles" means constraints on the nature of reality deduced from
> reasoning alone, involving no observation or experiment. This usage and
> maintaining the requirement that no miracles are admitted into physics
> breaks the seeming "circularity" in the reasoning.
You must start from some primitives. Otherwise you go on circles.
There is no indication you have provided enough well-founded
primitives to justify deduction of principles involving time,
causality, conservation etc. You allude to transcendental arguments
again and synthetic a priori principles. This can at best lead you to
a subjective perception of time and causality. Then, although there
are no miracles, the principles can fail to hold true for different
observers. For one observer an event is past but for another is still
in his future like in SR.
I think you're attempting to avoid getting cut by Ocam's Rasor and you
claim that your principles are derived from reasoning. But reasoning
based on what premises? The only one you gave is the no-magic premise.
No primitives. As such, your principles are actually disguised axioms
IMO.
Mike
[snip]
Bilge
>
>
>"Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>
>>> [tvf]: Lorentzian relativity (LR) competes with SR, has never been
>falsified, and allows FTL propagation and communication.
>
>> [Bilge]: You keep saying that, but you can't seem to explain how that
>works.
>
> The literature is now filled with articles about how LR
>works and about SR-LR comparisons. I recommend my own exposition, "What
>the Global Positioning System tells us about the twins paradox",
>Episteme #6 pt. II,
>http://www.dipmat.unipg.it/~bartocci/ep6/ep6-vanfl.htm (2002/12/21).
By the way, you didn't even get the url correct.
[...]
>>> [tvf]: As we show in that paper, it is actually the geometric
>interpretation of GR that violates causality because it proposes that
>gravity is not a force that propagates, but is rather *caused* by the
>curvature of "spacetime". However, comparisons of theory and
>observations must be done in 3-space plus time, and curvature cannot
>initiate 3-space motion unless a force acts. For example, the rubber
>sheet analogy fails unless gravity pre-exists as a force underneath the
>rubber sheet to make objects roll downhill.
>
>> [Bilge]: If that constitutes your understanding of general relativity,
>then your paper is non-sense. The fact that you published it foundations
>of physics rather than prl, indicates your paper was more of a
>hand-waving philosophical rambling than a research article.
>
> The trademark of a frustrated person without a cogent
>argument is that he/she makes unfounded assertions and attacks the
>messenger without providing any explanation or justification (other than
>the occasional appeal to authority) for his/her viewpoint. That seems to
>apply here.
Yes, to you. Let me refresh your memory. You said:
"See "Experimental Repeal of the Speed Limit for Gravitational,
Electrodynamic, and Quantum Field Interactions", T. Van Flandern and
J.P. Vigier, Found.Phys. 32(#7), 1031-1068 (2002), which would never
have been published if your assumption about causality being violated
by FTL propagation were true in physics."
That is called an appeal to authority. Impeaching the credibility of
the authority to whom you've appealed is perfectly legitimate. I've
given you numerous cogent arguments to which you never have responded
except with inappropriate analogies. Discuss your actual theory and
I'll have no reason to talk about the inappropriateness of your analogies
or impeach the authorities to whom you appeal.
> If you have an actual criticism or point to make, please
>state it. In any case, the editor, thorough reviewers, and subsequent
>readers of the article in question have expressed opinions that differ
>from yours.
I've made actual criticisms, but rather than answer those, you
are appealing to authority here again, in the form of the editor
and ``subsequent readers''.
>
>>> [tvf]: The same criticism applies to any form of curvature - it
>provides no cause to initiate motion. Moreover, the new 3-space momentum
>imparted by a source mass to an orbiting target body cannot be created
>ex nihilo in physics. It therefore requires a force by definition:
>"force is the time rate of change of momentum".
>
>> [Bilge]: In other words, nothing can move. A ``straight line'' cannot,
>in your terminology, ``initiate motion''.
>
> I believe I was restating Newton's first law of motion,
>which is still in effect as of the last time I checked.
I know you were. My intent was to demonstrate that you are entirely
oblivious to the hypocrisy of your own criticism. You said above ``The
same criticism applies to any form of curvature - it provides no cause
to initiate motion.''
A straight line is a form of of curvature which has exactly the same
properties as any other ``form of curvature''. Therefore, by your own
argument, there can be no motion in a straight line, for the reasons
you've just given.
>I don't know how you leapt to your statement from mine. So to make
>mine simpler, consider my phrase "initiate motion" to apply to a
>body at rest.
OK. In general relativity, an object on a geodesic is at rest. A straight
line happens to be only one particular case of a geodesic. You either
don't understand what you are talking about or else you're deliberately
engaging in sophistry.
>> [Bilge]: Did you really study any of this stuff, tom? The constant `c'
>is there to make timelike intervals use units based upon earth
>conventions. There is no physics in a unit conversion. Changing kg to
>lbs, for example, changes units invented by people. It doesn't alter any
>physics.
>
> That was my point, exactly. Time-like geodesics are proper
>time intervals with no spatial component. Changing their units to be
>space-like does not change their physical meaning, which is purely
>time-like.
Oh, I get it now. You don't understand the difference between human
the human convention of measuring distance and time using different
units and what spacelike and timelike means. So, if I choose to measure
vertical distances in meters and horizontal distances in furlongs
do I change the physical meaning of a horizontal distance when I
express it furlongs? After all, it contains no vertical component.
Sheesh...
[...]
>> [Bilge]: That may be, but there are no field theories which agree with
>anything you've said either, so what difference would it make?
>
> The field interpretation of GR I described in my chapter
>"Gravity" in the book "Pushing Gravity: New Perspectives on Le Sage's
>Theory of Gravitation" [M. Edwards, ed., Apeiron Press, Montreal, 93-122
>(2002)] is a counterexample to your claim.
Previous discussions with you regarding E&M indicate you do not
understand even a simple field theory. You've also been unwilling to even
state the assumptions upon which le sage gravity is based beyond some
wishful handwaving which is insufficient to derive anything at all. I have
no reason to believe that your chapter in a book published through a
vanity press stands a chance of being a counter example of anything.
>> [Bilge]: Please write down the equations for both the gravitational
>potential and electromagnetic potential and explain the difference as it
>relates to your point.
>
> Equations are oblivious to causality, constraints, and
>principles of physics.
Does that mean you think your model is viable because you like
the handwaving, but have no idea how obtain an equation that could
be used to validate the handwaving?
>One can learn nothing of relevance to my point from the equations you
>ask for.
On the contrary - physics is about putting your so-called point into
a form which may be used to test your point against physical data and
separate self-delusion from reality. As an experimental physicist, I
am used to interpreting equations in order to make such comparisons. I
think I could learn a great deal more from a few simple equations than
all of the verbiage you employ to avoid writing down any equations.
[...]
>> [Bilge]: Do you really think relativity tells you that if someone
>observes a clock which exceeds `c' that all of the clocks in both frames
>break?
>
> Again, I have no idea where you get these strawmen from.
From you, tom. For example, you have previously claimed:
``momentum are given by the same factor gamma as in SR. And
when a mechanical or atomic clock is driven past lightspeed,
it breaks, because the cesium atom transitions (for example)
cannot be completed.''
Since you've made the claim, I'm not attacking a straw man.
>I said simply that any single electromagnetic-based clock, pushed to
>an FTL speed relative to the gravitational potential field in which
>it is immersed, would indeed break, just as a sonic clock pushed to a
>faster-than-sound speed in an atmosphere would break. This is not a hard
>concept to grasp.
It is when you attribute that difficulty to relativity in which your
concept is a non-sequiter. Since you think that equations cannot help
make your point, I can't really say much about your theory other than
than what I get out of your use of such non-sensical statements to try
and justify it.
>
>> [Bilge]: C'mon, you can't be that dense. On the other hand, in your
>theory, you have an absolute frame, so that an absolute velocity has
>some meaning. You should be embarrassed to post arguments which are that
>ill-conceived.
>
> More frustration, I see. Why not consider the actual model,
>which is much more interesting and worth discussing than the flawed
>imitations you like to advance so you have something to beat up?
Because you won't post it and for that matter, just above, you
state flat out that equations won't help make your point. I've asked
you to post enough details so that I could precisely what your rhetorical
question above asks and fallaciously implies for an answer. Yet, here
you are doing everything but giving me the model for consideration. I
can only give consideration to that which you post for that purpose.
If you have a problem with what I consider in my responses, the problem
is with what you have provided for consideration.
Ken S. Tucker
[...]
>Note that despite repeated requests, Tom has never provided a mathematical
>definition -- an equation -- for the operation he calls a ``retarded
>gradient.'' Nor has such a definition appeared in any paper that I am
>aware of. The term seems to be a fantasy.
>
>In general relativity, roughly speaking, a gravitational source produces
>a set of potentials. Changes in the source cause changes in the potential
>that propagate at light speed. To compute the effective force on an
>-- of the potential at position x and time t. In other words, an object
>``here'' and ``now'' responds to the change in the potential ``here''
>and ``now,'' and not somewhere else at some other time.
Steve's "roughly speaking" is understood, ie don't
quote.
But the issue isn't about the magnitude of the
gradient of the g-potential, but rather it's vector
direction.
Tom's theory points the vector at the "instantaneous"
position of the sun, while GRist's like Steve are
obligated to use the aberated (apparent) position
of the sun for their gradient vector.
I see it this way, the fact that "freefall" exists even
when particles are following curved paths is evidence
of Principle of Equivalence, ie. the centrifugal
accelerations (inertia) caused by the curved paths are
exactly equal to the gravitational accelerations and so
the net acceleration is zero.
In GR's PoE it's simple to *see* that the inertial
acc (acceleration) is aberated in exactly the opposite
direction as the aberated g-acc, otherwise free-fall
would not occur.
The difficulty is how to PROVE that geodesically.
I tried to do this below.
[...]
>Steve Carlip
Steve and Tom might have a glance posted awhile
ago that provides a geodesical understanding
of the speed of gravity.
++++++++
Speed of Gravity Theory.
According to Newton the Speed of Gravity (Gs)
is infinite. Fig.1 shows the balance of the g-force
and centrifugal force and looks like,
Centrifugal Acceleration
/|\
|
|
|
<----(E)----- Orbital Direction of Earth
| (Circular orbit)
|
|
\|/
Solar Gravitational Acceleration Fig.1
(S)
Where (E) is the Earth and (S) is the Sun.
According to Einstein's GR, Gs=c, hence the
acceleration vector is directed toward the apparent
(aberated) position of the sun (s) as in this Fig.2
((seeing is believing))...
Centrifugal Acceleration
/\
/
/
/
<----(E)----- Orbital Direction of Earth
/ (Circular orbit)
/
/
\/
Solar Gravitational Acceleration Fig.2
(s) (S)
image^
IMO, the centrifugal acceleration is directly opposite
the g-acceleration, as shown in Fig.2. This is based on
the Principle of Equivalence, whereby the gravitational
acceleration and the inertial acceleration (centrifugal in
this example) precisely balance to produce a "freefall",
so that no acceleration can be detected on Earth due
to the sun's gravity.
A common misconception is to align the acceleration
vectors on (E) as in Fig.3
Centrifugal Acceleration
/|\
|
|
|
<-<----(E)----- Orbital Direction of Earth
/ (Circular orbit)
/
/
\/
Solar Gravitational Acceleration Fig.3
(s) (S)
This unbalanced gravitational and centrifugal
acceleration would produce a residual acceleration
and velocity accumulation "At" in the direction of
orbital velocity if it were true, and would lead to a
gross failure of Energy conservation as well as a
sense of acceleration on Earth, this doesn't happen.
But we now have a situation that needs to be
explained in terms of GR, specifically the
introduction of oblique X-Y axes relating the
sun's image and Earth as in Fig.4a,
Y-axis
/\
/
/
/
<----(E)----- X-axis
/
/
/
\/
(s) Fig.4a
Of course, it follows, if the direction of Earth's
velocity around the Sun were to reverse then
the X-Y axes obliqueness would also reverse
and produce Fig.4b,
Y-axis
/\
\
\
\
----(E)----> X-axis
\
\
\
\/
(s) Fig.4b
Mathematically, a unit vector e1 on X and e2 on Y
produces the following results,
(assuming V=dx/dt when y=r),
Fig 4a g12 = e1.e2 = -V/c (set c=1)
Fig 4b g'12 = e'1.e'2 = -V'
and g12 = -g'12 because V = -V' . (Eqs.1)
This understanding of the non-orthogonality
of the X-Y axes is adequate to solve the speed
of gravity problem, but it does not address
magnetism. For example let's be more clear
on the definition of rotational velocity V.
Set the rotational velocity defined wrt an
inertial system to,
V12 = (x1/r)*(dx2/dt) - (x2/r)*(dx1/dt)
where x1 == x and x2 == y,
then V12 = - V21.
One can see g12 == V12 but
g12 = -V21
At this point *I presume* V12 defines g12 and thus
g12 is anti-symmetrical and, of course, non-orthogonal.
In view of this developement, we might liken the anti-
symmetrical portion of g12 to the EM field tensored
by the magnetic force q*F12 as an asymmetrical stress
on the spacetime field.
I think anyone who has played with a pair of bar
magnetics has noticed weird attactions and repulsions
as these magnetics twist in relative orientation.
Aside from exotic theory, the medium connecting
these bar magnetics is only a spacetime field.
I can live with that.
Regards
Ken S. Tucker
Hayek
Mike wrote:
> "Bill Hobba" <bho...@hotmail.com> wrote in
> message
> news:<dPXjc.3029$TT....@news-server.bigpond.net.au>...
>
>
>> I have been meaning for a while to actually
>> tread Tom's views on why he believes gravity
>> propagates at speeds greater than c and Steve
>> Carlips reply. It has not really been a
>> priority because the lornentz transformations
>> prove casualty would be violated if you could
>> do it.
>>
>> But I have actually read Tom's view and am left
>> scratching my head at what the fuss is about.
>> Tom wrote:
>>
>> 'Indeed, it is widely accepted, even if less
>> widely known, that the speed of gravity in
>> Newton's Universal Law is unconditionally
>> infinite. (e.g., Misner et al., 1973, p.177)
>> This is usually not mentioned in proximity to
>> the statement that GR reduces to Newtonian
>> gravity in the low-velocity, weak-field limit
>> because of the obvious question it begs about
>> how that can be true if the propagation speed
>> in one model is the speed of light, and in the
>> other model it is infinite.'
>>
>> As Landau demonstrates the existence of a
>> classical potential implies forces modeled by
>> classical mechanics must propagate
>> instantaneously. This is associated with the
>> instantaneous propagation time required by the
>> Galilean transformation on which classical
>> mechanics is built. And it is true that in the
>> non relativistic limit Newtonian gravity
>> results and that requires instantaneous
>> propagation of forces. But what you have done
>> in taking the non relativistic limit is to say
>> we are dealing with speeds much smaller than
>> light so we make the speed of light to be
>> infinite ie we have introduced the assumption
>> the speed of interaction is infinite ie the
>> Galilean transformation now apply not the
>> lorentz transformations. It is hardly a
>> surprise that a theory based on instantaneous
>> interaction requires the speed of gravity to
>> act instantaneously. And is it also hardly a
>> surprise that it now violates the known
>> problems of having instantaneous transmission
>> of information - you have specifically decided
>> for the purpose of having a theory that applies
>> to velocities much less than c you want c to be
>> infinite and are willing to accept that it is
>> now not a theory that is in accord with other
>> known principles of nature. You can't say I,
>> for the sake of simplicity, will assume c to be
>> infinite then worry about c being finite. It
>> makes no sense AFAIKS.
>>
>> Of course I read Steve Carlip response and
>> naturally agree with it. But in view of what I
>> write above I am left with this feeling it is
>> an overkill. What do others think? - or am I
>> missing something (quite possibly).
>>
>> Thanks Bill
>
>
> Van Flandern's Meta Model is built around the
> concept of Le Sage's material graviton flux. It
> turns out that for that model to work and avoid
> issues like exploding planets due to the
> gravitons hitting matter at high speeds, these
> particles must have an ultra small mass and
> travel at about 10^20 c (!) if I recall correcly
> the number. Thus, in that model of his, gravity
> propagates at FTL speeds and there is a physical
> mechanism which is based on momentum exchange and
> shadowing. Gravity is thus a push force.
>
> Now, Van Flandern was upset when Kopeikin
> announced his measurement of the light deflection
> from Jupiter and pronounced the vg = c. This is
> because, if vg = c then the graviton, which is
> unobservable entity now my its properties, cannot
> exist. Furthermore, Van Flandern attacked the
> geometric interpretation of GR and has declared
> the field force interpretation as the only
> appropriate. This is because, the geometric is
> consistent with vg=c but the field one is
> probably not.
>
> I think Van Flandern is the last of physicalists
> reamining on the planet. He is to be respected
> for his intense effort to 'save the phenomena'
> and his quasi-static universe model in that
> respect. But he is subject to contradictions that
> arise in his model and the needd to continuously
> rearrange it and add new hypothesis in order to
> keep it up with empirical observations. But he
> worths respect. I wish Van Flandern's world was
> real but unfortunately it seems it is not. One
> think i definitevely agree with Dr. Al is that
> this wrold is strange and Newtonian or Le Sage
> models too naive to explain it.
Great post Mike.
As Aristotle (384 BC - 322 BC) said :
"It is the mark of an educated mind to be able to
entertain a thought without accepting it."
I also have a lot of respect for Tom Van Flandern.
It is through exchanging and discussing different
viewpoints that progress is made, not by stubbornly
clinging to old dogma. I think it was Einstein who
said "we should never stop asking : "what if?""
Uwe Hayek.
--
To be controlled in our economic pursuits,
is to be controlled in everything -- F.A.Hayek.
Mike
Van Flandern is a living database of astronomical facts and orbital
mechanics details. But his Meta Model violates the law of parsimony.
Too many hidden hypotheses can be found in his model. In constrast,
Einstein's SR survived 100 years because in the course of the attempt
to axiomatize relativity, only two hidden hypotheses were discovered.
In SR, all deductions about the world come from 4 principles. As soon
as a fifth principle about an absolute frame is added, this opens
Pandora's box. Needless to say, if unobservable entities are
postulated things become worse. I'm trying to pass this message to Van
Flandern. Any statements about Time, Space, Conservation etc. must
come from deductions based on primitive concepts and not a priori (or
synthetic a priori) principles involving them.
Mike
Tom Van Flandern
Bilge.
Steve Carlip <car...@no-physics-spam.ucdavis.edu> writes:
>> [tvf]: when the gradient of the potential is taken to derive an
expression for force, GR uses an *instantaneous* gradient, not a
retarded one.
> [Carlip]: Note that despite repeated requests, Tom has never provided
a mathematical definition -- an equation -- for the operation he calls a
"retarded gradient.'' Nor has such a definition appeared in any paper
that I am aware of. The term seems to be a fantasy.
The first equation in our "Foundations of Physics" paper in
the "Principles and definitions: section is the mathematical definition
of gradient you requested. See the web version at
http://metaresearch.org/cosmology/gravity/speed_limit.asp. The
accompanying paragraph explains that the coordinates used in this
definition must be chosen to be either instantaneous coordinates or
retarded coordinates. This is the same choice we must make in retarded
potential equations, where coordinates of distant points are evaluated
at time t-r/c instead of at time t, to allow for field retardation over
distance r at the speed of light.
The same reasoning applies to gradients. This is also
obvious when viewed physically instead of mathematically. The gradient
is just the slope of a hill in a particular direction. The gradient of a
gravitational potential created by a source mass is the slope of the
potential hill in the direction of the source mass. But for consistency,
that must be the *retarded* direction of the source mass, not its
instantaneous direction. These are one and the same for a fixed field
point or a target body at rest. But for a target body with transverse
speed v, the two directions differ by the angle v/V, where V is the
propagation speed of the phenomenon of interest. That is simply because
a photon or graviton from a source mass, moving along a linear, radial
path to a moving target body, will strike the target body at different l
ocations along its orbit depending on propagation speed of the photon or
graviton. So the angle of strike must vary with propagation speed.
Studying our animation #(4) and its caption at
http://metaresearch.org/media%20and%20links/animations/animations.asp
helps to visualize this.
The only way to recover the GR equations of motion is to set
V = infinity in this particular step (forming the gradient), which then
makes the gradient point toward the true, instantaneous direction of the
source mass, which is different from the direction of arriving photons
with V = c. Using V = infinity recognizes that forces (gradients)
propagate with infinite speed in GR, even though potential field changes
(gravitational waves) propagate at the speed of light.
> [Carlip]: In general relativity, roughly speaking, a gravitational
source produces a set of potentials. Changes in the source cause
changes in the potential that propagate at light speed. To compute the
effective force on an object at position x at time t, one takes the
gradient -- the derivative -- of the potential at position x and time t.
In other words, an object ``here'' and ``now'' responds to the change in
the potential ``here'' and ``now,'' and not somewhere else at some other
time.
I agree with this statement. But the gradient is a vector,
which has direction. And direction requires a minimum of two points to
specify. So the force/gradient cannot be determined purely from
consideration of the "here" and "now". It also requires knowledge of the
source mass location, which is the other point defining the direction.
And if the field point is moving relative to the source mass, then it
makes a difference whether we use the instantaneous or retarded source
mass position to define the gradient direction.
As you know well, only the instantaneous source mass
position gives the correct force. As I have been saying all along, here
and in print, gravitational force propagates strongly ftl in nature, and
with infinite speed in GR, in standard celestial mechanics, and in
computer experiments that emulate reality. Any propagation delay used
for gravitational force or for the direction of the gradient produces
spiral orbits.
The only escape from this reasoning is to adopt the view (as
in the geometric interpretation of GR) that the potential field changes
instantly in lockstep with source mass accelerations. But then we face
two new problems of physics: Curvature alone, without a force acting,
cannot initiate motion in 3-space. And the new momentum transferred to
the target body by gravity must be created by magic from nothing because
a static field cannot be a source of momentum. So we are left with the
view you recommend above: "Changes in the source cause changes in the
potential that propagate at light speed." And the problem with this is
that it is contradicted by binary pulsars, which clearly show that even
accelerations of a source mass register their effect on a target body
much faster than the light-time between them. The full argument and
equations for this appeared in "The speed of gravity - What the
experiments say", Phys.Lett.A, v. 250, #1-3, pp. 1-11 (1998), also
available at http://metaresearch.org/cosmology/speed_of_gravity.asp,
under the small heading "Myth: Gravity from an accelerating source
experiences light-time delay".
>> [tvf]: This creates forces acting between source masses and target
bodies over any distance instantaneously
> [Carlip]: No, it doesn't. This is a fantasy that has nothing at all to
do with the way GR works.
Authoritative declarations without explanation or
justification do not advance any dialog, but tend to derail it.
I know you are an expert at "how GR works" in theory. But my
professional expertise is in celestial mechanics, or "how GR works" in
physical reality, where comparisons of 3-space orbits with 3-space
observations are conducted to test the theory. So we will get nowhere by
arguing whose expertise trumps whose. But several things recommend the
new interpretation of GR using LR instead of SR. Among these are that
classical physics rules apply, "spacetime curvature" becomes a simple
refraction phenomenon in a light-carrying medium, paradoxes disappear
(in gravitation and in QM), and one of the greatest attractions of
physics -- its simple models of natural phenomena -- is restored. For
example, the simplest concept ever conceived by mankind to understand
the nature of gravity, the Le Sage "pushing gravity" mechanism, is back
on the table and very much alive and well. And that is a good thing.
In any case, thanks for your comments. It is always a
pleasure to engage with someone as knowledgeable as yourself.
and "Mike" <ele...@yahoo.gr> writes:
> [Mike]: If dimensions can be logically infinite, why couldn't
substance get also infinite? Infinity x infinity is a perfectly valid
operation producing infinity. Your 'theory' then has another implicit
hypothesis that dimensions are infinite but 'substance' finite. But
dimensions are logical terms and substance presumably physical entity. I
cannot understand the use of arbitrary assumptions in order to avoid
paradoxes of infinity. Those assumptions have a strong ontological
content and are thus metaphysics.
One goal in reasoned arguments is the avoidance of paradoxes
and contradictions. If only two choices are possible, e.g., a principle
and its converse, one is logically forced to choose the one that avoids
irresolvable paradoxes. So I can't imagine why you appear to be arguing
that we cannot eliminate paradoxical premises in favor on
non-paradoxical ones.
As for specifics, you appear to be still in the dark about
MM, and continue to make wrong assumptions about what it has to say
about the nature of reality. Without re-justifying these statements
here, I told you that the "infinities" paradoxes are resolved by having
infinite dimensions (dimensions being non-physical concepts), while all
forms (made of substance) are finite. Forms cannot "get infinite"
because of the logical principle that the finite cannot become infinite.
No matter how many finite pieces are assembled, the resulting structure
is still finite. The same applies to other infinite sets such as the set
of all integers. No matter how many integers are assembled from this
infinite set, the assembly still has only a finite number of integers in
it.
> [Mike]: Are you proposing infinite physical dimensions with finite
substances or infinite logical dimensions with finite substances?
Dimensions are non-physical concepts. Non-physical entities
can be infinite. But all physical forms must be finite, even if there
are an infinite number of them. (Just like the integers.)
> [Mike]: Is your space logically infinite, physically infinite or both?
If it is just logically infinite but substance cannot be, then you have
no space but only substance in your physical model. Then, you must tell
me how in the world substance is subjected to your causality principle.
The combination of no physical space, physical substance and causality
leads to the need for an active principle (See Leibniz). According to
Spinoza, this principle can only be God.
A simple reading of MM would clear all these matters up for
you in a flash. Read at least chapter one of "Dark Matter, Missing
Planets and New Comets", North Atlantic Books (2nd edition 1999). In MM,
it turns out )deductively, not by assumption) that substance and
existence are synonymous. Whatever has substance exists. Whatever exists
has substance. Because scale is infinite, no "space" (a dimension, and
therefore a concept) exists except what is occupied by substance on some
scale, however infinitesimal.
You are out on the limb of a tree, asking questions about
this branch vs. that branch. Each answer leads to new questions. But if
you start at the base, trace the trunk, and observe how all the branches
relate, then each branch (such as the answers I just gave) will make
sense and relate in a meaningful way to all the others. I urge you to
get a sense of the whole tree (read chapters 1 and 21 of the book)
before attempting any more limb trimming.
> [Mike]: Going to the physics side (to prevent your complain that this
is philosophy) you must tell me how to define acceleration in physics in
pure relational terms other than in relation to some absolute
space-time. As you may know, such attempt has been met with failure in
3-D physics. You need 4-D physics to resolve it but then it turns out
space-time becomes substantive.
The discussions of acceleration in 4-D have always been
strained and unphysical to me. In the real world, we have instant
recognition whether any body is accelerating in 3-space or not because
the Doppler shifts of all the objects in the universe change in a
predictable pattern as the speed of the body changes. Whether or not we
"feel" acceleration is and always was a red herring. We are capable of
"feeling" only force or pressure, not pure motion. So any force that
acts on every atom of our bodies equally and simultaneously, such as
gravity, cannot be felt because it produces no pressure differential.
See my article "Does gravity have inertia?" in Meta Research Bulletin
11, 49-53 (2002), which has an elegant solution for the riddle you pose.
> [Mike]: In this view, adopted by some Cartesians and Newton,
space-time is not a well-founded phenomenon because there are absolute
points in space and time but all observed motion is relative.
Although this paragraph covers a logical line that does not
apply to MM, I see a major problem in your thinking here because you
seem to have the common association between "spacetime" and "space plus
time". But that is not the case. "Spacetime" is the equivalent of proper
time, and has no spatial component. See
http://metaresearch.org/cosmology/gravity/spacetime.asp.
As you may be keenly aware, adopting just a single wrong
premise or conclusion is fatal to the reasoning process and to
understanding and predicting nature. So great care must be taken to
avoid such mistakes. The article I cited shows why thinking of space as
something tangible that can be curved is just such a mistake.
> [Mike]: Additionally, is your substance physically finite and
logically finite or physically finite but logically infinite?
Substance (the set of all forms) is a concept and is
infinite. But all forms (physical entities made of substance) are
finite. This is analogous to "the set of all integers" is infinite, but
all integers are finite.
> [Mike]: You can see from the above that any reference to 'substance'
lead to exercises in futility and the need for metaphysical
postulations. That was the purpose.
On the contrary. While it might appear that way with your
premises, MM has managed to straighten out all this mess and make sense
of existence. The crucial step in getting there was getting rid of *all*
assumptions. Then we can learn deductively from first principles how to
deal with infinities in a way that solves paradoxes (such as Zeno's)
rather than creates them.
>> [tvf]: You misrepresent the logic involved. There are no miracles
implied by the principles *and* miracles are required by their
converses. That eliminates the claimed logical fallacy.
> [Mike]: In other words, you do not justify why the principles exclude
an independent existence of magic but only the claim that if the
principles hold, then those principles entail no magic. I could insist,
that the very fact of these principles holding true is magic. Here is
your antinomy. These are the type of problems you run into with Kantian
type synthetic a priori statements arrived at by transcendental
arguments.
For purposes of discussing the principles of physics, we can
equate magic, miracles, and the supernatural. This last is, by
definition, outside the natural world. So the study of physics excludes
all these mechanisms by definition, and attempts to understand and
explain the natural world without supernatural processes. The reason is
simple: Once the Supernatural is allowed as an explanation, then there
is no point in further inquiry because everything can be explained as
simply "the Will of God".
The exclusion of these mechanisms from physics does not
exclude them from our experience of reality. However, if any principle
of physics were violated (any such would be a supernatural event), we
could then conclude that our experiences were not of a true reality, but
were rather of some kind of holodeck simulation of reality (e.g., "the
Mind of God"?), for that is the only kind of world in which supernatural
events that defy physical principles can occur.
So the principles of physics are not "proved" by logic, just
as you say in your protest. But they must nonetheless be adopted as
pragmatically necessary to make progress with understanding the natural
world unless or until such time as a proven violation occurs, at which
time further exploration of nature becomes pointless because our
simulated reality has supernatural events going on, anything is
possible, and understanding and predicting reality is not possible.
>> [tvf]: Sending matter back to the past is itself a change in the
matter and energy content of the universe in both past and present.
> [Mike]: Unless past, present and future are one and the same thing.
There are many possibilities. I get the impression you claim nowism, a
direction of time and possibly absolute, universal time. All [are]
metaphysical statements leading to many paradoxes.
SR has now been falsified in favor of LR [see "Experimental
Repeal of the Speed Limit for Gravitational, Electrodynamic, and Quantum
Field Interactions", T. Van Flandern and J.P. Vigier, Found.Phys.
32(#7), 1031-1068 (2002); similar to web preprint "The speed of
gravity - Repeal of the speed limit" at
http://metaresearch.org/cosmology/gravity/speed_limit.asp], which means
that "distant simultaneity" is back and there is a "universal time".
(Note: This is quite different from "absolute time". Time is simply a
measure of change, and change might occur at different rates on
different scales or in distant parts of the universe.) That simple
switch from SR to LR has eliminated all those famous paradoxes of
physics and QM. Physics and reality are simple again. And there is not a
single important paradox left.
Or does that threaten job security for philosophers? :-)
> [Mike]: For one observer an event is past but for another is still in
his future like in SR.
SR is now a thing of the past, of interest only to
historians, who seem likely to consider the era of its dominance as the
"Alice in Wonderland" era.
> [Mike]: I think you're attempting to avoid getting cut by Occam's
Razor and you claim that your principles are derived from reasoning. But
reasoning based on what premises? The only one you gave is the no-magic
premise. No primitives. As such, your principles are actually disguised
axioms IMO.
This is all detailed in chapter 21 of my book, "Dark Matter,
Missing Planets and New Comets". The solution is as I outlined above.
Only one path allows us to avoid supernatural events, and we must
pragmatically follow that path as long as it remains helpful in aiding
our understanding of existence, because adopting the converse of any
principle of physics immediately leads to contradictions and an end to
any hope of understanding.
and "Ken S. Tucker" <dyna...@vianet.on.ca> writes:
> [Tucker]: Fig.1 shows the balance of the g-force and centrifugal
force. IMO, the centrifugal acceleration is directly opposite the
g-acceleration, as shown in Fig.2. . the gravitational acceleration and
the inertial acceleration (centrifugal in this example) precisely
balance to produce a "freefall", so that no acceleration can be detected
on Earth due to the sun's gravity.
This is a misunderstanding of the equivalence principle. If
gravity and centrifugal force balanced and cancelled, then Earth would
experience no net force and would move on a straight line instead of an
orbit. In reality, gravity is the only important real force acting on
Earth, and Earth's acceleration is readily detectable in modern,
high-precision observations such as radar ranging and pulsar timings.
Centrifugal force is a pseudo-force, and does not exist for bodies in
free fall when dynamics is described in an inertial 3-space frame of
reference, which is the type you were using.
and "Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>> [tvf]: The literature is now filled with articles about how LR works
and about SR-LR comparisons. I recommend my own exposition, "What the
Global Positioning System tells us about the twins paradox", Episteme #6
pt. II, http://www.dipmat.unipg.it/~bartocci/ep6/ep6-vanfl.htm
(2002/12/21).
> [Bilge]: I've read that before and criticized the misconceptions it
promotes. By the way, you didn't even get the url correct.
It is unfortunate that you can't recall a single
misconception to use as an example so others can judge who has the
misconceptions.
As for the url, apparently some files were moved around on
that site. I was able to locate the paper again at this link:
http://www.dipmat.unipg.it/~bartocci/zip/ep6-pII.zip. Unfortunately, it
requires downloading half of the entire volume to get that one paper. I
will recommend to the Meta Research Board that we post this paper to our
own web site asap.
>> [tvf]: "See "Experimental Repeal of the Speed Limit for
Gravitational, Electrodynamic, and Quantum Field Interactions", T. Van
Flandern and J.P. Vigier, Found.Phys. 32(#7), 1031-1068 (2002), which
would never have been published if your assumption about causality being
violated by FTL propagation were true in physics."
> [Bilge]: That is called an appeal to authority. Impeaching the
credibility of the authority to whom you've appealed is perfectly
legitimate. I've given you numerous cogent arguments to which you never
have responded except with inappropriate analogies. Discuss your actual
theory and I'll have no reason to talk about the inappropriateness of
your analogies or impeach the authorities to whom you appeal.
Providing citations to back up an argument is now an "appeal
to authority"? Incredible. I note again the total lack of specifics in
your remarks: ". numerous cogent arguments .". I suggest you always
provide an example with each of your sweeping generalizations so you do
not appear to be all bluster.
I discussed "my theory" (the Meta Model) in my response to
Mike because he raised questions about it. But all your comments dealt
with my remarks about the correct physical interpretation of GR, not
about any theory of mine.
>> [tvf]: If you have an actual criticism or point to make, please state
it. In any case, the editor, thorough reviewers, and subsequent readers
of the article in question have expressed opinions that differ from
yours.
> [Bilge]: I've made actual criticisms, but rather than answer those,
you are appealing to authority here again, in the form of the editor and
``subsequent readers''.
Again, bluster in lieu of substance. Where is the relevant
discussion point?
>> [tvf]: The same criticism applies to any form of curvature - it
provides no cause to initiate motion.'
> [Bilge]: A straight line is a form of curvature which has exactly the
same properties as any other "form of curvature''. Therefore, by your
own argument, there can be no motion in a straight line, for the reasons
you've just given.
I see we have a language problem too. I did not say motion
was impossible, only that curvature could not initiate 3-space motion
for a body at rest unless a force acts.
So that we can make progress toward agreement, please state
that you now agree, or provide specifics on why you still disagree.
> [Bilge]: OK. In general relativity, an object on a geodesic is at
rest.
I prefaced my remarks with a clear statement that I was
speaking of 3-space, not 4-space. Please state that we now agree, or
provide specifics on why you still disagree.
> [Bilge]: You either don't understand what you are talking about or
else you're deliberately engaging in sophistry.
We can certainly agree that one of us is engaging in
sophistry.
>> [tvf]: Time-like geodesics are proper time intervals with no spatial
component. Changing their units to be space-like does not change their
physical meaning, which is purely time-like.
> [Bilge]: Oh, I get it now. You don't understand the difference between
the human convention of measuring distance and time using different
units and what spacelike and timelike means. So, if I choose to measure
vertical distances in meters and horizontal distances in furlongs do I
change the physical meaning of a horizontal distance when I express it
furlongs? After all, it contains no vertical component. Sheesh...
I gather that you do not bother to read the citations I
provide. My statement is explained and justified at
http://metaresearch.org/cosmology/gravity/spacetime.asp. It's a simple
argument. Either you understand it or you don't. If you do, then either
you see a fallacy or you don't. People reading this thread hope to see
stimulating discussions of the pros and cons of ideas in their areas of
interest. So please stay on topic and be specific, and drop the
sophistry about meters and furlongs. Sheesh.
> [Bilge]: You've also been unwilling to even state the assumptions upon
which le sage gravity is based beyond some wishful handwaving which is
insufficient to derive anything at all. I have no reason to believe that
your chapter in a book published through a vanity press stands a chance
of being a counter example of anything.
Le Sage gravity is based on the idea that the universe is
filled with ultra-fast, ultra-tiny "gravitons". Ordinary matter is
mostly transparent to these, but a small fraction of the gravitons do
strike matter. Then the apple falls from the tree because the normally
isotropic flux of gravitons is reduced below the apple by the Earth
blocking some gravitons. So the apple gets a net push from above - hence
the expression "pushing gravity".
That simple concept is then used to set up equations and
derive the properties of gravitation in the book "Pushing Gravity: New
Perspectives on Le Sage's Theory of Gravitation", M. Edwards, ed.,
Apeiron Press, Montreal (2002). See the chapter by V. Slabinski, "Force,
heat and drag in a graviton model", pp. 123-128.
If you consider all this "wishful hand-waving" or have no
further interest in this topic or in the possibility of learning
something new, then I suggest you drop out of this discussion. Aperion
Press is not a vanity publisher, and none of the (roughly 20)
peer-reviewed chapter authors paid a nickel to get into the book. On the
contrary, several authors who hoped to contribute had to be turned away.
And the publisher has already sold the rights to publish a Russian
version of the book. The English version is selling briskly and has
generated considerable interest worldwide.
>> [tvf]: Equations are oblivious to causality, constraints, and
principles of physics.
> [Bilge]: Does that mean you think your model is viable because you
like the handwaving, but have no idea how obtain an equation that could
be used to validate the handwaving?
Equations and five observational tests may be found in the
book chapters I cited, mine and Slabinski's. Get it and read it or stop
complaining.
> I think I could learn a great deal more from a few simple equations
than all of the verbiage you employ to avoid writing down any equations.
I put my equations in my technical papers, not is ascii
messages. But this yhread was about matters of physical interpretation,
not matters of math. To first order in potential and second order in
velocity, Le Sage gravitation has the same equations as GR. If you want
to see how those equations are arrived at from the Le Sage concept, see
any of several chapters in the book whose authors derive those
equations.
> [Bilge]: If you have a problem with what I consider in my responses,
the problem is with what you have provided for consideration.
Wherever you asked a specific question or made a specific
point, I addressed it. If you wish to study equations, see the book and
technical papers. This discussion was about the comparative physical
interpretation of the models. I'm sorry you find nothing of interest to
you in that area, but many of us do. -|Tom|-
Vern
> This replies to Steve Carlip, Mike, Ken S. Tucker, and
> Bilge.
[snipped most of this great post]
[Tom said]
> But several things recommend the
> new interpretation of GR using LR instead of SR. Among these are that
> classical physics rules apply, "spacetime curvature" becomes a simple
> refraction phenomenon in a light-carrying medium, paradoxes disappear
> (in gravitation and in QM), and one of the greatest attractions of
> physics -- its simple models of natural phenomena -- is restored. For
> example, the simplest concept ever conceived by mankind to understand
> the nature of gravity, the Le Sage "pushing gravity" mechanism, is back
> on the table and very much alive and well. And that is a good thing.
[and]
> The discussions of acceleration in 4-D have always been
> strained and unphysical to me. In the real world, we have instant
> recognition whether any body is accelerating in 3-space or not because
> the Doppler shifts of all the objects in the universe change in a
> predictable pattern as the speed of the body changes.
[and]
> If
> gravity and centrifugal force balanced and cancelled, then Earth would
> experience no net force and would move on a straight line instead of an
> orbit. In reality, gravity is the only important real force acting on
> Earth, and Earth's acceleration is readily detectable in modern,
> high-precision observations such as radar ranging and pulsar timings.
> Centrifugal force is a pseudo-force, and does not exist for bodies in
> free fall when dynamics is described in an inertial 3-space frame of
> reference, which is the type you were using.
[and]
> I see we have a language problem too. I did not say motion
> was impossible, only that curvature could not initiate 3-space motion
> for a body at rest unless a force acts.
It seems you are holding that gravitational forces are instantaneous
and you believe that the Le Sage model accounts for a radially
centripetal gravitational force and you also appear to believe in a
light-carrying medium. But all those pieces don't seem to fit
together for an overall model. The Le Sage model and instantaneous
gravitational forces are contradictory, first you have a particulate
medium for pushing, but then accept action-at-a-distance for
gravitational interactions between distant bodies. Then no
correlation between gravity and the supposed light-carrying medium.
The Rado ideal-gas-sink-type Aether model provides that correlation
and provides the mechanism for eliptical orbits. We have a study
group at yahoogroups for this model called "aethro-kinematics." Hope
to see you there.
Vern
Ken S. Tucker
>and "Ken S. Tucker" <dyna...@vianet.on.ca> writes:
>> [Tucker]: Fig.1 shows the balance of the g-force and centrifugal
.>force. IMO, the centrifugal acceleration is directly opposite the
>>g-acceleration, as shown in Fig.2. . the gravitational acceleration and
>>the inertial acceleration (centrifugal in this example) precisely
>>balance to produce a "freefall", so that no acceleration can be detected
>>on Earth due to the sun's gravity.
[tvf]
>If gravity and centrifugal force balanced and cancelled, then Earth would
>experience no net force
Of course! That's why it's called free fall.
>and would move on a straight line instead of an
>orbit.
No, of course NOT. Sum gravitational force and
centrifugal force in a circular orbit ie.
0 = -GMm/r^2 + mV^2/r = net force.
"r" is the orbital radius, and is NOT a straightline.
>In reality, gravity is the only important real force acting on
>Earth, Centrifugal force is a pseudo-force, and does not exist
>for bodies in free fall
Of course it does, (refering to circular orbits).your're
arguing against even basic well known solutions of
Newtonian Mechanics.
>when dynamics is described in an inertial
>3-space frame of reference, which is the type you were using.
No, in my "Speed of Gravity Theory" post (repeated in
this thread) I assumed, 4D spacetime curvature. It's
simplified by using digrams to appeal to readers who aren't
familiar with tensors.
>Tom Van Flandern - Washington, DC - see our web site on replacement
>astronomy research at http://metaresearch.org
Tom, have a look at my Fig 3a in my first post in the
thread. You're objection is well defined there.
For an explanation of how the speed of gravity can be "c"
based on Equivalence, see Fig. 4.
IMHO the fatal difficultly for Dr. Flandern's theory is
defining the direction of the gravitational and centrifugal
force as it has no immediate way of determining the
"true" position of the sun from the *apparent* location
of the sun. However GR works perfectly well using the
*apparent* position to define those opposing directions.
Regards
Ken S. Tucker
Mike
> "Tom Van Flandern" <to...@starpower.net> wrote in message news:<40a13db2$0$2985$61fe...@news.rcn.com>...
>
> >and "Ken S. Tucker" <dyna...@vianet.on.ca> writes:
> >> [Tucker]: Fig.1 shows the balance of the g-force and centrifugal
> .>force. IMO, the centrifugal acceleration is directly opposite the
> >>g-acceleration, as shown in Fig.2. . the gravitational acceleration and
> >>the inertial acceleration (centrifugal in this example) precisely
> >>balance to produce a "freefall", so that no acceleration can be detected
> >>on Earth due to the sun's gravity.
>
> [tvf]
> >If gravity and centrifugal force balanced and cancelled, then Earth would
> >experience no net force
>
> Of course! That's why it's called free fall.
Holy ...
>
> >and would move on a straight line instead of an
> >orbit.
>
> No, of course NOT. Sum gravitational force and
> centrifugal force in a circular orbit ie.
>
> 0 = -GMm/r^2 + mV^2/r = net force.
Action is always equal to reaction. See below.
>
> "r" is the orbital radius, and is NOT a straightline.
>
> >In reality, gravity is the only important real force acting on
> >Earth, Centrifugal force is a pseudo-force, and does not exist
> >for bodies in free fall
>
> Of course it does, (refering to circular orbits).your're
> arguing against even basic well known solutions of
> Newtonian Mechanics.
Listen, I suggest you don't challenge Van Flandern and his orbital
mechanics. You loose. You demonstrated you don't understand Newton's
Laws. When the sum of the forces acting on a body is zero, according
to Newton it moves on a rectilinear uniform velocity path.
Furthermore, centrifugal force is a ficticious force you need to
consider in a non-inertial reference frame in order to correctly apply
Newton's second law, which is valid only in inertial frames. The same
holds for Coriolis force.
When you whirl a stone tied at the end of a rope, the centrifugal
force is acting on your hand, not on the stone. The only force on the
stone is the centripetal. If you move your FoR on the stone, you must
add a ficticious force equal in magnitude and direction to the
centripetal force in order to explain why objects remain at rest in
that frame. That is an inertial ficticious force.
The need to add ficticious forces to explain motion in non-inertial
reference frames motivated Einstein to consider the principle of
covariance in GR. With that principle, which is founded on an
epistemological one claiming that all phenomena must have the same
interpretation in all moving reference frames, the need for
considering ficticious forces in any frame is eliminated in 4-D
spacetime geodesic motion obeying the equivalnce principle.
Mike
Jeff Krimmel
[...]
> Listen, I suggest you don't challenge Van Flandern and his orbital
> mechanics. You loose.
I simply don't see how one's sexual promiscuity enters into this debate,
but I may be missing something.
Jeff
--
Add an underscore between 'd' and 's' and remove the first three
letters of the alphabet for email.
Bilge
>and "Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>> [Bilge]: I've read that before and criticized the misconceptions it
>promotes. By the way, you didn't even get the url correct.
>
> It is unfortunate that you can't recall a single
>misconception to use as an example so others can judge who has the
>misconceptions.
>
> As for the url, apparently some files were moved around on
>that site. I was able to locate the paper again at this link:
>http://www.dipmat.unipg.it/~bartocci/zip/ep6-pII.zip. Unfortunately, it
>requires downloading half of the entire volume to get that one paper. I
>will recommend to the Meta Research Board that we post this paper to our
>own web site asap.
you _check_ the url you reference _before_ posting it rather than post
an excuse for referencing it incorrectly? (The url I gave above is
correct, however).
>> [Bilge]: That is called an appeal to authority. Impeaching the
>credibility of the authority to whom you've appealed is perfectly
>legitimate. I've given you numerous cogent arguments to which you never
>have responded except with inappropriate analogies. Discuss your actual
>theory and I'll have no reason to talk about the inappropriateness of
>your analogies or impeach the authorities to whom you appeal.
>
> Providing citations to back up an argument is now an "appeal
>to authority"?
No, tom, writing, ``which would never have been published if your
assumption about causality being violated by FTL propagation were true in
physics.'', is an appeal to authority. You seem to find it convenient
to misconstrue what people write.
>Incredible. I note again the total lack of specifics in
>your remarks: ". numerous cogent arguments .". I suggest you always
>provide an example with each of your sweeping generalizations so you do
>not appear to be all bluster.
I suggest you read the responses I've posted to your other posts.
You'll find them in the url I gave above.
>> [Bilge]: A straight line is a form of curvature which has exactly the
>same properties as any other "form of curvature''. Therefore, by your
>own argument, there can be no motion in a straight line, for the reasons
>you've just given.
>
> I see we have a language problem too. I did not say motion
>was impossible, only that curvature could not initiate 3-space motion
>for a body at rest unless a force acts.
Curvature doesn't ``initiate three-space motion'' unless a force acts.
So, then, what is your point?
> So that we can make progress toward agreement, please state
>that you now agree, or provide specifics on why you still disagree.
I think it's obvious where we disagree. You are attempting to single
out straight lines as being the ordained trajectories for inertial
motion without actually making your bias obvious. If you aren't biased,
you had no reason to bring up curvature at all.
>> [Bilge]: OK. In general relativity, an object on a geodesic is at
>rest.
>
> I prefaced my remarks with a clear statement that I was
>speaking of 3-space, not 4-space. Please state that we now agree, or
>provide specifics on why you still disagree.
Motion is not possible if you exclude time (recall that a velocity
is ds/dt). Since things do not move in four dimensions, we are obviously
talking about motion in three space regardless of the underlying theory.
>> [Bilge]: You either don't understand what you are talking about or
>else you're deliberately engaging in sophistry.
>
> We can certainly agree that one of us is engaging in
>sophistry.
>
>>> [tvf]: Time-like geodesics are proper time intervals with no spatial
>component. Changing their units to be space-like does not change their
>physical meaning, which is purely time-like.
>
>> [Bilge]: Oh, I get it now. You don't understand the difference between
>the human convention of measuring distance and time using different
>units and what spacelike and timelike means. So, if I choose to measure
>vertical distances in meters and horizontal distances in furlongs do I
>change the physical meaning of a horizontal distance when I express it
>furlongs? After all, it contains no vertical component. Sheesh...
>
> I gather that you do not bother to read the citations I
>provide.
I reply to what you write. The purpose for citation is to provide the
background for an argument, not the argument itself.
>My statement is explained and justified at
>http://metaresearch.org/cosmology/gravity/spacetime.asp. It's a simple
>argument.
I'll agree that it's simple.
>Either you understand it or you don't. If you do, then either
>you see a fallacy or you don't.
OK. First, I'll include a statement from that url which supports what
I said regarding your confusion between manmade units and what ``spacelike''
means:
``Multiplying the coordinate time interval by the speed of light has
turned time into a space-like coordinate, and allows it to be
combined with the coordinates for the three spatial dimensions.''
This is obviously wrong. The interval ds^2 = (cdT)^2 is obviously
not spacelike. It's timelike. Every textbook which discusses relativity
points that out and in particular, explains the difference between
intervals which are spacelike, timelike and null (lightlike). It's even
more than apparent that have confused manmade units (which are meaningless)
with proper intervals (which have physical meaning).
You also say:
``Finally, divide each term by c2, which converts the length-like interval
ds into a time-like interval that we can readily identify as the elapsed
proper time for the body, dt, as defined in the theory of relativity''
There is no such thing as a ``length-like'' interval, tom.
And finally, this (the ?'s you see are due to your failure to write your
web pages such that they conform to the protocol - I'm not going to retype
them):
``Some relativists may argue that ?space-time? is not simply space plus
time, but a higher-level concept that includes the notion of ?time?, so
the physical principles do not apply.''
That is obviously false. Relativity adheres to the physical principles
defined as a part of relativity - just like any other theory does.
Obviously, you are being deceptive, you don't know what you are talking
about or both.
The web page you cited supports precisely what I said regarding your
confusion between spacelike intervals and using manmade units of meters
and seconds to label them.
>People reading this thread hope to see stimulating discussions of the
>pros and cons of ideas in their areas of interest. So please stay on
>topic and be specific, and drop the sophistry about meters and furlongs.
>Sheesh.
If my example using furlongs and meters is sophistry, then it succeeded
in pointing out the sophistry in your argument, even if you didn't seem
to recognize that.
>> [Bilge]: You've also been unwilling to even state the assumptions upon
>which le sage gravity is based beyond some wishful handwaving which is
>insufficient to derive anything at all. I have no reason to believe that
>your chapter in a book published through a vanity press stands a chance
>of being a counter example of anything.
>
> Le Sage gravity is based on the idea that the universe is
>filled with ultra-fast, ultra-tiny "gravitons".
I know that, tom. That doesn't tell me anything useful.
>Ordinary matter is mostly transparent to these, but a small fraction
>of the gravitons do strike matter.
I know that, too, tom. That also doesn't tell me anything useful.
>Then the apple falls from the tree because the normally
>isotropic flux of gravitons is reduced below the apple by the Earth
>blocking some gravitons. So the apple gets a net push from above - hence
>the expression "pushing gravity".
All you've done is repeat a lot of meaningless verbiage in which I
see not a single equation as I requested you to include.
>
> That simple concept is then used to set up equations and
Which is what I requested you to provide in your response. How can
you sit there and make a bucnch of sanctimonious comments about what
readers expect to see in the way of an intelligent discussion when
you are the one responsible for not posting what would be needed for
such a discussion to take place? If usenet doesn't provide you with
the features you want to write equations, then either don't post on
usenet or don't complain about the responses you receive to what you
are willing to post.
> If you consider all this "wishful hand-waving" or have no
>further interest in this topic or in the possibility of learning
>something new, then I suggest you drop out of this discussion.
Since no one in this discussion seems willing to post anything
about le sage gravity which would make it more than wishfull thinking,
this discussion is about wishfull thinking.
>>> [tvf]: Equations are oblivious to causality, constraints, and
>principles of physics.
>
>> [Bilge]: Does that mean you think your model is viable because you
>like the handwaving, but have no idea how obtain an equation that could
>be used to validate the handwaving?
>
> Equations and five observational tests may be found in the
>book chapters I cited, mine and Slabinski's. Get it and read it or stop
>complaining.
Post it stop complaining about the responses you receive to what you
do post. Usenet is not an advertising service to promote books.
>> I think I could learn a great deal more from a few simple equations
>than all of the verbiage you employ to avoid writing down any equations.
>
> I put my equations in my technical papers, not is ascii
>messages.
So what? I've derived the qed lagrangian on this newsgroup several times
as well as written out explanations of the higgs mechanism by deriving a
theory of E&M with massive vector bosons. I don't consider ascii to be a
major impediment. TeX is ascii and since the preferred format of
practically all scientific journals for physics and math is some form of
TeX, which is ascii, it should be simple to post a technical article to
usenet from which I could even produce a typeset quality postscript file.
I was expecting something a little less ambitious, however.
>But this yhread was about matters of physical interpretation, not matters
>of math.
In that case, it was about wishfull handwaving.
>To first order in potential and second order in velocity, Le Sage
>gravitation has the same equations as GR.
An assertion unsupported by the equations needed for support.
>> [Bilge]: If you have a problem with what I consider in my responses,
>the problem is with what you have provided for consideration.
>
> Wherever you asked a specific question or made a specific
>point, I addressed it.
I disagree. All you've ever done is provide analogies. Analogies
do not address my questions.
>If you wish to study equations, see the book and
>technical papers. This discussion was about the comparative physical
>interpretation of the models. I'm sorry you find nothing of interest to
>you in that area, but many of us do. -|Tom|-
Then, perhaps alt.wishfull.thinking would be a better newsgroup for
your posts. This is a physics newsgroup and explanations of physical
theories typically involve some equations to indicate the theory is
really does what the interpretation claims it does.
shuba
> Tom Van Flandern:
> >My statement is explained and justified at
> >http://metaresearch.org/cosmology/gravity/spacetime.asp. It's a simple
> >argument.
[snip exposition of several elementary errors in that article]
> Obviously, you are being deceptive, you don't know what you are talking
> about or both.
Wow. No kidding. Near the end, Van Flandern even asserts that
Robert Wald says that spacetime geodesic paths "involve" the
"curvature of space". That's quite a revealing misrepresentation.
---Tim Shuba---
Ken S. Tucker
(I sniff ding bat)
>dyna...@vianet.on.ca (Ken S. Tucker) wrote in message news:<2202379a.04051...@posting.google.com>...
>> Of course! That's why it's called free fall.
>
>Holy ...
Enough said, join Hammond's Glee Club.
((Read the rest of your post and have no comment ))
[snip]
Ken S. Tucker
Mike
> Well to Mike only...
> (I sniff ding bat)
>
> >dyna...@vianet.on.ca (Ken S. Tucker) wrote in message news:<2202379a.04051...@posting.google.com>...
>
> >> Of course! That's why it's called free fall.
> >
> >Holy ...
>
> Enough said, join Hammond's Glee Club.
> ((Read the rest of your post and have no comment ))
> [snip]
> Ken S. Tucker
Before you fly with GR, it's a good idea you join the Mechanics 101 club.
Now open, at a community college near you!
Mike
Mike
>
> >and "Ken S. Tucker" <dyna...@vianet.on.ca> writes:
> >> [Tucker]: Fig.1 shows the balance of the g-force and centrifugal
> .>force. IMO, the centrifugal acceleration is directly opposite the
> >>g-acceleration, as shown in Fig.2. . the gravitational acceleration and
> >>the inertial acceleration (centrifugal in this example) precisely
> >>balance to produce a "freefall", so that no acceleration can be detected
> >>on Earth due to the sun's gravity.
>
> [tvf]
> >If gravity and centrifugal force balanced and cancelled, then Earth would
> >experience no net force
>
> Of course! That's why it's called free fall.
>
> >and would move on a straight line instead of an
> >orbit.
>
> No, of course NOT. Sum gravitational force and
> centrifugal force in a circular orbit ie.
>
> 0 = -GMm/r^2 + mV^2/r = net force.
>
> "r" is the orbital radius, and is NOT a straightline.
>
Go take an introductory mechanics course to learn that action+reaction
= 0, always, in mechanics. But action and reaction DO NOT act on the
same body. When your teacher was screaming that loud, you were playing
pin ball across the street.
Mike
Bilge
I didn't read that far. However, I've since looked at that reference,
and as you might expect, wald does _not_ say that. What wald says is
``curvature of the spacetime metric''. What I fail to understand is
that, if relativity has so many problems, why it's necessary to
misrepresent relativity in order to point them out. One would think that
a problem in the theory itself would serve the purpose without having
to manufacture a problem.
Ken S. Tucker
>dyna...@vianet.on.ca (Ken S. Tucker) wrote in message news:<2202379a.04051...@posting.google.com>...
>> Sum gravitational force and
>> centrifugal force in a circular orbit ie.
>> 0 = -GMm/r^2 + mV^2/r = net force.
>> "r" is the orbital radius, and is NOT a straightline.
>Go take an introductory mechanics course to learn that action+reaction
>= 0, always, in mechanics. But action and reaction DO NOT act on the
>same body. When your teacher was screaming that loud, you were playing
>pin ball across the street.
>Mike
The pinball machine had a warped surface ie. GR101.
Your action-reaction might apply to the sun-earth
revolving about a common point, CM, but that's a
minor correction, though technically accurate.
Ken S. Tucker
Tom Van Flandern
"Vern" <ve...@bealenet.com> writes:
> [Vern]: It seems you are holding that gravitational forces are
instantaneous and you believe that the Le Sage model accounts for a
radially centripetal gravitational force and you also appear to believe
in a light-carrying medium. But all those pieces don't seem to fit
together for an overall model.
The complete model is laid out in full detail in the new
20-author book "Pushing Gravity: New Perspectives on Le Sage's Theory of
Gravitation", M. Edwards, ed., Apeiron Press, Montreal (2002).
> [Vern]: The Le Sage model and instantaneous gravitational forces are
contradictory, first you have a particulate medium for pushing, but then
accept action-at-a-distance for gravitational interactions between
distant bodies.
That is a misunderstanding of my position. I have never held
or advocated instantaneous gravitational forces or action at a distance,
which violates two principles of physics and is therefore a logical
absurdity. I have simply pointed out that the six existing experiments
all set lower limits to the speed of gravity that is much faster than
light; and that GR works only because GR (the theory) uses instantaneous
gravitational forces along with light-speed gravitational waves. If it
used light-speed gravitational forces, orbits would be spirals and GR
would fail. So instantaneous gravitational forces are still the best
approximation we can use for the speed of gravity, even though reality
is that those forces must have a finite speed.
The complete Le Sage "pushing gravity" model shows roughly
how fast gravitons must propagate (billions of times faster than light),
and how this sets constraints that are consistent with the known size of
the gravitational constant and with other considerations such as heat
deposits in matter and the absence of medium drag.
> [Vern]: Then no correlation between gravity and the supposed
light-carrying medium.
?? I said that gravity induces a gradient in the
light-carrying medium near masses. That seems like a correlation to me.
> [Vern]: We have a study group at yahoogroups for this model called
"aethro-kinematics." Hope to see you there.
I appreciate the invitation, but my limited professional
time and out-of-control volumes of email do not allow me that luxury. I
can barely manage one or two posts a week to USENET newsgroups. And as
you see, those draw as much discussion as I can manage. But I do
encourage quoting things from my messages or the Meta Research web site
to chat groups so that people can become aware of the published papers
and books that explain these ideas. And I am always especially
appreciative of the infrequent comment or criticism that has not already
been covered in existing, published material. But that is getting to be
rare these days.
and "Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>> [tvf]: It is unfortunate that you can't recall a single misconception
to use as an example so others can judge who has the misconceptions.
> [Bilge]: http://groups.google.com
Very funny.
Most of your lengthy post just makes equally non-specific
complaints about my choice of wording, confusion, or general ignorance,
and contains very little on topic. I will reserve my comments here for
your occasional substantive remark.
Incidentally, the paper "What the GPS tells us about the
twin's paradox" is now available at
http://metaresearch.org/cosmology/gravity/gps-twins.asp, as I promised.
> [Bilge]: Curvature doesn't "initiate three-space motion'' unless a
force acts. So, then, what is your point?
Gravity does initiate 3-space motion from rest. So by
inference from your statement above, we seem to agree that gravity must
be a force because you agree that a force must act, and curvature alone
cannot provide that force.
If this is not a correct reading of your sentence, please
explain.
>> [tvf]: I prefaced my remarks with a clear statement that I was
speaking of 3-space, not 4-space. Please state that we now agree, or
provide specifics on why you still disagree.
> [Bilge]: Motion is not possible if you exclude time (recall that a
velocity is ds/dt). Since things do not move in four dimensions, we are
obviously talking about motion in three space regardless of the
underlying theory.
I did not know that you were unfamiliar with the difference
between "3-space plus time" and "4-space". I recommend a reading of an
introductory relativity book. The structure of the metric has an
opposite sign in front of the time term, which has the meaning in
practice that Minkowski diagrams must plot space against imaginary time,
not real time; i.e., "spacetime" is not "space plus time". In fact, as I
showed at http://metaresearch.org/cosmology/gravity/spacetime.asp,
"spacetime" is really a stand-in for "proper time", and has no spatial
component at all.
> [Bilge]: The interval ds^2 = (cdT)^2 is obviously not spacelike. It's
timelike.
That was the very point I made at the preceding link. It's
an expression for proper time with no spatial component. The
"length-like" terms of the metric, (dx^2+dy^2+dz^2), are really v^2
dT^2. And when we divide through by dT^2, we get a nice expression for
proper time in terms of coordinate time modified by velocity and
potential. Every term describes what happens to clocks, not to space.
Even when the metric represents a "space-like" interval, it
merely shows how lengths measured with light signals will vary as local
proper time varies. It does nothing to change the scale or orthogonality
of the flat, 3-space coordinate axes or the uniformity of the coordinate
time used by astronomers for the description of natural phenomena such
as light-bending or the Shapiro effect. Anyone familiar with the
analysis of pulsar timings can see the requirement for such unmodified,
frame-and-observer-independent coordinates to make sense of the data.
In other words, space is not curved, which was the main
point of my article. Please indicate whether you agree or dispute this
conclusion, independent of any quibbles you may still have about my
argument for it.
and "shuba" <tim....@eudoramail.com> writes:
>> [tvf, from preceding link]: [Figure shows that orbits involve no
curvature of space.] This again illustrates that "curved space-time"
geodesic paths do not involve any curvature of space. The contrary
viewpoint in many textbooks has been a source of confusion for physics
students for the last generation. For an extreme expression of this
contrary viewpoint, see any relativity books by Robert Wald; e.g., [R.M.
Wald (1984), General Relativity, U. of Chicago Press, Chicago, p. 67].
> [shuba]: Van Flandern even asserts that Robert Wald says that
spacetime geodesic paths "involve" the "curvature of space". That's
quite a revealing misrepresentation.
I see now that my wording could easily be misconstrued in
this way, so I have qualified it to say "The contrary viewpoint in many
textbooks in support of the geometric interpretation of GR has been a
source of confusion.". I was in fact meaning to contrast the entire
flat-space-time "field interpretation" of GR with the "geometric
interpretation" that Wald champions with these words from the cited
page: "The basic framework of the theory of general relativity arises
from considering ... that we cannot in principle -- even by complicated
procedures -- construct inertial observers in the sense of special
relativity and measure the gravitational force. This is accomplished by
the following bold hypothesis: The space-time metric is not flat, as was
assumed in special relativity. The world lines of freely falling bodies
in a gravitational field are simply the geodesics of the (curved)
space-time metric. In this way, the 'background observers' (geodesics of
the space-time metric) automatically coincide with what was previously
viewed as motion in a gravitational force field. As a result we have no
meaningful way of describing gravity as a force field; rather, we are
forced to view gravity as an aspect of space-time structure. Although
absolute gravitational force has no meaning, the relative gravitational
force (i.e., tidal force) between two nearby points still has meaning
and can be measured by observing the relative acceleration of two freely
falling bodies. ..."
It would be fair to say that I disagree with almost
everything Wald claims here, and have provided counterexamples in my
published papers. Indeed, celestial mechanics is build around inertial
3-space observers. So is GPS, which requires us to envision an infinite
set of imaginary underlying atomic clocks at rest in the Earth-centered
inertial frame, one of which coincides with any given satellite or
ground clock at any given instant of coordinate time.
If Wald's "bold hypothesis" is read as saying that proper
time varies in rate as a body rises and falls in a gravitational
potential *in flat space*, then it becomes possible to interpret the
meaning of the rest of his words correctly. But it seems clear to me
that Wald's paragraph misleads students into envisioning a curvature of
space, which is not correct. Wald should have said in so many words, as
MTW do, that it is a mistake to think of this as a curvature of space.
Then he should have said that "space-time" is really a stand-in for
proper time. I would then have had no complaint. But Wald's actual words
have misled a generation of teachers and students.
You think not? Just do a poll of this newsgroup and see how
many still think the "space-time curvature" includes space curvature as
one part. Even a relativist as eminent as Steve Carlip argued a few
years back in these newsgroups that half of relativistic light-bending
was caused by space curvature. Let's put an end to this erroneous
impression once and for all before it impedes progress for another
generation.
If you agree with this premise (that the curvature of space
is not involved in GR), as your remark quoted above seems to imply, then
the preceding suggestion appears to be a worthy goal we can both agree
upon. If not, please be specific about why not. -|Tom|-
Mike
> That is a misunderstanding of my position. I have never held
> or advocated instantaneous gravitational forces or action at a distance,
> which violates two principles of physics and is therefore a logical
> absurdity. I have simply pointed out that the six existing experiments
> all set lower limits to the speed of gravity that is much faster than
> light; and that GR works only because GR (the theory) uses instantaneous
> gravitational forces along with light-speed gravitational waves. If it
> used light-speed gravitational forces, orbits would be spirals and GR
> would fail. So instantaneous gravitational forces are still the best
> approximation we can use for the speed of gravity, even though reality
> is that those forces must have a finite speed.
>
In GR, planetary action is due to the state of the metrical field in
the immediate neighborhood of the planet. In this way action ta a
distance and instantenuous forces are not required. Changes in the
metrical field due to changes in the distribution of matter propagate
at c. I don't know where you get the notion that "GR (the theory) uses
instantaneous gravitational forces along with light-speed
gravitational waves." The first part of your sentence is wrong and the
second somewhat incomplete.
>
> You think not? Just do a poll of this newsgroup and see how
> many still think the "space-time curvature" includes space curvature as
> one part. Even a relativist as eminent as Steve Carlip argued a few
> years back in these newsgroups that half of relativistic light-bending
> was caused by space curvature. Let's put an end to this erroneous
> impression once and for all before it impedes progress for another
> generation.
>
> If you agree with this premise (that the curvature of space
> is not involved in GR), as your remark quoted above seems to imply, then
> the preceding suggestion appears to be a worthy goal we can both agree
> upon. If not, please be specific about why not. -|Tom|-
>
>
If you stop thinking about a gravitational field and replace it with
the proper term 'metrical field" g, all the confusion and red herrings
will go away. The gravitational field is the system of components into
which the metrical field is resolved in GR. The confusion arises from
the normal orthogonal values of the gravitation potential field gmn,
expressed as the sum of an inertial field gmn(bar) and an attributed
gravitational potential field gamma(mn) This was done to adopt a
terminology that fitted Newtonian mechanics so early students of GR
could comprehend it but created some of the difficulties you seem to
have because it is a wrong interpetation, i.e. a resolution into
inertial and gravitational field.
I'm not myself a fan of GR and I would prefer a scalar theory. In
order to do justice to the theory though, one should try to understand
it and especially refrain from confusing interpretation of GR for the
purpose of assisting its comprehension by students accustomed to
Newtonian concepts with the structure of the theory itself and its
objectives.
Mike
Mike
> This replies to Vern, Bilge, and Tim Shuba.
>
>
> The complete Le Sage "pushing gravity" model shows roughly
> how fast gravitons must propagate (billions of times faster than light),
> and how this sets constraints that are consistent with the known size of
> the gravitational constant and with other considerations such as heat
> deposits in matter and the absence of medium drag.
>
[snip]
There can be infinite theories based on unobservable entities that are
as good as a theory based on gravitons. One can appropriatelly adjust
the properties of those unobservable entities to have any desired
observational consequences.
As such, all those theories, including the material graviton flux, are
metaphysical and make ontological statements. Those theories must be
rejected a priori unless they can provide significant improvement in
predictions and a new explanation of phenomena that leads to an
imprpoved understanding of the world. Usually, the type of improvement
such theories offer is through specific experiments that can only be
performed assuming the unobservable entities are first detected and
controlled. This turns to be an oxymoron schemma and those theories
remain in the realms of metaphycics.
The question Dr, Van Flander for you is the following: why should I
believe gravitons exist and gravity is a push? Will that enhance my
understanding of the world? Will it assist me in making better
predictions?
Mike
Paul Stowe
>"Tom Van Flandern" <to...@starpower.net> wrote in message news:<40a799eb$0$2988$61fe...@news.rcn.com>...
>> This replies to Vern, Bilge, and Tim Shuba.
>>
>[snip]
>>
>> The complete Le Sage "pushing gravity" model shows roughly
>> how fast gravitons must propagate (billions of times faster than light),
>> and how this sets constraints that are consistent with the known size of
>> the gravitational constant and with other considerations such as heat
>> deposits in matter and the absence of medium drag.
>>
>
>[snip]
>
> There can be infinite theories based on unobservable entities that
> are as good as a theory based on gravitons.
No, there cannot. How can a finite phenomena create 'infinite' theories?
> One can appropriatelly adjust the properties of those unobservable
> entities to have any desired observational consequences.
Again, not true. If true then we'd have no criteria for ontological
foundation.
> As such, all those theories, including the material graviton flux,
> are metaphysical and make ontological statements.
This is true. True of gravitons, electrons, neutrinos, quarks ...etc.
> Those theories must be rejected a priori unless they can provide
> significant improvement in predictions and a new explanation of
> phenomena that leads to an imprpoved understanding of the world.
> Usually, the type of improvement such theories offer is through
> specific experiments that can only be performed assuming the
> unobservable entities are first detected and controlled. This turns
> to be an oxymoron schemma and those theories remain in the realms
> of metaphycics.
The question to you is, do you know anything about the details of
LeSage's hypothesis? It's specific mechanistic predictions?
> The question Dr, Van Flander(n) for you is the following: why should
> I believe gravitons exist and gravity is a push? Will that enhance my
> understanding of the world? Will it assist me in making better
> predictions?
The question to you Mike is can you provide another alternative
to the causative nature of the results we attribute to gravity?
Paul Stowe
Bilge
>> [Bilge]: Curvature doesn't "initiate three-space motion'' unless a
>force acts. So, then, what is your point?
>
> Gravity does initiate 3-space motion from rest.
And general relativity does not say that gravity ``initiates 3-space
motion from rest''. That is your personal misunderstanding of general
relativity and what ``at rest'' means in general relativity (as opposed
to what you mean by ``at rest'').
>So by inference from your statement above, we seem to agree that gravity
>must be a force because you agree that a force must act, and curvature
>alone cannot provide that force.
>
> If this is not a correct reading of your sentence, please explain.
It's not a correct reading of what I wrote. ``At rest'' in general
relativity means freely falling in a gravitational field.
>>> [tvf]: I prefaced my remarks with a clear statement that I was
>speaking of 3-space, not 4-space. Please state that we now agree, or
>provide specifics on why you still disagree.
>
>> [Bilge]: Motion is not possible if you exclude time (recall that a
>velocity is ds/dt). Since things do not move in four dimensions, we are
>obviously talking about motion in three space regardless of the
>underlying theory.
>
> I did not know that you were unfamiliar with the difference
>between "3-space plus time" and "4-space".
That's good, because if you thought that, you'd be wrong. I obviously
used the same 3+1 splitting you implied.
>I recommend a reading of an introductory relativity book. The structure
>of the metric has an opposite sign in front of the time term,
Gee, really? You should take your own advice. If you know this, why are
you making such silly arguments? Anyone who has done the reading you
recommend would realize that timelike, spacelike and null intervals are
defined by the sign of ds^2 in accordance with the signature of the metric
and also know that ds^2 is an invariant. Invariants are invariant because
they don't change.
>which has the meaning in practice that Minkowski diagrams must plot
>space against imaginary time, not real time; i.e., "spacetime" is not
>"space plus time".
That is obviously wrong. Spacetime diagrams generally plot x and t
as real numbers. If a spacetime diagram plotted x and it, the metric
would be euclidean and hyperbolas would become circles.
ds^2 = (idt^2 + dx^2)(-idt + dx^2) = dt^2 + dx^2
You seem to believe that \delta_ij was ordained by god as the one
``true'' metric and have a bit of difficulty accepting the fact that
nature had other ideas.
>In fact, as I
>showed at http://metaresearch.org/cosmology/gravity/spacetime.asp,
>"spacetime" is really a stand-in for "proper time", and has no spatial
>component at all.
No, what you've shown is that you've confused a spacelike interval
with the spatial components of a four vector. Tell me something,
what is the proper time for the interval defined by the events,
(0, 0, 0, 0) and (1, 0, 0, 2)? Can you make the spatial part of
that interval vanish with a lorentz transform? If you can, you've
made an error, since ds^2 is an invariant.
>> [Bilge]: The interval ds^2 = (cdT)^2 is obviously not spacelike. It's
>timelike.
>
> That was the very point I made at the preceding link.
Then why did you say that it was spacelike by virtue of the `c'
being present? It's timelike regardless of whether or not you
multiply by `c'.
>It's an expression for proper time with no spatial component.
OK, so what? The expression dr^2 = dx^2 + dy^2 is the 3-d euclidean
distance which has no z-component.
>The "length-like" terms of the metric, (dx^2+dy^2+dz^2),
>are really v^2 dT^2.
>And when we divide through by dT^2, we get a nice expression for
>proper time in terms of coordinate time modified by velocity and
>potential. Every term describes what happens to clocks, not to space.
Since there is no such thing as a ``length-like'' interval, you could
only be objecting to your own personal interpretation of general rela-
tivity. I'm fully prepared to agree that your inter- pretation is wrong.
>Even when the metric represents a "space-like" interval, it merely shows
>how lengths measured with light signals will vary as local proper time
>varies.
Say what? If an interval is spacelike, the points along that interval
cannot be connected by a light ray. Those points have no causal relation-
ship.
>It does nothing to change the scale or orthogonality of the flat,
>3-space coordinate axes or the uniformity of the coordinate time
>used by astronomers for the description of natural phenomena such
>as light-bending or the Shapiro effect.
Who claims that it does?
> Anyone familiar with the analysis of pulsar timings can see the
>requirement for such unmodified, frame-and-observer-independent
>coordinates to make sense of the data.
Anyone familiar with relativity can see that you are just babbling
at this point.
>In other words, space is not curved, which was the main point of my
>article.
And as I've pointed out, what general relativity says is that the the
spacetime metric is curved. Your article says a lot more about your mis-
understanding of general relativity than it does about general relativity.
>Please indicate whether you agree or dispute this conclusion,
>independent of any quibbles you may still have about my argument
>for it.
Since you are describing your own, personal misunderstanding of general
relativity, my objection is that you are misrepresenting your misunder-
standing of general relativity as general relativity. That is not a quibble.
Please explain something. What is your objection to formulating an
argument against relativity based upon the actual theory of relativity?
Ken S. Tucker
>
>> That is a misunderstanding of my position. I have never held
>> or advocated instantaneous gravitational forces or action at a distance,
>> which violates two principles of physics and is therefore a logical
>> absurdity. I have simply pointed out that the six existing experiments
>> all set lower limits to the speed of gravity that is much faster than
>> light; and that GR works only because GR (the theory) uses instantaneous
>> gravitational forces along with light-speed gravitational waves. If it
>> used light-speed gravitational forces, orbits would be spirals and GR
>> would fail. So instantaneous gravitational forces are still the best
>> approximation we can use for the speed of gravity, even though reality
>> is that those forces must have a finite speed.
>>
>In GR, planetary action is due to the state of the metrical field in
>the immediate neighborhood of the planet.
Na, your're reinventing aether. We know that the inertial
force on Mercury causes an orbital pertubation RELATIVE
to the sun, and we also know that there is no such thing as
velocity relative to space in you're so-called metrical field.
What you're asserting is a velocity induced component
by Mercury moving within a metric that induces precession.
GR is not that simple...
Relativity is about relationships between objects,
it has no relations to objects and imaginary fields.
(thinking otherwise trashes the objective reality
of relativity).....
>If you stop thinking about a gravitational field and replace it with
>the proper term 'metrical field" g, all the confusion and red herrings
>will go away.
I hear the *metrical kid* replacing GR by importing glubs of
jello.aka aether, to justify GR...
>The gravitational field is the system of components into
>which the metrical field is resolved in GR.
Add a ding-bat point.
>The confusion arises from
>the normal orthogonal values of the gravitation potential field gmn,
Add another ding-bat point. The field becomes nonorthogonal
when a g-field is present.
>expressed as the sum of an inertial field gmn(bar) and an attributed
>gravitational potential field gamma(mn) This was done to adopt a
>terminology that fitted Newtonian mechanics so early students of GR
>could comprehend it but created some of the difficulties you seem to
>have because it is a wrong interpetation, i.e. a resolution into
>inertial and gravitational field.
Flandern is already screwed up, do you think mixing
junk math (gamma + gmn) will help?
>I'm not myself a fan of GR
Evidentally....but continue...
>and I would prefer a scalar theory.
Well, you can always convert GR into tensor densities.
>In order to do justice to the theory though,
>one should try to understand it
Keep trying, you'll make it....
>and especially refrain from confusing interpretation of GR for the
>purpose of assisting its comprehension by students accustomed to
>Newtonian concepts with the structure of the theory itself and its
>objectives.
>Mike
Right, I was critical.
Ken S. Tucker
Thomas J Roberts
> GR works only because GR (the theory) uses instantaneous
> gravitational forces along with light-speed gravitational waves.
As has been pointed out many times, this is Tom Van Flandern's personal
MISUNDERSTANDING of GR. In truth, GR does not use "gravitational forces" at all,
and you will look in vain for them in the Einstein field equation.
[You are free to interpret certain connection components wrt
certain coordinates as "gravitational forces", but that is
not at all part of the theory itself (no such coordinate-
dependent quantities are part of the theory itself).
You are also free to work in any of various approximations
to GR, but such approximations are not the theory itself.]
Consider this: if you were to compare the surface of the earth to its center, in
the same way Tom Van Flandern looks at "gravitational force", then you would
conclude that the surface propagates at infinite speed from the center. Clearly
that is nonsense, as the surface does not "propagate from the center" at all --
the surface and the center move in mutual harmony. So, too, in GR the metric
does not "propagate" from any mass.
In GR, the metric at a given point determines all gravitational interactions at
that point, and is itself determined (via the field equation) from the local
energy-momentum tensor and the metric infinitesimally-far away (via derivatives
in the field equation). But the field equation must be obeyed at each and every
point, including ones nearby to the point in question, and including points a
bit further away than them, etc. -- the result is a self-consistency requirement
on the metric field determined by the process known as "solving the differential
equation". For the simple cases Tom Van Flandern considers, this self-consistent
solution is one in which the metric field acts as if it moved in mutual harmony
with the mass (just as the surface of the earth moves in mutual harmony with its
center). He claims this is "propagation with speed >> c from the mass", but it
really is no sort of "propagation from the mass" at all.
A field does not really "move"; I say it "acts as if it moved" in
the sense that if one plotted a contour map of the field in 3-space,
and watched it evolve over time, the contours on the map would move
as I discuss. This is, of course, coordinate dependent, but in the
weak-field approximation TVF limits his discussions to, there is a
clear choice of coordinates: the background Minkowski coordinates.
> If it
> used light-speed gravitational forces, orbits would be spirals and GR
> would fail. So instantaneous gravitational forces are still the best
> approximation we can use for the speed of gravity, even though reality
> is that those forces must have a finite speed.
This is just TVF foaming at the mouth -- GR does not use "gravitational forces"
at all, and in GR there is no "propagation" and no "instantaneous propagation".
And quite clearly, planetary orbits do not spiral. His final claim about
"rality" is, of course, merely his pious hope (shared by many, but still just a
hope).
> [... further amplification of TVF's confusions]
Tom Roberts tjro...@lucent.com
shuba
First, this is not Wald's "bold hypothesis", but Einstein's.
General relativity is unquestionably a geometric theory. Just
look at the field equations.
G^(\mu\nu) = k*T^(\mu\nu)
G and T are tensors in four dimensions. So are the Riemann and
Ricci tensors, et cetera. The curvature involved in general
relativity is an extension of the spatial curvature developed by
Gauss, in this case as applied to a four-dimensional manifold.
> But it seems clear to me
> that Wald's paragraph misleads students into envisioning a curvature of
> space, which is not correct. Wald should have said in so many words, as
> MTW do, that it is a mistake to think of this as a curvature of space.
> Then he should have said that "space-time" is really a stand-in for
> proper time. I would then have had no complaint. But Wald's actual words
> have misled a generation of teachers and students.
Your article and comments show an amazingly poor understanding of
general relativity. Spacetime is not "a stand-in for proper
time". Spacetime is a four-dimensional semi-Riemannian manifold
having a metric and connection. You'd be lucky to get a D grade
on your article if it were written for the midterm of an
introductory general relativity semester. Now you compound that
foolishness by accusing Wald of misleading. Well, readers of
this newsgroup have grown used to seeing authors published by
Apeiron resort to such unprofessional tactics. Welcome to the
club. It so happens that many people prefer Wald's text over MTW
because it is considered more rigorous. You have real gall to
defend your hack job of defining spacetime in your article while
attacking Wald's highly respected textbook presentation.
> If you agree with this premise (that the curvature of space
> is not involved in GR), as your remark quoted above seems to imply, then
> the preceding suggestion appears to be a worthy goal we can both agree
> upon. If not, please be specific about why not. -|Tom|-
The curvature of space (3-space) is indeed not part of
relativity. Nor is your concept above of "3-space observers" a
part of relativity, except in an approximation. The best way for
others to learn this is to read good presentations such as Wald's.
---Tim Shuba---
Mike
> On 16 May 2004 16:32:47 -0700, ele...@yahoo.gr (Mike) wrote:
>
> >"Tom Van Flandern" <to...@starpower.net> wrote in message news:<40a799eb$0$2988$61fe...@news.rcn.com>...
> >> This replies to Vern, Bilge, and Tim Shuba.
> >>
> [snip]
> >>
> >> The complete Le Sage "pushing gravity" model shows roughly
> >> how fast gravitons must propagate (billions of times faster than light),
> >> and how this sets constraints that are consistent with the known size of
> >> the gravitational constant and with other considerations such as heat
> >> deposits in matter and the absence of medium drag.
> >>
> >
> >[snip]
> >
> > There can be infinite theories based on unobservable entities that
> > are as good as a theory based on gravitons.
>
> No, there cannot. How can a finite phenomena create 'infinite' theories?
Theories do not necessarily correspond to observable phenomena, the
graviton is an example, so you must ask this question and answer it
yourself. Mental constructions of unobservables can get infinite in
number.
>
> > One can appropriatelly adjust the properties of those unobservable
> > entities to have any desired observational consequences.
>
> Again, not true. If true then we'd have no criteria for ontological
> foundation.
>
Indeed you have none. That's the problem.
> > As such, all those theories, including the material graviton flux,
> > are metaphysical and make ontological statements.
>
> This is true. True of gravitons, electrons, neutrinos, quarks ...etc.
>
> > Those theories must be rejected a priori unless they can provide
> > significant improvement in predictions and a new explanation of
> > phenomena that leads to an imprpoved understanding of the world.
> > Usually, the type of improvement such theories offer is through
> > specific experiments that can only be performed assuming the
> > unobservable entities are first detected and controlled. This turns
> > to be an oxymoron schemma and those theories remain in the realms
> > of metaphycics.
>
> The question to you is, do you know anything about the details of
> LeSage's hypothesis? It's specific mechanistic predictions?
I have read the book "Pushing Gravity". It is bold speculation. In
order to avoid the objections raised about the material flux, the
properties of the gravitons must be adjusted to yield unobservable
phenomena. Extreme realism that is.
>
> > The question Dr, Van Flander(n) for you is the following: why should
> > I believe gravitons exist and gravity is a push? Will that enhance my
> > understanding of the world? Will it assist me in making better
> > predictions?
>
> The question to you Mike is can you provide another alternative
> to the causative nature of the results we attribute to gravity?
>
The question for you is: what does 'a causative nature of the results
we attribute to gravity' mean? Is this physics or metaphysics?
Mike
> Paul Stowe
Paul Stowe
>Paul Stowe <p...@acompletelyjunkaddress.net> wrote in message news:<c10ga05j766js4f7i...@4ax.com>...
>> On 16 May 2004 16:32:47 -0700, ele...@yahoo.gr (Mike) wrote:
>>
>>> "Tom Van Flandern" <to...@starpower.net> wrote in message news:<40a799eb$0$2988$61fe...@news.rcn.com>...
>>>> This replies to Vern, Bilge, and Tim Shuba.
>>>>
>> [snip]
>>>>
>>>> The complete Le Sage "pushing gravity" model shows roughly
>>>> how fast gravitons must propagate (billions of times faster than light),
>>>> and how this sets constraints that are consistent with the known size of
>>>> the gravitational constant and with other considerations such as heat
>>>> deposits in matter and the absence of medium drag.
>>>>
>>>
>>> [snip]
>>>
>>> There can be infinite theories based on unobservable entities that
>>> are as good as a theory based on gravitons.
>>
>> No, there cannot. How can a finite phenomena create 'infinite' theories?
>
> Theories do not necessarily correspond to observable phenomena, the
> graviton is an example, so you must ask this question and answer it
> yourself. Mental constructions of unobservables can get infinite in
> number.
Ummm, this is a rather esoteric side issue but,... while theories with
'unobservables' exist, to be physical they MUST coorespond to observable
effects. For example, the neutrino have, and probably never will be,
'observed'. But, the physical properties associated to effects 'predicted'
from hypothesizing their existence MUST. As for infinite, while we can
conceive of the concept our minds cannot truly fathom or grasp the enormity
of it. No, no physical theory, even those positing unobservables can be
infinite in scope.
>>> One can appropriatelly adjust the properties of those unobservable
>>> entities to have any desired observational consequences.
>>
>> Again, not true. If true then we'd have no criteria for ontological
>> foundation.
>>
>
> Indeed you have none. That's the problem.
Then we have none for most accepted concepts, the all elemental
particles amoungst them.
>>> As such, all those theories, including the material graviton flux,
>>> are metaphysical and make ontological statements.
>>
>> This is true. True of gravitons, electrons, neutrinos, quarks ...etc.
>>
>>> Those theories must be rejected a priori unless they can provide
>>> significant improvement in predictions and a new explanation of
>>> phenomena that leads to an imprpoved understanding of the world.
>>> Usually, the type of improvement such theories offer is through
>>> specific experiments that can only be performed assuming the
>>> unobservable entities are first detected and controlled. This turns
>>> to be an oxymoron schemma and those theories remain in the realms
>>> of metaphycics.
>>
>> The question to you is, do you know anything about the details of
>> LeSage's hypothesis? It's specific mechanistic predictions?
>
> I have read the book "Pushing Gravity". It is bold speculation. In
> order to avoid the objections raised about the material flux, the
> properties of the gravitons must be adjusted to yield unobservable
> phenomena. Extreme realism that is.
What unobservable phenomena? LeSage's hypothesis posits some
energetic fluence. If you have indeed read the book then you know
that some interprete this fluence as a wave phenomena whilest others
corpuscular.
However, both are posited BECAUSE of observable effects and result
in predicted other effects. Many of these, such as 'Frame Dragging'
predate GR's by hundreds of years.
Just like we posit a neutrino from conservation of momentum and
predict it effects. Then use those predictions to search for
confirmation of its existence, the same is true of the so-call
LeSage mechanism, be it a wave or particulate corpuscle (graviton).
What is the difference?
>>
>>> The question Dr, Van Flander(n) for you is the following: why should
>>> I believe gravitons exist and gravity is a push? Will that enhance my
>>> understanding of the world? Will it assist me in making better
>>> predictions?
>>
>> The question to you Mike is can you provide another alternative
>> to the causative nature of the results we attribute to gravity?
>>
> The question for you is: what does 'a causative nature of the results
> we attribute to gravity' mean? Is this physics or metaphysics?
What causes ...? is an age old question in the physical sciences.
Is this metaphysics? I say its both physics and metaphysics.
Conservation is a foundational concept and is, at its core,
metaphysical. However, without this cornerstone we'd be lost in
the physical sciences. So, the question remains, what causes
gravitation, or, if you prefer, what causes the 'fabric' of
space-time to curve in the presence of matter/energy?
It happens, we can quantify it. In the weak, slow sped limit we
get Newton's equation. But what is the underlying process that
causes it all to happen?
Paul Stowe
car...@no-physics-spam.ucdavis.edu
> Steve Carlip <car...@no-physics-spam.ucdavis.edu> writes:
> >> [tvf]: when the gradient of the potential is taken to derive an
> expression for force, GR uses an *instantaneous* gradient, not a
> retarded one.
> > [Carlip]: Note that despite repeated requests, Tom has never provided
> a mathematical definition -- an equation -- for the operation he calls a
> "retarded gradient.'' Nor has such a definition appeared in any paper
> that I am aware of. The term seems to be a fantasy.
> The first equation in our "Foundations of Physics" paper in
> the "Principles and definitions: section is the mathematical definition
> of gradient you requested. See the web version at
> http://metaresearch.org/cosmology/gravity/speed_limit.asp.
As I said, there is no mathematical definition given there.
Tom, here's a function: f(x,y,z) = x^2 + yz^3. I know how to find
its gradient. What is its ``retarded gradient''?
> The accompanying paragraph explains that the coordinates used in this
> definition must be chosen to be either instantaneous coordinates or
> retarded coordinates.
This is again mathematically meaningless.
> The same reasoning applies to gradients. This is also
> obvious when viewed physically instead of mathematically. The gradient
> is just the slope of a hill in a particular direction. The gradient of a
> gravitational potential created by a source mass is the slope of the
> potential hill in the direction of the source mass.
No, it's not. This is an *elementary* misunderstanding, not of
physics but of math. The direction of the gradient is the direction
in which the slope is steepest. It has nothing to do with the
``dirrection of the source mass'' unless the hill happens to be
steepest in that direction.
> > [Carlip]: In general relativity, roughly speaking, a gravitational
> source produces a set of potentials. Changes in the source cause
> changes in the potential that propagate at light speed. To compute the
> effective force on an object at position x at time t, one takes the
> gradient -- the derivative -- of the potential at position x and time t.
> In other words, an object ``here'' and ``now'' responds to the change in
> the potential ``here'' and ``now,'' and not somewhere else at some other
> time.
> I agree with this statement. But the gradient is a vector,
> which has direction. And direction requires a minimum of two points to
> specify. So the force/gradient cannot be determined purely from
> consideration of the "here" and "now".
This is again trivially wrong mathematically.
Here is another slightly more complicated exercise. Look up the standard
Lienard-Weichert potential for a charge moving at a constant velocity.
Pick a point (x,y,z) and calculate the ordinary gradient of the function
at that point. Observe that this calculation does not require that you
know anything about where the function came from, or about the position
of the charge (or even that there is a charge); it's just a simple
mathematical operation. Don'y use, or even think about, ``retarded
coordinates''; just write down the function and take its gradient.
In what dirtection does the gradient point.
Steve Carlip
Bilge
> Ummm, this is a rather esoteric side issue but,... while theories with
> 'unobservables' exist, to be physical they MUST coorespond to observable
> effects.
By definition, something which is unobservable can have no physical
effect. If it could have a physical effect, it would be observable.
> For example, the neutrino have, and probably never will be, 'observed'.
Only if your criteria for ``observed'' means seeing one with your
eyes. On the otherhand, neutrino beams are produced at accelerators.
A search on google for ``neutrino beams'', turns up 5280 hits.
[...]
>> I have read the book "Pushing Gravity". It is bold speculation. In
>> order to avoid the objections raised about the material flux, the
>> properties of the gravitons must be adjusted to yield unobservable
>> phenomena. Extreme realism that is.
>
> What unobservable phenomena? LeSage's hypothesis posits some
> energetic fluence. If you have indeed read the book then you know
> that some interprete this fluence as a wave phenomena whilest others
> corpuscular.
If it's observable, why is there a debate? The observation would
have settled it. Apart from the fact that le sage gravity doesn't
doesn't work, even in principle, you have no evidence whatsoever
that could be remotely called credible for such a theory. Compared
to le sage gravity, one might consider string theory to be unassailable.
>
> However, both are posited BECAUSE of observable effects and result
> in predicted other effects. Many of these, such as 'Frame Dragging'
> predate GR's by hundreds of years.
OK. Provide an example of a calculation you think constitutes
``frame dragging'' and explain how it is related to frame dragging
in general relativity.
> Just like we posit a neutrino from conservation of momentum and predict
>it effects.
There exists lots of evidence for neutrinos, the most obvious
being a prediction of how neutrinos interact with matter, building
detectors based upon that prediction and actually observing what
was predicted. By contrast, not only does there exist absolutely
no evidence for your ``le sagian'' particles, there isn't even
a theory about them.
>Then use those predictions to search for
> confirmation of its existence, the same is true of the so-call
> LeSage mechanism, be it a wave or particulate corpuscle (graviton).
> What is the difference?
Neutrinos have been confirmed via numerous experiments. Your
``le sagian'' particles don't even have a theory that describes
them other than as some sort of handwaving that depends upon
what curve you're trying to fit at the moment.
[...]
> What causes ...? is an age old question in the physical sciences.
> Is this metaphysics? I say its both physics and metaphysics.
> Conservation is a foundational concept and is, at its core,
> metaphysical. However, without this cornerstone we'd be lost in
> the physical sciences. So, the question remains, what causes
> gravitation, or, if you prefer, what causes the 'fabric' of
> space-time to curve in the presence of matter/energy?
What would ``cause'' it to be ``straight''?
Mike
> On 18 May 2004 02:26:11 -0700, ele...@yahoo.gr (Mike) wrote:
>
> >Paul Stowe <p...@acompletelyjunkaddress.net> wrote in message news:<c10ga05j766js4f7i...@4ax.com>...
[snip]
>
> It happens, we can quantify it. In the weak, slow sped limit we
> get Newton's equation. But what is the underlying process that
> causes it all to happen?
>
> Paul Stowe
Ask your local priest about that. Or you local graviton
representative.
"...and I frame no hypotheses; for whatever is not deduced from the
phζnomena is to be called an hypothesis; and hypotheses, whether
metaphysical or physical, whether of occult qualities or mechanical,
have no place in experimental philosophy..." Newton
Got it?
All the best and good luck in your metaphysical search.
Mike
greywolf42
news:9c1b39be.04051...@posting.google.com...
> Paul Stowe <p...@acompletelyjunkaddress.net> wrote in message
news:<fd7la0l2ckmggh9fe...@4ax.com>...
> > On 18 May 2004 02:26:11 -0700, ele...@yahoo.gr (Mike) wrote:
> >
> > >Paul Stowe <p...@acompletelyjunkaddress.net> wrote in message
news:<c10ga05j766js4f7i...@4ax.com>...
>
> [snip]
> >
> > It happens, we can quantify it. In the weak, slow sped limit we
> > get Newton's equation. But what is the underlying process that
> > causes it all to happen?
> >
> representative.
Understanding why the universe works *is* the scientific method.
>
> "...and I frame no hypotheses; for whatever is not deduced from the
> phenomena is to be called an hypothesis; and hypotheses, whether
> metaphysical or physical, whether of occult qualities or mechanical,
> have no place in experimental philosophy..." Newton
>
> Got it?
Notice that Newton was not talking about the scientific method. Only about
'experimental philosophy.' Which is fine, as far as it goes. However,
Newton was only able to obtain his empirical (experimental) formula because
a fellow named Kepler made a major effort to understand *why* the planets
appeared to move in the way they did.
"It was (Kepler's) INTRODUCTION OF PHYSICAL CAUSALITY INTO THE FORMAL
GEOMETRY OF THE SKIES which made it impossible for him to ignore the eight
minutes (of) arc. So long as cosmology was guided by purely geometrical
rules of the game, regardless of physical causes, discrepancies between
theory and fact could be overcome by inserting another wheel into the
system. In a universe moved by real, physical forces, this was no longer
possible."
"The reason why nobody before him had asked the question is that nobody had
thought of cosmological problems in terms of actual physical forces. So
long as cosmology remained divorced from physical causation in the mind, THE
RIGHT QUESTION COULD NOT OCCUR IN THAT MIND." (italics in originals as
capitals in ascii)
-- Arthur Koestler ("Kepler -- Eight Minutes of Arc," 1959)
> All the best and good luck in your metaphysical search.
Perhaps you should try the scientific method. Instead of Talmudic
exercises.
--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}
Ken S. Tucker
>
>> That is a misunderstanding of my position. I have never held
>> or advocated instantaneous gravitational forces or action at a distance,
>> which violates two principles of physics and is therefore a logical
>> absurdity. I have simply pointed out that the six existing experiments
>> all set lower limits to the speed of gravity that is much faster than
>> light; and that GR works only because GR (the theory) uses instantaneous
>> gravitational forces along with light-speed gravitational waves. If it
>> used light-speed gravitational forces, orbits would be spirals and GR
>> would fail. So instantaneous gravitational forces are still the best
>> approximation we can use for the speed of gravity, even though reality
>> is that those forces must have a finite speed.
>>
>In GR, planetary action is due to the state of the metrical field in
>the immediate neighborhood of the planet.
Na, your're reinventing aether. We know that the inertial
force on Mercury causes an orbital pertubation RELATIVE
to the sun, and we also know that there is no such thing as
velocity relative to space in you're so-called metrical field.
What you're asserting is a velocity induced component
by Mercury moving within a metric that induces precession.
GR is not that simple...
Relativity is about relationships between objects,
it has no relations to objects and imaginary fields.
(thinking otherwise trashes the objective reality
of relativity).....
>If you stop thinking about a gravitational field and replace it with
>the proper term 'metrical field" g, all the confusion and red herrings
>will go away.
I hear the *metrical kid* replacing GR by importing glubs of
jello.aka aether, to justify GR...
>The gravitational field is the system of components into
>which the metrical field is resolved in GR.
Add a ding-bat point.
>The confusion arises from
>the normal orthogonal values of the gravitation potential field gmn,
Add another ding-bat point. The field becomes nonorthogonal
when a g-field is present.
>expressed as the sum of an inertial field gmn(bar) and an attributed
>gravitational potential field gamma(mn) This was done to adopt a
>terminology that fitted Newtonian mechanics so early students of GR
>could comprehend it but created some of the difficulties you seem to
>have because it is a wrong interpetation, i.e. a resolution into
>inertial and gravitational field.
Flandern is already screwed up, do you think mixing
junk math (gamma + gmn) will help?
>I'm not myself a fan of GR
Evidentally....but continue...
>and I would prefer a scalar theory.
Well, you can always convert GR into tensor densities.
>In order to do justice to the theory though,
>one should try to understand it
Keep trying, you'll make it....
>and especially refrain from confusing interpretation of GR for the
>purpose of assisting its comprehension by students accustomed to
>Newtonian concepts with the structure of the theory itself and its
>objectives.
>Mike
Right, I was critical.
Ken S. Tucker
Tom Van Flandern
Carlip. There were too many comments this week to reply to everybody, so
I picked the points raised of most general interest.
"Mike" <ele...@yahoo.gr> writes:
> [Mike]: If you stop thinking about a gravitational field and replace
it with the proper term 'metrical field" g, all the confusion and red
herrings will go away.
I don't agree. GR is a field theory and is primarily about
describing the potential field. Converting the metric solutions of the
field equations into 3-space equations of motion (expressions for
gravitational force) is almost an afterthought in GR, but is essential
to any comparison with observational reality.
You can't make an omelet without breaking some eggs, and you
can't test GR as a dynamical theory for real, physical bodies (not just
photons) without constructing expressions for 3-space force/acceleration
and comparing with 3-space + proper time observations. Failing to
appreciate that keeps some relativists in an "ethereal" fog. :-)
> [Mike]: There can be infinite theories based on unobservable entities
that are as good as a theory based on gravitons. One can appropriately
adjust the properties of those unobservable entities to have any desired
observational consequences.
This is simply not true. We have far more physical
constraints than we have adjustable parameters. So it is amazing that so
simple a theory as a Le Sage-type model can survive all these potential
falsification tests. Indeed, 18th century physicists thought this model
was falsified by its requirement that matter be transparent to most
gravitons. Only later did they come to appreciate that matter on all
observable scales really is mostly empty space. 19th century physicists
(especially via the debate between Maxwell and Kelvin) thought the model
was falsified by the excess heat it would deposit in bodies. Only
recently was it appreciated that minimal graviton absorption combined
with lots of scattering can produce big G with minimal excess heat,
consistent with the observed excess heat coming from the major planets.
20th century physicists thought the Le Sage model could not reproduce
the special GR effects such as light-bending. But the model now passes
that test too in a very simpler way: refraction in an optical medium
that can be equated with the gravitational potential field. All these
details are in the 20-author "Pushing Gravity" book I recommended.
As long as we can use such constraints to set bounds on the
adjustable parameters or to determine graviton properties (mass, flux
density, speed, absorption coefficients, etc.), you can't legitimately
call any of the needed entities "unobservable" because that is what we
mean by "observations" in physics - measurements of properties.
> [Mike]: The question Dr, Van Flandern for you is the following: why
should I believe gravitons exist and gravity is a push? Will that
enhance my understanding of the world? Will it assist me in making
better predictions?
Those are good questions, Mike. IMO, no one should ever
"believe" anything in science because "believe" means to take something
on faith. Theories remain viable while they are useful and are discarded
when they are not. Usefulness consists of adding insight or
understanding into the workings of nature, remaining consistent with
observations and experiments, and making testable predictions that
distinguish them from all alternatives, the failure of which will
falsify the theory.
Some of the Le Sage-type models in PG meet all these
requirements in spades. For example, none of the constraints set by
observations and experiments contradict one another (as it formerly
appeared that they would). These models provide a specific mechanism for
gravitational force and answer both "why" and "how" questions about
gravity. And in my chapter, I list five tests that distinguish a pushing
gravity model from all others, and describe the present status of
efforts to perform those tests. Some preliminary results have been
favorable. This is similar to the situation in 1918 when GR was first
being tested, and the initial results turned out favorable. There
remains room for doubt; but all things considered, the model remains
useful and in good standing.
In your other comments, it would help if you carefully
distinguished "unobservable" in the sense of pink unicorns from
"unobservable" in the sense of air molecules. The former can never be
observed because they have no physical existence, while the latter
simply require developing more sophisticated observing apparatus to
narrow constraints on their properties. Gravitons are in this latter
camp.
and "Thomas J Roberts" <tjro...@lucent.com> writes:
> [tvf]: GR works only because GR (the theory) uses instantaneous
gravitational forces along with light-speed gravitational waves.
> [Roberts]: As has been pointed out many times, this is Tom Van
Flandern's personal MISUNDERSTANDING of GR. In truth, GR does not use
"gravitational forces" at all, and you will look in vain for them in the
Einstein field equation.
This claim is highly confused. Gravitational forces are
absent only in the geometric interpretation of GR, which has now
(arguably) been falsified in favor of the field interpretation for
violating the causality principle and for needing to create changes in
the 3-space momentum of target bodies from nothing. However, when
working in 3-space, the momentum of target bodies is changed by gravity,
and the time rate of change of momentum is force by definition. Absent
force, the 3-space acceleration of target bodies would lack a cause,
which is one of the reasons the geometric interpretation is falsified --
curvature cannot initiate 3-space motion, and requires "magic", which is
forbidden in physics.
Roberts also writes as if equations of motion did not exist
in GR. But of course, they do, and are required for comparison with
observations. Equations of motion, as on p. 1095 of MTW, are expressions
for 3-space force/acceleration. And as I said above, you can't do real
GR for the dynamics of physical bodies without such expressions.
Yes, you will look in vain for forces in the Einstein field
equations. That is simply because the gravitational (potential) field
described by those equations does not produce forces. After the field is
described, one must form a gradient to get an expression for force to
describe the 3-space dynamics. That "gradient" step, incidentally, is
where the "infinite propagation speed" is introduced into GR.
Tom Roberts should learn all this before he speaks out in
CAPITAL LETTERS and reveals the limitations of his own knowledge. He
would do well to read the latest publication dealing with these matters:
"Experimental Repeal of the Speed Limit for Gravitational,
Electrodynamic, and Quantum Field Interactions", T. Van Flandern and
J.P. Vigier, Found.Phys. 32(#7), 1031-1068 (2002).
> [Roberts]: In GR, the metric at a given point determines all
gravitational interactions at that point.
This is untrue and is another manifestation of the part of
GR that Roberts is unfamiliar with. A point has no directionality, but
the 3-space acceleration of a target body does. So knowing the
gravitational potential at one point tells nothing about the motion
changes induced in a target body at that point. That would require
knowing the gradient of the potential at that point, which requires
knowing the potential in the neighborhood of the point. It also requires
knowing whether the target body is fixed or moving relative to the
source mass.
> [Roberts]: this self-consistent solution is one in which the metric
field acts as if it moved in mutual harmony with the mass (just as the
surface of the earth moves in mutual harmony with its center).
This is a great example of the difference between
mathematical GR and physical GR. In math, it is easy to merely say "the
metric field acts as if it moved in mutual harmony with the mass". But
in physics, nothing moves without a specific cause. So if we push one
end of a "rigid" rod, the pushed atoms push their neighbors, which push
theirs, and so on. A pressure wave advances through the rod at the speed
of sound. Then, when that wave reaches the far end of the "rigid" rod,
it begins to move. Nothing in real, physical bodies can ever be truly
instantaneous.
The same holds for a source mass and its potential field. If
the source mass accelerates, that must set off a wave of change
propagating outward at the speed of light. And that is why retarded
potentials are retarded. If potential gradients caused moving target
bodies to accelerate, they would have to accelerate toward the retarded
source mass position. But that is inconsistent with observations. So a
potential gradient does not cause force, but rather the other way
around: Gravitational force must induce gradients in potential fields
near masses. And if force is carried by Le Sage-type gravitons, their
speed must be very large compared with the speed of light to explain the
experimental findings.
> [Roberts]: He claims this is "propagation with speed >> c from the
mass", but it really is no sort of "propagation from the mass" at all.
That nicely illustrates one of the two reasons why the
geometric interpretation of GR is not viable. It provides no causal
connection between source mass and target body, a link that is essential
in physics, even if not in math.
>> [tvf]: If it used light-speed gravitational forces, orbits would be
spirals and GR would fail. So instantaneous gravitational forces are
still the best approximation we can use for the speed of gravity, even
though reality is that those forces must have a finite speed.
> [Roberts]: This is just TVF foaming at the mouth --
Note the display of frustration many people resort to when
they cannot find a logical argument to support their position.
> [Roberts]: GR does not use "gravitational forces" at all, and in GR
there is no "propagation" and no "instantaneous propagation". And quite
clearly, planetary orbits do not spiral. His final claim about "reality"
is, of course, merely his pious hope (shared by many, but still just a
hope).
Lacking a logical argument to counter mine, Roberts now
resorts to authoritative declarations.
and "shuba" <tim....@eudoramail.com> writes:
> [Shuba]: Spacetime is not "a stand-in for proper time".
I note that you do not even attempt to address the simple,
logical argument I laid out in the cited reference. Instead, you argue
science by ad hominem attacks, as in the following:
> [Shuba]: You'd be lucky to get a D grade on your article if it were
written for the midterm of an introductory general relativity semester.
Now you compound that foolishness by accusing Wald of misleading.
No substance whatever. Just attack the messenger.
> [Shuba]: Well, readers of this newsgroup have grown used to seeing
authors published by Apeiron resort to such unprofessional tactics.
Welcome to the club. . You have real gall to defend your hack job of
defining spacetime.
Very nice. I think this is analogous to a saying that ends
with ". and the horse you rode in on!"
Is this typical of the professional tactics of your club?
> [Shuba]: The curvature of space (3-space) is indeed not part of
relativity. Nor is your concept above of "3-space observers" a part of
relativity, except in an approximation. The best way for others to learn
this is to read good presentations such as Wald's.
Do tell how "relativity" gets compared with observations
without 3-space. I'm all ears.
and Steve Carlip <car...@no-physics-spam.ucdavis.edu> writes:
>> [tvf]: when the gradient of the potential is taken to derive an
expression for force, GR uses an *instantaneous* gradient, not a
retarded one.
> [Carlip]: Tom, here's a function: f(x,y,z) = x^2 + yz^3. I know how to
find its gradient. What is its ``retarded gradient''?
Your question makes no sense. How can anything be "retarded"
unless something in it is a function of time?
>> [tvf]: The accompanying paragraph explains that the coordinates used
in this definition must be chosen to be either instantaneous coordinates
or retarded coordinates.
> [Carlip]: This is again mathematically meaningless.
Then let's make it obvious. As I have stressed, there is no
difference between instantaneous and retarded gradients for a source
mass and target body with no relative motion. But consider a target body
fixed at an origin, with respect to which the source mass has a relative
motion. Now, tell me what the gradient of the potential at the origin
is. Obviously, it depends on the speed at which the field updates.
You will probably wish to argue that the gradient points
toward the instantaneous source when there is transverse motion. But
that requires that the potential field be static and not continually
updated. Then the field has no cause for initiating target motion and no
source of new momentum because it has no moving parts. And we know that
reality is that source masses, such as the Sun or the components of a
binary pulsar, are continually accelerating. This requires that their
potential field be continually updated. Yet the binary pulsar experiment
shows that the gradient is still near-instantaneous even when the source
accelerates. (This result was derived in my 1998 "speed of gravity"
paper in Phys.Lett.A.)
There is no physical means for the potential gradient in the
field of a source mass in relative motion around a target body to follow
a source mass instantaneously. One can simply declare it so by a
mathematical formula. But the physical interpretation of such a formula
would apparently involve instantaneous propagation of whatever causally
connects source masses to target bodies via gravitational fields.
>> [tvf]: The same reasoning applies to gradients. This is also obvious
when viewed physically instead of mathematically. The gradient is just
the slope of a hill in a particular direction. The gradient of a
gravitational potential created by a source mass is the slope of the
potential hill in the direction of the source mass.
> [Carlip]: No, it's not. This is an *elementary* misunderstanding, not
of physics but of math. The direction of the gradient is the direction
in which the slope is steepest. It has nothing to do with the "direction
of the source mass'' unless the hill happens to be steepest in that
direction.
Again, you choose to isolate your attention on the math and
ignore the physics. The cause of the steepness of the hill is the source
mass. So physically, it very much matters whether that steepness follows
the instantaneous source mass or the retarded source mass.
Mathematically, the change of origin from the source mass to
the target body won't change the gradient unless the two origins have a
relative motion. But if they do have a relative motion, that cannot be
ignored by claiming that only the gradient with fixed source mass
matters.
>> [tvf]: the gradient is a vector, which has direction. And direction
requires a minimum of two points to specify. So the force/gradient
cannot be determined purely from consideration of the "here" and "now".
> [Carlip]: This is again trivially wrong mathematically.
If we were speaking of the gradient at a fixed point in the
field of the source mass, then your point would be well-taken. But we
are speaking of the gradient from a moving target body, or equivalently,
from a fixed target body with a moving source mass. That condition makes
my statement correct.
> [Carlip]: Here is another slightly more complicated exercise. Look up
the standard Lienard-Wiechert potential for a charge moving at a
constant velocity. Pick a point (x,y,z) and calculate the ordinary
gradient of the function at that point. Observe that this calculation
does not require that you know anything about where the function came
from, or about the position of the charge (or even that there is a
charge); it's just a simple mathematical operation. Don't use, or even
think about, "retarded coordinates''; just write down the function and
take its gradient. In what direction does the gradient point?
Good example. This illustrates my point. L-W retarded
potentials have an internal inconsistency. They allow for retardation
for changes in distance of the charge and field point, but not for
changes in direction. How can one update at speed c but not the other?
If it were a light field instead of a charge field, there is obviously
delay in the transverse direction also.
To answer your question, the gradient points toward the
charge -- even if the charge accelerates, according to the
Sherwin-Rawcliffe experiment. Mathematically, it just does. Physically,
this means that the causal connection between the moving charge and the
fixed field point is near-instantaneous. Anything else would be a form
of "instantaneous action at a distance" (IAAAD) causation. I trust you
are not arguing for that in physics. But for anyone who doesn't
understand why it is physically impossible, I recommend my article
"Physics has its principles" at
http://metaresearch.org/cosmology/PhysicsHasItsPrinciples.asp.
Even if someone wished to maintain that IAAAD is physically
possible, it is unnecessary, because FTL propagation is now allowed in
physics. So there is no longer a need to jump through logical hoops to
avoid it. -|Tom|-
shuba
> > [Shuba]: Spacetime is not "a stand-in for proper time".
>
> I note that you do not even attempt to address the simple,
> logical argument I laid out in the cited reference.
There is nothing logical about the inability or unwillingness to
correctly use standard terms, unless your goal is to set up a
straw man. Your short article is riddled with several basic
errors, as has been pointed out already.
> > [Shuba]: You'd be lucky to get a D grade on your article if it were
> written for the midterm of an introductory general relativity semester.
> Now you compound that foolishness by accusing Wald of misleading.
>
> No substance whatever. Just attack the messenger.
When the messenger's main purposes are to perpetuate obvious
misstatements about relativity and demean a physicist of the
caliber of Robert Wald, kind words are somewhat out of place.
> > [Shuba]: Well, readers of this newsgroup have grown used to seeing
> authors published by Apeiron resort to such unprofessional tactics.
> Welcome to the club. . You have real gall to defend your hack job of
> defining spacetime.
>
> Very nice. I think this is analogous to a saying that ends
> with ". and the horse you rode in on!"
>
> Is this typical of the professional tactics of your club?
You may wish to board up your own glass house first. The two
other people who post to this newsgroup and are published along
with you in the "Pushing Gravity" book are hostile cranks who
have been denigrating physicists for years. One of them, Paul
Stowe, has written the following directly to physicists in this
newsgroup.
"And you're full of shit! The term Coulomb was coined because
charge units could not be resolved. Try again when you know
what the fuck you're talking about."
"So you echo endlessly, you pompous one dimensional
unimaginative parrot. You wouldn't know the difference
between physical processes and the mathematics used to
describe them if they jump up and bit you on the ass."
"I cannot help that your type is so unimaginative and
close-minded that they refuse to even think about an
issue."
Paul Stowe has also called Steve Carlip "duplicitous" and has
accused him of making "deliberate distortions".
Is *this* typical of the professional tactics of *your* club?
Maybe this is another good time for you to conveniently get busy
with other things, so as to avoid the unpleasant task of applying
your criteria of professionalism equally and fairly.
> Do tell how "relativity" gets compared with observations
> without 3-space. I'm all ears.
Drop the pretense. You could have learned the subject by now,
had you chosen to do so. It was your choice, and it is your loss.
---Tim Shuba---
Mike
>
[snip]
> In your other comments, it would help if you carefully
> distinguished "unobservable" in the sense of pink unicorns from
> "unobservable" in the sense of air molecules. The former can never be
> observed because they have no physical existence, while the latter
> simply require developing more sophisticated observing apparatus to
> narrow constraints on their properties. Gravitons are in this latter
> camp.
>
[snip]
I argue gravitons can never be detected due to the contraints
applied to comform such entities to the particular model of
gravitation. This is the irony and illustrates the well-defined
dichotomy between realism and anti-realism. Your exmple regarding air
molecules is irrelevant in many ways and even a red herring. The
properties of air molecules were not such that they would prohibit
observation a priori. Such observation was only limited by the ability
to build instrumentation. However, in the case of gravitons, BY
DEFINITION, instruments are transparrent to them, since the graviton
size is orders of magnitude smaller than the size of any detector.
Specifically, since gravitons are supposed to cause gravitational
effects, any such gravitational effects cannot be used as the proof of
gravitons. Therefore, the particle must be identified itself. But, how
can one identify something moving at 10^20 c when all observation
techniques use some light frequency? The only way of doing that is
creating a particle running at speeds higher than those of the
graviton and instrumentation based on the physics of such particle.
Let me say that the idea of the graviton clearly leads to an
unobservable cause, not different than 'pink unicorns'. This is plain
vanilla realism. I myself admire such attempts. Obviously, the
graviton hypothesis has allowed continuous manipulation of the
physical parameters involved and has falsification based on
observation. This is remarkable indeed and of course something that
has compelled may to look seriously into a pushing gravity theory
based on a material flux of minute particles. I thing those people are
entitled to the efforts and beliefs as I see the graviton hypothesis
as one of the last viable ones that save realism.
We must also keep in mind that eventually, any hypothesis about the
nature of gravitation inevitably entails a certain cosmology. A
bouncing signal from the end of the universe, for instance, may serve
of the grave stone of the graviton hypothesis. "Here rests in peace
the last effort by the brave Dr. Van Flandern to save the phenomena"
will be written on it.
Mike
Mike
In the following sentence:
"Obviously, the graviton hypothesis has allowed continuous manipulation of the
physical parameters involved and has falsification based on
observation."
I meant to say:
"Obviously, the graviton hypothesis has allowed continuous manipulation of the
physical parameters involved and has EVADED falsification based on
observation."
Mike
Tom Van Flandern
>> [tvf]: In your other comments, it would help if you carefully
distinguished "unobservable" in the sense of pink unicorns from
"unobservable" in the sense of air molecules. The former can never be
observed because they have no physical existence, while the latter
simply require developing more sophisticated observing apparatus to
narrow constraints on their properties. Gravitons are in this latter
camp.
> [Mike]: I argue gravitons can never be detected due to the constraints
applied to conform such entities to the particular model of
gravitation. . BY DEFINITION, instruments are transparent to them, since
the graviton size is orders of magnitude smaller than the size of any
detector.
I'm glad you said that because I've not understood where you
were coming from until now. But this clears up at least this one point.
No, you have that "DEFINITION" wrong. Gravitons are not like pink
unicorns. If you read the model, you will see that matter can become
dense enough that matter is no longer transparent to gravitons. So it is
just a matter of time and technology before we invent graviton
detectors.
> [Mike]: how can one identify something moving at 10^20 c when all
observation techniques use some light frequency?
Gravitons travel faster than 2x10^10 c. But what's 10 orders
of magnitude when we're having fun? :-)
Only observations that use photons worry about frequencies
in the electromagnetic spectrum. But we detect things in lots of ways
that do not involve photons, the most obvious being our other human
senses: sound, touch, smell and taste. Instruments detect other things
by other non-photonic properties such as charge (as for currents) or
density (as when displacing volumes of a liquid), all of which can be
measured without use of photons.
As for gravitons, in concept, we can simply use the "sail"
or the "windmill" principle and use gravitons for propulsion by
extracting energy (using super-dense matter) from the graviton wind
always blowing toward the Earth's surface (because the Earth blocks much
of the counterpart graviton flux traveling in the opposite direction).
> [Mike]: A bouncing signal from the end of the universe, for instance,
may serve of the grave stone of the graviton hypothesis. "Here rests in
peace the last effort by the brave Dr. Van Flandern to save the
phenomena" will be written on it.
Those trained in scientific method know better than to
engage in "save the phenomena" efforts. Adding any kind of ad hoc helper
hypothesis is contrary to scientific procedure. Scientists are always
supposed to be trying to falsify hypotheses, not save them; and anyone
caught doing the reverse is guilty of bias.
That said, a failure in any of the model's present five
predictions, or any future prediction, will falsify it. -|Tom|-
Tom Roberts
> and "Thomas J Roberts" <tjro...@lucent.com> writes:
>>[tvf]: GR works only because GR (the theory) uses instantaneous
>> gravitational forces along with light-speed gravitational waves.
>
>>[Roberts]: As has been pointed out many times, this is Tom Van
>> Flandern's personal MISUNDERSTANDING of GR. In truth, GR does not use
>> "gravitational forces" at all, and you will look in vain for them in the
>> Einstein field equation.
>
> This claim is highly confused.
No, your lack of understanding what I said is where your confusion lies.
> Gravitational forces are
> absent only in the geometric interpretation of GR, which has now
> (arguably) been falsified in favor of the field interpretation for
> violating the causality principle and for needing to create changes in
> the 3-space momentum of target bodies from nothing.
Nonsense (assuming I parsed that the way you intended, which is by no
means certain).
Physical theories yield mathematical predictions for the results of
physical measurements. When one does the comparison correctly between
theory and experiment, no interpretation is needed.
In actual practice, the geometrical interpretation of GR is live and
well, and is ESSENTIAL in all of the current investigations of quantum
gravity....
And your premise is false:
> However, when
> working in 3-space, the momentum of target bodies is changed by gravity,
> and the time rate of change of momentum is force by definition. Absent
> force, the 3-space acceleration of target bodies would lack a cause,
> which is one of the reasons the geometric interpretation is falsified --
> curvature cannot initiate 3-space motion, and requires "magic", which is
> forbidden in physics.
That is just plain false. In spaceTIME, curvature can indeed "initiate
3-space motion" -- you just chose to ignore it by focusing only in
3-space curvature.
What you are discussing here has no relation to GR at all, but is
directly related to the APPROXIMATION to GR that you love so much:
> Roberts also writes as if equations of motion did not exist
> in GR. But of course, they do, and are required for comparison with
> observations. Equations of motion, as on p. 1095 of MTW, are expressions
> for 3-space force/acceleration.
Please turn to page 1095 of MTW. Now elevate your eyes to the heading of
the chapter (which happens to be on the facing page), and please read
it: "Other theories of Gravity and Post-Newtonian Approximation". Those
equations are NOT the "equations of motion of GR", they are equations of
motion for an APPROXIMATION TO GR. People around here have told Tom Van
Flandern this many times, and he is still unable to comprehend this
important distinction.
Analyze the approximations to GR leading to these equations, and you
will realize that some aspects of the limit c->infinity have been
included. And this is an ESSENTIAL aspect of reducing the equations form
4-d spaceTIME to "3-space force/acceleration".
BUT I REPEAT: THIS IS NOT GR!!!
The equations of motion of GR are well known:
T^uv_;v = 0
TVF ignores this, probably because he knows full well that if he pursued
it he could never conclude that gravity "propagates >> c".
> Yes, you will look in vain for forces in the Einstein field
> equations. That is simply because the gravitational (potential) field
> described by those equations does not produce forces. After the field is
> described, one must form a gradient to get an expression for force to
> describe the 3-space dynamics. That "gradient" step, incidentally, is
> where the "infinite propagation speed" is introduced into GR.
ONLY if you work in a suitable APPROXIMATION TO GR. In GR itself one
NEVER performs such a gradient, one solves the field equation and/or the
geodesic equation. The only reason such approximations are used is that
it is vastly simpler to solve the approximate equations than the real
equations, and in practice the errors due to the approximation are
negligible (i.e. far smaller than measurement accuracies).
> Tom Roberts should learn all this before he speaks out in
> CAPITAL LETTERS and reveals the limitations of his own knowledge.
I know "all this". But you are unable to learn the simple truth that you
discuss an APPROXIMATION TO GR rather than GR itself, and in peforming
that APPROXIMATION the "speed of propagation of gravity" was sent to
infinity (implicitly, by choice of Newtonian coordinates and the
subsequent foliation of spacetime into 3-space and a global time).
>>[Roberts]: In GR, the metric at a given point determines all
>> gravitational interactions at that point.
>
> This is untrue [...]
Yes. I should have added "and its derivatives".
>>[Roberts]: this self-consistent solution is one in which the metric
>> field acts as if it moved in mutual harmony with the mass (just as the
>> surface of the earth moves in mutual harmony with its center).
>
> This is a great example of the difference between
> mathematical GR and physical GR. In math, it is easy to merely say "the
> metric field acts as if it moved in mutual harmony with the mass". But
> in physics, nothing moves without a specific cause.
Hmmm. That last is known to be wrong since Galileo. It is CHANGES IN
MOTION that "require a cause" (but that's implicitly using the naive
notions of "causality").
This is quite simple in GR: consider Schwarzschild spacetime outside a
spherical mass M. The field in Schw. coordinates is independent of time
t. Now boost to uniformly-moving coordinates, and the field will vary as
a function of time in the moving coordinates. And if one plotted a
contour map of the field wrt the moving coordinates, by golly the
contour lines move in mutual harmony with the mass M.
This is an elementary consequence of the coordinate-independence of GR.
> The same holds for a source mass and its potential field. If
> the source mass accelerates, that must set off a wave of change
> propagating outward at the speed of light.
So go back to Schw. spacetime outside that mass M, and transform to
accelerating coordinates. Same conclusion as before -- the contour lines
move in mutual harmony with the mass M.
> That nicely illustrates one of the two reasons why the
> geometric interpretation of GR is not viable. It provides no causal
> connection between source mass and target body, a link that is essential
> in physics, even if not in math.
You use the naive notion of causality; that is appropriate in everyday
speech, but is utterly absent in any modern theory of physics. Including GR.
> [... more of the same]
Tom Roberts tjro...@lucent.com
Mike
"Tom Roberts" <tjro...@lucent.com> wrote in message
news:QyKuc.17652$eH1.7...@newssvr28.news.prodigy.com...
>
> In actual practice, the geometrical interpretation of GR is live and
> well, and is ESSENTIAL in all of the current investigations of quantum
> gravity....
>
No need to even state this. GR offers a geometric model of relativistc
dynamics and only that. This is the only interpretation (geometric) that
satisfies the epistemological principle in the foundation of GR and which
states that all phenomena must have the same explanation in all moving
reference frames.
I have looked at the paper by Tom Van Flandern and it appears (Tom Roberts
correct me if I'm wrong) that he is using the flat space metric of Minkowski
spacetime to build some arguments involving causality in 3-D space. But the
flat, non-Euclidean metric does no involve gravity. (In philosophy of
science, the world this metric implies is called Parmenidean, i.e., a
timless, acausal, unchanging world). As soon as mass/energy is introduced in
the flat world, it curves according to GR and this 4-D curvature explains
geodesic inertial motion without the need of causal agents, because in his
theory, free fall is equivalent to inertial motion by definition of the EP.
Thus, the 3-D world of Van Flandern is just a projection of a relativistc
dynamics. In this projection, one is faced with dilemmas such as causality.
The power of GR is in eliminating the need for causal agents and
superluminal speeds from a model which, despite the philosophical
objections, seems to work very well.
I have also philosophical objections against GR and the world such model
implies. But that's much different from misunderstanding or distorting the
core of the theory in arguments involving metaphysical concepts such as
causality. I would like to inform Van Flandern that the causal relationship
between force and acceleration cannot even be established in Newtonian
Mechanics he seems to be a master of. I challenge Tom Van Flander to give me
an answer to the following question or refrain from any reference to
causality from his posts:
Tie a stone at the end of a rope and whirl it around Dr. Van Flandern. Is
the tension on the rope the cause of the circular orbit or the circular
orbit causes the tension on the rope?
The failure of NM to provide answers to such basic questions about its model
of the world gave power to GR. But when one mixes physics and metaphysics,
all sorts of paradoxes emerge. Just learn the theory (which I'm trying also
for the last ten years) and then make your statements. If you wrote that
paper as a midterm project for the course I took in Modern Physics (that's
how SR and GR was called then) you (Van Flandern) would have gotten a
straight F, I'm sorry to say.
Mike
Thomas J Roberts
> [example of a difficult question about causality]
> Tie a stone at the end of a rope and whirl it around Dr. Van Flandern. Is
> the tension on the rope the cause of the circular orbit or the circular
> orbit causes the tension on the rope?
Yes, your question exhibits one reason for the lack of NAIVE causality in all
modern theories of physics. And even in some not-so-modern theories.
In fact, AFAIK SR was really the first theory to have anything identifiable as
"causality" at all. And GR retains it. But it is not naive, and does not lead to
the difficulty you refer to above, nor to the infinite regress of naive causality.
Briefly stated: the values of all fields at a given point depend ONLY
upon values on the intersection of the past lightcone of the event in
question and a suitable achronal surface (aka "Cauchy surface").
Remarkably, ANY such surface will do (because of recursive application
of this theorem). You are free to read "caused by" for "values depend
upon".
[Mike appears not to need this, but others around here certainly
do, including TVF]
Study until you understand it: correlation is not causation.
[Newtonian mechanics describes the CORRELATION between tension
and circular path, but not any "causation"; classical
electrodynamics describes the CORRELATION between charge and
field, but not any "causation"; etc.]
Tom Roberts tjro...@lucent.com
greywolf42
news:40BCC5C1...@lucent.com...
> On 6/1/2004 7:57 AM, Mike wrote:
> > [example of a difficult question about causality]
> > Tie a stone at the end of a rope and whirl it around Dr. Van Flandern.
> > Is the tension on the rope the cause of the circular orbit or the
circular
> > orbit causes the tension on the rope?
>
> Yes, your question exhibits one reason for the lack of NAIVE causality in
> all modern theories of physics. And even in some not-so-modern theories.
>
> In fact, AFAIK SR was really the first theory to have anything
> identifiable as "causality" at all.
ROTFLMAO!!!!!
You forgot Maxwell's theory of electromagnetism. You forgot Maxwell's
theory of perfect gases. You also forgot phogiston, and all the other
theories we no longer use.
{snip the rest}
Tom Van Flandern
"Tom Roberts" <tjro...@lucent.com> raises a few interesting discussion
points. It is regrettable that they are somewhat buried in diatribe.
>> [tvf]: Gravitational forces are absent only in the geometric
interpretation of GR, which has now (arguably) been falsified in favor
of the field interpretation for violating the causality principle and
for needing to create changes in the 3-space momentum of target bodies
from nothing.
> [Roberts]: Nonsense . Physical theories yield mathematical predictions
for the results of physical measurements. When one does the comparison
correctly between theory and experiment, no interpretation is needed.
Your statement is a non-sequitur to mine. Many different
physical theories, even some drastically different ones (such as "dark
matter" versus MOdified Newtonian Dynamics -- MOND) have the same
mathematical representation, at least to observational accuracy. So
getting the right physical theory is very much a matter of
interpretation.
In the case under discussion, GR, the distinction between
the original field interpretation and the latter-day geometric
interpretation is not mine, but was an historical development commented
on most recently by no less a notable than Richard Feynman in Feynman
Lectures on Gravitation, Addison-Wesley, New York (1995). Section 8.4,
p. 113: "It is one of the peculiar aspects of the theory of gravitation,
that it has both a field interpretation and a geometrical
interpretation. ... the fact is that a spin-two field has this
geometrical interpretation: this is not something readily explainable --
it is just marvelous. The geometrical interpretation is not really
necessary or essential to physics."
To take just one aspect of GR, Einstein and Eddington were
already aware 80-90 years ago that "refraction in an optical medium"
gave a mathematically equivalent result to "curved spacetime". Would you
still say "no interpretation is needed" about that difference?
The complete, intuitive gravity model in [Pushing Gravity:
New Perspectives on Le Sage's Theory of Gravitation, M. Edwards, ed.,
Apeiron Press, Montreal, 93-122 (2002)] has the same math as GR to first
order in potential and second order in velocity. So it is the same
mathematical theory to that accuracy. Yet it predicts five phenomena
that GR does not. So in physics, mathematical theories definitely need
interpreting, and multiple interpretations need to be distinguished.
That has now happened in GR, and the geometric interpretation has lost
out to the field interpretation. But as Feynman said, the geometric
interpretation is not really necessary or essential to physics anyway.
> [Roberts]: In actual practice, the geometrical interpretation of GR is
live and well, and is ESSENTIAL in all of the current investigations of
quantum gravity....
Would those be the current investigations that have failed
to produce a quantum gravity model since GR was first introduced nearly
a century ago? Note that Le Sage gravitation ("pushing gravity") has
already produced a *complete* quantum gravity model. As long as it
continues to work well, we really have no need of a second quantum
gravity model. But if one ever does evolve, it will be fun to see which
version is simpler and makes the better predictions.
>> [tvf]: Absent force, the 3-space acceleration of target bodies would
lack a cause, which is one of the reasons the geometric interpretation
is falsified -- curvature cannot initiate 3-space motion, and requires
"magic", which is forbidden in physics.
> [Roberts]: That is just plain false. In spaceTIME, curvature can
indeed "initiate 3-space motion" -- you just chose to ignore it by
focusing only in 3-space curvature.
As I explained, "curvature" in the absence of a force (force
being the TIME rate of change of momentum) cannot initiate motion from
rest, just as the rubber sheet analogy shows. Without gravity (a force)
under the rubber sheet, a body on the side of a curved potential hill
will simply remain at rest there forever. What exactly are you proposing
as the causative physical mechanism to change non-motion into 3-space
motion when no force acts? An equation?
> [Roberts]: What you are discussing here has no relation to GR at all,
but is directly related to the APPROXIMATION to GR that you love so much
[equations of motion]
You have repeated this ad nauseam, rather mantra-like, but
never explained yourself. What difference does it make whether one uses
exact equations or approximate equations to compare against observations
as long as the error in the approximation is far less than the error of
observation?
What you say here makes no sense unless, by implication, you
also rule our using computers to evaluate sines and cosines or other
functions because these are just approximations, and the computed
approximations of these functions "have no relation at all" to the exact
functions.
Please do explain yourself.
>> [tvf]: Roberts also writes as if equations of motion did not exist in
GR. But of course, they do, and are required for comparison with
observations. Equations of motion, as on p. 1095 of MTW, are expressions
for 3-space force/acceleration.
> [Roberts]: Please turn to page 1095 of MTW. Now elevate your eyes to
the heading of the chapter (which happens to be on the facing page), and
please read it: "Other theories of Gravity and Post-Newtonian
Approximation". Those equations are NOT the "equations of motion of GR",
they are equations of motion for an APPROXIMATION TO GR.
Those equations are known throughout the civilized world as
"the GR equations of motion" for the simple reason that is what they
are. They are used in orbit computation and for definitive comparisons
of theory and observation. If they were in any way not representative of
GR, then only the "approximation" would have been observationally
confirmed, and GR would remain an untested theory.
However, speaking more directly to your point, turn to p.
1069 and read in the first paragraph there (with emphasis added by me):
"Consequently, the analysis of solar system experiments using any metric
theory of gravity can be simplified, WITHOUT SIGNIFICANT LOSS OF
ACCURACY, by a simultaneous expansion . Such a "weak-field, slow motion
expansion" gives . (3) post-Newtonian corrections . The formalism of
Newtonian theory plus post-Newtonian corrections is called the
"post-Newtonian approximation".
If there is no significant loss of accuracy, how do you
justify your extravagant claims?
> [Roberts]: People around here have told Tom Van Flandern this many
times, and he is still unable to comprehend this important distinction.
"People around here" refers to Tom Roberts. I concede that I
see no importance whatever to the distinction you wish to make for the
purposes of this discussion. Do other people also have trouble
comprehending your claims, or am I privileged to be the only one?
Perhaps if you did less bashing and more explaining, the point you are
trying to make would emerge. Or perhaps in the effort to explain, you
will discover that you were just beating a strawman.
> [Roberts]: Analyze the approximations to GR leading to these
equations, and you will realize that some aspects of the limit
c->infinity have been included. And this is an ESSENTIAL aspect of
reducing the equations form 4-d spaceTIME to "3-space
force/acceleration".
I have been through the full derivation of the equations of
motion line-by-line in Einstein-Infeld-Hoffmann, in Robertson and
Noonan, and in Damour's treatment too (which is more general). I have
been saying right along that the speed of gravitational force has been
set to infinity in these equations, not for reason of any convenience or
approximation, but because that step is (as you say) an ESSENTIAL aspect
of the equations, without which they would fail to represent reality.
But that is the only place where an infinite speed is used. The speed of
light always remains c and appears only as c^2 (an energy per unit mass,
not a speed) or higher powers, but the speed of gravitational force is
set to infinity.
Run through the derivations and see for yourself. I'd then
be interested in your explanation of the physical interpretation of this
use of infinity. You will plainly see that it has nothing to do with
lightspeed and cannot be approximated by c under any circumstances
without turning closed orbits into spirals.
> [Roberts]: The equations of motion of GR are well known: T^uv_;v = 0
TVF ignores this, probably because he knows full well that if he pursued
it he could never conclude that gravity "propagates >> c".
The equations you mention describe the potential field, not
the 3-space motion of bodies in that field. Changes in the potential
field propagate at speed c. That is now old news. Equally certain is
that the propagation speed of gravitational force, the entity described
by GR's 3-space equations of motion, is infinite in GR and
near-instantaneous in all experiments, as detailed in the references
previously provided.
So I definitely do conclude that gravity (meaning
gravitational force, the chief determinant of orbital motion in 3-space)
propagates >> c.
>> [tvf]: Yes, you will look in vain for forces in the Einstein field
equations. That is simply because the gravitational (potential) field
described by those equations does not produce forces. After the field is
described, one must form a gradient to get an expression for force to
describe the 3-space dynamics. That "gradient" step, incidentally, is
where the "infinite propagation speed" is introduced into GR.
> [Roberts]: ONLY if you work in a suitable APPROXIMATION TO GR. In GR
itself one NEVER performs such a gradient; one solves the field equation
and/or the geodesic equation. The only reason such approximations are
used is that it is vastly simpler to solve the approximate equations
than the real equations, and in practice the errors due to the
approximation are negligible (i.e. far smaller than measurement
accuracies).
Perhaps this is at the heart of our failure to communicate.
The field and geodesic equations describe only the potential field. One
cannot calculate orbits from those equations. Orbits and observations
are 3-space entities, and require 3-space equations of motion. Forming
those requires taking a gradient or the mathematical equivalent, such as
forming a Lagrangian or a Hamiltonian. (They all involve 3-space partial
derivatives.) So the purpose of these equations of motion is quite
different from the purpose of field equations. The former equations
involve forces, the latter involve potentials.
These two sets of equations are not related to one another
as "exact" versus "approximation". They are equations of completely
different kinds used for different purposes. It is unfortunate that you
are not familiar with equations of motion, which are in fact the subject
of my professional specialty (celestial mechanics). For a deeper
understanding of equations of motion and how to compute orbits from
them, I recommend J.M.A. Danby's "Fundamentals of Celestial Mechanics".
Notice especially that interactions between bodies are taken as
instantaneous. A light-speed propagation delay would be fatal because
the computed orbits would spiral.
> [Roberts]: consider Schwarzschild spacetime outside a spherical mass
M. The field in Schw. coordinates is independent of time t. Now boost to
uniformly-moving coordinates, and the field will vary as a function of
time in the moving coordinates. And if one plotted a contour map of the
field wrt the moving coordinates, by golly the contour lines move in
mutual harmony with the mass M. This is an elementary consequence of the
coordinate-independence of GR.
All true, but also beside the point here. Try adding
gradient lines to your contour map of the field using moving
coordinates. That is where the relevant action occurs. The gradient
lines cannot move in mutual harmony with the mass M unless either (1)
nothing propagates to regenerate the field (no causality, no source of
3-space momentum for target bodies), or (2) the field regenerates with
near-infinite speed. Obviously, only solution (2) is consistent with the
principles of physics. [See
http://metaresearch.org/cosmology/PhysicsHasItsPrinciples.asp.]
Perhaps you have worked in a GR field-equation world so long
that it has escaped your notice that the real world is not always
Lorentz invariant. The GR 3-space equations of motion are an obvious
example, as you may be able to see for yourself by inspection of MTW p.
1095.
Only the field and geodesic equations have that neat
covariant property. But once you take the gradient of the potential to
get descriptions of motions in 3-space versus time, you lose Lorentz
invariance. It is important to know that. Someone lacking that knowledge
might be inclined to make inappropriate generalizations about nature.
>> [tvf]: the geometric interpretation of GR is not viable. It provides
no causal connection between source mass and target body, a link that is
essential in physics, even if not in math.
> [Roberts]: You use the naive notion of causality; that is appropriate
in everyday speech, but is utterly absent in any modern theory of
physics. Including GR.
The causality principle in physics reads: "Every effect has
a proximate, antecedent cause." That arises from logic alone. Any
exception would be a form of "magic", and therefore outside the domain
of physics. As long as we can continue to describe reality in accord
with the causality principle, there will remain no need for miracles --
including a beginning to space or time. I am sorry you are not familiar
with this principle because it is fundamental to constraining
mathematical theories, which might otherwise entertain singularities,
unlimited dimensions, creation ex nihilo, and other miracles as
something more than mathematical abstractions. But then, you would have
lots of company to comfort you.
and "Mike" " <ele...@yahoo.gr> writes:
> [Mike]: GR offers a geometric model of relativistic dynamics and only
that.
It sounds as if the field interpretation of GR is a hole in
your knowledge.
> [Mike]: This is the only interpretation (geometric) that satisfies the
epistemological principle in the foundation of GR and which states that
all phenomena must have the same explanation in all moving reference
frames.
But you don't define what you mean by this coordinate
independence. As noted above, in the simplest interpretation
(covariance/Lorentz invariance), coordinate independence is simply wrong
for all of celestial mechanics and the GR 3-space equations of motion.
If that is not what you mean, then please provide a clear
definition. The murkiness of definitions of terms is one of the primary
reasons for failures to communicate in forms such as this one.
> [Mike]: I have looked at the paper by Tom Van Flandern and it
appears . that he is using the flat space metric of Minkowski spacetime
to build some arguments involving causality in 3-D space.
You might want to look again. Causality in 3-space follows
from logic alone, without need for Minkowski spacetime to exist outside
the world of mathematics. And remember that "curved spacetime" does not
involve any curvature of space. (If this is news to you, see "Does space
curve" at http://metaresearch.org/cosmology/gravity/spacetime.asp.)
> [Mike]: Thus, the 3-D world of Van Flandern is just a projection of a
relativistic dynamics. In this projection, one is faced with dilemmas
such as causality. The power of GR is in eliminating the need for causal
agents and superluminal speeds from a model which, despite the
philosophical objections, seems to work very well.
Apparently, one person's meat is another's poison. Inasmuch
as causality is contrasted with magic, I was always quite partial to the
former, and didn't feel I truly understood a phenomenon until I could
describe cause and effect. And why one would consider eliminating
superluminal speeds an *advantage* I cannot imagine. Look at all the
paradoxes that elimination created in cosmology and quantum physics that
have now vanished.
> [Mike]: I would like to inform Van Flandern that the causal
relationship between force and acceleration cannot even be established
in Newtonian Mechanics he seems to be a master of.
That is indeed news to me, especially since I have written
papers about that very causal relationship. My Meta Research Bulletin
[vol. 11#4, pp. 49-53 (2002)] article, "Does gravity have inertia",
would be a case in point. Have you an argument, experiment, or citation
to support your opinion?
> [Mike]: I challenge Tom Van Flandern to give me an answer to the
following question or refrain from any reference to causality from his
posts: Tie a stone at the end of a rope and whirl it around Dr. Van
Flandern. Is the tension on the rope the cause of the circular orbit or
the circular orbit causes the tension on the rope?
I have no idea why you ask this because Newton's first two
laws of motion explain this in classical physics. All bodies at rest in
3-space remain at rest, while those in motion remain in uniform, linear
motion unless a force acts. Your rock does not continue in uniform,
linear motion, so a force must be acting on it -- the tension in the
rope.
In the following, assume that a hand whirls the rope. Then
here is the sequence. The rock tries to move in a uniform, linear way in
3-space. That causes the distance between rock and hand to increase,
which creates tension in the rope. (I assume that the physics of tension
inside the rope is not the subject of your interest.) The tension
applies a centripetal force to the rock, curving its path into a circle.
So clearly in this example, tension causes the circular
motion. If the tension is removed by the hand releasing the rope, the
rock will resume its uniform, linear motion. If the rock is removed but
the rope remains, the rock's attempt to travel in linear motion can no
longer act to stretch the rope, so the rope tension (except the small
part from its own weight) is released, and the rope continues to whirl
without tension.
This seems a complete picture of cause and effect at the
rope-rock interface, with unambiguous causality. So why did you issue
your challenge?
> [Mike]: The failure of NM to provide answers to such basic questions
about its model of the world gave power to GR.
You and I also apparently were taught history differently as
well. What gave impetus to GR was the success of its three classical
post-Newtonian predictions. Other than for that, there was no "failure
of NM", which was doing just fine at explaining dynamics with Newton's
three laws of motion and his universal law of gravity.
> [Mike]: But when one mixes physics and metaphysics, all sorts of
paradoxes emerge.
This is something we can agree upon, although we probably
don't agree about who is doing the mixing. But the models I described
have eliminated (as contrasted with "resolved") every related paradox
without exception, as shown in the papers I have referenced. You sure
can't make that claim for your personal world model.
> [Mike]: If you wrote that paper as a midterm project for the course I
took in Modern Physics (that's how SR and GR was called then) you (Van
Flandern) would have gotten a straight F, I'm sorry to say.
That is an illuminating remark. Often, a poor background in
any subject area can be traced to bad teachers. You have my sympathies.
Truly, I have an unfair advantage in this area because I was
taught (in the Yale graduate school) by Brower, Clemence, Danby, Deprit,
and Szebehely among others, all authors and world-renowned figures in
celestial mechanics of both the Newtonian and Einsteinian variety; and I
did my dissertation on improvements in the lunar orbit using occultation
data (a "rock" on a "gravitational string", so to speak :-). -|Tom|-
shuba
> Note that Le Sage gravitation ("pushing gravity") has
> already produced a *complete* quantum gravity model.
Noted with glee. At what time and by whom was it *completed*?
---Tim Shuba---
Bilge
>
>> [Roberts]: In actual practice, the geometrical interpretation of GR is
>live and well, and is ESSENTIAL in all of the current investigations of
>quantum gravity....
>
> Would those be the current investigations that have failed
>to produce a quantum gravity model since GR was first introduced nearly
>a century ago?
It takes a little longer to come up with a theory which
has physical content and which answers the questions it's
expected to answer. I'm going to guess you have much lower
expectations and nothing in your ``theory'' wasn't addressed
more completely by newtonian mechanics. But, that is easy enough
to determinse since you claim:
> Note that Le Sage gravitation ("pushing gravity") has already
>produced a *complete* quantum gravity model.
Say, that is good news. There have been some other claims that le sage
gravity was a quantum theory, but so far no one has been able to make that
clear. At least one person seemed to think that ``quantum theory'' meant
``theory with particles'' but I'm going to assume you know better than
that, so we can stay focussed on your claim of complete rather rule out
the quantum aspect as the result of a misconception.
At the top of the list, of course, is how gravity fits in with
the strong, weak and electromagnetic interactions to produce the
world around us. I assume that your theory either explains all
four interactions or else explains why gravity isn't related
to the other forces.
>As long as it continues to work well, we really have no need of
>a second quantum gravity model. But if one ever does evolve, it
>will be fun to see which version is simpler and makes the better
>predictions.
Well, ok, then let's focus on something concrete, which I can solve with
general relativity and therefore should be a snap for you to solve with
your ``quantum theory''. Since your ``le sagian particles'' supposedly
interact with matter, I assume you can tell me the selection rules for
transitions between levels of a hydrogen atom which are caused by the
interaction of your ``le sagian'' particles wuth the electron in the atom.
What do you estimate for the average time required for the electron to be
excited from the ground state to the lowest excitation level allowed by
the selection rules for your gravitational interaction? I have quite a
few more questions, too.
>> [Roberts]: That is just plain false. In spaceTIME, curvature can
>indeed "initiate 3-space motion" -- you just chose to ignore it by
>focusing only in 3-space curvature.
>
> As I explained, "curvature" in the absence of a force (force
>being the TIME rate of change of momentum) cannot initiate motion from
>rest, just as the rubber sheet analogy shows. Without gravity (a force)
>under the rubber sheet, a body on the side of a curved potential hill
>will simply remain at rest there forever. What exactly are you proposing
>as the causative physical mechanism to change non-motion into 3-space
>motion when no force acts? An equation?
>
>> [Roberts]: What you are discussing here has no relation to GR at all,
>but is directly related to the APPROXIMATION to GR that you love so much
>[equations of motion]
>
> You have repeated this ad nauseam, rather mantra-like, but
>never explained yourself. What difference does it make whether one uses
>exact equations or approximate equations to compare against observations
>as long as the error in the approximation is far less than the error of
>observation?
None, except for the fact that you insist the approximation _is_
the theory. Tell me, do you think newtonian gravity is given by
F = mgh, with g = 9.8 m/sec^2 as a universal constant, just because
it works well as an approximation to F = GMm/r^2 here on earth for
small \Delta r?
[...]
> That is an illuminating remark. Often, a poor background in
>any subject area can be traced to bad teachers. You have my sympathies.
Then, by your own admission below, you have no excuse for having
such a poor background.
> Truly, I have an unfair advantage in this area because I was
>taught (in the Yale graduate school) by Brower, Clemence, Danby, Deprit,
>and Szebehely among others, all authors and world-renowned figures in
>celestial mechanics of both the Newtonian and Einsteinian variety; and I
>did my dissertation on improvements in the lunar orbit using occultation
>data (a "rock" on a "gravitational string", so to speak :-). -|Tom|-
What you had was an opportunity upon which you apparently didn't
capitalize. It can hardly be called unfair, unless by unfair, you
mean that it was insufficient to provide you with a background
on par with the average physics student at a university without
those faculty members.
FrediFizzx
news:40BCC5C1...@lucent.com...
Well, it was a trick question by Mike in the first place since he used the
word "cause" instead of correlation. Anyone can see that. The freakin'
cause is *someone* tied a rock to a rope and started its motion. Really a
bad example.
FrediFizzx
Tom Van Flandern
"shuba" <tim....@eudoramail.com> writes:
> [Shuba]: At what time and by whom was it *completed*?
The 20-author book "Pushing Gravity: New Perspectives on Le
Sage's Theory of Gravitation" [M. Edwards, ed., Apeiron Press, Montreal]
was published in the summer of 2002. Especially relevant are my chapter
"Gravity", pp. 93-122; and V. Slabinski's chapter "Force, heat and drag
in a graviton model", pp. 123-128.
and "Bilge" <dub...@radioactivex.lebesque-al.net> writes:
> [Bilge]: At the top of the list, of course, is how gravity fits in
with the strong, weak and electromagnetic interactions to produce the
world around us. I assume that your theory either explains all four
interactions or else explains why gravity isn't related to the other
forces.
I said a complete quantum gravity theory was now available,
not a GUFT. You do know the difference between a theory of gravity and a
theory unifying all the fundamental forces, don't you?
Apparently, as this Le Sage-type model shows, gravity is
related to the other forces, but not in any of the ways previously
contemplated. Precisely because the new gravity model is complete, is
has opened new doors in the unification struggle. A major step in that
direction appeared in "The structure of matter in the Meta Model" in
Meta Research Bulletin v.12#4, pp. 58-63 (2003), which discussed
possibilities for modeling baryons with gravitons and elysons. But there
is still a long way to go.
The rest of your message was redundant to the above point or
else contained invective, unworthy of comment in a scientific
newsgroup. -|Tom|-
Bilge
>> [Bilge]: At the top of the list, of course, is how gravity fits in
>with the strong, weak and electromagnetic interactions to produce the
>world around us. I assume that your theory either explains all four
>interactions or else explains why gravity isn't related to the other
>forces.
>
> I said a complete quantum gravity theory was now available,
>not a GUFT. You do know the difference between a theory of gravity and a
>theory unifying all the fundamental forces, don't you?
As a matter of fact, I do, but it appears you haven't really thought
this out in much detail before concluding you have a complete theory.
Let's take a neutron and proton. As a bound state called the deuteron, you
have a mass which is 2.2 MeV less than the sum of the neutron and proton
mass. Now, your so-called le sagean particles are supposed to explain
gravity by whatever ``shadowing'' results from the size and density of an
object. However, the contribution to the mass of an object from a deuteron
is less than the contribution from the neutron and proton separately. But,
the neutron and proton neither shrink nor become less dense by forming a
deuteron. Nothing about le sage gravity would explain why a neutron and
proton which are separated by 5 fm here on earth would contribute more to
the gravitational field than a neutron and proton which are separated by
2 fermis, but still part of the total earth mass.
I would have to conclude that the strong nuclear force has to have some
effect on your le sagean particles, so if you don't have a theory which
includes the other forces, so that binding energy affects the passage of
le sagean particles through matter, ``complete'' would seem to overstate
the case by a lot. I'd also guess that you've used ``quantum theory'' to
mean ``theory with really small particles'' rather than a theory in which
a commutator bracket and an i\hbar ever appears as part of an equations of
motion.
> Apparently, as this Le Sage-type model shows, gravity is
>related to the other forces, but not in any of the ways previously
>contemplated.
Well, if you've contemplated it why don't you simply get to the point
and tell me specifically what that means rather than spend a paragraph
just to tell me how wonderful it would be if you explained it and then
expect me to be overcome with curiosity once I quit oohing and ahhing.
>Precisely because the new gravity model is complete, is
>has opened new doors in the unification struggle. A major step in that
>direction appeared in "The structure of matter in the Meta Model" in
>Meta Research Bulletin v.12#4, pp. 58-63 (2003), which discussed
>possibilities for modeling baryons with gravitons and elysons. But there
>is still a long way to go.
Does a reference to an unavailable article which is supposed to
augment a nebulous description of a dubious model, count as a scientific
argument? I was Just wondering since below, you admonish me for comments
which you seem to feel aren't up to the level of your posts. However,
I'm at a loss to figure out what kind of a scientific comment you could
reasonably expect based upon the content of that paragraph.
I've said this before - rather than waste a lot of words not saying
anything, write a few that say something and I won't get the impression
that you are evading my question and that you think I'm too stupid to
realize it.
> The rest of your message was redundant to the above point or
>else contained invective, unworthy of comment in a scientific
>newsgroup.
As of the present time, your responses fall into roughly two
categories:
(1) Arguments that employ kiddie analogies and toy models suitable
for a handwaving argument to people who don't know any better,
an of which is that silly analogy about airplane propellers and
propagation speed of electromagnetic fields, and
(2) Arguments based upon misrepresntations of what you are arguing
against. Since you not only have never corrected the misrepresen-
tations in the articles of yours that you reference, but you
continue to use those arguments as if you had never been made
aware that what you refer to as relativity is not relativity,
I can only assume the misrepresentation is deliberate. If you
are insisting that I accept a caricature of relativity as a prop
for your argument against relativity, you aren't asking for
a scientific response, but you are receiving the response you
did ask for.
shuba
[re: Van Flandern's claim that Le Sage gravitation has produced
a "*complete* quantum gravity model"]
> > [Shuba]: At what time and by whom was it *completed*?
>
> The 20-author book "Pushing Gravity: New Perspectives on Le
> Sage's Theory of Gravitation" [M. Edwards, ed., Apeiron Press, Montreal]
> was published in the summer of 2002. Especially relevant are my chapter
> "Gravity", pp. 93-122; and V. Slabinski's chapter "Force, heat and drag
> in a graviton model", pp. 123-128.
So it was *completed* by you and Slabinski in 2002 in Apeiron?
Can you provide a citation to the complete quantum gravity model
in any respectable peer-reviewed journal?
---Tim Shuba---
Mike
news:40be9ad3$0$2961$61fe...@news.rcn.com...
>
> In the following, assume that a hand whirls the rope. Then
> here is the sequence. The rock tries to move in a uniform, linear way in
> 3-space. That causes the distance between rock and hand to increase,
> which creates tension in the rope. (I assume that the physics of tension
> inside the rope is not the subject of your interest.) The tension
> applies a centripetal force to the rock, curving its path into a circle.
>
> So clearly in this example, tension causes the circular
> motion.
Just read your own words:
A. "The rock tries to move in a uniform, linear way in 3-space. That
causes
the distance between rock and hand to increase, which creates tension
in the
rope"
B. "So clearly in this example, tension causes the circular motion"
In A you clearly state that the tension is caused by the motion of the
rock
In B you clearly state the tension causes the motion of the rock
Your own statements illustrate the epistemological confusion causality
brings about that you do not accept but cannot escape falling a victim
of
and exposing the limitations and contradictions of your concept of the
world
in a very obvious and direct way.
The causal connection between force and acceleration cannot be proved
in either direction, especially in the case of inertial and field
force (which you seem to adore).
You also seem not to value a very important principle, the principle
of parsimony. A theory is elegant when it explains more with less
assuptions, as Feynman always stressed in his lectures. Since causal
connections are very ellusive, especially when it comes to inertial
and gravitational motion, Relativistic dynamics turn out to be a much
more elegant theory according to the principle of parsimony and
especially it's ontological form which is what you have heard as
Ockham's Razor.
You always seem to wonder what is the cause of motion in a 3-D
projection of 4-D equations of motion, a really incomprehensible stand
from your part since as soos as a 4-D relativistic dynamics was
obtained the 3-D + time view of the wrold was flat demolished, gone
and it is only naive to ask such questions. First, you have no
epistemological or ontological grounds for insisting on the 3-D
projections as one that reflects reality more than being a matter of
convention. Second, the object of physics is not to try to understand
the ontology of spacetime, matter and energy but to provide the models
that are based in the fewest possible assumptions about those
metaphysics while being increasingly predictive and accurate.
Based on the above, I have labaled you a metaphysician Dr. Van
Flandern. Of course, there is nothing wrong with metaphysical
assertions, most of us like tham and dream of them in our free time.
The problem is when someone mixes physics and metaphysics in a way
that becomes an illusive science. Since Aristotle who defined the
term, serious scientists are careful enough to keep the distinctions
clear. Apparently, you insist on some type of ontology of spacetime
without admitting you are doing metaphysics. No one will blame you if
you do admit it. But if you continue to insist about 3-D projections
and causes of motion and that tyny particles moving at 10^10 speeds
solve these problems that you think are part of some reality, while
claiming you are doing physics, you will be an easy target.
Mike
Tom Van Flandern
"Bilge" <dub...@radioactivex.lebesque-al.net> writes:
> [Bilge]: your so-called le sagean particles are supposed to explain
gravity by whatever "shadowing'' results from the size and density of an
object. However, the contribution to the mass of an object from a
deuteron is less than the contribution from the neutron and proton
separately. But, the neutron and proton neither shrink nor become less
dense by forming a deuteron. Nothing about le sage gravity would explain
why a neutron and proton which are separated by 5 fm here on earth would
contribute more to the gravitational field than a neutron and proton
which are separated by 2 fermis, but still part of the total earth mass.
You are speaking here of a model for quantum entities, not a
model of gravitation. For purposes of a complete model of gravitation,
it suffices that the inertial mass changed. The reason for that change
need not be known.
Nonetheless, it so happens, because the gravitation part of
the Le Sage-type model is so complete, it does in fact already expect
the very phenomenon you cited. The preliminary model of deuterons is
presented in the MRB article I cited in my last message. When a proton
and an electron get together to form a neutron, the elysium envelope
each carries would normally repel like particles and attract opposite
particles. But in the model, when like particles are forced together,
the elysium envelope each carries is pierced, resulting in less elysium
mass surrounding the 2 fm combined particles than the 5 fm separated
particles. (Elysium is the light-carrying medium with gravitational
density gradient imposed, so it is the equivalent of a gravitational
potential field of the individual or combined masses.)
> [Bilge]: I'd also guess that you've used "quantum theory'' to mean
"theory with really small particles'' rather than a theory in which a
commutator bracket and an i\hbar ever appears as part of an equations of
motion.
No, I use "quantum" with its standard meaning in physics:
"the smallest discrete quantity of a physical property, or the smallest
unit used to measure a physical property; e.g., electromagnetic
radiation or angular momentum."
>> [tvf]: Apparently, as this Le Sage-type model shows, gravity is
related to the other forces, but not in any of the ways previously
contemplated.
> [Bilge]: Well, if you've contemplated it why don't you simply get to
the point and tell me specifically what that means .
The point needs to be read in context or I would have
summarized it for you. I'm not sure this will mean much out of context,
but the chief new features here are the presence of two interacting
mediums present on different scales, elysium and gravitons; the
equivalence of the light-carrying elysium to the gravitational potential
field; and the direction of causality being reversed: force induces a
(density) gradient on the potential (elysium), instead the gradient of
the potential causing gravitational force. Then Coulomb forces arise
from elysium pressures, and gravitational forces arise from gravitons.
But what could you expect to learn about any model (e.g.,
GR) in a few broad-brush descriptive sentences? The important thing
about this model is that it is neither the brainstorm nor the nightmare
of any person; but is rather derived deductively from assumption-free
first principles:
http://metaresearch.org/cosmology/PhysicsHasItsPrinciples.asp. Anyone
working from the same starting point and following the rules of logic
could reach the same conclusions.
>> [tvf]: Precisely because the new gravity model is complete, it has
opened new doors in the unification struggle. A major step in that
direction appeared in "The structure of matter in the Meta Model" in
Meta Research Bulletin v.12#4, pp. 58-63 (2003), which discussed
possibilities for modeling baryons with gravitons and elysons. But there
is still a long way to go.
> [Bilge]: Does a reference to an unavailable article which is supposed
to augment a nebulous description of a dubious model, count as a
scientific argument?
MRB has availability similar to any other peer-reviewed
journal in the field. See it at your local library, or have them order
it on inter-library loan, or borrow a subscriber's copy, or order a copy
from the publisher. Single back issues are $5, which barely pays for the
printing, postage and handling and is obviously not a source of support,
but is priced just to cover realistic costs.
> [Bilge]: you are receiving the response you did ask for.
I don't consider that a good excuse for rudeness, however
much you might wish to justify it.
and "shuba" <tim....@eudoramail.com> writes:
> [Shuba]: So it was *completed* by you and Slabinski in 2002 in
Apeiron? Can you provide a citation to the complete quantum gravity
model in any respectable peer-reviewed journal?
First, Apeiron Press (the book publisher I referenced) and
"Apeiron" the journal are two different entities. And Apeiron is not
only a respectable name, but has now assumed a leading position in
replacement physics. No one could be up-to-date in the field today in
gravitational physics, relativity, or cosmology without reading
Apeiron-the journal. The two chapters I mentioned were published as a
book by Apeiron Press.
But major parts of the model were previously published in
"Meta Research Bulletin, vol. 5, pp. 23-29 & 38-50, 1996 (about which
you are likely to have the same complaint) and in Astrophys.&SpaceSci.,
v. 244, pp. 249-261, 1996, which qualifies as respectable to anyone
without a specific ax to grind. A web version appears at
http://metaresearch.org/cosmology/gravity/possiblenewpropertiesofgravity.asp
for those who don't have a technical library conveniently nearby.
and "Mike" <ele...@yahoo.gr> writes:
>> [tvf]: In the following, assume that a hand whirls the rope. Then
here is the sequence. The rock tries to move in a uniform, linear way in
3-space. That causes the distance between rock and hand to increase,
which creates tension in the rope. . The tension applies a centripetal
force to the rock, curving its path into a circle. So clearly in this
example, tension causes the circular motion.
> [Mike]: Just read your own words: . In A you clearly state that the
tension is caused by the motion of the rock. In B you clearly state the
tension causes the motion of the rock. Your own statements illustrate
the epistemological confusion causality brings about that you do not
accept but cannot escape falling a victim of and exposing the
limitations and contradictions of your concept of the world in a very
obvious and direct way.
It is disturbing to me that you were never taught basic
mechanics. Newton's third law of motion states that "For every force,
there is an equal and opposite force." In my exposition of the causal
sequence, the rock's linear motion is the first cause, stretching the
rope and creating tension in it. That tension induces a reaction force
("equal and opposite") in the rock, forcing the rock to deviate from its
normal motion.
You then twisted my words to claim I said "the tension
causes the motion of the rock" when I said the tension causes a change
in the rock's motion (from linear to circular). That was what you asked
in your challenge: "What causes the rock's circular motion?" If you
understand basic mechanics, there is no circularity here or indeed any
conceptual problem at all. There is a clear chronological sequence of
cause and effect.
If you took basic mechanics and were not taught this, you
might consider asking for your tuition back because you were cheated.
> [Mike]: The causal connection between force and acceleration cannot be
proved in either direction, especially in the case of inertial and field
force (which you seem to adore).
This statement also reflects that you do not have the
meaning of some of the basic concepts of 3-space mechanics clear in your
mind. When two bodies impact, momentum (the product of mass and velocity
for each body, by definition) can be exchanged between them, but is
always conserved. A single collision produces a discontinuity in
velocity called an "impulse". A continuous series of impulses produces a
continuous series of velocity changes, such as for the rock in your
example. ("Velocity" is a vector and has both speed and direction. The
rock's direction continually changes. A circular path has continual
velocity change.) A change of velocity (note: not just speed) is called
an "acceleration" by definition. The time rate of change of momentum is
called a "force" by definition. So when mass is invariant, Newton's
second law of motion, "force equals mass times acceleration", is nothing
more than the statement that d/dt (mv) = ma, which is trivially true for
constant inertial mass m, where v is velocity, mv is momentum, a is
acceleration, d/dt means the "time rate of change", and d/dt (mv) is
force.
The connection between force and acceleration therefore
follows directly from the conservation of momentum, which in turn
follows from the first principles of physics; specifically, "no creation
ex nihilo" and "no demise ad nihil".
> [Mike]: You also seem not to value a very important principle, the
principle of parsimony. A theory is elegant when it explains more with
less assumptions, as Feynman always stressed in his lectures. Since
causal connections are very elusive, especially when it comes to
inertial and gravitational motion, relativistic dynamics turn out to be
a much more elegant theory according to the principle of parsimony and
especially its ontological form which is what you have heard as Ockham's
Razor.
I'm not only an advocate of Occam and parsimony, but in a
way, an extremist in that direction because I insist on *no assumptions*
whenever possible, as is the case here. I have examined causal specifics
in innumerable cases and not found causes to be "elusive" except in the
occasional impressive magician's trick. My book, "Dark Matter, Missing
Planets and New Comets" derives an entire cosmology from the same first
principles with no assumptions. Gravitation is very much a part of that
derived universe. The amazing part is that, despite no degrees of
freedom, the deductive results still manage to resemble reality, despite
some altered perspectives about what "space", "time", and "matter"
really are. Inertial and gravitational motion are especially easy to
model once the erroneous assumptions often invoked from inductive
reasoning are removed from the mix. The equivalence principle, in
particular, has been widely misunderstood and misapplied, the deductive
analysis shows. It should be replaced with what I call the "transparency
principle". Then the paradoxes just vanish.
> [Mike]: You always seem to wonder what is the cause of motion in a 3-D
projection of 4-D equations of motion, a really incomprehensible stand
from your part since as soon as a 4-D relativistic dynamics was obtained
the 3-D + time view of the world was flat demolished, gone and it is
only naive to ask such questions.
What is a 4-D "equation of motion"? In 4-space, nothing
moves! I assume you mean geodesic equations, which in and of themselves
contain no dynamics, but can be used to help derive the 3-space
equations of motion. And are you perhaps unaware that all observations
and experiments are conducted in 3-space plus proper time? Without
3-space equations of motion, a comparison of GR against observations
would not be possible for real, physical bodies.
But I realize this is not your field (it is mine), and that
you may be out of your depth here. However, a bit less pontificating and
a bit more substance could only elevate the intellectual level of this
discussion.
> [Mike]: Based on the above, I have labeled you a metaphysician Dr. Van
Flandern. . The problem is when someone mixes physics and metaphysics in
a way that becomes an illusive science. Since Aristotle who defined the
term, serious scientists are careful enough to keep the distinctions
clear. Apparently, you insist on some type of ontology of spacetime
without admitting you are doing metaphysics. No one will blame you if
you do admit it. But if you continue to insist about 3-D projections and
causes of motion and that tiny particles moving at 10^10 speeds solve
these problems that you think are part of some reality, while claiming
you are doing physics, you will be an easy target.
These are cases in point. -|Tom|-
Bilge
>"Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>
>> [Bilge]: your so-called le sagean particles are supposed to explain
>gravity by whatever "shadowing'' results from the size and density of an
>object. However, the contribution to the mass of an object from a
>deuteron is less than the contribution from the neutron and proton
>separately. But, the neutron and proton neither shrink nor become less
>dense by forming a deuteron. Nothing about le sage gravity would explain
>why a neutron and proton which are separated by 5 fm here on earth would
>contribute more to the gravitational field than a neutron and proton
>which are separated by 2 fermis, but still part of the total earth mass.
>
> You are speaking here of a model for quantum entities, not a
>model of gravitation. For purposes of a complete model of gravitation,
>it suffices that the inertial mass changed. The reason for that change
>need not be known.
Be serious. Your so-called ``theory'' predicts the gravitational mass of
an object that one measures as gravitational forces is due to shadowing
(plus a lot of parameterized legerdemain). In any case, the deuteron is
large enough that the neutron and proton aren't going to ``shadow'' any
less area when bound as a deuteron, than they will when separated by 1
more fermi. If you really think your so-called theory of gravity has
nothing to do with explaining gravitational mass, then your so-called
theory is complete only in the sense of being completely useless.
> Nonetheless, it so happens, because the gravitation part of
>the Le Sage-type model is so complete, it does in fact already expect
>the very phenomenon you cited.
Right. I can see that your post is replete with the equations that
make that evident... Tell me something. Over there in alternative
physicsland, do the self-exiled dissident physicists use mathematics
to communicate or do they all just sit around and tell stories about
the day relativity will be crushed by the weight of its predictive power?
> The preliminary model of deuterons is
>presented in the MRB article I cited in my last message. When a proton
>and an electron get together to form a neutron, the elysium envelope
>each carries would normally repel like particles and attract opposite
>particles.
That doesn't tell me anything (except perhaps you are totally oblivious
with respect to nuclear physics as well.) Neutrons are not made of electrons
and protons. When you put an electron and proton together, you what is
called a hydrogen atom. There is no bound state of a proton and electron
with a radius smaller than the bohr radius.
Also, the electron and proton each have a spin of 1/2. The only two
numbers you can get by adding their spins is 0 or 1. If you include
orbital angular momentum, you can have 0,1,2,.., i.e., only _integer_
values. The neutron is spin 1/2. 1/2 is not one of the possible values.
I leave it as an excercise to show that the sum of the electron and
proton magnetic moment isn't in the same ballpark as the magnetic
moment of the neutron (in case you didn't know, the neutron has a
magnetic moment and it's negative.).
[...]
>But in the model, when like particles are forced together,
>the elysium envelope each carries is pierced, resulting in less elysium
>mass surrounding the 2 fm combined particles than the 5 fm separated
>particles. (Elysium is the light-carrying medium with gravitational
>density gradient imposed, so it is the equivalent of a gravitational
>potential field of the individual or combined masses.)
At the risk of being blunt, you are insulting my intelligence if
you really think I'm going to mistake that for physics or even any
sort of answer that a turing machine could differentiate from the
output of a monte carlo algorithm.
Seriously, if you criticize mainstream physics for ignoring ``alter-
native physics'', you ought to take a closer look at your alternative
in case you think that ``alternative'' is supposed mean an alternative
to physical content.
>> [Bilge]: I'd also guess that you've used "quantum theory'' to mean
>"theory with really small particles'' rather than a theory in which a
>commutator bracket and an i\hbar ever appears as part of an equations of
>motion.
>
> No, I use "quantum" with its standard meaning in physics:
No, you don't, any more than you use the term ``relativity'' to mean
the same thing it does in physics, but at least you're consistent.
>"the smallest discrete quantity of a physical property, or the smallest
>unit used to measure a physical property; e.g., electromagnetic
>radiation or angular momentum."
``Quantum'' is not a synonym for ``smallest discrete quantity of a
physical property''. I was obviously over optimistic in assuming that
because you probably studied physics in the latter three-quarters of this
century, you would know the difference between ``quantum mechanics'' and
``real small particles described by newtonian physics''.
If you still have a quantum mechanics book, you might want to look in
the index under ``one dimensional harmonic oscillator'' so you can
follow along while I illustrate the basic feature of quantum mechanics
that makes it quantum mechanics. Also note that I am employing a
literary device used in physics a lot, called equations. Equations
are what separates meaningless jargon from terminology which one
physicist may use to convey something meaningful to another physicist.
(I mention this because I've requested that you post something
meaningful, but you don;t seem to understand what I mean by that).
The hamiltonian for the classical and the quantum harmonic oscillator
have the same form:
H = (1/2m) [p^2 + (mwx)^2]
I can factor this as follows:
(p + imwx)(p - imwx) = (1/2m)[p^2 + (mwx)^2] + (iw/2)[x,p]
= (1/2m)[p^2 + (mwx)^2] - (\hbarw/2)
Note the extra term due to the non-zero commutator of x and p that
_quantizes_ the system. We call this ``first quantization''. Quantizing
things is the feature of quantum mechanics which distinguishes it from
classical mechanics, since nothing precludes me using classical mechanics
to describe ``real small particles''. If you plan on discussing quantum
mechanics with physicists, this is what physicists will assume you mean,
at the very least.
My hamiltonian is then,
H = (1/2m)[p^2 + (mwx)^2]
= (1/2m)(p + imwx)(p - imwx) + (\hbar w/2)
Note that the very lowest energy level is not zero. It's \hbar w/2.
Without the commutator [x,p] = i\hbar, the harmonic oscillator would not
be quantized, regardless of what you assume about the particles in the
potential well being small, indivisible, purple, fuzzy or anything else.
We may define raising and lowering operators, (a+) and a, that will be
analogous to creation and destruction of particles in a more sophisticated
framework, called ``second quantization''. This too, involves the
commutation relations.
If I went too fast, I'll be happy to elaborate.
[...]
>
> But what could you expect to learn about any model (e.g.,
>GR) in a few broad-brush descriptive sentences?
Isn't that a rather silly question for you to be asking? Obviously,
the answer is nothing and you are doing as much as possible to insure
that it stays that way. On the other hand, if you stopped writing lots
of sentences that say absolutely nothing and concentrated on writing
a few that had some physical content, you could explain your model and
cut down the amount of typing required to respond by a factor of 10.
I could have derived the entire standard model several times over in
less space than you've wasted not saying anything.
>The important thing
>about this model is that it is neither the brainstorm nor the nightmare
>of any person; but is rather derived deductively from assumption-free
>first principles:
>http://metaresearch.org/cosmology/PhysicsHasItsPrinciples.asp. Anyone
>working from the same starting point and following the rules of logic
>could reach the same conclusions.
Yeah. I've read those so-called ``principles''. I can sum them up
in a single principle called self-promotion, since what you have
on that page has little to do with physics or logic in any context
more general than a prop for the rest of your site.
[...]
>> [Bilge]: Does a reference to an unavailable article which is supposed
>to augment a nebulous description of a dubious model, count as a
>scientific argument?
>
> MRB has availability similar to any other peer-reviewed
>journal in the field.
I imagine hustler magazine is similar in availability if not more so,
but I'm not going to hold out any great hope that I'll learn any physics
by buying one - except perhaps some novel ways to exploit it.
While others may hold out some hope that you could be goaded into making
a concrete statement about something which is ammenable to scientific
analysis, I don't. I assume you would have to be a masochist to not post
something that would make your point rigorous if legerdemain wasn't your
only option.
[...]
>> [Bilge]: you are receiving the response you did ask for.
>
> I don't consider that a good excuse for rudeness, however
>much you might wish to justify it.
Uh, I'm not trying to justify it. I'm pointing out that insulting my
intelligence (or anyone else's) by posting a load of vacuous statements
and meaningless jargon with the expectation that no one will catch on,
is quite rude. The responses you receive reflect that. I just address
what you post. Don't try to con me with meaningless jargon, and I
won't have anything to point out as meaningless jargon.
Mike
>
> >> [tvf]: In the following, assume that a hand whirls the rope. Then
> here is the sequence. The rock tries to move in a uniform, linear way in
> 3-space. That causes the distance between rock and hand to increase,
> which creates tension in the rope. . The tension applies a centripetal
> force to the rock, curving its path into a circle. So clearly in this
> example, tension causes the circular motion.
>
> > [Mike]: Just read your own words: . In A you clearly state that the
> tension is caused by the motion of the rock. In B you clearly state the
> tension causes the motion of the rock. Your own statements illustrate
> the epistemological confusion causality brings about that you do not
> accept but cannot escape falling a victim of and exposing the
> limitations and contradictions of your concept of the world in a very
> obvious and direct way.
>
> It is disturbing to me that you were never taught basic
> mechanics.
I see you are starting your usual ad hominen attacks when cornered. If there
is one person in this discussion who distorts basic mechanics to fit his own
fantasies, that is you.
> Newton's third law of motion states that "For every force,
> there is an equal and opposite force."
That is not what Newton's third law states. You make silly statements and
you expose yourself. Of course to every force there is NOT an equal and
opposite force. God forbit. Learn the law of action-reaction now:
"To every action there is always opposed an equal reaction, or, the mutual
actions of two bodies upon each other are always equal, and directed to
contrary paths" (Newton, Principia, Third Law)
Only forces resulting from mutual action-reeaction are equal and opposite.
Learn how to be exact and rigorous otherwise you expose yourself.
> In my exposition of the causal
> sequence, the rock's linear motion is the first cause,
Now Van Flandern discovered first causes also. Let's see what surprises will
come down the lines.
> stretching the
> rope and creating tension in it. That tension induces a reaction force
> ("equal and opposite") in the rock, forcing the rock to deviate from its
> normal motion.
>
So Van Flandern now asserts that the cause of the circular orbit has a
"first cause", which is a linear motion of the rock.
There is no linear motion of the rock when it is moving on a circular path.
The velocity vector changes direction continuously.
> You then twisted my words to claim I said "the tension
> causes the motion of the rock" when I said the tension causes a change
> in the rock's motion (from linear to circular).
You have misinterpreted the geometric arguments Newton made to construct
circular motion from infinitesimal linear motion changes. In modern
mechanics, the limit is taken and those linear changes vanish. There is no
linear motion of the rock in its circular path at any time t.
> That was what you asked
> in your challenge: "What causes the rock's circular motion?" If you
> understand basic mechanics, there is no circularity here or indeed any
> conceptual problem at all. There is a clear chronological sequence of
> cause and effect.
You have discovered it where Berkeley, Hume, Kant, Einstein, Reichenbach and
many others have failed to. But if you stop begging the question and just
look at a rock whirling around, can you establish cause and effect? Your
"science" of "first causes" does not explain anything about causality
because there is an infinite regression of causes that can be considered.
>
> If you took basic mechanics and were not taught this, you
> might consider asking for your tuition back because you were cheated.
You make unreasonable statements to the point I wonder whether having a
discussion with you is a waist of time. If you consider yourself an expert
and Donald T. Greenwood a cheater, just read carefully the quote below from
"Principles of Dynamics" by Greenwood:
"The concept of force as a fundamental quantity in the study of mechanics
has been criticized by various scientists and philosophers of science from
shortly after Newton's enunciation of the laws of motion until the present
time. Briefly, the idea of a force, and a field force in particular, was
considered to be an intellectual construction, which has no real existence.
It is merely another name for the product of mass and acceleration, which
occurs in the mathematics of solving a problem. Furthermore, the idea of
force as a cause of motion should be discarded since the assumed cause and
effect relationship cannot be proved." (Greenwood 1965, Principles of
Dynamics)
>
> > [Mike]: The causal connection between force and acceleration cannot be
> proved in either direction, especially in the case of inertial and field
> force (which you seem to adore).
>
> This statement also reflects that you do not have the
> meaning of some of the basic concepts of 3-space mechanics clear in your
> mind.
Neither does Greenwood, but you do?
[snip rudimentary and elementary, even wrong exposition on Newton's second
law]
>
> The connection between force and acceleration therefore
> follows directly from the conservation of momentum, which in turn
> follows from the first principles of physics; specifically, "no creation
> ex nihilo" and "no demise ad nihil".
You now change the worlds "causal connection" to just "connection". This is
plain avoidance.
The principles you refer to are not principles of physics but of
Metaphysics. In physics, particular propositions based on ontological forms
of those principles are used, such as invariance of mass and conservation of
energy. Obviously, you confuse physics and metaphysics but also do not
understand how one can make the transition between the two in a
scientifically accepted way.
>
> > [Mike]: You also seem not to value a very important principle, the
> principle of parsimony. A theory is elegant when it explains more with
> less assumptions, as Feynman always stressed in his lectures. Since
> causal connections are very elusive, especially when it comes to
> inertial and gravitational motion, relativistic dynamics turn out to be
> a much more elegant theory according to the principle of parsimony and
> especially its ontological form which is what you have heard as Ockham's
> Razor.
>
> I'm not only an advocate of Occam and parsimony, but in a
> way, an extremist in that direction because I insist on *no assumptions*
> whenever possible, as is the case here. I have examined causal specifics
> in innumerable cases and not found causes to be "elusive" except in the
> occasional impressive magician's trick. My book, "Dark Matter, Missing
> Planets and New Comets" derives an entire cosmology from the same first
> principles with no assumptions.
if your first principles are not assumptions what are they? Self evident
propositions? Experimental facts? I have explained to you several times that
your so called first principles are plain, bold hypotheses that are not
falsifiable and have no place in physics.
> Gravitation is very much a part of that
> derived universe. The amazing part is that, despite no degrees of
> freedom, the deductive results still manage to resemble reality, despite
> some altered perspectives about what "space", "time", and "matter"
> really are. Inertial and gravitational motion are especially easy to
> model once the erroneous assumptions often invoked from inductive
> reasoning are removed from the mix. The equivalence principle, in
> particular, has been widely misunderstood and misapplied, the deductive
> analysis shows. It should be replaced with what I call the "transparency
> principle". Then the paradoxes just vanish.
Your deductions arise from universally quantified propositions that cannot
be proved.
>
> > [Mike]: You always seem to wonder what is the cause of motion in a 3-D
> projection of 4-D equations of motion, a really incomprehensible stand
> from your part since as soon as a 4-D relativistic dynamics was obtained
> the 3-D + time view of the world was flat demolished, gone and it is
> only naive to ask such questions.
>
> What is a 4-D "equation of motion"? In 4-space, nothing
> moves! I assume you mean geodesic equations, which in and of themselves
> contain no dynamics, but can be used to help derive the 3-space
> equations of motion. And are you perhaps unaware that all observations
> and experiments are conducted in 3-space plus proper time? Without
> 3-space equations of motion, a comparison of GR against observations
> would not be possible for real, physical bodies.
>
> But I realize this is not your field (it is mine), and that
> you may be out of your depth here. However, a bit less pontificating and
> a bit more substance could only elevate the intellectual level of this
> discussion.
That ad hominen remark will do nothing to conceal the fact that your posts
are full of incomplete and inaccurate metaphysics while offering no physical
insight that can be confirmed by experiment or any predictions of any sort.
Look at my new post on Slabinski's missapplication of Newton's second law to
force the graviton flux model to look like the LUG.
Mike
[snip]
shuba
> First, Apeiron Press (the book publisher I referenced) and
> "Apeiron" the journal are two different entities. And Apeiron is not
> only a respectable name, but has now assumed a leading position in
> replacement physics.
Replacement physics? Now there's a well-known discipline!
> No one could be up-to-date in the field today in
> gravitational physics, relativity, or cosmology without reading
> Apeiron-the journal.
The truth is that no one up-to-date in those subject areas writes
in that journal.
> The two chapters I mentioned were published as a
> book by Apeiron Press.
I'm aware of that. Is obfuscatory nonsense supposed to distract
from the fact that you have never provided any citation for your
claim:
"Note that Le Sage gravitation ("pushing gravity") has
already produced a *complete* quantum gravity model."
One more time: Is this model "completely" defined in that book?
If not, where, when, and by whom was it "completely" defined?
---Tim Shuba---
Tom Van Flandern
"Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>> [tvf]: You are speaking here of a model for quantum entities, not a
model of gravitation. For purposes of a complete model of gravitation,
it suffices that the inertial mass changed. The reason for that change
need not be known.
> [Bilge]: Be serious. Your so-called "theory'' predicts the
gravitational mass of an object that one measures as gravitational
forces is due to shadowing (plus a lot of parameterized legerdemain). In
any case, the deuteron is large enough that the neutron and proton
aren't going to "shadow'' any less area when bound as a deuteron, than
they will when separated by 1 more fermi.
You have no idea what the model you are challenging is like
because you insist upon not reading it, and instead you keep making
false assumptions about what it must be like. In the real model, elysium
has inertial mass too, so naturally the effective inertial mass will
differ depending on how close or far apart the neutron and proton are
because elysium is an essential part of the binding force.
Are you actually upset that the model had a good answer to
your challenge? Can any new model that challenges an existing model meet
your criteria for being worth a look?
>> [tvf]: Nonetheless, it so happens, because the gravitation part of
the Le Sage-type model is so complete, it does in fact already expect
the very phenomenon you cited.
> [Bilge]: Right. I can see that your post is replete with the equations
that make that evident... Tell me something. Over there in alternative
physicsland, do the self-exiled dissident physicists use mathematics to
communicate or do they all just sit around and tell stories about the
day relativity will be crushed by the weight of its predictive power?
Well, that's a good question, because apparently many of our
communication troubles stem from the answer to that very point.
Pure math solves problems that are not yet known to exist in
nature, or at least not in any useful applications. Applied physics is
intended to aid in the solution to existing problems and useful
applications. Physics is only concerned with the latter field in the
here and now, although it reserves the right to make use of pure math in
future applications.
So applied math must be motivated by a problem that
pre-exists. To have any realistic hope of a correct model emerging to
solve a problem, one must first develop the physics, reasoning,
observations and experiments that describe everything we know about the
problem's subject area. One then envisions a physical solution, whether
inductively or deductively. That solution must be consistent with
reasoning, observation, and experiment, both real and gedanken. That
means it must obey the principles of physics, which means nothing more
(but nothing less) than that magic is not allowed in any step of the
model. These principles impose constraints on the model.
Once all these pieces are in place, one can begin the
process of searching for equations to represent and help develop the
model. The model must precede the choice of equations because equations
lack intelligence; the symbols are useful only when we can associate
them with real, physical bodies or properties or concepts; and equations
are generally blind to physical constraints. Moreover, math often
describes statistical average properties of bodies rather than exact
values. So in that sense, however exact or "beautiful" equations may be,
equations are usually just approximations to reality, and are then sure
to be incomplete and subject to improvement in the future.
Many of your remarks eschew developing the physical model
beyond primitive or vague descriptions before bringing in equations.
IMO, that is how GR and QM got into the pickle they find themselves in,
with progress blocked on several fronts and even an irresolvable paradox
or two. ["No deep reality"? !!]
Despite these difficulties, the current mainstream model
might have been the best we could do. However, such is emphatically not
the case. Alternative physical interpretations exist for many of the
successful equations now in use. And by developing the physics more
fully before turning to math, we can now see why. Several "paths not
taken" are proving much more promising than we had any right to hope
for, much less expect.
So in answer to your question, applied-math-oriented people
like me recognize that math is useful for many things, but not for
telling us which of two physical interpretations of some equations is
better. We must first be able to formulate the right questions before we
can expect math to provide an assist with the answers.
I see that yours as more of a pure math mentality. You first
learn an equation, get to like its simplicity and beauty, learn one set
of physical associations for its symbols, and rebel when someone else
says "But those associations are not unique. Here's another set." Our
communication problems seem to mostly be of that variety. Mike, at
least, picked up the "Pushing Gravity" book and began burrowing into the
Slabinski derivation of the basic Le Sage model properties. He will
either find a fault with them, or not find one and be satisfied that
they work, if he can ever get past the flame-fest he is engaged in and
concentrate on the physics and interpretation issues. With either
outcome, progress is made. But to judge from your public positions, you
will apparently never be any smarter in this field than you already are,
so you had better hope you have made no wrong choices in your career.
> [Bilge]: if you criticize mainstream physics for ignoring "alternative
physics'' .
I think you deal with so many correspondents that you can no
longer keep track of who said what. I don't find good physicists
ignoring viable replacement models. Each is evaluated on its merits, as
it should be.
The rest of your message seemed to have no point except
posturing and put-down. If I missed anything of importance, feel free to
mention it again.
and "Mike" <ele...@yahoo.gr> writes:
>> [tvf]: It is disturbing to me that you were never taught basic
mechanics.
> [Mike]: I see you are starting your usual ad hominen attacks when
cornered. If there is one person in this discussion who distorts basic
mechanics to fit his own fantasies, that is you.
I apologize. It was not my intent to insult you. But I am
puzzled. You asked me questions, the answers to which required reciting
Newton's three laws of motion. If you already knew those, then why did
you ask those questions as if you had never heard of those three laws?
Beyond that, you answered what you perceived as an insult
with a pretty good one of your own. Is it your intention to drive this
discussion away from its main points? You raised a challenge about
causality, I gave an answer from basic mechanics, and you started
questioning the meaning of basic mechanics. Shall we stay on point or
just play "top that insult"? I notice you doing that in other threads.
How can you ever teach or learn new things if you do that?
>> [tvf]: Newton's third law of motion states that "For every force,
there is an equal and opposite force."
> [Mike]: That is not what Newton's third law states. You make silly
statements and you expose yourself. Of course to every force there is
NOT an equal and opposite force. God forbid. Learn the law of
action-reaction now: "To every action there is always opposed an equal
reaction, or, the mutual actions of two bodies upon each other are
always equal, and directed to contrary paths" (Newton, Principia, Third
Law) Only forces resulting from mutual action-reaction are equal and
opposite. Learn how to be exact and rigorous otherwise you expose
yourself.
Let's see now. I count five insults here, and in the final
analysis, I still have no idea in what important way my choice of words
differs from yours. What is the relevance of your correction to the
point of this discussion? Or are you trying to divert attention from a
losing or indefensible position instead of accepting my answer to your
challenge?
>> [tvf]: stretching the rope and creating tension in it. That tension
induces a reaction force ("equal and opposite") in the rock, forcing the
rock to deviate from its normal motion.
> [Mike]: So Van Flandern now asserts that the cause of the circular
orbit has a "first cause", which is a linear motion of the rock. There
is no linear motion of the rock when it is moving on a circular path.
The velocity vector changes direction continuously.
You asked for the cause. I answered. There certainly was
linear motion of the rock prior to the circular motion because the rope
did not always have tension on it. Moreover, the rope would never have
tension on it if it did not initially start moving linearly, thereby
stretching the rope and creating tension. You seem to be in denial of
the obvious -- the sequential order in which cause and effect proceed.
No matter how many confused authors you cite, when it comes to
causality, reason trumps all opinions.
> [Mike]: You have misinterpreted the geometric arguments Newton made to
construct circular motion from infinitesimal linear motion changes. In
modern mechanics, the limit is taken and those linear changes vanish.
There is no linear motion of the rock in its circular path at any time
t.
Try to get the math out of your head until the physics is
straight. We can't even begin applying limits until the motion of the
rock approaches equilibrium. If you want causes, we have to talk about
the pre-equilibrium stages. Then (and only then) it becomes obvious how
cause and effect proceed after equilibrium is achieved.
> [Mike[: if you stop begging the question and just look at a rock
whirling around, can you establish cause and effect? Your "science" of
"first causes" does not explain anything about causality because there
is an infinite regression of causes that can be considered.
Same comment.
> [Mike]: If you consider yourself an expert and Donald T. Greenwood a
cheater, just read carefully the quote below from "Principles of
Dynamics" by Greenwood:
"The concept of force as a fundamental quantity in the study of
mechanics has been criticized by various scientists and philosophers of
science from shortly after Newton's enunciation of the laws of motion
until the present time. Briefly, the idea of a force, and a field force
in particular, was considered to be an intellectual construction, which
has no real existence. It is merely another name for the product of mass
and acceleration, which occurs in the mathematics of solving a problem.
Furthermore, the idea of force as a cause of motion should be discarded
since the assumed cause and effect relationship cannot be proved."
(Greenwood 1965, Principles of Dynamics)
I feel sorry for this confused chap. But the definition of
force is the time rate of change of momentum, not the product of mass
and acceleration. That latter is a derived property that holds only for
fixed masses, but not (for example) to a rocket burning fuel. Substance
and momentum are the two entities that we can be certain are real if
anything is.
Just because some philosophers did not have all their
physical concepts straight is no cause to jump to absurd conclusions,
such as that elementary rock-rope problems cannot be described uniquely
in terms of a sequence of causes and effects.
> [Mike]: if your first principles are not assumptions what are they?
Self evident propositions? Experimental facts? I have explained to you
several times that your so called first principles are plain, bold
hypotheses that are not falsifiable and have no place in physics.
The principles of physics are based on logic alone, using
only the requirements of internal consistency and no magic allowed. The
reasoning behind each is summarized in the article "Physics has its
principles". They have no need of experimental verification.
(Experiments apply to testing the laws of physics, a completely
different category of proposition.) The principles are obviously not
self-evident to everyone until one is forced to reason through the
consequences of assuming the opposite. The principles are a unique
category of human knowledge, and do not fit into any of the categories
you named.
and "shuba" <tim....@eudoramail.com> writes:
> [Shuba]: Is this model "completely" defined in that book? If not,
where, when, and by whom was it "completely" defined?
Yes, the model is as completely laid out in [Pushing
Gravity: New Perspectives on Le Sage's Theory of Gravitation, M.
Edwards, ed., Apeiron Press, Montreal (2002)] as any theory is in any
single book. See especially my chapter and that by Slabinski, pp.
93-128. These two cover the basic physics and math (respectively) of the
most complete version of the model, its unique predictions that
differentiate it from GR, and the observational status of those. -|Tom|-
Mike
> > [Mike]: So Van Flandern now asserts that the cause of the circular
> orbit has a "first cause", which is a linear motion of the rock. There
> is no linear motion of the rock when it is moving on a circular path.
> The velocity vector changes direction continuously.
>
> You asked for the cause. I answered. There certainly was
> linear motion of the rock prior to the circular motion because the rope
> did not always have tension on it. Moreover, the rope would never have
> tension on it if it did not initially start moving linearly, thereby
> stretching the rope and creating tension. You seem to be in denial of
> the obvious -- the sequential order in which cause and effect proceed.
> No matter how many confused authors you cite, when it comes to
> causality, reason trumps all opinions.
>
You are becoming arrogant here, calling world renowned experts "confused
authors" just to support your naive view which arises from a simplistic and
shallow interpretation of physical phenomena.
We are talking here about causality issues in laws of mechanics and not
subjective interpretations of what happens during transients and
non-equilibrium phases. One more time you have resorted to qualitatitive
thinking and hand waiving arguments but if you try to quantitatively
describe what you stated you will soon find out that it is not as an easy
explanation as you might first think. Look, there is nothing in F = dp/dt
that specifies whether F or dp/dt happens first, there is no explicit
causality in the laws of mechanics. Your hand waiving cannot mitigate that
because it is based on naive arguments about a priori causal connections and
it is a petitio principii argument, the type of fallacy your whole model of
the world is subject to.
> > [Mike]: You have misinterpreted the geometric arguments Newton made to
> construct circular motion from infinitesimal linear motion changes. In
> modern mechanics, the limit is taken and those linear changes vanish.
> There is no linear motion of the rock in its circular path at any time
> t.
>
> Try to get the math out of your head until the physics is
> straight. We can't even begin applying limits until the motion of the
> rock approaches equilibrium. If you want causes, we have to talk about
> the pre-equilibrium stages. Then (and only then) it becomes obvious how
> cause and effect proceed after equilibrium is achieved.
>
You mean the cause and effect connection that exists in pre-equilibrium or
whatever your hand waiving implies is lost when equilibrium is reached? And
when is that done exactly? In asymptotically stable systems in time is there
a specific time that cause and effect relationships hide themshelves and are
not obvious any longer?
How is it that pre-equilibrium causal connections establish equilibrium
states without being evident from the physical laws that describe the later
phenomena? If what you say is true, then the true laws of mechanics are
those that exactly establish that transitions. But such laws cannot be
established in macrocosmic events but can be possibly part of quantum
mechanics. You have failed though to provide a quantitative system of laws
that describe such causal connections and the transitions to macrocosmic
events and I also would like to inform you that such link is an unsolved
problem in physics to date and obviously cannot be answered by your type of
hand waiving arguments.
> > [Mike[: if you stop begging the question and just look at a rock
> whirling around, can you establish cause and effect? Your "science" of
> "first causes" does not explain anything about causality because there
> is an infinite regression of causes that can be considered.
>
> Same comment.
Same answer what? Space and time in NM are infinitely divisible I would like
to inform you. Observe a physical phenomenon and try to find its "first
cause" you advocate. There is an infinite regression of causes you can think
of.
>
> > [Mike]: If you consider yourself an expert and Donald T. Greenwood a
> cheater, just read carefully the quote below from "Principles of
> Dynamics" by Greenwood:
> "The concept of force as a fundamental quantity in the study of
> mechanics has been criticized by various scientists and philosophers of
> science from shortly after Newton's enunciation of the laws of motion
> until the present time. Briefly, the idea of a force, and a field force
> in particular, was considered to be an intellectual construction, which
> has no real existence. It is merely another name for the product of mass
> and acceleration, which occurs in the mathematics of solving a problem.
> Furthermore, the idea of force as a cause of motion should be discarded
> since the assumed cause and effect relationship cannot be proved."
> (Greenwood 1965, Principles of Dynamics)
>
> I feel sorry for this confused chap. But the definition of
> force is the time rate of change of momentum, not the product of mass
> and acceleration. That latter is a derived property that holds only for
> fixed masses, but not (for example) to a rocket burning fuel. Substance
> and momentum are the two entities that we can be certain are real if
> anything is.
>
Yes right. Now you will make empty arguments about the definitions of force.
I'd like to inform you that F = dp/dt is also a derived law from a higher
variational principle.
> Just because some philosophers did not have all their
> physical concepts straight is no cause to jump to absurd conclusions,
> such as that elementary rock-rope problems cannot be described uniquely
> in terms of a sequence of causes and effects.
>
You have failed to provide such sequence other than by hand waving
argumentation.
> > [Mike]: if your first principles are not assumptions what are they?
> Self evident propositions? Experimental facts? I have explained to you
> several times that your so called first principles are plain, bold
> hypotheses that are not falsifiable and have no place in physics.
>
> The principles of physics are based on logic alone, using
> only the requirements of internal consistency and no magic allowed. The
> reasoning behind each is summarized in the article "Physics has its
> principles". They have no need of experimental verification.
> (Experiments apply to testing the laws of physics, a completely
> different category of proposition.) The principles are obviously not
> self-evident to everyone until one is forced to reason through the
> consequences of assuming the opposite. The principles are a unique
> category of human knowledge, and do not fit into any of the categories
> you named.
>
>
Try to come up with physics that will produce your principles as results not
as priori or synthetic a priori logical propositions. You underestimate the
amount of circularity and bold speculations those principles hide if assumed
a priori based on some "no magic" principle you advocate. The reason you
resort to those principles is because you have no physical model they can be
derived from. Assuming those principles hold a priori can easily lead to
accepting any absurd model of reality on top of them, as you have done in
assuming a graviton flux as the nature of gravitation. Can you start with
these simple principles:
1. All phenomena must have the same explanation in all moving reference
frames
2. The only well-defined quantities of motions are the relative ones.
If you do this, you will soon arrive at GR or some other 4-D spacetime
geometry and associated dynamics and most of your so called principles will
be conclusions from the model. But it takes a lot of effort and knowledge to
do that. As such, crackpots resort to assumptions that basically entail a
whole physics and then fit on top of them some absurd model they think it
works. This is what you have done:
1. You assume almost everything in your principles
2. You derive almost nothing from your theory.
Try the reverse. It's the scientific way.
Mike
Tom Roberts
> "Tom Van Flandern" <to...@starpower.net> wrote in message
> news:40c898aa$0$2996$61fe...@news.rcn.com...
> We are talking here about causality issues in laws of mechanics [...]
Hmmm. No modern theory of physics has the type of NAIVE causality you two are
trying to discuss.
For instance, the common notion that charge "causes" E&M
fields is unwarranted. The theory merely states how charge
and fields are inter-related.
Repeat until you understand: correlation is not causation.
Anything expressed as an equation indicates a correlation, not any sort of
"cause". Tom Van Flandern's attempts to discuss "causes" are just so much blather.
GR does have a property that is known as causality, and is not naive but is
specific, rigorous, and testable:
The values of all fields at a given point in the manifold depend
only upon the values of all fields on the intersection of the
event's past lightcone and any suitable Cauchy surface.
A rather well-known consequence of this is that no energy, mass, or information
can be transferred faster than the local speed of light.
[Without such a limit there could be no naive notions of
causality -- the "finger of God" could reach in from
infinity and do anything. All would be chaos.]
This is, of course, part and parcel of why Tom Van Flandern's claims that in GR
gravity "propagates" much faster than c are so bizarre. And so wrong.
Tom Roberts tjro...@lucent.com
shuba
> and "shuba" <tim....@eudoramail.com> writes:
>
> > [Shuba]: Is this model "completely" defined in that book? If not,
> where, when, and by whom was it "completely" defined?
>
> Yes, the model is as completely laid out in [Pushing
> Gravity: New Perspectives on Le Sage's Theory of Gravitation, M.
> Edwards, ed., Apeiron Press, Montreal (2002)] as any theory is in any
> single book. See especially my chapter and that by Slabinski, pp.
> 93-128. These two cover the basic physics and math (respectively) of the
> most complete version of the model, its unique predictions that
> differentiate it from GR, and the observational status of those. -|Tom|-
Thanks. I'll make sure to look into it in the unlikely event
that I get a favorable recommendation from someone credible.
Another easy question: Does the term "amplitude" come up in
either the physics or math portion of this complete quantum
theory, as laid out in the above publication? This is a yes/no
question; elaboration is not necessary, but go ahead if you want.
---Tim Shuba--
Bilge
>
>
>"Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>
>>> [tvf]: You are speaking here of a model for quantum entities, not a
>model of gravitation. For purposes of a complete model of gravitation,
>it suffices that the inertial mass changed. The reason for that change
>need not be known.
>
>> [Bilge]: Be serious. Your so-called "theory'' predicts the
>gravitational mass of an object that one measures as gravitational
>forces is due to shadowing (plus a lot of parameterized legerdemain). In
>any case, the deuteron is large enough that the neutron and proton
>aren't going to "shadow'' any less area when bound as a deuteron, than
>they will when separated by 1 more fermi.
>
> You have no idea what the model you are challenging is like
>because you insist upon not reading it,
You insist on not posting it. In fact, you insist on not posting an
answer to anything anyone asks. By comparison, usenet nutcase, jack sarfatti
comes up with new stuff on almost a daily basis which is more plausible
than what you have posted. I mean that to be a comparison for the sake of
perspective, not a suggestion that sarfatti posts anything credible.
>and instead you keep making false assumptions about what it must be like.
First, I have no way to know one way or the other whether my assumptions
are false, since you haven't posted anything from which I could determine
that one way or the other.
Second, if someone asks me a question, about qed or the standard model
or anything else for that matter, I can either provide the mathematics
they request or I can tell them I don't know the answer and suggest
references. If you don't know how to do the mathematics required to answer
my question, fine. It's your theory. If you can't address what I've said
any better than with toy analogies and meaningless jargon, then neither
can anyone else. In that case, you've told me all I could ever need to
know about your so-called ``theory'' and that it isn't going to answer
any questions relevant to understanding nature.
> Are you actually upset that the model had a good answer to
>your challenge?
In order for that question to arise, you would have to provide a
good answer, after which you could determine whether or not I
became upset because of that answer. In the meantime, your question
is as much idle speculation as your so-called ``theory''.
> Can any new model that challenges an existing model meet
>your criteria for being worth a look?
No. In order to challenge an existing model, a model needs to
say something about the physics it purports to explain. This might
seem unreasonable, but without a few equations here and there, it's
simply impossible to identify any relationship between some data
and the model, assuming it would even be possible to identify an
experiment that has some relationship to the model.
>>> [tvf]: Nonetheless, it so happens, because the gravitation part of
>the Le Sage-type model is so complete, it does in fact already expect
>the very phenomenon you cited.
>
>> [Bilge]: Right. I can see that your post is replete with the equations
>that make that evident... Tell me something. Over there in alternative
>physicsland, do the self-exiled dissident physicists use mathematics to
>communicate or do they all just sit around and tell stories about the
>day relativity will be crushed by the weight of its predictive power?
>
> Well, that's a good question, because apparently many of our
>communication troubles stem from the answer to that very point.
>
> Pure math solves problems that are not yet known to exist in
>nature, or at least not in any useful applications.
Pure math solves nothing but mathematical questions. Applying math
to physics is not pure math. Physicists have to do that in order to
perform experiments and compare data to theories. Would you fly on an
airplane that was designed by analogies and handwaving? If so, then
I can safely assume asking any more would be an exercise in futility,
(not that it hasn't been such an exercise, so far).
> Applied physics is
>intended to aid in the solution to existing problems and useful
>applications.
No one but the kooks on usenet have ever accused me of being too
mathematical. I'm an experimentalist. Your appeal to some sort of
physicality argument over my request for some mathematics is laughable.
You are supposed to be making a case for a theory which you are advocating.
If you can't present it in enough detail to satisfy an experimentalist,
you might as well throw in the towel and find something else to occupy
your time.
Mike
> On 6/10/2004 3:15 PM, Mike wrote:
> > "Tom Van Flandern" <to...@starpower.net> wrote in message
> > news:40c898aa$0$2996$61fe...@news.rcn.com...
> >> You asked for the cause. I answered. [...]
> > We are talking here about causality issues in laws of mechanics [...]
>
> Hmmm. No modern theory of physics has the type of NAIVE causality you two
are
> trying to discuss.
>
I am not trying to discuss causality but just to rebut the hand waving
arguments Van Flandern is offering in support of his notions.
> For instance, the common notion that charge "causes" E&M
> fields is unwarranted. The theory merely states how charge
> and fields are inter-related.
>
I fully agree.
> Repeat until you understand: correlation is not causation.
>
Obviously, this is the point I'm trying to make to Van Flandern. Physical
laws such as F = dP/dt denote correlation and no causal connections can be
infered from them.
> Anything expressed as an equation indicates a correlation, not any sort of
> "cause". Tom Van Flandern's attempts to discuss "causes" are just so much
blather.
>
Van Flandern makes some naive arguments about causality. He fails to see
that these arguments entail a host of hypotheses he cannot prove and also
allude to certain physics and metaphysics that are not grounded or supported
by any laws.
>
> GR does have a property that is known as causality, and is not naive but
is
> specific, rigorous, and testable:
>
> The values of all fields at a given point in the manifold depend
> only upon the values of all fields on the intersection of the
> event's past lightcone and any suitable Cauchy surface.
>
This worths 10 cents IMO. This type of argument implies a space-time
structure that is much richer than GR's, i.e. it includes many more
possibilities in the domain of which GR may be a simple heuristic. More
importantly, it is a posteriori explanation.
> A rather well-known consequence of this is that no energy, mass, or
information
> can be transferred faster than the local speed of light.
>
A priori or a posteriori? While you make up your mind as to whether
postulates are derived as a conclusion in a theory I toss your 10 cents to
see if there is a bias for heads or tails.
> [Without such a limit there could be no naive notions of
> causality -- the "finger of God" could reach in from
> infinity and do anything. All would be chaos.]
>
>
> This is, of course, part and parcel of why Tom Van Flandern's claims that
in GR
> gravity "propagates" much faster than c are so bizarre. And so wrong.
>
Well, Van Flandern likes the naive interpretation of GR offered as a
transition from NM to Relativistic dynamics in early years.
The gravitational field in such naive interpretation of GR is the system of
components into
which the metrical field is resolved. The naive interpretation arises from
the normal orthogonal values of the gravitation potential field gmunu,
expressed as the sum of an inertial field gmunu(bar) and an attributed
gravitational potential field gamma(munu) This was done to adopt a
terminology that fitted Newtonian mechanics so early students of GR could
comprehend it but created some of the difficulties Van Flandern seems to
have because it is a wrong interpetation resulting from this resolution of
the metrical field into an inertial and a gravitational field.
Mike
>
> Tom Roberts tjro...@lucent.com
>
Tom Roberts
>> are trying to discuss.
>
> I am not trying to discuss causality but just to rebut the hand waving
> arguments Van Flandern is offering in support of his notions.
Yes. I had intended to mention that you apparently didn't need this
lesson, but it got omitted. Van Flandern sure does.
>>GR does have a property that is known as causality, and is not naive but
>> is specific, rigorous, and testable:
>>The values of all fields at a given point in the manifold depend
>>only upon the values of all fields on the intersection of the
>>event's past lightcone and any suitable Cauchy surface.
>>
> This worths 10 cents IMO. This type of argument implies a space-time
> structure that is much richer than GR's, i.e. it includes many more
> possibilities in the domain of which GR may be a simple heuristic.
I'm not quite sure what you are trying to say. Certainly GR has more
content than I mentioned: it describes how to determine the values of
the fields at that point from their values on that region of the past
Cauchy surface.
AFAICT a "much richer spacetime structure" is irrelevant, as GR has one
that is rich enough. And I'm no so sure that GR is more limited than
your "richer structure" because of that "any" in there -- that is an
incredibly strong constraint, as is the recursive application of this
principle to any point on any such surfaces....
> More
> importantly, it is a posteriori explanation.
I'm not sure what you mean by that. And I probably don't care (all
physics is "a posteriori", AFAICT)....
>>A rather well-known consequence of this is that no energy, mass, or
>> information can be transferred faster than the local speed of light.
>>
> A priori or a posteriori? While you make up your mind as to whether
> postulates are derived as a conclusion in a theory I toss your 10 cents to
> see if there is a bias for heads or tails.
Ah. I can see I definitely don't care -- I am interested in physics....
Tom Roberts tjro...@lucent.com
Tom Van Flandern
Bilge.
"Mike" <ele...@yahoo.gr> writes:
>> [tvf]: You asked for the cause. I answered. There certainly was
linear motion of the rock prior to the circular motion because the rope
did not always have tension on it. Moreover, the rope would never have
tension on it if it did not initially start moving linearly, thereby
stretching the rope and creating tension. You seem to be in denial of
the obvious -- the sequential order in which cause and effect proceed.
No matter how many confused authors you cite, when it comes to
causality, reason trumps all opinions.
> [Mike]: You are becoming arrogant here, calling world renowned experts
"confused authors" just to support your naive view which arises from a
simplistic and shallow interpretation of physical phenomena.
I repeat: Reason trumps all opinions. Either you or one of
your "world renowned experts" has a counterargument, or you don't. In
science, logic, experiment, and observation count; the number and weight
of experts does not.
From where I stand, what you call "arrogant" I see as trying
to pin you down. What exactly is wrong with my answer to your challenge?
What I'm getting in response so far is all manner of dodging and weaving
(changes of subject and insult after insult, such as "arrogant", "naïve"
, "simplistic", "shallow" in the above sentence alone). And aren't you
the one who complained earlier about ad hominem attacks? How about
cleaning up your act and sticking to the scientific subject without any
side remarks about me personally?
> [Mike]: We are talking here about causality issues in laws of
mechanics and not subjective interpretations of what happens during
transients and non-equilibrium phases. One more time you have resorted
to qualitative thinking and hand waving arguments but if you try to
quantitatively describe what you stated you will soon find out that it
is not as an easy explanation as you might first think. . Your hand
waving cannot mitigate that because it is based on naive arguments about
a priori causal connections and it is a petitio principii argument, the
type of fallacy your whole model of the world is subject to.
Cases in point: Dodging and weaving instead of responding to
my logical argument. Everything here is about me instead of the issue on
the table. Instead of just making abstract claims of logical fallacies
without any obvious referent or justification, how about providing a
specific syllogism I used and pointing out how it qualifies as a petitio
principii argument.
> [Mike]: Look, there is nothing in F = dp/dt that specifies whether F
or dp/dt happens first, there is no explicit causality in the laws of
mechanics.
Uh oh. Math has no intelligence. None of the principles of
physics appear in mathematical form. Yet they are essential to
describing and understanding physical processes. If this is news to you,
you have some catching up to do. You cannot ask questions about
causality and expect to find answers in the laws of mechanics. Such
answers exist in the principles of physics only, not in its laws.
As nearly as I can tell, that answer is the bottom line to
this whole discussion. You seem to have been looking for answers to
causality in physical laws and math, where those answers do not exist.
And when directed to the principles of physics for answers, you rebel
because these appear to you to be "qualitative thinking and hand waving
arguments" that cannot be made quantitative. Now it is certainly true
that the principles are unrelated to the laws and cannot be described in
mathematical form. But they are rigorous nonetheless because they are
based on logic alone, and any violation would be a form of magic or
require a miracle or invoking the supernatural -- things forbidden in
physics.
If you think any of the principles is not logical, then I
would like to see your argument to that effect. Failing that, the
principles provide answers and constraints on models that can be found
nowhere else. Without those constraints, people would waste unlimited
amounts of time pursuing models that are physically impossible.
>> [tvf]: Try to get the math out of your head until the physics is
straight. We can't even begin applying limits until the motion of the
rock approaches equilibrium. If you want causes, we have to talk about
the pre-equilibrium stages. Then (and only then) it becomes obvious how
cause and effect proceed after equilibrium is achieved.
> [Mike]: You mean the cause and effect connection that exists in
pre-equilibrium or whatever your hand waving implies is lost when
equilibrium is reached? And when is that done exactly? In asymptotically
stable systems in time is there a specific time that cause and effect
relationships hide themselves and are not obvious any longer? How is it
that pre-equilibrium causal connections establish equilibrium states
without being evident from the physical laws that describe the later
phenomena?
After any system reaches thermal equilibrium, how can you
tell if it was previously hotter or colder? After any system reaches
dynamical equilibrium, how can you tell what path it took to get there?
Which came first, the chicken or the egg? Again, you betray
unfamiliarity with an ordinary physics concept. Equilibrium by
definition is a state in which some previously variable quantity has
ceased to vary. Given a function, we can derive a limit. But given just
the limit, we cannot derive the function whose limit it is. This is the
difference between deduction and induction -- the former is unique, the
latter is not.
> [Mike]: If what you say is true, then the true laws of mechanics are
those that exactly establish that transitions. But such laws cannot be
established in macrocosmic events but can be possibly part of quantum
mechanics. You have failed though to provide a quantitative system of
laws that describe such causal connections and the transitions to
macrocosmic events and I also would like to inform you that such link is
an unsolved problem in physics to date and obviously cannot be answered
by your type of hand waving arguments.
Your generalizations are mistaken. Read my book, "Dark
Matter, Missing Planets and New Comets", to see an entire cosmology
derived deductively from first principles. This does indeed provide "a
quantitative system of laws that describe such causal connections". It
is qualitative in the derivation, and becomes quantitative when compared
with observation and experiment, which allows us to determine values or
set limits for the parameters of the qualitative, deductive model.
Or continue to believe that it is an unsolved problem, as
you wish. I understand that not knowing some things can be comforting.
> [Mike]: Space and time in NM are infinitely divisible I would like to
inform you. Observe a physical phenomenon and try to find its "first
cause" you advocate. There is an infinite regression of causes you can
think of.
Your challenge did not ask for me to trace causes back
infinitely far. You just asked which was the first cause in the case of
a rock twirled on a rope. I answered. You have said nothing about the
correctness of my answer, but have persisted in arguing, apparently to
insist that no possible answer exists.
In the light of my specific answer to your challenge, what
problem remains to be addressed? Where are you headed?
> [Mike]: Try to come up with physics that will produce your principles
as results not as priori or synthetic a priori logical propositions. You
underestimate the amount of circularity and bold speculations those
principles hide if assumed a priori based on some "no magic" principle
you advocate.
I address that issue head on and break the circularity. See
chapter 20 of my book. I also referred you to my published technical
paper on the principles of physics. If you had a more specific question
or challenge, I could provide a more specific answer.
> [Mike]: The reason you resort to those principles is because you have
no physical model they can be derived from. Assuming those principles
hold a priori can easily lead to accepting any absurd model of reality
on top of them, as you have done in assuming a graviton flux as the
nature of gravitation.
I made no assumptions, as I've already told you several
times. Read the book and see for yourself. Or point to where in the
paper on "principles" that I made an assumption. The principles come
from reasoning alone, and conform to the prohibition against magic that
defines physics. (Even for that, a reason is provided in the paper.)
Circularity is broken by showing that assuming any of the principles is
false leads to error or magic.
and "Tom Roberts" <tjro...@lucent.com> writes:
> [Roberts]: GR does have a property that is known as causality, and is
not naive but is specific, rigorous, and testable: "The values of all
fields at a given point in the manifold depend only upon the values of
all fields on the intersection of the event's past lightcone and any
suitable Cauchy surface." A rather well-known consequence of this is
that no energy, mass, or information can be transferred faster than the
local speed of light.
If your "well-known consequence" were true, then GR would
not be falsified because gravity is an example of the transfer of
momentum faster than the local speed of light; for example, in binary
pulsars.
However, your "consequence" is not true in GR, but only in
SR, which is now falsified on that account in favor of LR. GR, by
contrast, has an infinite propagation speed for the transfer of
gravitational momentum built in, as my several published papers show.
(Have you read them yet?) Please do comment on the substance of that
published argument, rather than just offering declarations of your
personal opinions on the grounds that they are "well known". Many "well
known things" are nonetheless wrong.
and "shuba" <tim....@eudoramail.com> writes:
> [shuba]: Does the term "amplitude" come up in either the physics or
math portion of this complete quantum theory, as laid out in the above
publication? This is a yes/no question; elaboration is not necessary,
but go ahead if you want.
Yes.
and "Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>> [tvf]: You have no idea what the model you are challenging is like
because you insist upon not reading it,
> [Bilge]: You insist on not posting it.
I've written a book about it, and the book "Pushing Gravity"
is also about the gravitational parts. You expect me to post a book or
two here? I've answered most of your questions with specific citations
to where you can read about the answers, their derivation, and the
background that led to them. If you want specific details, ask specific,
limited questions and I'll answer here.
You give me the impression that you really have no interest
in being exposed to anyone's new ideas if they challenge something you
think you already know. I am reminded of this quote from Stephen Jay
Gould: "The most erroneous stories are those we think we know best - and
therefore never scrutinize or question." But you happen to be having a
discussion with a person who works for an organization that scrutinizes
and questions everything in the field of astronomy.
>> [tvf]: Can any new model that challenges an existing model meet your
criteria for being worth a look?
> [Bilge]: No. In order to challenge an existing model, a model needs to
say something about the physics it purports to explain. This might seem
unreasonable, but without a few equations here and there, it's simply
impossible to identify any relationship between some data and the model,
assuming it would even be possible to identify an experiment that has
some relationship to the model.
Yes, you are correct. That does seem unreasonable to me.
Many of my papers are counter-examples to your expectations.
> [Bilge]: You are supposed to be making a case for a theory which you
are advocating. If you can't present it in enough detail to satisfy an
experimentalist, you might as well throw in the towel and find something
else to occupy your time.
I no longer have any idea what specific thing you might want
to see that is not of book length. So I'll just take a wild guess. How
about the new equation of motion for the Le Sage-type gravity model? I
use Math Type for equations, so I'll have to give you a link. Let me
know if you were willing and able to follow this link, or if any of the
symbol meanings are not obvious. I assume that r, v, and c and e (base
for natural logarithms) are obvious, <rho> is density, M is source mass,
arrows indicate vectors, dots indicate time derivatives, and I think
everything else is explained. See:
http://metaresearch.org/public/LeSage-ulg.asp.
Is that the kind of thing you are looking for? Details for
the five experimental tests of this equation are in the PG book. -|Tom|-
Tom Van Flandern
should have been "now". Please excuse the typo, which changed the
meaning of the sentence. -|Tom|-
Mike
>
> As nearly as I can tell, that answer is the bottom line to
> this whole discussion. You seem to have been looking for answers to
> causality in physical laws and math, where those answers do not exist.
> And when directed to the principles of physics for answers, you rebel
> because these appear to you to be "qualitative thinking and hand waving
> arguments" that cannot be made quantitative. Now it is certainly true
> that the principles are unrelated to the laws and cannot be described in
> mathematical form. But they are rigorous nonetheless because they are
> based on logic alone, and any violation would be a form of magic or
> require a miracle or invoking the supernatural -- things forbidden in
> physics.
>
> If you think any of the principles is not logical, then I
> would like to see your argument to that effect. Failing that, the
> principles provide answers and constraints on models that can be found
> nowhere else. Without those constraints, people would waste unlimited
> amounts of time pursuing models that are physically impossible.
>
You follow a certain strategy always that is not very legitimate. First you
ignore the arguments, you do not respond and resort to hand waving and ad
hominen attacks. Your opponents do not have a choice but to respond to them.
The, you reverse the positions and accuse your opponents of attacking you.
The arguments you are asking for were stated at the beginning of the
discussion but you do not have any answers to offer. I repeat your dogma
below:
1. Every effect has an antecedent, proximate cause
2. No time reversal
3. No true action at a distance
4. No creation ex nihilo
5. No demise ad nihil
6. The finite cannot become infinite
Are you so naive to assert that causality issues in mechanics are just
resolved by stating a causality principle #1? Answering a fundamental
question by just stating a principle, or dogma to that effect, you have not
achieved anything but just to show that type of naive science you are
proposing. I repeat again: are you here to assert that questions about
causality are resolved if we juts state a principle that enforces causality?
What you have missed in you so called "principle", which is actually
garbage, is that there is nothing primitive about it. This is because you
already use the terms "effect" and "cause" in the statement of the
principle. Before one can accept the principle, one must know how to
differentiate between cause and effect. But a general principle of causality
must be such that it not only defines the relationship between cause and
effect but allows us to differentiate between cause and effect. This is so
basic and shows how naive your answers are.
Thus, in the whirling rock example, your principle is useless because even
if there is some cause and effect, the distinction cannot be established a
priori. It is a meaningless statement your principle #1. You just assume the
cause and effect and then you claim that according to your principle they
are causally connected. But that's a plain tautology which leads to a
petitio principii.
My answer is that such science is no different than religion. Serious
science will look for primitive relations or correlations that will support
or lead to your principles and render them general. You instead choose the
naive, senseless approach of resolving the issue by stating principles, like
#1 above.
Since we are operating at a very different level of thinking and approach to
scientific issues, I recommend we drop this conversation because it leads
nowhere. I simply find it impossible to accept principles like yours a
priori and call that a science. My type of science is the one that will
offer your principles are conclusions from its model. As you see, we are
diametrically opposed here. From one side there is your dogma, and from the
other the search for answers based on demonstration.
Mike
Bilge
>
>>> [tvf]: You have no idea what the model you are challenging is like
>because you insist upon not reading it,
>
>> [Bilge]: You insist on not posting it.
>
> I've written a book about it, and the book "Pushing Gravity"
>is also about the gravitational parts. You expect me to post a book or
>two here?
No, I expect you to post something other than lengthy analogies. What I
originally requested would have been far less a book than the responses
you've given so far without coming any closer to telling me anything.
>I've answered most of your questions with specific citations
>to where you can read about the answers, their derivation, and the
>background that led to them. If you want specific details, ask specific,
>limited questions and I'll answer here.
I have read the citations which are available online and made specific
comments about them. I'll elaborate further below.
> You give me the impression that you really have no interest
>in being exposed to anyone's new ideas if they challenge something you
>think you already know.
And how exactly could you draw this conclusion since you've given
me no new idea to consider, much less challenge anything but your
own misconceptions about relativity? If you had some idea that solved
some problem, I'd consider it. But you don't.
I've read whatever references are online from among the ones you've
cited. In the articles you've written, you make many misstatements
about relativity and in general go to a lot of effort to misconstrue
relativity into a caricature of the theory.
If what you say regarding relativity is not what relativity says about
relativity, what possible reason could I have for being interested in how
you solve problems for a theory that doesn't exist? The only point upon
which I'd agree with you is that, if relativity were anything like your
description of relativity, I wouldn't consider it viable either. But, you
also don't seem particularly interested in arguing against relativity as
physicists understand it.
>I am reminded of this quote from Stephen Jay
>Gould: "The most erroneous stories are those we think we know best - and
>therefore never scrutinize or question."
Try spending less time finding quotes of which you are reminded and
which are irrelevant to addressing physics, unless you are hell bent
on reinforcing my point that you don't post any physics or address
anything that has been said.
>But you happen to be having a discussion with a person who works for
>an organization that scrutinizes and questions everything in the field
>of astronomy.
Then why have you failed to scrutinize relativity well enough to
write your web pages without making blatant errors in your explanations?
You can tell me how much you scrutinize and question everything all you
like, but what you actually write and the care you take in constructing
your argument is a better indicator of whether you put those principles
into practice.
>> [Bilge]: No. In order to challenge an existing model, a model needs to
>say something about the physics it purports to explain. This might seem
>unreasonable, but without a few equations here and there, it's simply
>impossible to identify any relationship between some data and the model,
>assuming it would even be possible to identify an experiment that has
>some relationship to the model.
>
> Yes, you are correct. That does seem unreasonable to me.
>Many of my papers are counter-examples to your expectations.
Then you should be addressing philosophers, not physicists, although I
think philosophers will have higher standards than your articles currently
meet. Physics is about understanding nature and quantifying things is
essential to that goal. Nature tells us how nature works, regardless of
whether or not that offends our personal beliefs in how nature should do
things. Your ``principles of physics'' are prime examples of one of your
papers in which you are imposing your own ideas about what is and isn't
sensible on nature. Personally, I don't even most of the principles you
consider beyond question to be sensible.
> I no longer have any idea what specific thing you might want
>to see that is not of book length.
I'm sure you don't after all the time you've spend digressing.
>So I'll just take a wild guess. How
>about the new equation of motion for the Le Sage-type gravity model?
How about a derivation of le sage gravity that starts from the
most fundamental assumptions?
[...]
>everything else is explained. See:
>http://metaresearch.org/public/LeSage-ulg.asp.
>
> Is that the kind of thing you are looking for?
Thanks, but not really. I actually don't really even care about
equations that are claimed to be the end result. I only care about the
fundamental assumptions and the equations which state those assumptions
mathematically. Contrary to your assumptions that I have some fascination
with equations for their own, sake, what I care about first are the
assumptions that represent the physics. What I care about second is having
those assumptions clearly defined mathematically, so that there is no
question whether or not something follows from the assumptions. What I
care about third is physical justification for any approximations made to
obtain a result used to claim agreement with data. If you really don't
understad the necessity of laying down some assumptions that define
your theory and commtting yourself to those assumptions by quantifying
the physical meaning of those assumptions in the theory, I really don't
think I could explain it to you.
Tom Van Flandern
"Mike" <ele...@yahoo.gr> writes:
>> [tvf]: If you think any of the principles [of physics] is not
logical, then I would like to see your argument to that effect. Failing
that, the principles provide answers and constraints on models that can
be found nowhere else. Without those constraints, people would waste
unlimited amounts of time pursuing models that are physically
impossible.
> [Mike]: You follow a certain strategy always that is not very
legitimate. First you ignore the arguments; you do not respond and
resort to hand waving and ad hominem attacks. Your opponents do not have
a choice but to respond to them. Then, you reverse the positions and
accuse your opponents of attacking you.
Translation: You are unfamiliar with the use of logic to set
constraints on math and philosophy, so you dismiss it with a hand wave
as "hand-waving and ad hominem". Note that you provide no examples of
either. Having reversed my argument and turned it back on me by
declaration alone, you ignore that I listed specific examples of your
evasions and ad hominem arguments. As one example from my previous post,
I said in response to one of your declarations: "What I'm getting in
response so far is all manner of dodging and weaving (changes of subject
and insult after insult, such as 'arrogant', 'naïve', 'simplistic',
'shallow' in your above sentence alone)."
That is what I mean by providing examples to back up claims.
I stand by my list of specifics over your broad declaratory accusations
without examples or specifics.
>> [tvf list of principles of physics]:
1. Every effect has an antecedent, proximate cause
2. No time reversal
3. No true action at a distance
4. No creation ex nihilo
5. No demise ad nihil
6. The finite cannot become infinite
> [Mike]: Are you so naive to assert that causality issues in mechanics
are just resolved by stating a causality principle #1?
None of these principles is declaratory. Each is a summary
of the reasoned argumentation presented in the publication I cited, also
available on the web at
http://metaresearch.org/cosmology/PhysicsHasItsPrinciples.asp. In the
briefest possible terms, the reason why these principles must be
accepted in physics (even if not in math or philosophy) is because their
opposite is a form of magic, which is forbidden to be used in physical
models because invoking magic is the equivalent of "God made it that
way", which ends further inquiry without either understanding or the
ability to predict.
The causality principle is an obvious case in point. I
always identified with Newton's way of describing "action at a distance"
(an obvious violation of the "proximate" part of the causality
principle):
"It is inconceivable that inanimate gross matter, without
the mediation of something immaterial, might affect some other matter
with no mutual contact, as it should happen if gravitation (in the sense
proposed by Epicurus) were essential and inherent to matter. This is one
of the reasons why I do not wish innate gravity to be attributed to me.
For me it is totally absurd that gravitation should be innate, inherent
and essential to matter, so that a body might act upon another body from
a distance, through vacuum, without the mediation of something else,
through which its action and force should be transported from one to the
other; it is so absurd that I believe no man with philosophical
questions in mind might believe it. Gravity must be caused by an agent
constantly acting according to certain laws; but I should let my readers
decide whether such agent is material or immaterial." (Newton Optics,
edition of 1717, Foreword)
So is "action at a distance" as described by Newton
conceivable or inconceivable to you? If the latter, you accept half of
the causality principle already. But if it is conceivable, your defense
of "action at a distance" in physics (not in math or philosophy) will
make most interesting reading.
> [Mike]: Answering a fundamental question by just stating a principle,
or dogma to that effect, you have not achieved anything but just to show
that type of naive science you are proposing. I repeat again: are you
here to assert that questions about causality are resolved if we just
state a principle that enforces causality?
Is your definition of "naïve science" equivalent to my
definition of "science without magic"? If so, I would have to plead
guilty to advocating "naïve science". Reason dictates that, in physical
models, the causality principle must be respected, because the
alternative is to introduce magic in some step of the model.
That said, physics is all about determining the actual
agents of causality, which are often initially unobservable until better
theory and instrumentation are developed. What I flatly reject here is
your assertion (repeated many times now) that the principles of physics
are products of assertion rather than reasoning. Perhaps this form of
reasoning is unfamiliar to you, but such principles nonetheless have
been debated by scholars for centuries. And there exists a core of
thoughtful persons who could never accept in a serious way any theory
that needed a violation of one of them to remain viable. So anyone who
hopes to communicate with such "naïve" persons will need to address this
issue head on: Cite an example of a violation of a principle that does
not involve magic, or a reason why magic should be re-admitted into
physics.
Please do not duck this direct challenge.
> [Mike]: . your so called "principle", which is actually garbage. But a
general principle of causality must be such that it not only defines the
relationship between cause and effect but allows us to differentiate
between cause and effect. This is so basic and shows how naive your
answers are.
Look up the word "antecedent". The cause is antecedent to
the effect (meaning it happens first). For example, for a rope and rock,
the rock tries to move linearly, which stretches the rope. That creates
tension in the rope. (Cause and effect.) Then the tension in the rope
rises until the material strength of the rope halts the stretching, and
the rope pulls back on the rock, causing its motion to deviate from
linear. (Cause and effect.)
Instead of simply sputtering and hurling insults ("garbage",
"naïve"). Please direct your attention to this example and discuss in
clear language what you see as wrong with this application of the
causality principle. Stick to physics. You have no legitimate need to
make off-topic assertions about the messenger, his motives, ancestry, or
competence.
> [Mike]: You just assume the cause and effect and then you claim that
according to your principle they are causally connected. But that's a
plain tautology which leads to a petitio principii.
The motion of the rock carries the rope with it, which
stretches the rope because it is anchored at its other end, which makes
tension appear in the rope. The tension appears only when the attached
rock attempts to move linearly, and is released when the rock stops
moving. Because of this, because the motion of the rock is linear in the
absence of the rope, and because the rock and rope are in contact with
the rope moving only when the rock moves, these meet the necessary and
sufficient conditions for a causal relationship for most physicists. How
would you propose to test and verify your hypothesis that these actions
are not related as cause and effect, but are instead presumably
coincidental?
When we are born, we arrive with little knowledge or
experience of the natural world. It might have been the case that
material things appeared spontaneously from nothingness or suddenly
vanished into nothingness. It might have been the case that finite
things could collect and become infinite. It might have been the case
that time could flow backwards, or that effects did not need causes, or
that causes could produce their effects at a distance without
intermediaries. But as we grow up and learn to reason, we begin to
realize that such things are impossible and require miracles. So the
adult mind trained in reasoning must eventually conclude (in any of the
preceding scenarios) that the world is not as it appears. Some possible
explanations for such behavior are:
** (1) These things are only appearances caused by limitations of our
abilities to observe what is really happening.
** (2) The world is a holodeck illusion created by more advance beings
than ourselves.
** (3) A Supernatural Being made it that way. [This is indistinguishable
from (2) unless the Supernatural Being chooses to reveal Him/Herself to
us.]
At this point in the existence of humanity, we have yet to
observe any phenomenon that cannot be explained by (1). So we have no
need of (2) or (3) as yet. This means the principles of physics remain
valid, and may therefore be freely invoked to aid our understanding of
nature and to falsify models that violate them. If you do not agree,
please specify a definite violation of a principle of physics (as
opposed to a theory or equation that requires such a violation), or
state precisely what you find disagreeable about this whole line of
reasoning.
Your "petitio principii" argument is not applicable here. It
is logically valid (not fallacious) to assume the opposite of what one
is trying to prove and show that the opposite leads to an unacceptable
outcome (e.g., requiring magic or a miracle). Again, even if you are
unfamiliar with this way of reasoning, that does not make it any less
valid or compelling.
> [Mike]: Since we are operating at a very different level of thinking
and approach to scientific issues, I recommend we drop this conversation
because it leads nowhere. I simply find it impossible to accept
principles like yours a priori and call that a science. My type of
science is the one that will offer your principles are conclusions from
its model. As you see, we are diametrically opposed here. From one side
there is your dogma, and from the other the search for answers based on
demonstration.
Despite your words, it is not the principles you are
refusing to accept, but that they are products of reasoning such as the
preceding. Because you are unaccustomed to reasoning at this fundamental
level, you are insisting that the principles are dogma when they are
not. So here again is my challenge: Take any of the principles (your
choice) and outline a procedure that could possibly arrive at that
principle as the "conclusion from a model". What could such a model
possibly be based upon? I'm asking about possibilities here, not
practicalities. Once you see that principles cannot be conclusions from
models, perhaps then you might be willing to take a second look at the
only way we *can* arrive at them: Their opposites require miracles.
and "Bilge" <dub...@radioactivex.lebesque-al.net> writes:
> [Bilge]: In the articles you've written, you make many misstatements
about relativity and in general go to a lot of effort to misconstrue
relativity into a caricature of the theory.
You provide no examples, no clarifications, no information
of any form that would help me or anyone else learn from such "mistakes"
as you assert exist in my papers. This makes your assertions useless. In
the meantime, despite often encountering referees with your same outlook
initially, I continue to get my papers peer-reviewed and published
because most such claims have proved indefensible in the opinion of
neutral editors.
I think you are mischaracterizing an alternative
interpretation of equations as a misstatement about the theory of
relativity itself. If you mistakenly believed that the Lorentz
transformation equations of SR or the metric solutions of the field
equations of GR had only one physical interpretation, then your claims
would be understandable. However, that is not the case. Standard GR has
two known physical interpretations, and even such notables as Einstein
himself, Dirac, and Feynman preferred the field interpretation over the
geometric interpretation. And in SR, the Lorentz interpretation has now
won out over the Einstein interpretation.
So are my published articles to that effect mistaken in a
way that you can successfully argue, or are we dealing with a limitation
of your own knowledge about the physical implications of relativity?
Neither of us nor other readers can tell unless you engage this issue
with specifics.
> [Bilge]: Then why have you failed to scrutinize relativity well enough
to write your web pages without making blatant errors in your
explanations? You can tell me how much you scrutinize and question
everything all you like, but what you actually write and the care you
take in constructing your argument is a better indicator of whether you
put those principles into practice.
This is another useless and self-serving assertion. Where is
an example? Or do you hesitate to be specific because anything you use
as an example just might be successfully countered, thereby undermining
your position? Certainly, I have no choice but to assume the latter in
the presence of unfounded assertions lacking in specifics. From your
words, There is nothing I can learn, and no one else reading this can
judge whether you have a point or are just pontificating. Specifics,
please.
> [Bilge]: Personally, I don't even [think] most of the principles you
consider beyond question to be sensible.
Um.okay. Again, a specific example of something non-sensible
about a principle of physics, and your reasoning to support it, would be
nice -- assuming you do have a reasoned position rather than a personal
belief system.
>> [tvf]: I no longer have any idea what specific thing you might want
to see that is not of book length.
> [Bilge]: I'm sure you don't after all the time you've spend
digressing.
You just missed another opportunity to provide an example,
as I did just below.
>> [tvf]L So I'll just take a wild guess. How about the new equation of
motion for the Le Sage-type gravity model?
> [Bilge]: How about a derivation of le sage gravity that starts from
the most fundamental assumptions?
That is in Slabinski's chapter of the book "Pushing Gravity"
. The derivation is several pages, is by another author, and is
copyrighted by the publisher, so I can't scan and post pages here for
your benefit. Because most useful knowledge is not yet on the internet,
someone invoking a blanket refusal to look in published books and papers
because their content is not available on the web would get that person
a failing grade in one of my classes.
There's no need to reply unless you wish to open a specific
scientific issue for debate. The fact that you and I don't see eye to
eye about how to do science in general and how to best interpret
relativity in particular, or even about how to remedy ignorance, is no
longer a secret. :-) -|Tom|-
Bilge
>
>> [Bilge]: In the articles you've written, you make many misstatements
>about relativity and in general go to a lot of effort to misconstrue
>relativity into a caricature of the theory.
>
> You provide no examples, no clarifications, no information
>of any form that would help me or anyone else learn from such "mistakes"
>as you assert exist in my papers.
examples, taken verbatim from the articles you've referenced, the most
recent of which was not more than a couple of responses back.
>This makes your assertions useless.
OK, so it's in character with what you post. What's your point, if
it isn't that I'm addressing what you write in an appropriate fashion?
>the meantime, despite often encountering referees with your same outlook
>initially, I continue to get my papers peer-reviewed and published
>because most such claims have proved indefensible in the opinion of
>neutral editors.
See your previous comments regarding ``appeal to authority'' the
last time you posted that sort of remark and I shot it down.
Then look up hypocrisy, legerdemain, deceit and dishonest.
> I think you are mischaracterizing an alternative
>interpretation of equations as a misstatement about the theory of
>relativity itself.
An alternative interpretation of relativity is no longer relativity,
even if you managed to get the content correct, which you don't.
>If you mistakenly believed that the Lorentz
>transformation equations of SR or the metric solutions of the field
>equations of GR had only one physical interpretation, then your claims
>would be understandable. However, that is not the case.
I never said that it was the case and you know it. What I said was
that you have misconstrued relativity in order to argue against it.
This has nothing to do with any interpretation of the equations. It
has to do with making deliberately incorrect statements about the
interpretation of those equations called special relativity.
[...]
> So are my published articles to that effect mistaken in a
>way that you can successfully argue, or are we dealing with a limitation
>of your own knowledge about the physical implications of relativity?
>Neither of us nor other readers can tell unless you engage this issue
>with specifics.
You've been given specifics and what you've done is stalled for several
posts and now claimed I've never given you anything specific. All you
are doing is going in circles to evade all requests that post something
substantive. As soon as I would repost the comments you say I didn't
make, you would accuse me of not discussing the theory you won't post.
>> [Bilge]: Then why have you failed to scrutinize relativity well enough
>to write your web pages without making blatant errors in your
>explanations? You can tell me how much you scrutinize and question
>everything all you like, but what you actually write and the care you
>take in constructing your argument is a better indicator of whether you
>put those principles into practice.
>
> This is another useless and self-serving assertion.
Self-serving doesn't necessarily imply false.
>Where is
>an example? Or do you hesitate to be specific because anything you use
>as an example just might be successfully countered, thereby undermining
>your position?
I've posted specific examples each time you've given an online
reference. Just because you found it convenient to ignore those
examples, doesn't mean the examples weren't posted.
>Certainly, I have no choice but to assume the latter in the presence
>of unfounded assertions lacking in specifics.
Correction. You have no choice but to make false statements because you
don't consider having any honest ones you could make, blown away by the
facts, to be a choice.
[...]
>> [Bilge]: Personally, I don't even [think] most of the principles you
>consider beyond question to be sensible.
>
> Um.okay. Again, a specific example of something non-sensible
>about a principle of physics, and your reasoning to support it, would be
>nice -- assuming you do have a reasoned position rather than a personal
>belief system.
Mike provided you with an excellent analysis of your so-called principles.
[...]
>> [Bilge]: How about a derivation of le sage gravity that starts from
>the most fundamental assumptions?
>
> That is in Slabinski's chapter of the book "Pushing Gravity"
Naturally, you complain about not asking you something specific,
and when I ask you something specific, you evade it. The reason you
are a crackpot is not because you are promoting some alternative
to standard physics. You are a crackpot because you can't support
your alternative with a scientific argument and resort to
evasion, deceit and hypocrisy as your method of ``proof''.
>. The derivation is several pages, is by another author, and is
>copyrighted by the publisher, so I can't scan and post pages here for
>your benefit.
I didn't ask you to scan it. I asked you post the mathematics. If
you don't want to do that, fine. I was certain that would be the case
and I wasn't expecting you to post anything other than exactly what
you posted - an evasion to deal with any of the specifics about which
you've whining.
>Because most useful knowledge is not yet on the internet,
>someone invoking a blanket refusal to look in published books and papers
>because their content is not available on the web would get that person
>a failing grade in one of my classes.
Sincce you seem to thrive on irrelevant and trite analogies to avoid
the subject at hand try this one: Requiring your students to purchase a
book in which you have a financial interest to obtain a passing grade,
is called a conflict of interest, which I would equate to selling the
opportunity to pass your course. You wouldn't have the opportunity
to assign a grade before I had you fired for being unethical and talked
with the district attorney to see if you could be charged with a crime.
> There's no need to reply unless you wish to open a specific
>scientific issue for debate.
You're not only an idiot, you are shamelessly dishonest. How can you
possibly say that you have any interest at all in anything scientific,
when you just spent the entire article trying to avoid it? In the
paragraph just before this one, you just told me you aren't going to post
the ``scientific'' material I requested.
>The fact that you and I don't see eye to eye about how to do science
That's because you don't do science. A scientist has to support his/her
claims with more than wishful thinking, while wishful thinking, coupled
with deceit and hypocrisy, is your idea of an impeccable argument. When I
say I can derive a result, I'll derive if asked, because I can. Since
you apparently cannot, and won't, the difference in what I call science
and what you call science is obvious.
>in general and how to best interpret relativity in particular, or
>even about how to remedy ignorance, is no longer a secret. :-) -|Tom|-
Then you should avail yourself of the now-public knowledge, since I'm
not excusing you for ignorance if you don't. Basically, the institution
that granted your degree owes you a refund and an apology.
Tom Van Flandern
> [Bilge]: An alternative interpretation of relativity is no longer
relativity, even if you managed to get the content correct, which you
don't.
So which interpretation of GR is the real relativity, and
which is the pretender? Is it the field interpretation, as preferred by
Einstein, Dirac, and Feynman; or the geometric interpretation, as
preferred by Eddington, Misner-Thorne-Wheeler, and Wald? Why did
relativity originally suggest that all motion is relative, but later
changed that to state that only inertial motion is relative? (Hint:
Sagnac effect, 1913.) Why did relativity originally claim that mass
increased with speed, and later changed that to agree that "rest mass"
is invariant with speed, and the change is only in momentum?
Or is it that you are unfamiliar with the history of
relativity and the many debates over its interpretation?
> [Bilge]: you have misconstrued relativity in order to argue against
it. This has nothing to do with any interpretation of the equations. It
has to do with making deliberately incorrect statements about the
interpretation of those equations called special relativity.
This is getting boring. First, I have never argued against
relativity. You made that claim up. Second, why can't you simply put an
example into the discussion instead of making sweeping generalizations,
from which no one (including me) can tell if you have a point or are
just pontificating? Because I've asked for specific examples several
times now and you refuse to provide even one, the latter interpretation
of your messages must now become the default.
> [Bilge]: Requiring your students to purchase a book in which you have
a financial interest to obtain a passing grade, is called a conflict of
interest, which I would equate to selling the opportunity to pass your
course. You wouldn't have the opportunity to assign a grade before I had
you fired for being unethical and talked with the district attorney to
see if you could be charged with a crime.
It is common practice for professors to assign their own
books as required reading material in courses. The students don't buy
from the professor, but from a book seller; and the extra few dollars in
royalties is hardly a motivator for corruption by the professor.
However, more to the point, neither I nor any of the other
19 authors of the "Pushing Gravity" book I referenced (containing the
equations and derivation you seek) has any financial interest in that
book whatsoever. We don't get so much as a cent in royalties. And I
presume you have heard of public libraries? And inter-library loans?
Your excuses for not reading books and articles are transparently
excuses for not having to deal with new information.
> [Bilge]: you just told me you aren't going to post the "scientific"
material I requested.
I said: "That [derivation] is in Slabinski's chapter of the
book 'Pushing Gravity'. The derivation is several pages, is by another
author, and is copyrighted by the publisher, so I can't scan and post
pages here for your benefit." What part of that did you not understand,
and exactly what is your proposed alternative? The derivation contains
many equations, and USENET does not yet allow equations from Math Type
(the equation editor I use). And asking me to post his paper is asking
me to violate copyright laws. The whole paper is derivation of Le
Sage-related gravity relations. Just getting from starting premises to
Newton's law is already 18 numbered equations.
Your request is unreasonable. My alternative (beg, borrow,
buy or steal the book and read it) is reasonable. No more dodges. Do it
or cease pontificating about it.
> [Bilge]: the institution that granted your degree owes you a refund
and an apology.
Assuming you mean my Ph.D. rather than Bachelors or Masters
(astronomers are partial to a 3-degree background :-), that would be
Yale University. See resume and bibliography at the link at bottom of
this web page:
http://metaresearch.org/home/about%20meta%20research/vanflandern.asp.
And to which institution and for what degree should I write my
compliments about your fine education? :-) -|Tom|-
Cozmo Man
> "Bilge" <dub...@radioactivex.lebesque-al.net> writes:
>
>> [Bilge]: An alternative interpretation of relativity is no longer
> relativity, even if you managed to get the content correct, which
> you don't.
>
> So which interpretation of GR is the real relativity,
> and which is the pretender? Is it the field interpretation, as
> preferred by Einstein, Dirac, and Feynman; or the geometric
> interpretation, as preferred by Eddington, Misner-Thorne-Wheeler,
> and Wald? Why did relativity originally suggest that all motion is
> relative, but later changed that to state that only inertial motion
> is relative? (Hint: Sagnac effect, 1913.)
I could not find the phrase "all motion is relative" in Einstein's
1905 paper on electrodynamics. Though I did find the phrase "uniform
translational motion relative to each other" in Einstein's first
postulate of the principle of relativity. Do you consider "uniform
translational motion" to be different from "inertial motion"? And, why
the "Hint: Sagnac effect, 1913"? You do realize that Einstein
introduced "systems that are accelerated relative to each other" long
before 1913, don't you?
>
> Assuming you mean my Ph.D. rather than Bachelors or
> Masters (astronomers are partial to a 3-degree background :-), that
> would be Yale University.
May I ask whom you studied astronomy with at Yale?
Bilge
I'm just not going to accomodate your attempt to address every question
regarding your claim of having a quantum theory of gravity, by a series of
endless digressions. Either you do or you don't. Either you can post some-
thing more substantive than a bad analogy based upon a misrepresentation
of relativity, or you can't. Either your so-called theory addresses some
question about nature better than the boring, mundane, physics of the
opressive orthodoxy, or it doesn't. If you don't, can't and it doesn't,
that's just fine and you've resolved the issue in the simplest way for me,
as it's straight-forward to evaluate the merit of the nothing you've
provided.
I'm not going digress on a tangents such as some strawman debate on
what ``quantum'' means so you can buy time to bury the original question
in a few hundred rambling lines spread out over a few irreularly posted
responses. If you want to use it mean a theory about some particles and
feign bewilderment as to how someone would connect the concept of a com-
mutator bracket to the concept of a quantum theory, fine. You've answered
every question I could ask that pertains to any physics. If you manage to
post something with any physical content, I'll address the physical
content. If all you want to do is play word games, I can address that
too.
Gerald Lasser
> [a large number of elementary misunderstandings]
If F(x,y,z,t) is the potential of a conservative field, do you agree
that the force on a particle at the specific location x0,y0,z0 and
time t0 is proportional to the gradient of F evaluated at those
coordinates?
Tom Van Flandern
"Cozmo Man" <cozmo...@scientist.com> writes:
> [Cozmo]: Do you consider "uniform translational motion" to be
different from "inertial motion"? And, why the "Hint: Sagnac effect,
1913"? You do realize that Einstein introduced "systems that are
accelerated relative to each other" long before 1913, don't you?
Yes, but as late as 1920 in answer to a question by Sagnac,
whom Einstein had not yet met, Einstein claimed that special relativity
had nothing to say about accelerated motion, to which Sagnac responded
"Then special relativity has nothing to say about reality!" The whole
concept of Lorentz boosts and the modern interpretation of SR has all
evolved since those early days, and in the light of hard experimental
facts such as those presented by Sagnac and de Sitter, both of which
were originally presented as contradictions of SR.
De Sitter's argument was even simpler than Sagnac's. Both
components of a double star have high velocities in different
directions. Therefore, the aberration of starlight cannot depend on the
relative velocity between source and observer (whether accelerated or
not) because both components of the double have the same aberration v/c,
where v is the velocity of the double star center of mass relative to
the observer.
> [CM]: May I ask whom you studied astronomy with at Yale?
G.M. Clemence was my dissertation advisor. I took classes
from Brower, Clemence, Szebehely, Danby, and Deprit - all authors and
well-known names in the field of celestial mechanics.
and "Gerald Lasser" <gla...@nospam-me.com> writes:
> [Lasser]: If F(x,y,z,t) is the potential of a conservative field, do
you agree that the force on a particle at the specific location x0,y0,z0
and time t0 is proportional to the gradient of F evaluated at those
coordinates?
That is an excellent question, and draws out an important
point that is in my published papers but widely overlooked in the field
at large. If the coordinate origin is fixed at the field center and a
body is at rest at x0,y0,z0, then the situation is as simple as you
describe: force on the body equals the gradient of the potential field
at the body, and is directed toward the origin.
However, if the body moves with respect to the origin, then
the potential field gradient it sees is displaced from the origin, and
points toward the retarded position of the source (which is moving
relative to the body). So the answer to your good question is not so
straightforward as it might have seemed when you asked. -|Tom|-
Gerald Lasser
>If the coordinate origin is fixed at the field center and a body is
>However, if the body moves with respect to the origin, then the
>potential field gradient it sees is displaced from the origin, and
>points toward the retarded position of the source (which is moving
>relative to the body).
Let's take electromagnetism as an example. The electromagnetic
force on a charged test particle at x0,y0,z0,t0 is strictly a function
of the electric and magnetic potentials (and their derivatives) and
the velocity of the test particle and at those coordinates. Do you
agree?
If the source and the test body are each moving with constant
velocities (and have been for a time greater than D/c where D is the
distance between them) with respect to a given inertial coordinate
system, then the force on the test body at t0 points directly toward
the position of the source at that same time t0. Do you agree?
Also, do you agree that the electric and magnetic potentials at
x0,y0,z0,t0 are fully determined by the conditions on and inside the
past light cone of that point?
> Yes, but as late as 1920 in answer to a question by Sagnac, whom
> Einstein had not yet met, Einstein claimed that special relativity had
> nothing to say about accelerated motion, to which Sagnac responded
> "Then special relativity has nothing to say about reality!"
Could you provide the full quote (or a reference) for Sagnac's
question and Einstein's reply?