Problems with the Program of Relativity
Hayek
Phil wrote:
[The Program of Relativity,Problems with the Program of Relativity]
Great stuff, brilliantly explained !
I do not quite agree on the Collapsar theory,
but I am sure you do not mind, after reading the last
chapter, The Modern and Renaissance Scientific Methods
:-), which also hit the nail on the head.
Hayek.
--
...The times have been,
That, when the brains were out,
the man would die. ...
--Macbeth
Dirk Van de moortel
"Hayek" <hay...@nospam.xs4all.nl> wrote in message news:3D8304BF...@nospam.xs4all.nl...
>
>
> Phil wrote:
>
> [The Program of Relativity,Problems with the Program of Relativity]
>
>
> Great stuff, brilliantly explained !
>
> I do not quite agree on the Collapsar theory,
> but I am sure you do not mind, after reading the last
> chapter, The Modern and Renaissance Scientific Methods
> :-), which also hit the nail on the head.
It's a shame that the physics part is such nonsense.
It's also a shame that there are no other parts.
If you want to read some *really* great stuff, written by
someone who *knows* about physics, try this set of
reflections http://www.mathpages.com/rr/rrtoc.htm
Dirk Vdm
Bilge
Problems with the Program of Relativity to usenet:
Is there some reason you find it necessary to post html?
Hayek
Dirk Van de moortel wrote:
> It's a shame that the physics part is such nonsense.
> It's also a shame that there are no other parts.
I disagree. It is much easier to explain relativity from
an absolute viewpoint and then showing that most
experiments have relativistic results. Phil explains
this here at length. From an absolute viewpoint the twin
paradox becomes easy and intuitive to understand for
everyone, and is not even a paradox. I think relativity
is the worst name ever chosen for this theory. Because
it also works absolute. Or it is an absolute theory that
also works relatively. Why complicate things needlessly?
Most the discussions on this ng can be reduced to this
misunderstanding. And both sides are basically talking
about the same thing. This is exactly what phil tried to
address. You should try the absolute approach, you cannot
find inconsistencies.
> If you want to read some *really* great stuff, written by
> someone who *knows* about physics, try this set of
> reflections http://www.mathpages.com/rr/rrtoc.htm
Been there before. I get the impression that the author
is very careful not to thread outside the generally
accepted paths. Again Phil addresses this problem in the
"problems of the scientific method".
Dirk Van de moortel
"Hayek" <hay...@nospam.xs4all.nl> wrote in message news:3D835D46...@nospam.xs4all.nl...
>
>
> Dirk Van de moortel wrote:
>
> > It's a shame that the physics part is such nonsense.
> > It's also a shame that there are no other parts.
>
>
> I disagree.
That does not surprise me since neither the author nor you
seem a clue about the subject.
> It is much easier to explain relativity from
> an absolute viewpoint and then showing that most
> experiments have relativistic results. Phil explains
> this here at length. From an absolute viewpoint the twin
> paradox becomes easy and intuitive to understand for
> everyone, and is not even a paradox.
So now you understand it for the wrong reasons.
> I think relativity
> is the worst name ever chosen for this theory.
It certainly is not. And if it were what would that have
to do with the validity?
> Because
> it also works absolute. Or it is an absolute theory that
> also works relatively. Why complicate things needlessly?
Because there is no evidence for the absolute and because
there is no reason for the absolute. If we needed the
absolute, things would become *more* complicated.
> Most the discussions on this ng can be reduced to this
> misunderstanding.
No, most discussions can be reduced to ignorance and
stubornness.
> And both sides are basically talking
> about the same thing.
One side is usually ignorant.
> This is exactly what phil tried to
> address.
Yes, exactly. From the ignorant's viewpoint. You will devour
his stuff since you are even more ignorant.
> You should try the absolute approach, you cannot
> find inconsistencies.
Give me an abolute frame and I'll show you that you don't
need it.
>
>
> > If you want to read some *really* great stuff, written by
> > someone who *knows* about physics, try this set of
> > reflections http://www.mathpages.com/rr/rrtoc.htm
>
>
> Been there before.
I know.
That must be about a year ago.
Since then you learned nothing.
> I get the impression that the author
> is very careful not to thread outside the generally
> accepted paths. Again Phil addresses this problem in the
> "problems of the scientific method".
I would call it "problems when you have no clue".
Remember
http://groups.google.com/groups?&as_umsgid=3D81FE55...@nospam.xs4all.nl
The kind of error you make when you need the absolute.
Read a good book and learn something.
Dirk Vdm
Phil
thought that too much
clarity (not to mention time) would be lost converting it to text.
Phil
Phil
Hayek wrote:
> Phil wrote:
>
> [The Program of Relativity,Problems with the Program of Relativity]
>
>
> Great stuff, brilliantly explained !
>
> I do not quite agree on the Collapsar theory,
I think the idea that the energy of the early CMBR photons "mystically
disappears" and then "mystically reappears" is the most obvious,
unarguable error. There is *no way* that that energy could not still be
here, making the current discussions on whether and how the universe
will collapse just ridiculous. The proof of problems with black holes is
definitely less solid. An infinite quantity of kinetic energy is needed
(in the form of accumulated, or extra, mass) to bring an object's
time-rate to zero. Is the same true for gravitational energy? If so,
would an infinite quantity of gravitational energy really produce an
infinitely large, infinitely strong gravitational field? Is so, then
there are almost certainly no black holes, because the idea that
gravitational energy comes from anywhere other than the medium of space
just leads to too many problems. However, that does leave a couple of
big "ifs," so I have to agree that the conclusions on black holes are,
unlike the conclusions on photon energy, uncertain.
However, the idea that space adds mass to a gas cloud coalescing into a
star, and a great deal of mass into a collapsing star does nicely
explain the initial formation of galaxies (I think). If space does not
add mass, then the gravitational fields surrounding collapsing stars do
not change at great distances, meaning that orbital patterns of nearby
stars are not affected, and there is no reason for the initial galactic
clusters to form. However, if space adds mass, then the patterns are
disrupted, and a method for forming galactic clusters appears,
especially when several collapsars/black holes join together to form the
beginnings of the super collapsars/black holes at the center of those
clusters. Given the problems of assuming that gravitational energy comes
from anywhere other than space, plus the ability of this to explain the
early cluster formation, I think that this aspect of the paper is more
likely to be quickly accepted than the conclusions about black holes. I
guess we will see!
> but I am sure you do not mind, after reading the last chapter, The
> Modern and Renaissance Scientific Methods :-), which also hit the nail
> on the head.
Actually, the last one was "Problems with the Modern Scientific Method."
Did you get that one? I am finding out that various servers posted a few
here, a few there ... Weird
Phil
Hayek
Dirk Van de moortel wrote:
> That does not surprise me since neither the author
> nor you seem a clue about the subject.
This is an excerpt from the site you recommended,
http://www.mathpages.com/rr/rrtoc.htm
Upon deeper inspection it was not so bad after all.
Chapter 4.7 The Inertia of Twins
"
In the general theory of relativity, spacetime is not
simply the totality of all the relations between
material objects. The traditional relational-absolute
debate is rendered moot by endowing the spacetime metric
field with its own ontological existence, as is clear
from the fact that gravity itself is a source of
gravity. In other words, the non-linearity of general
relativity is an expression of the ontological existence
of spacetime itself, and on this basis it's not possible
to draw the classical distinction between relational and
absolute.
"
and
"
"the clock paradox is due to a false application of the
special theory of relativity, namely, to a case in which
the methods of the general theory should be applied"
"
and from :
4.6 The Field of All Fields
"
In fact, the special theory of relativity is not only
falsifiable, it is falsified , and was superceded in
1916 by a superior and more comprehensive theory.
Nevertheless, strict epistemological scruples don't have
a great deal of relevance to the actual day-to-day
practice of science.
"
en nog wat :
uit 4.1 Immovable Spacetime
"
Furthermore, in the context of the general theory of
relativity, spacetime itself is a field, i.e., a
physical entity, which not only acts upon material
objects but is also acted upon by them, so the
absolute-relational distinction may seem to disappear
totally. However, it remains possible to regard fields
as only representations of effects, and to insist on
materiality for ontological objects, in which case the
absolute-relational question remains both relevant and
unresolved.
"
> So now you understand it for the wrong reasons.
Your opinion. The site you referred to, mentions that
one of the reasons Einstein moved on to General
Relativity is the difficulty to identify "inertial frames".
>> I think relativity is the worst name ever chosen
>> for this theory.
> It certainly is not. And if it were what would that
> have to do with the validity?
Where did I question validity ?
Although I have an experiment that could cause trouble
for the equivalence of acceleration and gravitation.
Exactly this is also questioned by Phil but in a
completely different form.
>
> Because there is no evidence for the absolute and
> because there is no reason for the absolute. If we
> needed the absolute, things would become *more*
> complicated.
Just as GR is more complicated than SR.
>> Most the discussions on this ng can be reduced to
>> this misunderstanding.
>>
>
> No, most discussions can be reduced to ignorance and
stubornness.
>
>
>
>> And both sides are basically talking about the
>> same thing.
>>
>
> One side is usually ignorant.
>
>
>> This is exactly what phil tried to address.
>>
>
> Yes, exactly. From the ignorant's viewpoint. You
> will devour his stuff since you are even more
> ignorant.
>
>
>> You should try the absolute approach, you cannot find
>> inconsistencies.
>>
>
> Give me an abolute frame and I'll show you that you
> don't need it.
Einstein needed it to make GR.
>>> http://www.mathpages.com/rr/rrtoc.htm
> I know. That must be about a year ago. Since then
> you learned nothing.
>> I get the impression that the author is very
>> careful not to thread outside the generally accepted
>> paths.
Again Phil addresses this problem in the "problems
>> of the scientific method".
>>
>
> I would call it "problems when you have no clue".
>
> Remember
http://groups.google.com/groups?&as_umsgid=3D81FE55...@nospam.xs4all.nl
What is wrong with it ?
> The kind of error you make when you need the
> absolute. Read a good book and learn something.
I am working on one myself.
Dirk Van de moortel
"Hayek" <hay...@nospam.xs4all.nl> wrote in message news:3D8386C7...@nospam.xs4all.nl...
>
>
> Dirk Van de moortel wrote:
[snip - what I have done? Wake another potential josX?]
> > Remember
> http://groups.google.com/groups?&as_umsgid=3D81FE55...@nospam.xs4all.nl
>
> What is wrong with it ?
You don't even want to know what is wrong with it.
What is this xs4all.nl? A breeding ground for idiots?
Do they require an IQ below 70 to subscribe?
>
> > The kind of error you make when you need the
> > absolute. Read a good book and learn something.
>
> I am working on one myself.
Your good friend josX will devour it.
He will quote from it abundantly.
We can hardly wait.
Dirk Vdm
Ronald Stepp
news:3D837CD9...@austin.rr.com...
> Well thanks! How nice to hear such a positive review!
Well golly.. its so refreshing to know that the laws of the universe only
require good reviews by people to make them valid explanations.. science
reigns supr.... uh, no wait, Thank God thats NOT how it works.
I mean I would enjoy the explanation that the earth is a disc carried on the
backs of four giant elephants carried on the back of a giant space turtle
more..
Voila! Thus reality rearranges itself to suit my tastes!
Ronald Stepp
> Yeah, it has a ton of superscript, subscript, italics, etc. I just
> thought that too much
> clarity (not to mention time) would be lost converting it to text.
Well Golly.. I guess its too much to ask that you just post a link then? Or
maybe I should email you 50 or 60 more copies of the stuff you posted?
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D838630...@austin.rr.com...
If you use text format for your post, I might be able to read it.
Off to a wedding party now.
Dirk Vdm
Phil
Oops! My bad.
Dirk Van de moortel wrote:
>[snip]
>That does not surprise me since neither the author nor you
>seem a clue about the subject.
>[snip]
>No, most discussions can be reduced to ignorance and
>stubornness.
>[snip]
>One side is usually ignorant.
>[snip]
>Yes, exactly. From the ignorant's viewpoint. You will devour
>his stuff since you are even more ignorant.
>
Damn, Dirk, why don't you tell us what you really think? ;-)
But ...
>Give me an abolute frame and I'll show you that you don't
>need it.
>
I will give you one thing. At least you have the balls to put forth a
challenge, to stick your neck out and say "I will prove that you're an
idiot." Unlike some, who merely hurl insults while never sticking their
own necks out, never providing an opening for someone to respond to.
Kind of like those useless brats we all knew when we were kids, who
would yell insults from the front door, and then run inside and hide
when you started walking toward them, or hide behind their big brothers.
God those types disgust me!
Okay, chew on this (from the "Mechanical Methods for ..." paper).
"For example, suppose that we do live in a closed universe, so that an
observer leaving the earth at high speed and traveling in a straight
line would eventually, after several billion years, travel completely
around the universe and find himself back on earth. Now suppose that two
spaceships leave the earth in opposite directions, right and left, at
equal speeds as seen by the earth observers. If the earth's absolute
velocity is zero, then both spaceships will return to the earth after an
equal amount of time. However, if the earth is moving toward the right
at 0.25c, and two spaceships leave the earth left and right at 0.8c as
seen by the earth and spaceship observers, then the left and right
spaceships will have absolute velocities of 0.6875 c left and 0.875c
right, respectively. The earth will therefore travel 0.25c/(0.6875 c +
0.25c ) = 26.7% around the universe before the left spaceship returns,
and 0.25 c/(0.875 c - 0.25 c ) = 40% around the universe before the
right spaceship returns. The difference between the return times of the
two ships can then be used to determine the earth's absolute velocity.
Notice that instead of using absolute velocities, you could make
*exactly* the same predictions by declaring that the earth had a
velocity of 0.8c relative to a second, inertial observer. Calculations
by the second observer show that the difference in the return times of
the spaceships is a function of the earth's velocity relative to the
second observer. I don't know how familiar you are with some of the more
subtle aspects of relativity, but this is most emphatically *not*
supposed to happen! Specifically, the earth observer *must* be able to
correctly predict the results of this experiment using only *local*
velocities, the velocities of the two spaceships relative to himself. In
every other problem that I am aware of (with the *possible* exception of
the two other experiments I describe in the papers) this is the case. In
other words, as according to the calculations of the second inertial
observer, the results of all experiments done by the earth are
completely independent of the earth's velocity relative to either space,
or to the second observer. Furthermore, the second observer's actual
observations of earth experiments will confirm these calculations. That
is the principle of relativity! (Well, it's one the many valid
viewpoints which surround the PofR). Not so this experiment. Whether the
earth's velocity is taken to be relative to the second observer, or to
the medium of space, the results *vary* as a function of that velocity.
So, my response to your challenge is, show me how the earth observer can
correctly predict the results using *only* local velocities, the
velocities of the two spaceships relative to the earth as seen by either
the earth or the spaceship observers, without having to take his
absolute velocity into account. To paraphrase Bill Murray in
Ghostbusters, "Go get him, Dirk!"
>The kind of error you make when you need the absolute.
>Read a good book and learn something.
>
You know, I'm just sure that when Einstein first published his theories,
you would have been first in line to say "Gee, what innovative, great
stuff, what fine thinking!" You would never have said, "Einstein, you
idiot, read a book and get a clue."
Yeah, right.
Phil
Hayek
Dirk Van de moortel wrote:
> "Hayek" <hay...@nospam.xs4all.nl> wrote in message news:3D8386C7...@nospam.xs4all.nl...
>
>>
>>Dirk Van de moortel wrote:
>>
>
> [snip - what I have done? Wake another potential josX?]
You referred me to an "interesting site"
I quoted from this site.
This site was not written by JosX,
but, using your own words "written by
someone who *knows* about physics".
[snip shouting]
Phil
Okay, I'm confused. Which of my ideas do you think contradicts reality?
Would it be the idea that the energy lost by photons as the universe
expands does not just "mystically disappear" from the universe? (From
the third paper)
Would it be that gravitational energy does not just "mystically appear,"
but must instead come from the medium of space? (From the 1st paper)
I could go on, but my point is that it is one thing to hand out general
criticisms without any supporting examples -- an old and accepted
debating trick -- but in real science, it is better to at least
occasionally give a few examples of where a person is being stupid.
Hey, I've had a few of my other ideas and beliefs blown away by members
of this group, there's no reason I can think of why you shouldn't do the
same! Go for it, Ron!
Realistic Phil
Phil
No no! You've definitely made your point! I should clarify for others that
Ron mailed me two copies each of all of my posts. :-(
Humbled Phil
Stephen Speicher
> You know, I'm just sure that when Einstein first published his theories,
> you would have been first in line to say "Gee, what innovative, great
> stuff, what fine thinking!" You would never have said, "Einstein, you
> idiot, read a book and get a clue."
>
> Yeah, right.
>
Oh my, comparing yourself to Einstein are you now. Unlike
Einstein, _you_ wrote almost 200k of complete blather. And, to
boot, you spewed it all over the group in html. And then, as
icing on the cake, you balme others for not embracing your
garbage.
The circle of delusion is complete -- take off the mask and
reveal yourself. Are you really josX?
--
Stephen
s...@compbio.caltech.edu
Printed using 100% recycled electrons.
-----------------------------------------------------------
Phil
>
> Oh my, comparing yourself to Einstein are you now. Unlike
> Einstein, _you_ wrote almost 200k of complete blather. And, to
> boot, you spewed it all over the group in html. And then, as
> icing on the cake, you balme others for not embracing your
> garbage.
>
> The circle of delusion is complete -- take off the mask and
> reveal yourself. Are you really josX?
>
Stephen, don't you recognize me? It's your old buddy, cancer, back
problems (which you helped immensely) and all! My other server was
refusing to listen to me, so I had to use this one.
You really thought I was josx??? ;-(
Hurt Phil
Ronald Stepp
Heheheh.. and he took it remarkably well considering the extreme I went to
to make the point that not everyone likes having the complete contents of
someones web page posted to a newsgroup they look at.
Phil
>>
>>>"Phil" <tri...@austin.rr.com> wrote in message
>>>
>>No no! You've definitely made your point! I should clarify for others that
>>
>>Ron mailed me two copies each of all of my posts. :-(
>>
>
> Heheheh.. and he took it remarkably well considering the extreme I went to
> to make the point that not everyone likes having the complete contents of
> someones web page posted to a newsgroup they look at.
>
Amazing what a litle FEAR will do for your ability to "take things well!"
Actually, it was no problem, because I wanted to BEAT a guy on another
list a while back on a totally different issue, so I understood where
you were coming from. :-)
BTDT Phil
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D8398A...@austin.rr.com...
> Dirk Van de moortel wrote:
>
> >"Phil" <tri...@austin.rr.com> wrote in message news:3D838630...@austin.rr.com...
> >
> >If you use text format for your post, I might be able to read it.
> >Off to a wedding party now.
> >
> >Dirk Vdm
> >
> Oops! My bad.
That is much better.
>
> Dirk Van de moortel wrote:
>
> >[snip]
> >That does not surprise me since neither the author nor you
> >seem a clue about the subject.
> >[snip]
> >No, most discussions can be reduced to ignorance and
> >stubornness.
> >[snip]
> >One side is usually ignorant.
> >[snip]
> >Yes, exactly. From the ignorant's viewpoint. You will devour
> >his stuff since you are even more ignorant.
> >
> Damn, Dirk, why don't you tell us what you really think? ;-)
What I really think, is that you should wade into the task of
carefully wading through the entire subthread under:
http://groups.google.com/groups?&as_umsgid=3C680D22...@jump.net
and find out what, despite repeated advice, you still have not
learned since 11-Feb-2002.
Furthermore, having written the very first sentence of the very first
paragraph of your very first chapter, you could have a look at
http://www.google.com/search?&q=%22relativistic+mass%22+obsolete
and rewrite that first chapter entirely, *after* having read those two
books that were recommended to you on so many occasions since
that dreadful 11-Feb-2002
There is a lot more that I really think, but with a hangover like
this, I think I'll take my bike and get some air.
Dirk Vdm
Bilge
Re: Problems with the Program of Relativity to usenet:
>Dirk Van de moortel wrote:
>> So now you understand it for the wrong reasons.
>
>Your opinion. The site you referred to, mentions that one of the
>reasons Einstein moved on to General Relativity is the difficulty
>to identify "inertial frames".
Sure, but the subtlety addressed by that is probably least frequently
mentioned aspect of the paradox. In fact, that is rarely the issue.
The majority of so-called "problems" are due to simply not understanding
how to perform a coordinate transformation or to what the path length of
a world line refers. In any case, general relativity exists for that reason,
and once you've decided which twin is inertial, the rest does not require
anything but special relativity.
Bilge
Re: Problems with the Program of Relativity to usenet:
>Okay, chew on this (from the "Mechanical Methods for ..." paper).
>
>"For example, suppose that we do live in a closed universe, so that an
>observer leaving the earth at high speed and traveling in a straight
>line would eventually, after several billion years, travel completely
>around the universe and find himself back on earth.
You've already created an ill-defined argument. What is a
"straight line"? How do you if you are traveling in a "straight
line"? (Without making your definition circular).
> Now suppose that two
>spaceships leave the earth in opposite directions, right and left, at
>equal speeds as seen by the earth observers. If the earth's absolute
>velocity is zero, then both spaceships will return to the earth after an
>equal amount of time. However, if the earth is moving toward the right
>at 0.25c, and two spaceships leave the earth left and right at 0.8c as
>seen by the earth and spaceship observers, then the left and right
This isn't even classically correct. Anything which leaves the earth
in opposite directions with "equal speeds", leaves the earth at the
center of momentum.
>spaceships will have absolute velocities of 0.6875 c left and 0.875c
>right, respectively. The earth will therefore travel 0.25c/(0.6875 c +
>0.25c ) = 26.7% around the universe before the left spaceship returns,
>and 0.25 c/(0.875 c - 0.25 c ) = 40% around the universe before the
>right spaceship returns. The difference between the return times of the
>two ships can then be used to determine the earth's absolute velocity.
In other words, what you are claiming is equivalent to saying that
if you're on an airplane traveling at 600 mph, and drop your pen to the
floor, it will fall to the floor of the plane at an angle.
[...]
>So, my response to your challenge is, show me how the earth observer can
>correctly predict the results using *only* local velocities, the
I don't think you know what "local" means.
>velocities of the two spaceships relative to the earth as seen by
>either the earth or the spaceship observers, without having to take
>his absolute velocity into account.
The correct prediction by special relativity is that the world lines
of inertial observers can't intersect more than once. Your scenario
doesn't make sense in special relativity. It's always possible to
frame a question that a theory can't address because the question
makes no sense in the theory. Unless the scenario is actually possible
then the theory better not have an answer, either.
Patrick Reany
Hayek wrote:
> Dirk Van de moortel wrote:
>
> > It's a shame that the physics part is such nonsense.
> > It's also a shame that there are no other parts.
>
> I disagree. It is much easier to explain relativity from
> an absolute viewpoint and then showing that most
> experiments have relativistic results.
You refer to "the Program of Relativity" yet you
don't seem to understand what a research program
is. It is a particular, biased way of looking at some
problem of theoretical research. In the case of relativity,
it is the bias that physics SHOULD be built on
laws that owe the least amount of debt to ANY
concept of a preferred invisible frame of reference,
i.e., a frame of reference NOT defined by the
distribution of matter. In SR this was accomplished
by making all inertial reference frames "preferred"
just as Newtonian mechanics did, though SR
accomplished the unification of mechanics with
electrodynamics with SR. To do this, Einstein
treated acceleration as absolute just as Newton
had, but left velocities as relative, just as Newton
had.
> Phil explains
> this here at length. From an absolute viewpoint the twin
> paradox becomes easy and intuitive to understand for
> everyone, and is not even a paradox.
Using a Minkowski diagram is the ONLY aid
I need to understand the "Clocks in motion"
problem.
> I think relativity
> is the worst name ever chosen for this theory.
It is a perfect name!! It is all about NOT building
a notion of "law of physics" based on preferred
(i.e., "absolute") reference frames, which would
presumably define absolute positions, velocities,
and/or accelerations for ALL particles in the
universe.
> Because
> it also works absolute.
Not in general relativity and Einstein's theory of
gravitation -- it is pure relative, using no mention
of any absolute kinematical variable. The only
"absolute" left in GR is the differential quantity ds,
a term left over from differential geometry and NOT
from the history of physics.
> Or it is an absolute theory that
> also works relatively.
In the absolute research programs of physicists,
such as Lorentz, one starts off with a constructive
model of some space as the embodiment of some
invisible space that is supposed to define absolute
quantities. To Lorentz, this model was of the
luminiferous ether, which assigned absolute velocities
to all particles in the universe. This was a free choice
of his from the start, and a founding bias in Lorentz's
research program! In relativity Einstein chose to get
away from the constructive approach and employ
what he call the "principled" approach, by which he
meant to use principles, or rather constraining rules,
which he felt confident would not be contradicted by
experiment. These principles were to form the logical
foundation to his theory. This approach has two
advantages: First, that a theory based on principles
should have a very long lifetime, and second, that
such a theory should reasonably be regarded as
having a greater chance of having internal logical
consistence than a constructive theory.
> Why complicate things needlessly?
> Most the discussions on this ng can be reduced to this
> misunderstanding.
I certainly agree with you on this one. But some
posters here are too biased against SR to even
give it fair chance. They are brain bead because
of their allegiance to "commonsense." Others
are just too lazy to do the work to learn the
math and physics to get SR. Let's NOT forget
about that!
> And both sides are basically talking
> about the same thing.
There are three sides here: The relativists, the
absolutists, and the weirdoes who want to
found scientific knowledge on the two
principles: The clock goofed and seeing equals
believing.
> This is exactly what phil tried to
> address. You should try the absolute approach, you cannot
> find inconsistencies.
If one starts off with the physics known at the
time of 1904/5 and insists that one has to adopt
the modeling bias to incorporate an invisible frame
of reference which is the embodiment (a formal
model) of a speculative notion of medium in which
light propagates absolutely (a space which effectively
defines absolute velocities for all particles in the
universe), then one ends up with Lorentz's LET.
But if one starts off from the research bias that
one is NOT allowed to assume a model of ANY
space that assigns absolute velocities to particles,
then one ends up with Einstein's SR.
For more on this see
http://ajnpx.com/html/Relativity.html
Patrick
Patrick Reany
Hayek wrote:
> Dirk Van de moortel wrote:
>
> > That does not surprise me since neither the author
> > nor you seem a clue about the subject.
>
> This is an excerpt from the site you recommended,
> http://www.mathpages.com/rr/rrtoc.htm
> Upon deeper inspection it was not so bad after all.
> Chapter 4.7 The Inertia of Twins
> "
> In the general theory of relativity, spacetime is not
> simply the totality of all the relations between
> material objects. The traditional relational-absolute
> debate is rendered moot by endowing the spacetime metric
> field with its own ontological existence, as is clear
> from the fact that gravity itself is a source of
> gravity.
Spacetime is a formal model, an instrument of
thought for the formation of a predictive theory.
It need have no ontological correspondence to
anything "real."
Patrick
Robert Kolker
Patrick Reany wrote:
> It is a perfect name!! It is all about NOT building
> a notion of "law of physics" based on preferred
> (i.e., "absolute") reference frames, which would
> presumably define absolute positions, velocities,
> and/or accelerations for ALL particles in the
> universe.
-The Theory of Lorentz Invariance- might be more accurate, but it has no
pizzazz. Sort of like the 3 horsemen of the apocolypse. It just does not
fly right.
Bob Kolker
Stephen Speicher
> Phil said some stuff about
> Re: Problems with the Program of Relativity to usenet:
>
> >Okay, chew on this (from the "Mechanical Methods for ..." paper).
> >
> >"For example, suppose that we do live in a closed universe, so that an
> >observer leaving the earth at high speed and traveling in a straight
> >line would eventually, after several billion years, travel completely
> >around the universe and find himself back on earth.
>
> You've already created an ill-defined argument. What is a
> "straight line"? How do you if you are traveling in a "straight
> line"? (Without making your definition circular).
>
Yes, exactly.
But, not only that, even if he could meaningfully define a
"straight line" vis-a-vis direction, what could it possibly mean
to "travel completely around the universe and find himself back
on earth?" That which is in universe is dynamic, and there are no
cosmic markers which define "here." The Earth would no longer be
"where" it was; in fact, the Earth may no longer _be_ by the end
of the journey.
This whole notion of his just belies his misguided attempt to
sneak in the "absolute" in such a way to make it appear to have
meaning, when in fact it does not. He has done this repeatedly
with relativity in general -- trying to introduce the "absolute"
-- and his "absolute" is nothing but a floating abstraction
which has no ties to physical reality. Ironic that he who wants
to "fix" relativity by tying it to the physical world himself
devises notions in doing so which have no connection to reality.
Phil
> Phil said some stuff about
> Re: Problems with the Program of Relativity to usenet:
>
> >Okay, chew on this (from the "Mechanical Methods for ..." paper).
> >
> >"For example, suppose that we do live in a closed universe, so that an
> >observer leaving the earth at high speed and traveling in a straight
> >line would eventually, after several billion years, travel completely
> >around the universe and find himself back on earth.
>
> You've already created an ill-defined argument. What is a
> "straight line"? How do you if you are traveling in a "straight
> line"? (Without making your definition circular).
This technically falls under the category of TSTRT -- Too Stupid To
Respond To -- but what the hell. For this experiment, a straight line
means that the spaceship would follow the same path that a beam of light
would follow, assuming that the light does not travel through a strong
gravitational field, in which case, the spaceship would have to follow
the path that light would have traveled had it not encountered the field.
From Steven Weinberg's "The First Three Minutes," page 34 of the
updated paperback version:
"On the other hand, if the density of the universe is *greater* than
this critical value, then the gravitational field produced by the matter
curves the universe back on itself; it is finite though unbounded, like
the surface of a sphere. (That is, if we set off on a journey in a
straight line, we do not reach any sort of edge of the universe, but
simply come back to where we began.)
And if you think Steven Weinberg is an idiot, then I have no further use
for you. I may believe that I figured out something that he didn't --
that the energy lost by photons as the universe expands does not just
"mystically disappear" from the universe, but instead remains with the
medium of space (see the paper on "The Missing Mass of the Universe") --
but I am here to tell you that that is at most just an oversight on his
part, because that man can THINK! (Great book, recommended even if the
ideas in my paper are true.)
Weinberg uses the analogy of a sphere, where a plane is effectively
"wrapped around" a three-dimensional sphere, allowing the surface area
of the plane to be unbounded, yet finite. A four-dimensional sphere --
the accepted name is "hypersphere" -- is similar, except that the
"surface" is actually a volume, not a plane, so that a three-dimensional
space is "wrapped around" the hypersphere. That is our universe under
GR, assuming that the density of the universe does indeed exceed the
critical value. We live in a three-dimensional space which curves back
on itself, wrapped around a hypersphere, so that the volume of space is
finite, and yet unbounded, similar to a two-dimensional surface wrapped
around a (three-dimensional) sphere.
This is why, as Weinberg says, "if we set off on a journey in a straight
line, we do not reach any sort of edge of the universe, but simply come
back to where we began."
>
>
> > Now suppose that two
> >spaceships leave the earth in opposite directions, right and left, at
> >equal speeds as seen by the earth observers. If the earth's absolute
> >velocity is zero, then both spaceships will return to the earth after an
> >equal amount of time. However, if the earth is moving toward the right
> >at 0.25c, and two spaceships leave the earth left and right at 0.8c as
> >seen by the earth and spaceship observers, then the left and right
>
> This isn't even classically correct. Anything which leaves the earth
> in opposite directions with "equal speeds", leaves the earth at the
> center of momentum.
I am going to assume that you were simply not thinking when you wrote
this. If you and I are in the same IRF, and we measure the velocity of a
third observer moving directly away from us as being +0.25c, and this
third observer sends out two objects at velocities of +0.8c and -0.8c as
seen by him, one directly toward us (-0.8c), and the other directly away
from us (+0.8c, in the same direction from us as the third observer),
then we will measure velocities for the two objects as being -0.6875c
and +0.875c, according to standard Lorentz transformation SR.
>
> >spaceships will have absolute velocities of 0.6875 c left and 0.875c
> >right, respectively. The earth will therefore travel 0.25c/(0.6875 c +
> >0.25c ) = 26.7% around the universe before the left spaceship returns,
> >and 0.25 c/(0.875 c - 0.25 c ) = 40% around the universe before the
> >right spaceship returns. The difference between the return times of the
> >two ships can then be used to determine the earth's absolute velocity.
>
> In other words, what you are claiming is equivalent to saying that
> if you're on an airplane traveling at 600 mph, and drop your pen to the
> floor, it will fall to the floor of the plane at an angle.
TSTRT
>
> [...]
>
> >So, my response to your challenge is, show me how the earth observer can
> >correctly predict the results using *only* local velocities, the
>
> I don't think you know what "local" means.
TSTRT
>
> >velocities of the two spaceships relative to the earth as seen by
> >either the earth or the spaceship observers, without having to take
> >his absolute velocity into account.
>
> The correct prediction by special relativity is that the world lines
> of inertial observers can't intersect more than once. Your scenario
> doesn't make sense in special relativity. It's always possible to
> frame a question that a theory can't address because the question
> makes no sense in the theory. Unless the scenario is actually possible
> then the theory better not have an answer, either.
SR does not assume a finite, yet unbounded universe, and so does not run
into this problem. In that respect your thinking is quite good! However,
we cannot say, simply because SR, GR, and the principle of relativity
find it to be *inconvenient*, that we do not have to even consider the
implications that follow if we live in a bounded universe, in the
volume/surface of a hypersphere. Would Einstein have done that? Not
ever, not under any circumstances. He was too scientifically principled
to ignore either experimental results or logical conclusions (thought
experiments, if you prefer) merely because they appeared to run counter
to the assumptions upon which his theories were based.
If we live in a closed universe, and two spaceships leave the earth in
opposite directions at equal velocities as seen by the earth and
spaceship observers, and travel in straight lines, then they will
eventually return to earth. However, an observer moving with the earth
will predict that they will return *at the same time,* while a second
observer moving at a velocity of 0.25c relative to the earth is forced
to predict that they will arrive at different times. And that is a
direct contradiction of the principle of relativity. In any other
experiment you can name performed by the earth observers, both the earth
observers and the second observer moving at 0.25c relative to the earth
will predict the same result for that experiment, in accordance with the
principle of relativity.
Now, you and Stephen Speicher (who mirrored your comments in his
response to your post) can honestly deal with this, as Einstein would
have done, or you can simply argue with a bunch of pointless BS, such as
"you can't define straight lines without circular reasoning," or "well,
we probably live in an open universe, so this doesn't count." Responding
with a bunch of BS is, however, *scientifically* meaningless, and I'm
not going to waste any more of my time on it. Maybe you have a well
thought out response, that uses the rules of real science, instead of
the rules of politics and debate, that *demonstrates* a flaw in my
reasoning. If so, good for you! You did a good job, and I will be the
wiser for it. But if not, then it may be time to ask about the
implications for relativity (there are not that many, to be honest), and
about the question of whether concepts like absolute velocity -- i.e., a
velocity relative to the medium of space -- might in fact have some
scientific validity after all.
If so, it isn't going to change any of the laws of relativity. The main
thing that will change is really a *philosophical* conclusion, namely
that since we don't need to take absolute velocity into account in order
to solve (all other) problems, that it is scientifically meaningless,
and we should drop it. That's the only thing of any real consequence
that will have to change. So what? If that change more accurately
reflects the real universe we live in, and does not require us to dump
relativity, why would that be a problem? Okay, so the PofR is merely
99.9999999999% correct, instead of 100% perfect. Until you find a more
accurate principle, it will still remain king. Get over it.
But don't try to find some BS to "cover up" reality! Because at that
point, you have abandoned science, and adopted a religious fanaticism in
Einstein's name instead -- something Einstein himself would have hated.
Phil
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D864BE4...@austin.rr.com...
The sentence between parentheses obviously refers to the
example of the surface of the sphere, and not to the actual
universe.
>
> And if you think Steven Weinberg is an idiot, then I have no further use
> for you.
Perhaps Weinberg was writing *for* idiots, as compared to
Weinberg.
Dirk Vdm
Stephen Speicher
>
> Now, you and Stephen Speicher (who mirrored your comments in his
> response to your post) can honestly deal with this, as Einstein would
I did more than "mirrored" some comments; I acknowledged the
correctness of Bilge's point and added a crucial one of my own,
one which you have not seen fit to address. Permit me to draw
your attention to the point again, and perhaps this time you will
address it rather than taking the evasive route of tossing it
away as "pointless BS." I will make the same point in regard to a
quote you made in this post. You said:
"This is why, as Weinberg says, 'if we set off on a
journey in a straight line, we do not reach any sort of
edge of the universe, but simply come back to where we
began.'"
Quoting from a source, or even appeal to authority, does not make
it so. Of course in a finite, unbounded universe there is no
edge; that is obvious, by definition. But, in addition, what may
not be so obvious to you is that there is no "where we began."
There are no cosmic markers that sit in an absolute grid that
mark your point of departure. The entities which comprise the
universe are continually dynamic, and after your several billion
years journey your "where we began" is no longer "here." Where is
"here" when billions of years of dynamic action change
relationships in such a way that they no longer relate to "where
we began."
Where will be your Earth, from whence you started, after billions
of years? In fact, your Earth may no longer even be in
existence. The universe is simply not susceptible to laying down
a fixed grid and making a mark on some cosmic graph with a big X
that says "You are here." We can approximate such measurements
over short-enough times and short-enough distances, but there
simply is no place which was "here" to return to over
cosmological times and distances.
I suspect you chose to evade this issue and toss it off as
"pointless BS" because on some level you recognized that the
overall point I made was so right, namely this is your attempt to
sneak in the notion of the "absolute" when such a notion bears no
relation to the facts of reality. That that which is, is, is
absolute, but "place" is a relational concept and your attempt to
smuggle in the "absolute" in regard to place suffers from the
very same unjustified attempts to incorporate the "absolute" in
your version of relativity.
This is the kind of issue which you yourself, in principle, have
acknowledged -- nay, promoted -- as being so important _because_
it is broad philosophy, not just science. I agree, that is
correct, but you do not realize that many of us have given years
of thought to these issues and you are simply not the first to
address them. There are a dozen similar issues I could identify
if I were to spend the time in analyzing any one of the nine
different essays you wrote. What you simply do not realize is
just how naive so many of your formulations are, when looked at
in the light of clear, rational thought tied to reality. Perhaps
you would be less presumptuous to lecture people like Bilge if
you truly understood more of what he has to say.
Do you understand what I have had to say, right here?
>
> But don't try to find some BS to "cover up" reality! Because at that
> point, you have abandoned science, and adopted a religious fanaticism in
> Einstein's name instead -- something Einstein himself would have hated.
>
I truly hope you are able to listen to your own words written here.
You're not in Kansas anymore.
Phil
Dirk Van de moortel wrote:
The sentence *does* refer to the actual universe, *not* merely to the
surface of a sphere. My god people! This is merely written in every
other book on relativity. What do you think they mean when they talk
about the universe -- our universe, not the surface of a sphere -- being
finite and yet unbounded??? (Although you wind up back where you started
only if the universe is closed.)
If everyone else is as confused on this issue as you, Dirk, then I will
try to find some other examples, but this really is GR 101.
>
>
>>And if you think Steven Weinberg is an idiot, then I have no further use
>>for you.
>>
>
> Perhaps Weinberg was writing *for* idiots, as compared to
> Weinberg.
Very cute! And just coincidently, it allows you to avoid actually
answering my response to your challenge, by using the time-honored
technique of running away!
If you ever decide to actually answer my comments with something other
than "It just isn't so," or "You need to read books," do let me know.
You could start with either showing, not just claiming, that flaws exist
in the idea that:
The energy lost by photons as the universe expands does not just
mytically disappear, but stays with the medium of space.
Or:
That 100% of the kinetic and gravitational energy which an object
accumulates as it falls into a gravitational well comes from the medium
of space.
Or:
The argument, whose precepts do *not* violate any accepted ideas of GR,
that objects moving in opposite directions from the earth will travel
all the way around the universe and return at different times, depending
on the absolute velocity of the earth.
Of course, answering questions like these *honestly* this might cause
you to lose the argument, but if your first principle is to have
scientific integrity and honesty, so what? Why would that matter more to
you than the truth?
I think I will give up on all three of you. If I thought any of you were
primarily interested in truth and understanding, as opposed to merely
"winning an argument," using every debating technique available (don't
respond to hard questions, attack the person, not his ideas, etc.), it
would be different, but at this time, fairly or unfairly, I'm going to
have to put Dirk, Stephen, and Bilge into the category of
"scientifically useless," although you would all be great in politics!
Well, maybe one or more of you will show me otherwise. Until then, I'm
just going to put TSTRT in the subject heading and be done with it.
I mean, really:
"The sentence between parentheses obviously refers to the example of the
surface of the sphere, and not to the actual universe."
Pull the cork out.
Phil
Phil
Stephen Speicher wrote:
> On Mon, 16 Sep 2002, Phil wrote:
>
>>Now, you and Stephen Speicher (who mirrored your comments in his
>>response to your post) can honestly deal with this, as Einstein would
>>have done, or you can simply argue with a bunch of pointless BS...
>>
>
> I did more than "mirrored" some comments; I acknowledged the
> correctness of Bilge's point and added a crucial one of my own,
> one which you have not seen fit to address. Permit me to draw
> your attention to the point again, and perhaps this time you will
> address it rather than taking the evasive route of tossing it
> away as "pointless BS." I will make the same point in regard to a
> quote you made in this post. You said:
>
> "This is why, as Weinberg says, 'if we set off on a
> journey in a straight line, we do not reach any sort of
> edge of the universe, but simply come back to where we
> began.'"
>
> Quoting from a source, or even appeal to authority, does not make
> it so.
That's true, good point. But when SW says something, it cannot be
"merely dismissed," either.
Of course in a finite, unbounded universe there is no
> edge; that is obvious, by definition. But, in addition, what may
> not be so obvious to you is that there is no "where we began."
> There are no cosmic markers that sit in an absolute grid that
> mark your point of departure. The entities which comprise the
> universe are continually dynamic, and after your several billion
> years journey your "where we began" is no longer "here." Where is
> "here" when billions of years of dynamic action change
> relationships in such a way that they no longer relate to "where
> we began."
Thought experiments have the advantage of *potentially* avoiding such
complications. For example, it is not against any laws of physics to
postulate that a body moving in space will not be significantly affected
by any other bodies for several billion years, simply because there are
so many vast stretches of essentially empty space. Assume for a moment
that, relative to the average movement of all the other masses in the
universe, that our solar system does not change either in speed or
direction. Then an object leaving earth, moving in a straight line, will
indeed return to earth, if Weinberg is correct. For this thought
experiment, I don't need an "absolute marker." The earth will do quite
nicely, since I am claiming that the time required for objects to travel
around the universe and return to the earth varies depending on the
absolute velocity of the earth. However, now that I think about it, I
will grant you that it would be necessary to send objects in the same
and opposite directions as the earth's motion, otherwise the earth will
"move to the side" during the object's journey. You do come up with good
points, you just don't seem to be able to distinguish them from points
that make no sense (I realize that you did not actually realize that an
object must move in the same or opposite direction as the earth in order
to return to earth billions of years later, but you made me realize it).
>
> Where will be your Earth, from whence you started, after billions
> of years? In fact, your Earth may no longer even be in
> existence.
Now you're just being silly. Is it impossible to measure the velocity of
light because the machine "might blow up" during the experiment? Come on ...
> The universe is simply not susceptible to laying down
> a fixed grid and making a mark on some cosmic graph with a big X
> that says "You are here." We can approximate such measurements
> over short-enough times and short-enough distances, but there
> simply is no place which was "here" to return to over
> cosmological times and distances.
>
> I suspect you chose to evade this issue and toss it off as
> "pointless BS" because on some level you recognized that the
> overall point I made was so right, namely this is your attempt to
> sneak in the notion of the "absolute" when such a notion bears no
> relation to the facts of reality. That that which is, is, is
> absolute, but "place" is a relational concept and your attempt to
> smuggle in the "absolute" in regard to place suffers from the
> very same unjustified attempts to incorporate the "absolute" in
> your version of relativity.
Arrogance in motion. I didn't even remember "this issue" when I was
writing the other post, in part because my memory isn't that good, and
also because it simply isn't so great or significant that I would have
any reason to remember it. Think, Stephen, are you *really* going to
claim that if we live in a closed universe, that it would be impossible
to leave, travel in a straight line, and eventually return to earth?
You're going to look pretty dumb to a lot of people if you do. Besides,
I agree with you that place is meaningless when regarding the medium of
space itself, and I said so in one of the papers.
>
> This is the kind of issue which you yourself, in principle, have
> acknowledged -- nay, promoted -- as being so important _because_
> it is broad philosophy, not just science. I agree, that is
> correct, but you do not realize that many of us have given years
> of thought to these issues and you are simply not the first to
> address them. There are a dozen similar issues I could identify
> if I were to spend the time in analyzing any one of the nine
> different essays you wrote. What you simply do not realize is
> just how naive so many of your formulations are, when looked at
> in the light of clear, rational thought tied to reality. Perhaps
> you would be less presumptuous to lecture people like Bilge if
> you truly understood more of what he has to say.
Perhaps you or Bilge or Dirk could give an example of where I made
errors using something more intelligent than "Gee, the earth might not
be here."
For example, where else have you seen the idea that the energy that a
photon loses as the universe expands does not just "mystically
disappear," but remains with the medium of space? You said that I am not
the first to address the ideas described in these papers, fine, where
have you seen this? Or perhaps it is known in "professional circles"
that this cannot be true. Any references to articles on this point? No?
Prediction, you will simply run away from this, and pretend I never said
anything about photons. Not because I do not have a good point, but
because to do so would put you at a disadvantage, from the viewpoint of
debate and politics.
>
> Do you understand what I have had to say, right here?
See above.
>
>
>>But don't try to find some BS to "cover up" reality! Because at that
>>point, you have abandoned science, and adopted a religious fanaticism in
>>Einstein's name instead -- something Einstein himself would have hated.
>>
>>
>
> I truly hope you are able to listen to your own words written here.
> You're not in Kansas anymore.
This is stupid, and if I let it continue, then I need to start wearing a
shirt that says, "Even More Stupid" on it.
Stephen, one of us believes that he is fully grounded and living in
Kansas, when in fact, his mind is completely in Oz ...
... and it isn't me.
Phil
>
Hayek
Phil wrote:
> Well thanks! How nice to hear such a positive review!
> Actually, the last one was "Problems with the Modern Scientific Method."
> Did you get that one? I am finding out that various servers posted a few
> here, a few there ... Weird
No, I got it, but I hastily clicked on the wrong one and
copy and pasted the wrong title. :-)
Phil
>
> Phil wrote:
>
>> Well thanks! How nice to hear such a positive review!
>
>> Actually, the last one was "Problems with the Modern Scientific
>> Method." Did you get that one? I am finding out that various servers
>> posted a few here, a few there ... Weird
>
> No, I got it, but I hastily clicked on the wrong one and copy and pasted
> the wrong title. :-)
>
> Hayek.
Ah, good. Yours remains my only positive review! Jon Hurwitz is going to
the not inconsiderable work of reading them, which I also take as a
compliment, although he may hate them when he's done!
I think the thing that stuns me the most is that except for your doubts
on collapsars, there has been not one word, nothing, on the idea that
space supplies the energy of gravity, that objects increase in mass from
gravitational collapse (clouds into stars or stars into neutron stars,
black holes, whatever) which can explain the initial formation of
galaxies (lots of "new mass" in one area from supermassive collapsars
can change the motions of nearby stars), and most of all, the idea that
energy does not "mystically disappear" from the universe when the
wavelength of a photon is increased by the expansion of the universe. I
mean, these are seriously big ideas! True, they may be full of crap, but
that's merely all the more reason why *someone* would send posts on the
subjects! Well, maybe later in the week ...
Phil
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D867304...@austin.rr.com...
>
>
> Dirk Van de moortel wrote:
>
> > "Phil" <tri...@austin.rr.com> wrote in message news:3D864BE4...@austin.rr.com...
[snip]
> >> From Steven Weinberg's "The First Three Minutes," page 34 of the
> >>updated paperback version:
> >>
> >>"On the other hand, if the density of the universe is *greater* than
> >>this critical value, then the gravitational field produced by the matter
> >>curves the universe back on itself; it is finite though unbounded, like
> >>the surface of a sphere. (That is, if we set off on a journey in a
> >>straight line, we do not reach any sort of edge of the universe, but
> >>simply come back to where we began.)
> >>
> >
> > The sentence between parentheses obviously refers to the
> > example of the surface of the sphere, and not to the actual
> > universe.
>
>
> The sentence *does* refer to the actual universe, *not* merely to the
> surface of a sphere.
>
> My god people! This is merely written in every
> other book on relativity. What do you think they mean when they talk
> about the universe -- our universe, not the surface of a sphere -- being
> finite and yet unbounded??? (Although you wind up back where you started
> only if the universe is closed.)
>
> If everyone else is as confused on this issue as you, Dirk, then I will
> try to find some other examples, but this really is GR 101.
On the surface of a perfect sphere you "simply come back
where you began".
On the surface of a perfect ellipsoid or a perfect torus, which
is are finite though unbounded, you "simply do *not* come
back where you began".
On the surface of Earth, which is finite though unbounded,
you "simply do *not* come back where you began".
If the Universe is the analogue of a perfect sphere, you
"simply come back where you began" - if you manage to
define what "where you began" actually means in the first
place (I guess Stephen has been and will be entertaining
you on that topic).
What if the Universe is the analogue of an ellipsoid or a
torus, or a "somewhat less perfect sphere"?
What if the Universe is not empty and the presence of
matter disturbs the "perfect sphere"?
Do you "simply come back where you began"?
> >>And if you think Steven Weinberg is an idiot, then I have no further use
> >>for you.
> >>
> >
> > Perhaps Weinberg was writing *for* idiots, as compared to
> > Weinberg.
>
>
> Very cute! And just coincidently, it allows you to avoid actually
> answering my response to your challenge, by using the time-honored
> technique of running away!
Your response to my challenge has been dealt with. You just don't
realize it yet.
I know for a fact that despite everything I formally learned (a lot)
and read (a lot) on some of the subjects Weinberg is writing about,
*I* still feel like an idiot, as compared to Weinberg.
But perhaps you are much smarter than I am. Perhaps you should
write a book.
[snip]
> Pull the cork out.
This wine needs at least another 5 years to ripen.
Dirk Vdm
Phil
why, assuming they want to bother. You have proven to me that you either
do not understand logical reasoning, or you do not care about it. Either
way, I'm done with you. Goodbye Dirk.
Phil
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D86CE43...@austin.rr.com...
> Sorry, this one really is TSTRT -- and I'll let others explain to you
> why, assuming they want to bother. You have proven to me that you either
> do not understand logical reasoning, or you do not care about it. Either
> way, I'm done with you. Goodbye Dirk.
>
> Phil
I'd be very glad to learn from others why it is TSTRT and
where the logical reasoning went astray.
If am prepared to put myself on
http://users.pandora.be/vdmoortel/dirk/Physics/ImmortalFumbles.html
Perhaps your Hayek can have a go at it.
Dirk Vdm
Stephen Speicher
Phil, take a deep breath and slowly let it out, and then consider
the possibility that maybe, just maybe, you are missing something
quite basic here. I'm sure you realize that the Earth is in
motion orbiting the Sun. But, do you realize that the entire
solar system is in motion around our galaxy? Do you realize that
our galaxy is part of a cluster of galaxies which are moving
through intergalctic space? And along with other clusters there
are superclusters of galaxies, all moving together through space.
You say the "earth will do quite nicely." Leaving aside the (very
important) issue of what a "straight line" would mean on a
cosmological scale, granted the above motions exactly what "same
or opposite direction" should you take on your "straight line"
journey which will allow you "to return to earth billions of
years later?"
> >
> > Where will be your Earth, from whence you started, after billions
> > of years? In fact, your Earth may no longer even be in
> > existence.
>
>
> Now you're just being silly. Is it impossible to measure the velocity of
> light because the machine "might blow up" during the experiment? Come on ...
>
I'm not being silly. I'm trying to get you to understand that
"place" or "location" is a relational concept, one which we
denote in relation to actual objects which exist. Where will the
"place" where you started your journey billions of years ago be?
There is no absolute cosmic marker upon which you put a big X
which says "You are here." We understand "place" as a
relationship between objects, and that relationship is a dynamic
one within the universe. Over short-enough times and short-enough
distances we can think in terms of a fixed relationship, but
travelling cosmological times and travelling cosmological
distances the relationships between objects are no longer the
same. There is no place marked "here" to which we can return.
> Think, Stephen, are you *really* going to
> claim that if we live in a closed universe, that it would be impossible
> to leave, travel in a straight line, and eventually return to earth?
Yes, that is what I am "*really*" claiming for a finite unbounded
universe. And, I have (again) given you some of the basic
arguments for why this is so. Are you going to understand and
deal with them this time, or are you instead going to write silly
little emotional statements such as this one below.
>
> You're going to look pretty dumb to a lot of people if you do.
>
Fortunately, for me, I have an independent mind and I am more
interested in what is right or wrong, than in what other people
think.
>
> This is stupid, and if I let it continue, then I need to start wearing a
> shirt that says, "Even More Stupid" on it.
>
Whatever you feel comfortable with, Phil.
Stephen Speicher
[...]
>
>
> Ah, good. Yours remains my only positive review!
>
[...]
>
> I mean, these are seriously big ideas! True, they may be full
> of crap, but that's merely all the more reason why *someone*
> would send posts on the subjects!
>
Let me get this straight. If, in the past I have determined that
your "theorizing" is, using your words, "full of crap," then now
that you have made nine separate posts, totalling almost 200k, of
the same, that to you is "all the more reason" why I should "send
posts on the subjects?"
Has it occurred to you that hardly anyone cares about "Phil's
Principia" _because_ they have already determined that your
"theorizing" is, using your words, "full of crap?"
Phil
Dirk, I'll let others point out the errors in your "scientific"
reasoning, assuming anyone cares.
Phil
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D86CE43...@austin.rr.com...
> Sorry, this one really is TSTRT -- and I'll let others explain to you
> why, assuming they want to bother.
While I wait for someone to prove to me that I "either do not
understand logical reasoning, or do not care about it", I have
created your first entry:
http://users.pandora.be/vdmoortel/dirk/Physics/ImmortalFumbles.html#TSTRT
"This one really is Too Stupid To Respond To. Pull the cork out."
Dirk Vdm
Stephen Speicher
>
> "Phil" <tri...@austin.rr.com> wrote in message news:3D86CE43...@austin.rr.com...
> > Sorry, this one really is TSTRT -- and I'll let others explain to you
> > why, assuming they want to bother. You have proven to me that you either
> > do not understand logical reasoning, or you do not care about it. Either
> > way, I'm done with you. Goodbye Dirk.
> >
>
> where the logical reasoning went astray.
I'll be happy to explain it to you, Dirk. "TSTRT" is a shorthand
code for Phil, which to him means he doesn't understand, or
doesn't _want_ to understand, what you have to say. And, besides,
if he did understand, that would mean he could no longer hold on
to his own mistaken views.
As to "where the logical reasoning went astray," I'm afraid that
occurred when you assumed you could have a rational conversation
with Phil.
> If am prepared to put myself on
> http://users.pandora.be/vdmoortel/dirk/Physics/ImmortalFumbles.html
Hardly necessary, but I think you need to make some big room for
Phil, who is knocking on your door, just begging to be let in.
Stephen Speicher
> Sorry, but I'm going to have to add this to the list of TSTRT. As with
> Dirk, I'll let others point out the errors in your "scientific"
> reasoning, assuming anyone cares.
>
Translation: I do not understand, or I do not _want_ to
understand, so if I pretend hard enough I can hold on to my
views, even if they are wrong.
Bilge
Re: Problems with the Program of Relativity to usenet:
>Bilge wrote:
>
>> Phil said some stuff about
>> Re: Problems with the Program of Relativity to usenet:
>>
>> >Okay, chew on this (from the "Mechanical Methods for ..." paper).
>> >
>> >"For example, suppose that we do live in a closed universe, so that an
>> >observer leaving the earth at high speed and traveling in a straight
>> >line would eventually, after several billion years, travel completely
>> >around the universe and find himself back on earth.
>>
>> You've already created an ill-defined argument. What is a
>> "straight line"? How do you if you are traveling in a "straight
>> line"? (Without making your definition circular).
>
>
>This technically falls under the category of TSTRT -- Too Stupid To
>Respond To -- but what the hell.
For some reason, when someone makes this comment, I can count on
the not ever receiving an explanation. This is either because the
person was wrong about the question being stupid and couldn't actually
answer it, or doesn't seem to understand the problem well enough to
realize he/she can't answer the question.
> For this experiment, a straight line
>means that the spaceship would follow the same path that a beam of light
>would follow, assuming that the light does not travel through a strong
>gravitational field, in which case, the spaceship would have to follow
>the path that light would have traveled had it not encountered the field.
How does the spaceship know what that path "should have been" such that
it is straight?
> From Steven Weinberg's "The First Three Minutes," page 34 of the
>updated paperback version:
>
>"On the other hand, if the density of the universe is *greater* than
>this critical value, then the gravitational field produced by the matter
>curves the universe back on itself; it is finite though unbounded, like
>the surface of a sphere. (That is, if we set off on a journey in a
>straight line, we do not reach any sort of edge of the universe, but
>simply come back to where we began.)
A straight line being defined as? My guess is that he meant,
"the path of light or a null ray".
>And if you think Steven Weinberg is an idiot, then I have no further use
>for you.
Sheesh... Since a lot of my graduate career was spent doing experi-
mental weak interaction nuclear physics (read: weinberg-salaam model
of the electroweak), I'll let you figure that one out.
> I may believe that I figured out something that he didn't --
>that the energy lost by photons as the universe expands does not just
>"mystically disappear" from the universe, but instead remains with the
>medium of space (see the paper on "The Missing Mass of the Universe") --
Since I saw him give a colloquim in which he discussed this somewhat
just about 5 months ago, I'm rather hard-pressed to see that you've even
discovered the problems.
>but I am here to tell you that that is at most just an oversight on his
>part, because that man can THINK! (Great book, recommended even if the
>ideas in my paper are true.)
"The First Three Minutes" is a great book for a basic outline of origin
of the universe at a level many people can understand. It doesn't qualify
as a substitute for the standard model (of which the SU(2) x U(1) part
of SU(3)xSU(2)xU(1), he was one of the authors).
[...]
>
>This is why, as Weinberg says, "if we set off on a journey in a straight
>line, we do not reach any sort of edge of the universe, but simply come
>back to where we began."
Then, it should be just as obvious, that what defines a straight line
in opposite directions is the same great circle on the sphere, making
the proposition a tautology by the definition of "straight".
[...]
>>
>> This isn't even classically correct. Anything which leaves the earth
>> in opposite directions with "equal speeds", leaves the earth at the
>> center of momentum.
>
>
>I am going to assume that you were simply not thinking when you wrote
>this.
No. I was thinking when I wrote it. Assume that, since it's correct.
>If you and I are in the same IRF, and we measure the velocity of a
>third observer moving directly away from us as being +0.25c, and this
>third observer sends out two objects at velocities of +0.8c and -0.8c as
>seen by him, one directly toward us (-0.8c), and the other directly away
>from us (+0.8c, in the same direction from us as the third observer),
>then we will measure velocities for the two objects as being -0.6875c
>and +0.875c, according to standard Lorentz transformation SR.
Is there some reason that you introduced extraneous reference frames
other than to confuse yourself? You have:
1 earth 2
<---- O ---->
The earth is the center of momentum, by definition of observers
1 and 2 starting with equal momentum in opposite directions. Otherwise,
they aren't equivalent.
First get that part right, before convoluting with an unnecessary
additional observer. This is just simple _classical_ physics.
>> >spaceships will have absolute velocities of 0.6875 c left and 0.875c
>> >right, respectively. The earth will therefore travel 0.25c/(0.6875 c +
>> >0.25c ) = 26.7% around the universe before the left spaceship returns,
>> >and 0.25 c/(0.875 c - 0.25 c ) = 40% around the universe before the
>> >right spaceship returns. The difference between the return times of the
>> >two ships can then be used to determine the earth's absolute velocity.
>>
>> In other words, what you are claiming is equivalent to saying that
>> if you're on an airplane traveling at 600 mph, and drop your pen to the
>> floor, it will fall to the floor of the plane at an angle.
>
>
>TSTRT
See my first comment regarding "inability to respond".
>
>
>>
>> [...]
>>
>> >So, my response to your challenge is, show me how the earth observer can
>> >correctly predict the results using *only* local velocities, the
>>
>> I don't think you know what "local" means.
>
>
>TSTRT
OK. Then it should be simple for you to define. Do so.
>> The correct prediction by special relativity is that the world lines
>> of inertial observers can't intersect more than once. Your scenario
>> doesn't make sense in special relativity. It's always possible to
>> frame a question that a theory can't address because the question
>> makes no sense in the theory. Unless the scenario is actually possible
>> then the theory better not have an answer, either.
>
>
>SR does not assume a finite, yet unbounded universe, and so does not run
>into this problem. In that respect your thinking is quite good!
And obviously, yours is not.
>However, we cannot say, simply because SR, GR, and the principle of
>relativity find it to be *inconvenient*, that we do not have to even
>consider the implications that follow if we live in a bounded universe,
It's not an issue for general relativity, in which the universe can be
open, closed or asymptotically flat. Since geberal relativity wouldn't
exist if special relativity was adequate to describe the universe, what's
your point?
[...]
>
>If we live in a closed universe, and two spaceships leave the earth in
>opposite directions at equal velocities as seen by the earth and
>spaceship observers, and travel in straight lines, then they will
>eventually return to earth.
So what? General relativity has no problem with this.
>
>Now, you and Stephen Speicher (who mirrored your comments in his
>response to your post) can honestly deal with this, as Einstein would
>have done, or you can simply argue with a bunch of pointless BS, such as
>"you can't define straight lines without circular reasoning," or "well,
>we probably live in an open universe, so this doesn't count."
(1) The comment about straight lines being circular was only
my first objection, (which you haven't met);
(2) I didn't assume that we lived in an open universe. Prior to
using that as an excuse to avoid all of the spots you marked,
TST..whatever, show me whare I assumed that;
(3) A question can't be too pointless if you can't even attempt
to answer it;
>Responding with a bunch of BS is, however, *scientifically* meaningless,
>and I'm not going to waste any more of my time on it.
OK. Don't.
Phil
tomorrow, but:
Dirk:
>On the surface of a perfect sphere you "simply come back
>where you began".
>On the surface of a perfect ellipsoid or a perfect torus, which
>is are finite though unbounded, you "simply do *not* come
>back where you began".
>On the surface of Earth, which is finite though unbounded,
>you "simply do *not* come back where you began".
>If the Universe is the analogue of a perfect sphere, you
>"simply come back where you began" - if you manage to
>define what "where you began" actually means in the first
>place (I guess Stephen has been and will be entertaining
>you on that topic).
>What if the Universe is the analogue of an ellipsoid or a
>torus, or a "somewhat less perfect sphere"?
>What if the Universe is not empty and the presence of
>matter disturbs the "perfect sphere"?
>Do you "simply come back where you began"?
The problem here is that only a single set of relativity laws are
supposed to apply to all of these situations. In other words, it is the
amount of mass/energy in the universe determines the shape of space, but
there are not several sets of laws, one for each possible configuration
of the universe. And if *any* of the configurations for which the laws
are supposed to be valid shows defects in those laws, it can only be
because those defects actually exist. Once such a defect has been shown
to exist, we cannot make it go away by looking at a different
configuration, because the *laws themselves* do not change! To assert
otherwise would be equivalent to saying that prior to the MMX, that not
only did light travel at a constant velocity relative to the ether, but
lengths did not contract, because all our experiments and views of
nature did not reveal otherwise. Those beliefs were defective whether
anyone could see that fact or not. Similarly, it doesn't matter whether
we live in a galaxy, and in a universe, that will not allow us to
perform some experiment. The laws of physics are supposed to valid for
both open and closed universes, and if one of those configurations
reveals a defect, then those laws are wrong, regardless of the actual
configuration of our universe.
One of the valid configurations for the universe is basically a
hypersphere. It does not violate any laws of physics to assume that a
spaceship can leave a planet *somewhere* in the universe, travel in what
appears to be a straight line (actually a giant circle, as Bilge says in
his latest post, but that's not how it appears to us, who live in the
universe), and then return to its world, without having to worry about
finding that world (due to both advanced technology, and the fact that
the motion of this world is not significantly affected by gravity).
Again, from Bilge's latest post:
(Phil) If we live in a closed universe, and two spaceships leave the
>earth in opposite directions at equal velocities as seen by the earth
>and spaceship observers, and travel in straight lines, then they will
>eventually return to earth.
(Bilge) So what? General relativity has no problem with this.
Bilge may chip in here and say otherwise, but I think he is agreeing
with my hypothesis that *in theory*, the scenario in which two
spaceships leave the earth in opposite directions at equal velocities as
seen by the earth and spaceship observers, travel in straight lines, and
eventually return to earth, is a valid thought experiment. *If* this
thought experiment leads to contradictions, then relativity has a
problem -- and it may be a very small problem -- on its hands. At that
point, "running away" to an open universe will not solve the problem,
because the laws are *supposed* to be valid in both configurations.
In other words, why are you wasting your time stating that the universe
could have different configurations from the one in my experiment, when
that will not save those laws should they turn out to have problems in
my configuration? That is my point -- although now that I look at it, it
is a lot more complicated than I thought. I apologize for saying that
your error was too stupid to bother with; it obviously is not.
Stephen:
>I'm not being silly. I'm trying to get you to understand that
>"place" or "location" is a relational concept, one which we
>denote in relation to actual objects which exist. Where will the
>"place" where you started your journey billions of years ago be?
>There is no absolute cosmic marker upon which you put a big X
>which says "You are here." We understand "place" as a
>relationship between objects, and that relationship is a dynamic
>one within the universe. Over short-enough times and short-enough
>distances we can think in terms of a fixed relationship, but
>travelling cosmological times and travelling cosmological
>distances the relationships between objects are no longer the
>same. There is no place marked "here" to which we can return.
This is true. As I would put it, absolute position is meaningless,
because there are no characteristics of space (to our knowledge) that
vary as a function of position. The only "position" available to us is
that which is determined relative to non-universal objects, such as
stars, galaxies, and planets, and by definition these are *relative*
positions, not absolute positions. I am with you 100% here, and it is a
good point.
However, it has nothing to do with my thought experiment, which is why I
keep dismissing it. My experiment uses the relative position set by the
earth (or any other body which is *not* significantly affected by
interstellar gravitational fields; an assumption which lies within the
laws of physics, making it valid for a thought experiment). Granted, its
"position" in space may change, but that will not stop the spaceships
from returning, as long as they go in the right direction (and since the
laws of physics do not prevent the spaceships from going in the right
direction, I am free to use such a condition in my thought experiment).
Take as a given that some world can send two spaceships out in the
manner I described, because although we can waste time saying it is
technically beyond our current abilities, the earth might vanish, etc.,
the laws of physics do not forbid such a thing. Hell, such an experiment
may be nearing completion somewhere in the universe now, as we speak!
Now for the important part: If the spaceships leave at equal velocities,
the observers on the planet can rightly assume that they will return at
the same time. However, an inertial observer who is moving in the same
direction as one of the spaceships (albeit at much lower velocity) will
measure the velocity of the spaceships *relative to the earth* as being
unequal, a natural consequence of the Lorentz transform.
To put numbers on it, the spaceships leave the planet at 0.8c in
opposite directions as measured by the planet observers. Now, assume
that the earth is moving away from the inertial observer at 0.25c as
seen by the inertial observer (who of course believes himself to be
motionless). This inertial observer will then measure velocities for the
two spaceships of 0.875c for the spaceship moving away from himself, and
0.6875c for the spaceship moving toward him.
My claim -- and it is here that you will find a flaw, if one exists --
is that the inertial observer predicts that the planet will travel
0.25c/(0.6875c + 0.25c) = 26.7% around the universe before the second
spaceship returns, and 0.25c/(0.875c - 0.25c) = 40% around the universe
before the second spaceship returns. Of course these times are not
exact, since they do not take into account the expansion or contraction
of the universe, but while taking that into account would change the
actual distance that the planet traveled around the universe before the
spaceships returned, they would still return at very different times.
The main point is that the planet observer predicts that the spaceships
will return at the same time, while the inertial observer predicts that
they will return at different times (barring a potential flaw, as
mentioned above).
The principle of relativity can be stated from several different
viewpoints, one of which states that when two observers, moving in
different inertial reference frames, observe the same experiment, they
will *always* predict the same results for the experiment. This is
simply another way of stating that the results of experiments are the
same in all inertial reference frames. Under the principle of
relativity, both the planet observer and the earth observer are supposed
to predict the same result for the return times of the spaceship, but
they do not. This experiment therefore violates the principle of
relativity. In theory, this experiment could be done by thousands of
planets, all moving at different velocities. All of them will predict
that their spaceships will return at the same time, but that will occur
for at most one of the planets. That planet's observers can then
correctly conclude that they are motionless relative to -- whatever it
is that the velocity of light, time-dilation, etc. are actually relative
to. For convenience, I call it the medium of space, but you are free to
use whatever term you want.
Of course, now that I look at this, it is also very complicated, so I
owe you an apology too, Stephen, for saying that it was too stupid to
respond to. Okay, you guys had good attacks, and you got me frustrated,
dammit!
Now, to restate, you guys can blow this away by showing that *both*
observers predict equal return times for the spaceships, but it looks
impossible to me. Of course, I have been convinced that certain
experiments violated the PofR for as long as *8 years* before finally
going, "Oh, wait a minute...," and this might turn out to be the same.
Nevertheless, it is, at this time, the best I have ever seen.
Finally, on the other point that's been driving me to drink, not to
mention ill manners: There are a *lot* of ideas in these papers, and the
ones in this thread are actually the last ones I thought anyone would
want to discuss. Among them are:
That all of the energy, kinetic and gravitational, accumulated by an
object falling into a gravitational well, comes from the medium of space.
This implies that the first really big collapsed stars, be they black
holes or "merely" collapsars, would have experienced significant
increases in mass and in the size of their gravitational fields as
energy from the medium of spacer poured into them, thereby making it
possible for the first galactic clusters to form.
That the energy lost by photons as the universe expands does not just
mystically disappear, but instead remains with the medium of space
(although Bilge says he saw Stephen Weinberg discussing this issue 5
months ago, curse it). My own conclusion from this is that space must
contain a quantity of energy at least a trillion times greater than all
the mass in all the galaxies combined, although I do not know what SW's
conclusions were.
To cut to shreds my thought experiment, completely ignore all my other
ideas, and then claim that the entire set of papers is nothing but
nonsense is not just unfair, it's scientifically inaccurate! You can't,
or at least you shouldn't, draw a conclusion from one subject, shift to
a different subject, and then apply the conclusion there. Now, if you
just want to win an argument, by all means attack any perceived weak
points, and ignore any strong points. My idea of science, however, is
that you must be willing to occasionally lose an argument, and state
what you really think about something, even if that leaves you in a
"weak" position. For example, what's wrong with "I think that's wrong
but I don't know why," or "That looks interesting, it might actually be
useful to physicists," or "I don't have a clue."?
I was wrong to apply the TSTRT label on you guys, and again I apologize,
but I must mention that I am not interested in discussions which focus
*solely* on perceived weak points, while ignoring all other points. If
your interest is only attacking what you perceive to be "attackable"
ideas, then we go different ways, and I will be forced to limit the time
I can spend on any of you. If you have scientific thoughts on any of the
other points I have addressed, those thoughts would be appreciated. Even
if it's just references to other papers which have either "been there
done that," or which show that my conclusions are wrong. Simply
*claiming* that everything is wrong falls back into the realm of
arguments, since such claims are not backed up by anything real. If
that's all you've got -- generalized criticisms with nothing real to
back them up -- then I will still have to end any discussions with you
(although I will *not* apply the TSTRT label!), simply because I have
very little interest in spending my time in that manner.
Phil
Dirk Van de moortel wrote:
Phil
You don't just have good points here, you have very *interesting*
points! I see now that I have misinterpreted what you were saying, and I
apologize for the TSTRT label. Unfortunately it is very late, so I will
have to send a "real" response tomorrow.
Phil
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D883B64...@austin.rr.com...
Of course. No problem, well put.
*If* you find a flaw in the theory for the empty universe,
you found a flaw in the theory tout court.
[snip]
But Phil, this is so basic. It is relativity of simultaneity.
For this discrepancy to take place, the ships don't even
*have* to go "around a universe".
Just suppose that, as seen on Earth, both ships send out
a flash of light at the same time, let's say 2 Earth-minutes
after their departures.
Then, as measured on the "the inertial observer", the flashes
will *not* be simultaneous, neither will they be as measured
on the ships themselves. Only Earth will find them to be.
That is not a flaw. That is page one of SR-001. Right?
[ here is where you get the opportunity to be
removed from my fumblepage. How about that? ]
Dirk Vdm
Stephen Speicher
[Enormous snip...(Succinctness can be a virtue).]
> However, it has nothing to do with my thought experiment, which
> is why I keep dismissing it. My experiment uses the relative
> position set by the earth (or any other body which is *not*
> significantly affected by interstellar gravitational fields...
Look, once again, I will put aside the (most fundamental) issue
of what it would mean to go in a "straight line direction" over
cosmological distances for many billions of years. However, as to
Earth and your assumption, you do not seem to be aware of the
cosmological gravitationally bound systems and their effects
which I mentioned. The Earth orbits the Sun at about 30 km/s;
the solar system itself is moving through our galaxy at about 220
km/s; Our local cluster of galaxies is traveliling towards
another cluster at about 70 km/s/Mpc; our supercluster is headed
elsewhere at about another 75 km/s/Mpc; and, if the "expanding
universe" concept were correct, the space between the galactic
clusters will expand at about 70 km/s/Mpc. And, all this is
dynamically changing across cosmological distance and
cosmological times.
So, I ask again, exactly what "straight line direction" will
permit a traveller to leave the Earth and travel many billions of
years across the finite unbounded universe, and arrive back at
Earth again? As I keep saying to you, the Earth will not be
"here," here.
Bilge
Re: Problems with the Program of Relativity to usenet:
>The problem here is that only a single set of relativity laws are
>supposed to apply to all of these situations. In other words, it is the
>amount of mass/energy in the universe determines the shape of space, but
>there are not several sets of laws, one for each possible configuration
>of the universe.
And general relativity does exactly what you require, through
general covariance.
> And if *any* of the configurations for which the laws
>are supposed to be valid shows defects in those laws, it can only be
>because those defects actually exist.
Which is why special relativity is only a limiting case of the
general theory.
[...]
>anyone could see that fact or not. Similarly, it doesn't matter whether
>we live in a galaxy, and in a universe, that will not allow us to
>perform some experiment. The laws of physics are supposed to valid for
>both open and closed universes, and if one of those configurations
>reveals a defect, then those laws are wrong, regardless of the actual
>configuration of our universe.
Yes, it does matter and nothing requires the laws of physics to
be compatible with any universe imaginable. One of, if not the,
biggest questions in physics is whether or not any other universe
is possible. If any type of universe were possible, there would be
no point in doing physics at all, since there would be no reason,
a priori, to expect any relationships between phenomena to exist.
>One of the valid configurations for the universe is basically a
>hypersphere. It does not violate any laws of physics to assume that a
>spaceship can leave a planet *somewhere* in the universe, travel in what
>appears to be a straight line (actually a giant circle, as Bilge says in
>his latest post, but that's not how it appears to us, who live in the
>universe), and then return to its world, without having to worry about
>finding that world (due to both advanced technology, and the fact that
>the motion of this world is not significantly affected by gravity).
It may or may not violate physical laws for such a trip to be
possible. The question of whether it does or not is a major one.
In addition, the only effects you are attributing to gravity are
the direct, localized effects. But gravity has a more fundamental
role here, because gravity is what determines if your trip is even
possible. No gravity means no closed universe.
[...]
>
>(Bilge) So what? General relativity has no problem with this.
>
>Bilge may chip in here and say otherwise, but I think he is agreeing
>with my hypothesis that *in theory*, the scenario in which two
>spaceships leave the earth in opposite directions at equal velocities as
>seen by the earth and spaceship observers, travel in straight lines, and
>eventually return to earth, is a valid thought experiment.
It's a valid question for a thought experiment, but you can't assume
the outcome to prove something that depends upon the answer until you
first answer that question.
>*If* this thought experiment leads to contradictions, then relativity
>has a problem --
Not necessarily, since it's possible that the possibilty of such a
trip would lead to a universe which can't exist.
[...]
>In other words, why are you wasting your time stating that the universe
>could have different configurations from the one in my experiment, when
>that will not save those laws should they turn out to have problems in
>my configuration?
Because the scenario you've chosen may very well be contradicted by
the physical laws required for any universe to exist. Since what we
are trying to discover is what those laws are, there is no way to know
whether the trip you've imagined is, in fact, possible regardless of
the types of physically permissible universes that may exist. So, while
such a trip is valid as a question that might help ascertain whether
the trip is possible, it's not valid to assume that it must be. The
fact that general relativity permits different possible answers is
a liability, not an asset. If we had a complete theory, we would not
only need to allow for a single possibility - the correct one.
Phil
Well now! Chances for redemption are indeed rare, let's see here ...
I'll set this up first as A is the "inertial observer," while B is the
earth observer, moving at, say, 0.866c "toward the right" away from A.
As you say, A and B see certain things differently. A better example
than my universe experiment is for both A and B to measure c by sending
a pulse of light up and down on a round-trip for a total distance of 3
m, which requires 10 ns. Both observers see the pulse of light simply
moving straight up and down, but when A looks at B's experiment, he sees
that the light must travel along a diagonal due to B's horizontal
velocity. In fact, the light must travel a distance of 6 m, not 3 m, on
its round-trip. However, A also sees that B's clocks run half as fast,
causing B to measure a velocity of 6 m/20 ns = 300,000 km/s, the same
result that A gets.
The point is that while the *processes* of B's experiments appear
differently to A than they do to B -- the "SR-001" you mentioned -- the
*predicted results* are exactly the same. In fact, A and B will predict
the same results for *all* of B's experiments (although by different
means) that fall under the principle of relativity. In other words, in
order for one of B's experiments to fall under the PofR, A and B *must*
be able to predict the same results for that experiment. This is a
corollary of the PofR. Were they to predict different results, one of
them would be wrong, thereby invalidating either the laws of physics, or
the manner in which those laws were used.
Obviously this is *not* SR-001, although it is still fairly simple --
once you think about it. The problem in my thought experiment,
therefore, is not that A and B see different velocities for the
spaceships (SR-001), but rather that they predict different results for
the experiment, namely when those spaceships will return.
I see that Stephen and Bilge both have good points too, so I will cut it
short there, but hopefully that mostly answers your question -- at
least, enough to secure my redemption!
Phil
Phil
I think it will be similar to two men who start together at some point
on the equator of the earth. One of them starts walking east, while the
other gets in a plane and starts flying east. Eventually, the plane will
"return to the man," but he will no longer be "here," where "here" is
relative to the earth. It is possible for the flyer to return to the
man, but they won't necessarily be at the same place on the earth.
The example I like to use is the ocean's surface. Does "place" really
have a meaning on the ocean's surface? I say no, because for vast
stretches, there are (pragmatically speaking) no characteristics that
vary as a function of position. In order for position to have meaning,
there has to be something that distinguishes one place from another.
Now, with help from GPS satellites, we can *assign* a position to any
position on the ocean's surface, but these positions are determined not
by the ocean's surface, but by using objects that can refer to *land
positions*. In other words, "position," when used on the ocean's
surface, is actually obtained by using characteristics of land, rather
than the characteristics of the ocean.
A similar situation exists for space. As far as we know, space has no
characteristics that vary as a function of position, making a "position
in space" as meaningless as position on the ocean. Instead, we must use
ordinary objects and the distances/angles between them to specify
position. And just like the man walking on the equator, those positions
can and usually do change relative to their "positions in space" (even
if that has any meaning). Now, if we *assume* that the CMBR is
motionless relative to space, then we can use that to determine
velocity, and then declare that since object X is motionless, that it
has the same position "in space." However, such a claim will be no more
correct (although no less) than claiming that a ship has the same
"position" on the ocean's surface. It does have a meaning, but that
meaning is different from the meaning that position has on land
surfaces. We almost need two different versions of position, one that is
"real," like the position in a city (which definitely has
characteristics that vary as a function of position), and one which is
"artificial," a position which is imposed on something from outside,
using characteristics of the "outside" reference to define position.
Well, I've spent a lot of time agreeing with you, haven't I? The reason
that my thought experiment works is because it is not, at its core, an
"absolute position" experiment, in spite of the fact that it is most
easily explained by imposing artificial positions upon space by using
objects such as planets and spaceships, along with their distance/angle
relationships with all the other normal objects in the universe. It is
instead an "absolute velocity" experiment, and space does have
characteristics that vary as a function of velocity (otherwise both the
inertial observers and the planet observers would predict the same
return times for the spaceships).
Does it look like I understand your point, and have I given a good
answer, at least in regards to how the spaceship can arrive back "here"
on earth (from the viewpoint of earth), even though "here" isn't here
anymore (from the viewpoint of space)? I realize that this is only one
point, and even if you agree with it, I don't expect you to be convinced
this easily that my thought experiment violates the PofR, which is an
entirely different point.
Phil
Phil
> Phil said some stuff about
> Re: Problems with the Program of Relativity to usenet:
> >Bilge wrote:
> >
> >> Phil said some stuff about
> >> Re: Problems with the Program of Relativity to usenet:
> >>
> >> >Okay, chew on this (from the "Mechanical Methods for ..." paper).
> >> >
> >> >"For example, suppose that we do live in a closed universe, so that an
> >> >observer leaving the earth at high speed and traveling in a straight
> >> >line would eventually, after several billion years, travel completely
> >> >around the universe and find himself back on earth.
> >>
> >> You've already created an ill-defined argument. What is a
> >> "straight line"? How do you if you are traveling in a "straight
> >> line"? (Without making your definition circular).
> >
> >
> >This technically falls under the category of TSTRT -- Too Stupid To
> >Respond To -- but what the hell.
>
> For some reason, when someone makes this comment, I can count on
> the not ever receiving an explanation. This is either because the
> person was wrong about the question being stupid and couldn't actually
> answer it, or doesn't seem to understand the problem well enough to
> realize he/she can't answer the question.
That is indeed oftenthe case, but here -- possibly in addition to the
reasons you give above -- I misunderstood what you were saying, and got
unjustifiably frustrated.
>
> > For this experiment, a straight line
> >means that the spaceship would follow the same path that a beam of light
> >would follow, assuming that the light does not travel through a strong
> >gravitational field, in which case, the spaceship would have to follow
> >the path that light would have traveled had it not encountered the field.
>
> How does the spaceship know what that path "should have been" such that
> it is straight?
>
> > From Steven Weinberg's "The First Three Minutes," page 34 of the
> >updated paperback version:
> >
> >"On the other hand, if the density of the universe is *greater* than
> >this critical value, then the gravitational field produced by the matter
> >curves the universe back on itself; it is finite though unbounded, like
> >the surface of a sphere. (That is, if we set off on a journey in a
> >straight line, we do not reach any sort of edge of the universe, but
> >simply come back to where we began.)
>
> A straight line being defined as? My guess is that he meant,
> "the path of light or a null ray".
>
> >And if you think Steven Weinberg is an idiot, then I have no further use
> >for you.
>
> Sheesh... Since a lot of my graduate career was spent doing experi-
> mental weak interaction nuclear physics (read: weinberg-salaam model
> of the electroweak), I'll let you figure that one out.
Whoa. Okay, not only do you respect him, but you *understand* why he
should be respected far better than I do.
>
> > I may believe that I figured out something that he didn't --
> >that the energy lost by photons as the universe expands does not just
> >"mystically disappear" from the universe, but instead remains with the
> >medium of space (see the paper on "The Missing Mass of the Universe") --
>
> Since I saw him give a colloquim in which he discussed this somewhat
> just about 5 months ago, I'm rather hard-pressed to see that you've even
> discovered the problems.
I am seriously sorry to hear that! Shouldn't have waited 13 years to say
something ... Oh well. Did he agree with my conclusion that the medium
of space contains at least a trillion times more energy that that
contained in all the matter in all the galaxies combined, or did he
address that issue at the colloquim you attended? (Numbers from my paper
on "The Missing Mass of the Universe.")
>
> >but I am here to tell you that that is at most just an oversight on his
> >part, because that man can THINK! (Great book, recommended even if the
> >ideas in my paper are true.)
>
> "The First Three Minutes" is a great book for a basic outline of origin
> of the universe at a level many people can understand. It doesn't qualify
> as a substitute for the standard model (of which the SU(2) x U(1) part
> of SU(3)xSU(2)xU(1), he was one of the authors).
I'll take your word for it, since you are already over my head.
>
> [...]
> >
> >This is why, as Weinberg says, "if we set off on a journey in a straight
> >line, we do not reach any sort of edge of the universe, but simply come
> >back to where we began."
>
> Then, it should be just as obvious, that what defines a straight line
> in opposite directions is the same great circle on the sphere, making
> the proposition a tautology by the definition of "straight".
I thought that "straight" in space would be automatically understood by
physicists as eventually being the "great circle on the sphere." It
appears straight to us, because our "straight" in fact curves (in closed
and saddle universes).
>
> [...]
> >>
> >> This isn't even classically correct. Anything which leaves the earth
> >> in opposite directions with "equal speeds", leaves the earth at the
> >> center of momentum.
> >
> >
> >I am going to assume that you were simply not thinking when you wrote
> >this.
>
> No. I was thinking when I wrote it. Assume that, since it's correct.
>
> >If you and I are in the same IRF, and we measure the velocity of a
> >third observer moving directly away from us as being +0.25c, and this
> >third observer sends out two objects at velocities of +0.8c and -0.8c as
> >seen by him, one directly toward us (-0.8c), and the other directly away
> >from us (+0.8c, in the same direction from us as the third observer),
> >then we will measure velocities for the two objects as being -0.6875c
> >and +0.875c, according to standard Lorentz transformation SR.
>
> Is there some reason that you introduced extraneous reference frames
> other than to confuse yourself? You have:
>
> 1 earth 2
> <---- O ---->
>
> The earth is the center of momentum, by definition of observers
> 1 and 2 starting with equal momentum in opposite directions. Otherwise,
> they aren't equivalent.
>
> First get that part right, before convoluting with an unnecessary
> additional observer. This is just simple _classical_ physics.
Here is where I misunderstood you -- partly because I did not make
myself clear and you misunderstood me. I agree that momentum is
conserved, whether as measured by the earth observer or by the inertial
observer moving at 0.25c relative to the earth. However, while the earth
observer measures the spaceships as leaving at equal speeds, the
inertial observer measures them as leaving at different speeds, although
the changes in mass (again seen from the inertial observer's
perspective) leave the earth at the center momentum.
>
>
> >> >spaceships will have absolute velocities of 0.6875 c left and 0.875c
> >> >right, respectively. The earth will therefore travel 0.25c/(0.6875 c +
> >> >0.25c ) = 26.7% around the universe before the left spaceship returns,
> >> >and 0.25 c/(0.875 c - 0.25 c ) = 40% around the universe before the
> >> >right spaceship returns. The difference between the return times of the
> >> >two ships can then be used to determine the earth's absolute velocity.
> >>
> >> In other words, what you are claiming is equivalent to saying that
> >> if you're on an airplane traveling at 600 mph, and drop your pen to the
> >> floor, it will fall to the floor of the plane at an angle.
> >
> >
> >TSTRT
>
> See my first comment regarding "inability to respond".
Hopefully my clarification above is a better response.
> >
> >
> >>
> >> [...]
> >>
> >> >So, my response to your challenge is, show me how the earth observer can
> >> >correctly predict the results using *only* local velocities, the
> >>
> >> I don't think you know what "local" means.
> >
> >
> >TSTRT
>
> OK. Then it should be simple for you to define. Do so.
Really, really local positions, velocities, and accelerations are those
measured by a particular observer, preferably an inertial observer
(otherwise the calculations must, in one way or another, take any
changes in velocity into account, although this can sometimes be done by
using imaginary gavitational fields). I sometimes take liberties with
the word, as when referring to the velocity of each spaceship relative
to the earth as measured by either the spaceship observers or the earth
observers. Since they measure the same speed for the spaceships relative
to the earth (although not when one spaceship observer observes the
other spaceship), I refer to their measurements as "local velocities,"
as seen by the inertial observer.
>
> >> The correct prediction by special relativity is that the world lines
> >> of inertial observers can't intersect more than once. Your scenario
> >> doesn't make sense in special relativity. It's always possible to
> >> frame a question that a theory can't address because the question
> >> makes no sense in the theory. Unless the scenario is actually possible
> >> then the theory better not have an answer, either.
> >
> >
> >SR does not assume a finite, yet unbounded universe, and so does not run
> >into this problem. In that respect your thinking is quite good!
>
> And obviously, yours is not.
>
> >However, we cannot say, simply because SR, GR, and the principle of
> >relativity find it to be *inconvenient*, that we do not have to even
> >consider the implications that follow if we live in a bounded universe,
>
> It's not an issue for general relativity, in which the universe can be
> open, closed or asymptotically flat. Since geberal relativity wouldn't
> exist if special relativity was adequate to describe the universe, what's
> your point?
I think, based on your new post, that you already know what I am going
to say, so I will be somewhat brief from here on. The point is that
asking whether the principles and laws of relativity lead to
contradictions under the assumption of a closed, unbounded and yet
finite universe is a valid test and exercise.
>
> [...]
> >
> >If we live in a closed universe, and two spaceships leave the earth in
> >opposite directions at equal velocities as seen by the earth and
> >spaceship observers, and travel in straight lines, then they will
> >eventually return to earth.
>
> So what? General relativity has no problem with this.
Yes, but when the inertial observer moving at 0.25c relative to the
earth has *different* predictions for when the spaceships will return
than the earth observer, then the principle of relativity does have a
problem. Under the PofR, both the inertial and earth observers *must* be
able to predict not only the correct time for the spaceship's return,
but the *same* time for thier return. It may seem like the distinction
between "correct" and "same" is meaningless, but if they are not the
same, then relativity is in trouble the moment the spaceships leave,
regardless of whether they ever return.
Phil
>Now, you and Stephen Speicher (who mirrored your comments in his
>response to your post) can honestly deal with this, as Einstein would
>have done, or you can simply argue with a bunch of pointless BS, such as
>"you can't define straight lines without circular reasoning," or "well,
>we probably live in an open universe, so this doesn't count."
>
> (1) The comment about straight lines being circular was only
> my first objection, (which you haven't met);
Straight lines in a closed universe are indeed parts of great circles,
but I think that that is no problem for my thought experiment. Indeed, I
suspect that it is essential to its functioning!
>
> (2) I didn't assume that we lived in an open universe. Prior to
> using that as an excuse to avoid all of the spots you marked,
> TST..whatever, show me whare I assumed that;
Good point, I think I got that from one of the other posts, and I was
most happy to see you say that a closed universe is fine with you.
>
> (3) A question can't be too pointless if you can't even attempt
> to answer it;
Oh it could be, but yours weren't. My apologies again.
>
> >Responding with a bunch of BS is, however, *scientifically* meaningless,
> >and I'm not going to waste any more of my time on it.
>
> OK. Don't.
>
I won't! But I will try to be honest and admit when I am wrong!
Phil
Phil
> Phil said some stuff about
> Re: Problems with the Program of Relativity to usenet:
>
> >The problem here is that only a single set of relativity laws are
> >supposed to apply to all of these situations. In other words, it is the
> >amount of mass/energy in the universe determines the shape of space, but
> >there are not several sets of laws, one for each possible configuration
> >of the universe.
>
> And general relativity does exactly what you require, through
> general covariance.
>
> > And if *any* of the configurations for which the laws
> >are supposed to be valid shows defects in those laws, it can only be
> >because those defects actually exist.
>
> Which is why special relativity is only a limiting case of the
> general theory.
>
> [...]
> >anyone could see that fact or not. Similarly, it doesn't matter whether
> >we live in a galaxy, and in a universe, that will not allow us to
> >perform some experiment. The laws of physics are supposed to valid for
> >both open and closed universes, and if one of those configurations
> >reveals a defect, then those laws are wrong, regardless of the actual
> >configuration of our universe.
>
> Yes, it does matter and nothing requires the laws of physics to
> be compatible with any universe imaginable.
I think you have something of a point here, although you address it more
fully later.
One of, if not the,
> biggest questions in physics is whether or not any other universe
> is possible. If any type of universe were possible, there would be
> no point in doing physics at all, since there would be no reason,
> a priori, to expect any relationships between phenomena to exist.
Are you certain? Our universe exists, and we can obtain its laws. So
what if infinitely many other universe can or even do exist? Maybe I'm
missing your point
> >One of the valid configurations for the universe is basically a
> >hypersphere. It does not violate any laws of physics to assume that a
> >spaceship can leave a planet *somewhere* in the universe, travel in what
> >appears to be a straight line (actually a giant circle, as Bilge says in
> >his latest post, but that's not how it appears to us, who live in the
> >universe), and then return to its world, without having to worry about
> >finding that world (due to both advanced technology, and the fact that
> >the motion of this world is not significantly affected by gravity).
>
> It may or may not violate physical laws for such a trip to be
> possible. The question of whether it does or not is a major one.
> In addition, the only effects you are attributing to gravity are
> the direct, localized effects. But gravity has a more fundamental
> role here, because gravity is what determines if your trip is even
> possible. No gravity means no closed universe.
Yes, the whole thought experiment depends on a closed universe. By the
way, is it possible for a closed universe under GR to be anything other
than the "surface" (which is actually a volume) of a four-dimensional
sphere, a hypersphere? I've been wondering about this since Dirk
suggested the possibility of a "toroid universe" and other
possibilities. No disrespect to Dirk here, I'm just curious as to
whether GR narrows the possibilities for closed universes, to your
knowledge.
>
> [...]
> >
> >(Bilge) So what? General relativity has no problem with this.
> >
> >Bilge may chip in here and say otherwise, but I think he is agreeing
> >with my hypothesis that *in theory*, the scenario in which two
> >spaceships leave the earth in opposite directions at equal velocities as
> >seen by the earth and spaceship observers, travel in straight lines, and
> >eventually return to earth, is a valid thought experiment.
>
> It's a valid question for a thought experiment, but you can't assume
> the outcome to prove something that depends upon the answer until you
> first answer that question.
Well, I can say that *given* a closed universe, such and such
necessarily follows, assuming that my reasoning is valid.
>
> >*If* this thought experiment leads to contradictions, then relativity
> >has a problem --
>
> Not necessarily, since it's possible that the possibilty of such a
> trip would lead to a universe which can't exist.
Yes, but still have the *possibility* of showing that one of GR's more
significant configurations, namely a closed universe, leads to
contradictions for the PofR, and that is something which I personally
believe that Einstein himself would never have ignored as being minor or
irrelevant. Of course, I didn't know the man personally.
>
> [...]
> >In other words, why are you wasting your time stating that the universe
> >could have different configurations from the one in my experiment, when
> >that will not save those laws should they turn out to have problems in
> >my configuration?
>
> Because the scenario you've chosen may very well be contradicted by
> the physical laws required for any universe to exist. Since what we
> are trying to discover is what those laws are, there is no way to know
> whether the trip you've imagined is, in fact, possible regardless of
> the types of physically permissible universes that may exist. So, while
> such a trip is valid as a question that might help ascertain whether
> the trip is possible, it's not valid to assume that it must be. The
> fact that general relativity permits different possible answers is
> a liability, not an asset. If we had a complete theory, we would not
> only need to allow for a single possibility - the correct one.
>
I think you have a significant, but not overwhelming, point here. Our
universe may not be closed, in which case this experiment could not be
done, giving it no chance of contradicting the PofR. However, it may
well be closed (depending on the ratio of "kinetic energy to
gravitational force," so to speak), and in that case, it will be hard to
argue that we cannot do what is claimed in so many textbooks, namely
leave earth (or a better planet, one infinitely more free of unbalanced
gravitational effects), travel in a "straight line" (which is actually
part of a "great circle"), and return to the planet we left from. In
that case, unless we can figure out how and why the inertial and planet
observers will in fact predict the same return times for the spaceships,
this remains a contradiction of the PofR, given the assumption of a
closed universe (I say "we" because if I figure out what is wrong with
my thought experiment, I will post it in a heartbeat; always better to
point out your own errors, rather than have someone else do so).
Even if this contradiction relies on a closed universe, the possibility
of that is so great that this *potential* contradiction cannot, in my
opinion, be ignored. At least not by people who are truly ruthless in
their search for the truth, regardless of which theories get trampled,
or at least slightly modified, in the process.
Which then brings us back to the question of whether it really does
contradict the PofR given the assumption of a closed universe. I will
repeat, the weak point of this thought experiment is whether the two
inertial observers really do predict different return times for the
spaceships. Show that they predict the same times, and you have solved
at least half the problem.
Phil
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D896885...@austin.rr.com...
Imagine a circle - or better, take a piece of paper and draw one.
Put a point A somewhere on the circle. The circle is Universe.
The point A is Earth. By definition, moving along the circle is
moving along a straight line.
At a certain event, let a ship B depart counterclockwise and
ship C clockwise from A, both having the same speed.
Since the departures take place at the same place and time,
B and C depart simultaneously according to every possible
observer.
Imagine yourself (point P) moving somewhere along the circle
in some direction with some speed. For you B and C departed
simultaneously.
At the event where B and C get back together, either on paths
crossing, or on return to A because either they completed the
circle, or because they decided to return after 12 minutes,
they will do so simultaneously for every observer, including for
you. B and C don't even have to have the same speeds wrt
A: they can do whatever they want, accelerate, decelerate,
go to the bathroom, whatever. When they are sitting on top
of each other, they do so simultaneously for every observer.
If on the other hand they are not together, events on B and C
considered to be simultaneous by A, will generally not be
considered simultaneous by you (P).
Do you have a problem with any of this?
So I repeat my question:
There is no flaw. This is page one of SR-001. Right?
Dirk Vdm
Phil
Agreed.
>
> At a certain event, let a ship B depart counterclockwise and
> ship C clockwise from A, both having the same speed.
As measured by A, yes, they have the same speed.
> Since the departures take place at the same place and time,
> B and C depart simultaneously according to every possible
> observer.
Yes.
>
> Imagine yourself (point P) moving somewhere along the circle
> in some direction with some speed. For you B and C departed
> simultaneously.
Yes.
>
> At the event where B and C get back together, either on paths
> crossing, or on return to A because either they completed the
> circle, or because they decided to return after 12 minutes,
> they will do so simultaneously for every observer, including for
> you. B and C don't even have to have the same speeds wrt
> A: they can do whatever they want, accelerate, decelerate,
> go to the bathroom, whatever. When they are sitting on top
> of each other, they do so simultaneously for every observer.
Totally agreed, by definition, two objects that meet at a single point
in space do so at a single point in time, as seen from any RF.
>
> If on the other hand they are not together, events on B and C
> considered to be simultaneous by A, will generally not be
> considered simultaneous by you (P).
Yes.
>
> Do you have a problem with any of this?
No, not a bit.
> So I repeat my question:
> There is no flaw. This is page one of SR-001. Right?
With apologies to Bill Clinton, it depends on what the meaning of "this"
is. If "this" simply refers to the question of when events seen as
simultaneous by A are seen as simultaneous by P, then we agree; if the
events occur at a single point, they are always simultaneous, if at
different points, they are usually not simultaneous. However, if "this"
includes a *shift* from the question of simultaneity to my thought
experiment, then you haven't told the whole story.
Let's add numbers to your example, which I like very much because it is
"as simple as possible, without being too simple." The circle is 1 light
second, i.e. 1 cs, in circumference, and A sends out two ships at 0.8c
as seen by A. Since the circle is 1 cs in circumference it will take
each ship 1 cs/0.8c = 1.25 s to return, and they will not merely meet
each other simultaneously; B's return to A and C's return to A are also
simultaneous events. That is, as seen by anyone, A, B, and C will meet
at a single point in space at a single moment in time.
Now, let's add P, who measures A as having a speed of 0.25c, moving away
from P. P then measures the speed of B and C at the moment they leave A,
and finds that B is moving toward P at 0.6875c, while C is moving away
from P at 0.875c. This is "SR-001," via the Lorentz transform. After
all, C's speed cannot be (0.25c + 0.8c) = 1.05c, now can it? P then
calculates that B will take 1 cs/(0.6875c + 0.25c) = 1.067 s to return
to A, while C will take 1 cs/(0.875c - 0.25c) = 1.6 s to return to A.
B's return to A and C's return to A are no longer simultaneous events,
not as seen by anyone -- including A -- in any reference frame.
Now, which is it? Does A see/measure B and C as returning at the same
moment, or does A see them returning at very different times? Two
inertial observers, two different predictions for the return times. One
of these observers is going to conclude the the laws of physics, when
combined with the assumption that he is motionless with regard to the
circle, handed him the wrong answer for the result of this experiment.
That isn't supposed to happen, not in any reference frame, and not in
any physics.
You have a point, because my claim that all observers predict the same
results for *all* experiments is not true when the experiment involves
widely separated events; the two flashes of light on a moving train is
the classic example. However, here the results occur at a single
location, a point on A, and in that case the return of the two ships to
A *must*, as you imply above, be seen as either simultaneous by
everyone, or by no one. A physics which predicts both is flawed,
period. In this case, we have to know the velocity of A relative to the
circle -- A's absolute velocity -- in order to correctly predict the
outcome of this experiment, as seen by anyone.
Phil
Stephen Speicher
Amazingly, you still miss the point. Unlike your analogy to the
"man" on the Earth who "starts walking east," over billions of
years the Earth is subject to complex dynamics for which it will
not simply be travelling "east." And, your other traveller, the
one leaving Earth in your "straight line direction" will not be
subject to the same dynamics as is the Earth.
Why can't you get this? The Earth is part of the solar system,
the galaxy, the local cluster, the supercluster, etc., a complex
set of dynamics which is constantly changing. Over cosmological
distances and times -- in the many billions of years of your
"straight line" traveller -- planets come and go, stars are born
and die, galaxies collide and the entire dynamic structure which
encompasses the Earth is not waiting idly around for your
"straight line" traveller to return.
>
> Well, I've spent a lot of time agreeing with you, haven't I?
>
My god, no! How can you say such a thing?
> The reason
> that my thought experiment works is because...
Your "thought experiment" does _not_ work, because you are taking
an extremely naive approach in which your "thought experiment" is
not tied to reality. I have only been focusing on this one silly
notion that somehow your "straight line" traveller will return to
Earth. As I stated several times, I am ignoring a more
fundamental problem with your "thought experiment," namely just
what is meant by a "straight line" in your finite, unbounded
universe. You naively think in terms of motion on a sphere, which
indicates to me that you have not even started to come to grips
with the real issues. But, that is another story, one whose depth
is hardly worth pursuing if you are having such difficulty
grasping why your "straight line" traveller will not return to
Earth.
>
> Does it look like I understand your point, and have I given a good
> answer, at least in regards to how the spaceship can arrive back "here"
> on earth...
>
Nope. Try harder to understand.
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D89E5EC...@austin.rr.com...
> Dirk Van de moortel wrote:
[snip]
> > Do you have a problem with any of this?
But your numbers are wrong and you should know that because
it has been pointed out to you before.
You have used the Lorentz transformation and composed the
velocities (P,B) and (P,C) as if all the velocities are constant, i.o.w.
as if the paths are intrinsically straight. But the paths are not *really*
straight, since your space is intrinsically curved.
On a circle the paths are not straight lines. We are free to *define*
them as straight, or *call* them straight because there really is no
other choice, but they still are curved.
In that case you cannot simply use the Lorentz transformation,
since the velocities are not constant. That is page one of SR-001.
Calculating what the clocks will show for all events for all
observers is much more complicated in this case. It can be
done with SR though, but not on page one.
I vaguely recall (+-8 months ago?) having drawn your attention to an
exact calculation somewhere, by - perhaps - Daryl McCullough
or Tom Roberts... I'm not sure.
I also recall that you surprised me by being *very* enthusiastic
about it, but - alas - for the wrong reasons. You actually hadn't
really understood it.
I have looked around for a while but I can't find it anymore.
Perhaps you can retrieve it.
Dirk Vdm
Phil
I think you are completely wrong on this. A distance is a distance,
whether it is curved or not, because both the path that an object
follows from Y to Z, and any measurements of the distance from Y to Z,
follow the same curved path (curved as seen by an "outside" viewer, not
by an observer on the curved path). The distances used by the Lorentz
transform are in fact the distances that objects will actually travel,
and the fact that the path is curved through the fourth dimension is
irrelevant. In other words, we do not measure distance along the chord,
and then travel distance along the curve.
However, let's say that you are correct, and that the curvature of the
universe affects things. We can in theory measure this curvature by
measuring the angles of a very, very large triangle (millions of light
years?). If we can get a big enough triangle, the angles will add to
just over 180 degrees (Gauss actually tried this on earth, but the
curvature of space wasn't great enough over such a small region to
measure). However, suppose that P is only 1 km from the point on A where
B and C leave. P will immediately measure a huge difference between
the speeds of B and C, and if this measurement is incorrect, it will
soon be apparent from the fact that B will not reach P when predicted.
To put it another way, over distances of 1 km, there is *no way* that
the infinitesimal curvature of space can interfere with the predictions
of special relativity to the point where measurements of velocity are
off by 50%!
>
> Calculating what the clocks will show for all events for all
> observers is much more complicated in this case. It can be
> done with SR though, but not on page one.
>
> I vaguely recall (+-8 months ago?) having drawn your attention to an
> exact calculation somewhere, by - perhaps - Daryl McCullough
> or Tom Roberts... I'm not sure.
> I also recall that you surprised me by being *very* enthusiastic
> about it, but - alas - for the wrong reasons. You actually hadn't
> really understood it.
> I have looked around for a while but I can't find it anymore.
> Perhaps you can retrieve it.
I can't find it either (and I'm sure I saved it *somewhere* ...),
however, not only do I remember the situation, I also remember where I
was confused! I said that an observer circling the earth at a constant
distance of 0.728 light-years (or so) and a velocity of 0.866c would see
the earth observers as living at twice normal speed, year after year
(which is true), and that GR could not explain that (which is stupid).
With help from Russell Blackadar (sp?) I finally understood the
difference between gravitational potential and gravitational force. In
GR, the orbiting observer sees both himself and the earth as motionless,
but assumes that he is at the bottom of a gravitational well with a
constant slope of 1 g from him to the earth. When you add up the amount
of energy that it would take to "climb up" this well, it turns out to be
a huge amount of energy, enough to double the spaceship's mass and
reduce its time-rate to 0.5 -- which then causes the spaceship observers
to see the earth's time-rate as being 2.0, as expected.
Even here, however, an observer measuring the velocities of other
objects traveling along his orbital path will not observe discrepancies
between the time required by objects to complete an orbit and the
apparent velocity of those objects. The curvature of space does affect
things, but since both the distances that objects travel and the
measurements of those distances must follow the same curved path, it
does not affect measurements of velocity in the way you think, certainly
not by magnitudes of 50%, which is what you would need to disprove my
thought experiment.
By the way, if it turns out that this thought experiment really does
reveal a flaw in relativity, you won't really care, will you? I mean, if
flaws exist, won't the discovery of those flaws bring us a step closer
to the truth? Surely your purpose is not *only* to defend relativity, as
if the world will come crashing down if it is revealed that flaws exist,
but also to determine whether something may be true, as well as false.
Also, the technique I use for all of your posts is to look not only at
the internal consistency of your arguments (which is usually very good),
but also at the *external* alignment between each of the elements of
your arguments and reality. The above argument sounds great, but if I
*shift* to an examination of whether, in a 1 cubic km volume of space,
the curvature of the universe can cause errors in velocity measurements
of 50%, I immediately get a "duh" answer. It's a very powerful
technique, and I get the feeling that it is rarely taught today.
Phil
Phil
Yes Stephen, the earth won't *actually* be where it is expected to be by
the returning spaceships. Once again, I agree with you. But how many
times have said, forget the earth, and select a planet that is not
subject to all those forces? This is a thought experiment, and we are
permitted to do that. Or use a spacestation instead of a planet. With
technology advanced enough to send spaceships around the universe, I
believe our spacestation will have no problem mapping out all the
significant gravitational fields, measuring the CMBR, and using all of
this to insure that they travel through space at constant speed in a
single direction. Since this is a thought experiment -- which primarily
tests the internal consistency of theories -- we can even go back in
time to before the electrons combined with the protons and alpha
particles, and send two spaceships from a spacestation then! If you
disagree, i suppose we could start a thread on "Thoughts about thought
experiments," their limitations, rules, etc., but I see little point.
Whether you claim that the experiment is impossible because of
technological limitations, or limitations of the earth, makes little
difference. In both cases you are taking a conclusion from one
viewpoint, the *pragmatic* execution of an experiment, and concluding
that the *concept* of the experiment is flawed, and that it cannot be
used even to examine the internal consistency of the theories involved.
That is an error, a "shift error" (these occur when we draw a conclusion
from one viewpoint, shift to a second viewpoint, and then apply the
conclusion to the second viewpoint, where it is almost never valid) and
if you insist on defending relativity by using such errors, I'm going to
have to quit, and let you claim whatever you want. Maybe it would be
worth asking the other guys to state their opinions on the limitations
of thought experiments?
I will ask you the same questions I asked Dirk. Would it really bother
you to find out that relativity has flaws? Isn't the recognition of
previously unseen errors a step forward, not backward? Shouldn't you
attempt to determine whether a new idea is true, as well as trying to
find arguments that suggest that it is false?
>
>>Well, I've spent a lot of time agreeing with you, haven't I?
>>
>>
> My god, no! How can you say such a thing?
Because I agree with your criticisms concerning the meaning of absolute
position.
>
>>The reason
>>that my thought experiment works is because...
>>
>
> Your "thought experiment" does _not_ work, because you are taking
> an extremely naive approach in which your "thought experiment" is
> not tied to reality. I have only been focusing on this one silly
> notion that somehow your "straight line" traveller will return to
> Earth. As I stated several times, I am ignoring a more
> fundamental problem with your "thought experiment," namely just
> what is meant by a "straight line" in your finite, unbounded
> universe. You naively think in terms of motion on a sphere, which
> indicates to me that you have not even started to come to grips
> with the real issues. But, that is another story, one whose depth
> is hardly worth pursuing if you are having such difficulty
> grasping why your "straight line" traveller will not return to
> Earth.
So, just after the electrons combined with protons and neutrons, and a
photon could easily travel billions of light years without running into
anything (and no significant unbalanced gravitational had appeared), the
path followed by the photon would *not* suffice as an example of a
straight line, as they exist on the "surface" of our hypersphere
universe? Simple is not necessarily naive, but by all means, if you want
to give up due to my inability to understand the "depths" of the "real
issues," -- assuming that these actually exist, of course -- then feel
free to do so.
>
>
>>Does it look like I understand your point, and have I given a good
>>answer, at least in regards to how the spaceship can arrive back "here"
>>on earth...
>>
>>
> Nope. Try harder to understand.
Color me stupid, but for some reason I don't think that I'm the one who
needs to try harder to understand.
Phil
Robert Kolker
Phil wrote:
>
>
> Yes Stephen, the earth won't *actually* be where it is expected to be by
> the returning spaceships.
How do you put an X (which marks the spot) in space and expect it to
stay where it is, so you know when you have gone around and returned to
it? You are implicitly assuming that absolute position has some meaning.
Your gedanken is categorically flawed.
Bob Kolker
Robert Kolker
Phil wrote:
>
>
> Yes Stephen, the earth won't *actually* be where it is expected to be by
> the returning spaceships.
How do you put an X (which marks the spot) in space and expect it to
Dirk Van de moortel
"Phil" <tu...@jump.net> wrote in message news:3D8AE48...@jump.net...
>
>
> Dirk Van de moortel wrote:
>
> > "Phil" <tri...@austin.rr.com> wrote in message news:3D89E5EC...@austin.rr.com...
> >
[snip]
> >
> > But your numbers are wrong and you should know that because
> > it has been pointed out to you before.
> > You have used the Lorentz transformation and composed the
> > velocities (P,B) and (P,C) as if all the velocities are constant, i.o.w.
> > as if the paths are intrinsically straight. But the paths are not *really*
> > straight, since your space is intrinsically curved.
> > On a circle the paths are not straight lines. We are free to *define*
> > them as straight, or *call* them straight because there really is no
> > other choice, but they still are curved.
> > In that case you cannot simply use the Lorentz transformation,
> > since the velocities are not constant. That is page one of SR-001.
>
>
> I think you are completely wrong on this.
I know that is what you think and why you think it.
[snip]
> > I vaguely recall (+-8 months ago?) having drawn your attention to an
> > exact calculation somewhere, by - perhaps - Daryl McCullough
> > or Tom Roberts... I'm not sure.
> > I also recall that you surprised me by being *very* enthusiastic
> > about it, but - alas - for the wrong reasons. You actually hadn't
> > really understood it.
> > I have looked around for a while but I can't find it anymore.
> > Perhaps you can retrieve it.
>
>
> I can't find it either (and I'm sure I saved it *somewhere* ...),
A somewhat deeper google search reveals that it was not
Daryl or Tom, but Jan Bielawski:
My post to you:
http://groups.google.com/groups?&as_umsgid=43db8.144098$rt4....@afrodite.telenet-ops.be
pointing to Jan's article:
http://groups.google.com/groups?&as_umsgid=c2893ecb.01100...@posting.google.com
and your reaction:
http://groups.google.com/groups?&as_umsgid=3C6ED4A6...@jump.net
Phil, here's my recommendation:
Have a *quick* refresher look at the links and the complete
thread I just provided, and then take a very deep breath...
Then read:
"General Relativity from A to B"
and then:
"Spacetime Physics"
and then again:
"General Relativity from A to B"
and then:
http://www.mathpages.com/rr/rrtoc.htm
and then again:
"General Relativity from A to B"
and then again - making *all* the exercises this time:
"Spacetime Physics"
and finally again:
the links and thread I just provided.
Take - at least - 4 months for this program.
"GR A-B" is a little book, you can do it in 2 to 3 days.
This might help. Nothing else might.
Dirk Vdm [ going for an Alps trip next week ]
Phil
Read my previous response to Stephen from 9-19-02 at 1:28 AM, it
explains why such an X is unnecessary (basically the Earth serves as the
X, even though it does not remain at some fictional absolute position).
Phil
>
Robert Kolker
Phil wrote:
> Read my previous response to Stephen from 9-19-02 at 1:28 AM, it
> explains why such an X is unnecessary (basically the Earth serves as the
> X, even though it does not remain at some fictional absolute position).
You make the happy assumption that every force acting on the Earth can
be used to track the Earth and undo its motions. Now support that
assumption.
Bob Kolker
Phil
Let me see if I actually have this straight, just for the record:
P is motionless, and A, who is 1 km to the right of P, is moving toward
the right (0 degrees) at 0.25c. A then sends out two objects, B and C,
at velocities of 0.8c as seen/measured by A. B is moving directly toward
P (180 degrees), and C is moving in the opposite direction, directly
away from P (0 degrees).
You are actually claiming, here, in the public domain for all to see,
that the curvature of space so warps P's measurements of the speeds of
A, B, and C -- call these speeds As, Bs, and Cs -- that he will conclude
that As + Bs (the + sign indicating that these speeds are in the
opposite direction, although the numbers would actually be As - (-Bs),
the - sign indicating that B's speed is in the opposite direction from A
and C), and As - Cs, are equal, causing P to predict that B's return to
A and C's return to A will occur at the same moment.
Furthermore, you claim that if I read:
> http://groups.google.com/groups?&as_umsgid=43db8.144098$rt4....@afrodite.telenet-ops.be
> pointing to Jan's article:
> http://groups.google.com/groups?&as_umsgid=c2893ecb.01100...@posting.google.com
> and your reaction:
> http://groups.google.com/groups?&as_umsgid=3C6ED4A6...@jump.net
and then:
> "General Relativity from A to B"
> and then:
> "Spacetime Physics"
> and then again:
> "General Relativity from A to B"
> and then:
> http://www.mathpages.com/rr/rrtoc.htm
> and then again:
> "General Relativity from A to B"
> and then again - making *all* the exercises this time:
> "Spacetime Physics"
>
> and finally again:
> the links and thread I just provided.
and then :
>
> Take - at least - 4 months for this program.
> "GR A-B" is a little book, you can do it in 2 to 3 days.
>
> This might help. Nothing else might.
that I will be so brainwashed that I will actually conclude that P's
results for [As - (-Bs)] and (As - Cs) are the SAME???? Good-bye Lorentz
transforms over distances of just 1 km! When A sends out objects at +/-
0.8c, the curvature of space causes P to measure velocities for the two
objects that are *completely* different, literally +/- 25% different,
from what the Lorentz transform says!
Now THAT is very, very funny! I think that this time we have not just a
real, but an unavoidable, entry for your Immortal Fumbles!
Either that, or else you have developed such an emotional need to defend
relativity that your intellectual processes are gone. Your reply (if you
send one) should tell us which is the case. If you continue to claim
that P will measure velocities for B and C that differ from the Lorentz
predictions by +/- 25%, we'll know you're gone, and I, for one, will
simply say, "Right Dirk, whatever you say," and let it go!
Highly Amused Phil
>
> Dirk Vdm [ going for an Alps trip next week ]
All kidding and ribbing aside, however, I hope you have great fun on
your trip. Sounds fantastic!
Marco Nelissen
> Dirk,
>
> Let me see if I actually have this straight, just for the record:
>
> P is motionless, and A, who is 1 km to the right of P, is moving toward
> the right (0 degrees) at 0.25c. A then sends out two objects, B and C,
> at velocities of 0.8c as seen/measured by A. B is moving directly toward
> P (180 degrees), and C is moving in the opposite direction, directly
> away from P (0 degrees).
>
> You are actually claiming, here, in the public domain for all to see,
> that the curvature of space so warps P's measurements of the speeds of
> A, B, and C -- call these speeds As, Bs, and Cs -- that he will conclude
> that As + Bs (the + sign indicating that these speeds are in the
> opposite direction, although the numbers would actually be As - (-Bs),
> the - sign indicating that B's speed is in the opposite direction from A
> and C), and As - Cs, are equal, causing P to predict that B's return to
> A and C's return to A will occur at the same moment.
What do you mean with "B's return to A" and "C's return to A"?
Your earlier problem-description above makes no mention of the
two objects turning around and moving back to A. If we assume
that that is what you mean though, we can say that P will see
B and C move with different speeds (where A sees them move at
the same speed), which is of course necessary in P's frame of
reference in order for objects B and C to move away from the
moving (in P's frame of reference) object A and return to it
at the same time. Also note that for example in P's frame of
reference the distance traveled by A, B and C will be different
than in A's frame of reference, and that the turnaround-point is
simultaneous in A's frame of reference, but not in P's.
Dirk Van de moortel
"Phil" <tu...@jump.net> wrote in message news:3D8B6CB...@jump.net...
> Dirk,
>
> Let me see if I actually have this straight, just for the record:
>
> P is motionless
P is motionless with respect to P. If you want P to be motionless
wrt something else, you introduce another observer. Since, in
what you write below, you haven't mentioned another observer
wrt whom P would be motionless, I will suppose that this was
an unnecessary remark, and that you actually meant to say
"P is an observer".
So the first 3 words of what you wanted to have straight, were
wrong, just for the record.
I will stop straightening as from here, because I could, but do
not intend to write 8 lines for every 3 words of your post.
>, and A, who is 1 km to the right of P, is moving toward
> the right (0 degrees) at 0.25c. A then sends out two objects, B and C,
> at velocities of 0.8c as seen/measured by A. B is moving directly toward
> P (180 degrees), and C is moving in the opposite direction, directly
> away from P (0 degrees).
It is extremely tempting, but I'm not going to straighten.
>
> You are actually claiming, here, in the public domain for all to see,
that, if B and C return simultaneously on A according to A, they
will also return simultaneously on A according to P, whatever the
Universe in which A,B,C and P are living is like, whatever kind
of daft trip anyone of A,B,C, and P might make, whatever they
might eat, drink, smoke, sniff, inhale or shoot, and whatever you
can fantasise about any parameter or property of the entire setup.
I also claim that if you apply the correct equations correctly to
calculate the coordinates of all the relevant events in the 4 different
frames, that everything fits perfectly and that you will not find a
flaw. You apply the Lorentz transformation as if the setup deals
with uniform linear motion in a flat space-time. One or both of
these conditions are not met.
Finally I claim and predict that 8 months from now, you will have
exactly the same discussion as today and as 8 months ago.
Someone will provide a google pointer to this thread.
[snip]
Dirk Vdm
Dirk Van de moortel
"Marco Nelissen" <mar...@xs4.xs4all.nl> wrote in message news:amfrt8$66k$1...@news1.xs4all.nl...
[snip]
Marco, I'm afraid you'll have to wade through the entire thread
in chronological order. There are some nifty subtleties.
Dirk Vdm
Phil
Phil
Dirk Van de moortel wrote:
Phil
the brief answer is that B and C travel completely around the closed
universe, thereby returning to A.
Phil
Stephen Speicher
> With
> technology advanced enough to send spaceships around the universe, I
> believe our spacestation will have no problem mapping out all the
> significant gravitational fields, measuring the CMBR, and using all of
> this to insure that they travel through space at constant speed in a
> single direction.
You simply have no conception of dynamics.
> Since this is a thought experiment -- which primarily
> tests the internal consistency of theories --
Thought experiments which are not necessarily connected to the
real world, is what is known as science fiction. I happen to
love science fiction, and there are groups devoted to that.
However, this group (supposedly) deals with science fact.
>
> I will ask you the same questions I asked Dirk. Would it really bother
> you to find out that relativity has flaws?
I am already aware of the flaws of relativity, so why should it
bother me?
> Isn't the recognition of
> previously unseen errors a step forward, not backward?
Yes. And we are hoping that some day soon you might take such a
step.
> Shouldn't you
> attempt to determine whether a new idea is true, as well as trying to
> find arguments that suggest that it is false?
>
That depends on my objective. If I am learning something new --
like right now I am studying D'Eath's "Supersymmetric Quantum
Cosmology" -- then I file away any false ideas I find and
continue to learn and discover what may be true. On the other
hand, when I am deluged by every anti-relativist who has access
to the internet, finding one false idea is sufficient for me not
to waste any more time reading their "theory." Different strokes,
for different folks.
> >>Well, I've spent a lot of time agreeing with you, haven't I?
> >>
> >>
> > My god, no! How can you say such a thing?
>
>
> Because I agree with your criticisms concerning the meaning of absolute
> position.
>
That is what you claim, but in fact that is just window dressing
over the frame of an absolutist, from start to finish.
(Incidentally, there is a proper meaning to the term
"absolutist," but here I use it to refer to any attempt to remove
what is in fact relative from relativity.)
> Simple is not necessarily naive, but by all means, if you want
> to give up due to my inability to understand the "depths" of the "real
> issues," -- assuming that these actually exist, of course -- then feel
> free to do so.
>
Hmm. Your usual fare is on the order of: Okay, you win by
debating tactics, but...
Now you seem just forlorn. I'm not sure which is better.
> >
> > Nope. Try harder to understand.
>
>
> Color me stupid, but for some reason I don't think that I'm the one who
> needs to try harder to understand.
>
I also see from another post that you want Dirk to brush up a bit
on his understanding of relativity. Perhaps Dirk and myself can
start our own study group, and we will report back to you for
further analysis when we have made some progress.
Stephen Speicher
IIRC, Phil has said that he has been working on his book for 13
years, so 4 months of even such a healthy program as this may be
too optimistic.
> Dirk Vdm [ going for an Alps trip next week ]
>
Cool! :)
Have a nice trip, and be sure to go in a "straight line"
direction.
Stephen Speicher
>
> "Phil" <tu...@jump.net> wrote in message news:3D8B6CB...@jump.net...
> > Dirk,
> >
> > Let me see if I actually have this straight, just for the record:
> >
>
> Finally I claim and predict that 8 months from now, you will have
> exactly the same discussion as today and as 8 months ago.
> Someone will provide a google pointer to this thread.
>
As succinct and most likely correct a summary as can be made.
(Perhaps it can be reworked into a plot line for a "Twilight
Zone" script?)
Dirk Van de moortel
"Phil" <tu...@jump.net> wrote in message news:3D8B9B0...@jump.net...
> Right Dirk, whatever you say. Have fun in the Alps!
You bet I phil... er... will.
Do read Geroch.
Dirk Vdm
Dirk Van de moortel
"Stephen Speicher" <s...@compbio.caltech.edu> wrote in message news:Pine.GSO.4.44.0209201806450.25589-100000@blinky...
>
> IIRC, Phil has said that he has been working on his book for 13
> years, so 4 months of even such a healthy program as this may be
> too optimistic.
I am an optimist indeed.
>
> > Dirk Vdm [ going for an Alps trip next week ]
> >
>
> Cool! :)
>
> Have a nice trip, and be sure to go in a "straight line"
> direction.
Thanks.
There's four of us. We can do some really interesting round-trip
experiments.
Bags & Stuff packed.
See you next week.
Give my regards to Luttgens when he shows up ;-)
Dirk Vdm
Paul B. Andersen
"Phil" <tu...@jump.net> wrote in message news:3D8B6CB...@jump.net...
> Dirk,
>
> Let me see if I actually have this straight, just for the record:
>
> P is motionless, and A, who is 1 km to the right of P, is moving toward
> the right (0 degrees) at 0.25c. A then sends out two objects, B and C,
> at velocities of 0.8c as seen/measured by A. B is moving directly toward
> P (180 degrees), and C is moving in the opposite direction, directly
> away from P (0 degrees).
>
> You are actually claiming, here, in the public domain for all to see,
> that the curvature of space so warps P's measurements of the speeds of
> A, B, and C -- call these speeds As, Bs, and Cs -- that he will conclude
> that As + Bs (the + sign indicating that these speeds are in the
> opposite direction, although the numbers would actually be As - (-Bs),
> the - sign indicating that B's speed is in the opposite direction from A
> and C), and As - Cs, are equal, causing P to predict that B's return to
> A and C's return to A will occur at the same moment.
I suppose the scenario still is that they are moving around
a circle with a circumference 1 light second.
If we are discussing the prediction of SR, we have to assume
a flat space time.
Then - as opposed to what you seem to think - it isn't the same
scenario when P is stationary and A is moving, as when A is
stationary and P is moving. The difference is that in the former
case P is inertial while A is accelerated and vice versa in
the latter case. A very significant difference indeed.
In your scenario quoted above, you can indeed calculate that
C and D will NOT meet A simultaneously.
You are wrong when you assume that A would calculate that
they are. A is in an accelerated frame, and cannot use SR
as if he were in an inertial frame. A can calculate it
correctly using SR only, but it isn't very easy. But if he
did, he would, like P, find that B and C would not meet
him simultaneously.
If you let A be inertial and P move around the circle, you can
calculate that C and D will meet A simultaneously.
P is accelerated, and cannot use SR as if he were inertial.
But doing the calculation properly in an accelerated frame,
he would find that they meet simultaneously.
Two different scenarios.
Two different results.
A and P will agree in both cases.
But the one in an accelerated frame cannot ignore the fact.
Paul
Phil
Yours is the first truly scientific response I have seen! All the others
have been "what's a straight line," "you can't return to the earth
(never mind what Stephen Weinberg says)," "the universe *might* be
open," or "the numbers just add up, so there," blah blah blah ...
Paul B. Andersen wrote:
> "Phil" <tu...@jump.net> wrote in message news:3D8B6CB...@jump.net...
>
>>Dirk,
>>
>>Let me see if I actually have this straight, just for the record:
>>
>>P is motionless, and A, who is 1 km to the right of P, is moving toward
>>the right (0 degrees) at 0.25c. A then sends out two objects, B and C,
>>at velocities of 0.8c as seen/measured by A. B is moving directly toward
>>P (180 degrees), and C is moving in the opposite direction, directly
>>away from P (0 degrees).
>>
>>You are actually claiming, here, in the public domain for all to see,
>>that the curvature of space so warps P's measurements of the speeds of
>>A, B, and C -- call these speeds As, Bs, and Cs -- that he will conclude
>>that As + Bs (the + sign indicating that these speeds are in the
>>opposite direction, although the numbers would actually be As - (-Bs),
>>the - sign indicating that B's speed is in the opposite direction from A
>>and C), and As - Cs, are equal, causing P to predict that B's return to
>>A and C's return to A will occur at the same moment.
>>
>
> I suppose the scenario still is that they are moving around
> a circle with a circumference 1 light second.
> If we are discussing the prediction of SR, we have to assume
> a flat space time.
Almost correct. They are not moving around "a circle" with a
circumference of 1 light-second. The universe itself has a circumference
of 1 light second (now that I think about it, *maybe* this is where Dirk
and I got our wires crossed?). In this scenario you can travel in a
straight line and return to your starting point, because that straight
line has been curved around a 2-dimensional locus of points, i.e., a circle.
The "flatland" example is more common in math, in which we imagine
beings that move in a plane. There is no way for them to move in the 3rd
dimension, when that 3rd dimension is defined as being perpendicular to
their plane. In other words, they cannot leave the plane, or for that
matter even picture in their minds what motion in "the 3rd dimension"
would be like. However, if this plane is curved around a 3-dimensional
locus of points -- a sphere -- then although still confined to their
plane, these beings will note that large triangles (smaller, but not
immensely smaller than the sphere) have angles that sum to more than 180
degrees. They also notice that by traveling in "a straight line" --
straight for them, that is -- that they can return to their original
starting position. Indeed, if the sphere is not too big, they can simply
stare straight ahead and eventually see the backs of their own heads!
Under a closed universe in GR, our 3-dimensional space is curved around
a 4-dimensional locus of points -- a hypersphere. The same strange
things observed by "the flatlanders" then apply here. Large triangles
have angles that sum to > 180 degrees, we can travel in "a straight
line" (as seen by us, of course) and return to our starting position,
and if the universe was much smaller than it is, we could even stare
straight ahead and eventually see the backs of our heads. All courtesy
of a curvature through the 4th dimension, something that we can conceive
of, but not actually picture in our minds.
Now, it is at least conceivable that a being who travels around the
universe by moving in what appears to be a straight line (the same path
that photons take, ignoring effects from local gravitational fields)
would in fact be "accelerating," since from the viewpoint of a
4-dimensional being, that is in fact what is occurring. However, this
raises the question of whether it is possible for us to actually measure
this acceleration, using any experiment real or imaginable. Using the
CMBR does *not* count, since it merely measures our velocity to
something which we believe to be motionless relative to the medium of
space. In other words, the CMBR is an "outside reference," as opposed to
a measurable change in the results of our experiments. We need something
to show us that we are accelerating through the 4th dimension, something
similar to would we observe while stationary in a gravitational well, or
moving in a circle 1 light-second in circumference.
But there is a problem. Anything that would show us the magnitude of our
acceleration in the 4th dimension -- an acceleration which exists solely
because we are traveling around the hypersphere whose "surface" is in
fact the universe we live in -- would also show us our absolute
velocity! No, if the principle of relativity is to remain intact, we
must assume that it is impossible to see any effects from this 4th
dimensional acceleration. In other words, in terms of *velocity*, there
are no observable differences in the results of experiments between a
universe that is Euclidean (flat), closed (hypersphere), or open
(saddle). Now, the sum of the angles of a triangle will be =, >, or <
180 degrees respectively depending on the shape of our universe, but we
have to assume that this and all other experiments have results that are
independent of absolute velocity, of our velocity relative to the medium
of space, or we have an immediate exception to the principle of relativity.
>
> Then - as opposed to what you seem to think - it isn't the same
> scenario when P is stationary and A is moving, as when A is
> stationary and P is moving. The difference is that in the former
> case P is inertial while A is accelerated and vice versa in
> the latter case. A very significant difference indeed.
Yes it is.
>
> In your scenario quoted above, you can indeed calculate that
> C and D will NOT meet A simultaneously.
> You are wrong when you assume that A would calculate that
> they are. A is in an accelerated frame, and cannot use SR
> as if he were in an inertial frame. A can calculate it
> correctly using SR only, but it isn't very easy. But if he
> did, he would, like P, find that B and C would not meet
> him simultaneously.
This is off the main subject, since it deals with an "ordinary"
situation where someone travels in a circle at high speed, something
which does require an observable/measurable acceleration. The slightly
more simple example I like to use is the one where an observer circles
an inertial observer at 0.866c with a radius of 0.728 light-years,
giving the circling observer an acceleration of 1 g or 9.8 m/s^2, the
same as here on earth. Here, the earth observers would appear to the
circling observer to have a time-rate of 2.0, walking, talking, and
living at twice the rate of the circling observer. However, if we model
this in GR using the equivalence principle, we have two observers, both
motionless, where the "circling" observer is at the bottom of a
gravitational well a little over 0.728 light-years deep (longer than
0.728 light-years due to the warping of space) with a constant slope of
1 g. The amount of energy needed to escape from this well is 1 kg of
energy per kg of mass, effectively doubling the mass of any object at
the position of the "bottom" observer, and causing him to have a
time-rate of 0.5 -- exactly what we expect when an observer is actually
circling the earth.
However, even here, an observer at the bottom of the well who sends out
two objects in opposite directions will expect them to return at the
same time, because they follow symmetric paths. There are some problems
that cannot be solved using the equivalence principle. In other words,
there are some problems that can *only* be solved by knowing who is and
isn't the inertial observer. The standard clock paradox is an example,
where this requirement is known and accepted (I think it is even in the
FAQ). Space-time diagrams are used to solve such problems, because,
being drawn from the viewpoint of a single inertial reference frame,
they can easily take all *changes* in absolute velocity into account,
thereby making it clear which observers are inertial.
Anyway, getting back to the subject of this thread ...
>
> If you let A be inertial and P move around the circle, you can
> calculate that C and D will meet A simultaneously.
> P is accelerated, and cannot use SR as if he were inertial.
> But doing the calculation properly in an accelerated frame,
> he would find that they meet simultaneously.
>
> Two different scenarios.
> Two different results.
> A and P will agree in both cases.
> But the one in an accelerated frame cannot ignore the fact.
>
> Paul
If we assume that P is inertial, and that A notices no effects from his
4th dimensional acceleration as he travels around the universe -- which
again, *must* be the case if he is to fall under the principle of
relativity -- then A *must* calculate that B and C, which *appear* to
him to be moving at 0.8c, will indeed return at the same time.
Given that A appears to P to be moving at 0.25c along the positive
x-axis (or as I usually say, "toward the right"), P will calculate that
C moves at 0.875c, also along the positive x-axis, and B moves at
-0.6875c, in the direction of the negative x-axis. This does give C a
larger velocity relative to the universe as seen by P, but C must travel
a greater distance, due to the fact that A is moving in the same
direction as C. In this situation, we can *assume* a circumference (such
as 1 light-second) and directly calculate the answers, or we can just
use the velocities and obtain answers in terms of A's journey around the
universe. In this example, A will travel .25c/(.6875c + .25c) = 26.7%
around the universe before B returns, and .25c/(.875c - .25c) = 40%
around the universe before C returns, as calculated by P.
Now, there are situations, as Dirk says, where we *expect* two observers
to predict different results, but those experiments always involve
differences in space and/or time. Here, where A predicts that B's return
to A and C's return to A will occur at the same time, all other
observers *must* predict that B's return and C's return will also occur
at a single moment in time, if the principle of relativity is to be
valid. Dirk's other point is that the curvature of space changes P's
measurements of the velocities of B and C, but these values would have
to change by +/- 25% in order for P to conclude that B and C will return
at the same moment, and the idea that the 4th dimensional curvature of
space, which is extremely small over distances of light-years, let alone
1 km, could cause P to measure velocities that differ from those
produced by the Lorentz transform by +/- 25% is clearly false. The only
conclusion I have been able to find so far, non-scientific arguments
against it not withstanding, is that this experiment is an exception to
the principle of relativity.
I don't see this as a "step backwards," because if it is true, then we
live in a world where the laws of nature are still essentially relative.
It is only the conclusion that absolute velocity is a *completely*
meaningless concept that must go. From another point of view, we used to
believe that everything was absolute, now we believe that everything is
relative, but the truth is that while about 99% of everything is
relative, the absolute -- at least in terms of velocity and
acceleration, although probably not position -- does have at least a
limited place in our understanding of the universe around us. In other
words, Einstein's achievements, which were magnificent in my opinion,
were nevertheless a classic case of 99 steps forward, 1 step back. It's
time to correct the 1 step back, thereby giving us an even greater
understanding of the world around us, which is exactly what Einstein
most wanted.
The scientific part of your response, by the way, is the fact that if A
knows that he has an acceleration in the 4th dimension, he will indeed
calculate that B and C will *not* return at the same time, making his
prediction the same as P's prediction. The problem is that the ability
to measure a 4th dimensional acceleration, since this centripetal
acceleration is the direct result of A's velocity relative to space,
will itself be a measurement of absolute velocity, thereby defeating the
principle of relativity even more quickly than if A and P do not have
the same predictions for the return of B and C.
Phil
Jon Hurwitz
> Now, there are situations, as Dirk says, where we *expect* two observers
> to predict different results, but those experiments always involve
> differences in space and/or time. Here, where A predicts that B's return
> to A and C's return to A will occur at the same time, all other
> observers *must* predict that B's return and C's return will also occur
> at a single moment in time, if the principle of relativity is to be
> valid. Dirk's other point is that the curvature of space changes P's
> measurements of the velocities of B and C, but these values would have
> to change by +/- 25% in order for P to conclude that B and C will return
> at the same moment, and the idea that the 4th dimensional curvature of
> space, which is extremely small over distances of light-years, let alone
> 1 km, could cause P to measure velocities that differ from those
> produced by the Lorentz transform by +/- 25% is clearly false. The only
> conclusion I have been able to find so far, non-scientific arguments
> against it not withstanding, is that this experiment is an exception to
> the principle of relativity.
>
If curvature worked the way you suggest, a ball that I threw up wouldn't
come down in my lifetime. How else can you explain 180 degree turn around
(that's a 200% change in velocity) in just 1 foot? Doesn't this make a 25%
change over one kilometer seem easy?
> The scientific part of your response, by the way, is the fact that if A
> knows that he has an acceleration in the 4th dimension, he will indeed
> calculate that B and C will *not* return at the same time, making his
> prediction the same as P's prediction. The problem is that the ability
> to measure a 4th dimensional acceleration, since this centripetal
> acceleration is the direct result of A's velocity relative to space,
> will itself be a measurement of absolute velocity, thereby defeating the
> principle of relativity even more quickly than if A and P do not have
> the same predictions for the return of B and C.
How can anyone measure this 4th spacial dimensional acceleration? The
centripetal force is provided by gravity, putting the ships in freefall wrt
the curvature, so they won't feel it. They can't measure the curvature with
rulers or light beams, because they would just bend too. They also can't
see into a fourth spacial dimension, if such a thing exists.
Did you see the post on Yilmaz by Scott Berg. If not and you didn't know
about it, I recommend you follow the link. It seems as though Yilmaz
provided a full solution to the field equations which predicts that black
holes are impossible. Some technical ammo for you. <g>
Jon
Phil
>>Now, there are situations, as Dirk says, where we *expect* two observers
>>to predict different results, but those experiments always involve
>>differences in space and/or time. Here, where A predicts that B's return
>>to A and C's return to A will occur at the same time, all other
>>observers *must* predict that B's return and C's return will also occur
>>at a single moment in time, if the principle of relativity is to be
>>valid. Dirk's other point is that the curvature of space changes P's
>>measurements of the velocities of B and C, but these values would have
>>to change by +/- 25% in order for P to conclude that B and C will return
>>at the same moment, and the idea that the 4th dimensional curvature of
>>space, which is extremely small over distances of light-years, let alone
>>1 km, could cause P to measure velocities that differ from those
>>produced by the Lorentz transform by +/- 25% is clearly false. The only
>>conclusion I have been able to find so far, non-scientific arguments
>>against it not withstanding, is that this experiment is an exception to
>>the principle of relativity.
>>
>>
>
> If curvature worked the way you suggest, a ball that I threw up wouldn't
> come down in my lifetime. How else can you explain 180 degree turn around
> (that's a 200% change in velocity) in just 1 foot? Doesn't this make a 25%
> change over one kilometer seem easy?
No, I'm referring to situations in space where no effects from gravity
exist except for the curvature of space around an *extremely* large
hypersphere, where A sends out two objects, B and C, at a velocity as
seen by A of 0.8c "left and right," and the question is whether P, who
sees A as moving away at 0.25c "toward the right," will measure
velocities for B and C that are in accordance with the Lorentz transform
or not. If P is just 1 km away from A, then there is realistically no
way that the curvature of the universe, at around one billionth of a
degree or less, can affect the predictions of the Lorentz transform by
such a large amount. It's like asking the curvature of space caused by
the earth's gravity to mess up the predictions of Newtonian mechanics
over a distance of 1 um by +/- 25%; it just isn't going to happen.
Remember, we're not just talking about the effects of gravity here, such
as tossing a ball up and watching it come down, but *discrepencies* in
the SR and Newtonian laws for motion and gravity of 25% over a region of
space that is nothing compared to the universe as a whole.
That's all right, because you and John are trying to put HONEST bullet
holes in my thought experiment, which I find unbelievably refreshing
after the largely, although not entirely (Bilge had some good points)
dishonest nonsense I've had to answer so far. I hope you keep at it,
because that way you'll either find why it is false, or prove to
yourselves that there really are exceptions to the PofR, after all.
>>The scientific part of your response, by the way, is the fact that if A
>>knows that he has an acceleration in the 4th dimension, he will indeed
>>calculate that B and C will *not* return at the same time, making his
>>prediction the same as P's prediction. The problem is that the ability
>>to measure a 4th dimensional acceleration, since this centripetal
>>acceleration is the direct result of A's velocity relative to space,
>>will itself be a measurement of absolute velocity, thereby defeating the
>>principle of relativity even more quickly than if A and P do not have
>>the same predictions for the return of B and C.
>>
>
> How can anyone measure this 4th spacial dimensional acceleration? The
> centripetal force is provided by gravity, putting the ships in freefall wrt
> the curvature, so they won't feel it. They can't measure the curvature with
> rulers or light beams, because they would just bend too. They also can't
> see into a fourth spacial dimension, if such a thing exists.
That's my point; we can't measure this acceleration, partly because of
the reasons you listed (I hadn't thought of most of those), and partly
because such a measurement would itself be a violation of the PofR
(since it would allow A to deduce his absolute velocity). And yet
without that measurement, A *must* predict that B and C will both return
during the same moment after their "around the universe" journey. Since
P *must* predict that A and B will *not* return to A during the same
moment, as seen by A or anyone else, A and P have different predictions
for the results of this experiment, which is still a violation of the
PofR (if two objects converge at a single point in space, A, during a
single moment as seen by one observer, then under any theory of physics,
not just the PofR, *all* observers must agree that the two objects
converge on A at a single moment, although it won't necessarily be the
particular moment seen by the first observer).
>
> Did you see the post on Yilmaz by Scott Berg. If not and you didn't know
> about it, I recommend you follow the link. It seems as though Yilmaz
> provided a full solution to the field equations which predicts that black
> holes are impossible. Some technical ammo for you. <g>
No I didn't, thanks! I will have to look at that -- although I suspect
that there will be large sections which I cannot understand at all. :-(
Phil
Jon Hurwitz
Newtonian mechanics has gravity built in. SR doesn't. *All* gravity and
*all* curvature of space is a departure from the standard SR model. Perhaps
you haven't thought about what throwing the ball up actually means.
Remember that the figures I gave about 200% deviation in 1 foot works as
well on the moon as it does on the Earth. It isn't independent of the
curvature because the time for the ball to go up and down differs, but it is
possible to go right down to microgravity and still get this same deviation
in velocity. Now you are talking about the gravity effects of the entire
Universe and you think that because the curvature as you measure it is
slight the effect must be low. Well you give a centripetal analogy so let
me give you a centrifugal one.
Consider an spinning ring space station. In fact consider concentric rings.
In a central section there will be no force and people will float. In the
first rotating ring out there will be some force pushing to the outside of
the ring, but possibly not a lot. In the next ring out there will be more
force, and in the next one there will be even more. By the time you reach
the twentieth ring out you may be pulling twenty g's. Clear? Now consider
the curvature of those rings. The further out the rings are, the smaller
the curvature, and the greater the force. Yet it is the curvature that is
causing the force. No paradox here, it just isn't a linear relationship.
>
> That's my point; we can't measure this acceleration, partly because of
> the reasons you listed (I hadn't thought of most of those), and partly
> because such a measurement would itself be a violation of the PofR
> (since it would allow A to deduce his absolute velocity). And yet
> without that measurement, A *must* predict that B and C will both return
> during the same moment after their "around the universe" journey.
No. Without it he predicts they will never return. Either there is a
curvature and the ships may return, or there isn't and the Universe isn't
closed. When they do return, he can use the fact of the return to
back-calculate the rate of curvature, and as Dirk says, at that point the
figures all match. But not until. Relativity is all about prediction based
on assumption and ex post facto deduction. If we can't know *now* what is
happening 100 feet away, because it takes light a finite time to traverse
the 100 feet, what hope do we have of knowing the outcome of your thought
experiment as it happens? We can only predict and say that if there is such
and such a curvature it will have such and such an effect, or we can measure
and deduce it after the fact. This is as true of P as it is of A. Either
they both use an assumption of curvature (and a closed universe is itself an
assumption of curvature), in which case they will both make the same
prediction regarding the return of the ships with Earth, or they wait and
see what happens and they both find after the fact that their measurements
will tally with a consistent value of curvature.
Jon
Phil
All of this is true, but it is irrelevant to the situation I describe.
Let me try to state things with a couple of new viewpoints included:
Whether two observers P and A, 1 km apart, are in "gravity free" space
or near the surface of the sun, if A is moving at a velocity of 0.25c as
measured by P, and A sends out objects at 0.8c as measured by A in
various directions, the velocities of those objects as *measured* by P,
and the velocities of those objects as *predicted* by the combination of
the Lorentz transform and the Newtonian gravity laws (when near the
sun), are going to be the same to within a tiny fraction of a percent,
maybe a billionth of a percent. In this small, local situation, the
"universal curvature" of space (as opposed to the local curvature caused
by the sun) cannot possibly cause P's measurements of the objects'
velocities to differ from the values predicted by the Lorentz transform
by +/- 25%. We would have noticed such a staggering anomaly long ago, if
it actually existed. It doesn't matter that, given time, the moon's
gravity can cause objects to orbit. In the situation I describe the
universal curvature of space simply does not affect the motion of
objects to such a degree that two observers, 1 km apart, can see
measured velocities that differ from the Lorentz transform predictions
by 25%. It simply doesn't happen, period! You might as well expect
deviations from the Newtonian gravity laws to cause Mercury's perihelion
to advance not by 43 arc-seconds per century, but by 25 degrees per year!
I don't know how else to say this. When two observers are 1 km apart and
send out objects in various directions -- especially when small local
gravitational effects are present -- the measured velocities are
extremely close to those predicted by the Lorentz transform. Conversely,
the measured values are *not* wildly different from those predictions.
To an extremely high degree of precision -- *way* under one thousandth
of 1% -- the Lorentz transform will *correctly* predict the measured
velocities of objects, at least when no large local gravity fields are
present, which is an assumption of my thought experiment.
>
>>That's my point; we can't measure this acceleration, partly because of
>>the reasons you listed (I hadn't thought of most of those), and partly
>>because such a measurement would itself be a violation of the PofR
>>(since it would allow A to deduce his absolute velocity). And yet
>>without that measurement, A *must* predict that B and C will both return
>>during the same moment after their "around the universe" journey.
>>
>
> No. Without it he predicts they will never return. Either there is a
> curvature and the ships may return, or there isn't and the Universe isn't
> closed.
We're talking about two different things here. The presence of universal
gravity is needed to curve our volume of space in the 4th dimension into
a 4-D locus of points; a hypersphere. So yes, A must assume that he does
live in a closed universe, with a universal gravity. However, as seen by
a 4-D being, A's motion around this hypersphere contains a centripetal
acceleration. We 3-D beings observe that a "flatlander" has a similar
centripetal acceleration when traveling around a 3-D sphere. Were it
possible for us to "measure" this 4th dimensional centripetal
acceleration, we could then derive our velocity relative to the
hypersphere, our absolute velocity.
> When they do return, he can use the fact of the return to
> back-calculate the rate of curvature, and as Dirk says, at that point the
> figures all match.
You can't just claim that they match and expect it to "mystically" be
true. The numbers have to support that claim, and in this case they do not.
But not until. Relativity is all about prediction based
> on assumption and ex post facto deduction. If we can't know *now* what is
> happening 100 feet away, because it takes light a finite time to traverse
> the 100 feet, what hope do we have of knowing the outcome of your thought
> experiment as it happens?
Don't be ridiculous. You can perform an experiment 1 year from now, and
if I know the laws that control the outcome of that experiment, I can
predict the results today. If you think you have a point here, then you
don't understand the problems that my thought experiment presents for
relativity. I'll get into that in a minute.
We can only predict and say that if there is such
> and such a curvature it will have such and such an effect, or we can measure
> and deduce it after the fact. This is as true of P as it is of A. Either
> they both use an assumption of curvature (and a closed universe is itself an
> assumption of curvature), in which case they will both make the same
> prediction regarding the return of the ships with Earth,
Hello! I can make the same assumption about the shape of a racetrack,
but if two cars move around it at different speeds, I will probably not
conclude that they will travel around it in equal times! Now you're
either getting crazy on me, or we have some serious miscommunication
going on. I repeat, it is *not enough* to simply claim that A and P will
both predict that B and C will return within 1 minute of each other as
seen by A (instead of a billion years apart). The laws and assumptions
of relativity have to make that same prediction possible! If those laws
and assumptions lead to different predictions, then there is a problem,
period. The proper way to dispute my claim is to *show*, not merely
claim, that I have made an error. Find the error and you have the answer!
or they wait and
> see what happens and they both find after the fact that their measurements
> will tally with a consistent value of curvature.
All right, let's see if we can keep this very, very simple, since that's
the way my stupid brain likes it. First, we assume that we live in a
closed universe -- although that may not be necessary for this
experiment, as I will *briefly* mention later.
Situation 1: A is motionless relative to P and the medium of space, and
he sends out B and C at 0.8c in opposite directions. A and P both
predict that B and C will return at the same time, and several billion
years later, they do. Not surprising, since B and C follow the same path
around the universe, just in opposite directions. Any problems so far? I
did state that A was motionless relative to space, but we can ignore
that is you prefer, since A and P can simply assume that they are
"motionless" -- the normal practice in relativity -- and still correctly
predict that B and C will return at the same time. Again, any questions
or doubts?
Situation 2: As above, except that several hours after sending out B and
C, A starts moving in the same direction as C at 0.2c. As predicted by
both A and P, after object B travels 80% around the universe, and A
travels 20% around the universe, B and A will meet. Also as predicted by
both A and P, C will travel 4/3 around the universe, and A will travel
1/3 around the universe, before C and A will meet. Any problems here? I
apologize for sounding patronizing, but I want to make sure that we
agree at what I consider to be each step. Besides, I can be an asshole
when I get impatient!
Situation 3: A and P are again motionless, and A sends C out at 1.0c,
and B out at 0.6c. A then starts moving in the same direction as C at
0.2c. This is the same as #2, except that B and C were launched at
different speeds. If A and P predict the results while A is still
motionless, and Av, Bv, and Cv are the velocities of A, B, and C, both A
and P will predict that once A gets moving, (Cv - Av) = 0.8c, and (Bv -
Av) = -0.8c (the minus sign denoting the opposite direction). They also
predict that B and C will meet A at the same time. Are we in agreement?
Also, P will confirm these predicted velocities and velocity differences
ions with actual measurements, although A's new velocity of 0.2c will
cause him to see different numbers. Nevertheless, A is *aware* that his
velocity has changed, and sticks with his original prediction that B and
C will return at the same time. He is correct.
Now, important conclusion #1: As seen and measured by P, the *only* way
that B and C will meet A at the same moment is if, again as seen by P,
(Cv - Av) and (Bv - Av) have the same magnitude. If P concludes that
they do not have the same magnitude, then P must conclude that they will
not return to A at the same moment. Any problems yet? The question now
becomes, can this requirement always be met?
Situation 4: P is motionless, A is moving along the positive x-axis at
0.25c, and A sends out B and C in opposite directions along the same
x-axis at speeds of 0.8c, as measured by A. In order for P to predict
that B and C will meet A at the same time, (Cv - Av) and (Bv - Av)
*must* have the same magnitudes, where Av, Bv, and Cv are measured by P.
(The only way for P to get around this would be to assume that the
distance around the universe is shorter in one direction than in the
other direction, an assumption which I am rejecting as false.) The
problem is that the Lorentz transform doesn't work this way. When P
measures the speeds of B and C relative to himself, he will find that Bv
= 0.875c, and Cv = 0.6875c, making (Cv - Av) = [.25c - (-.6875c)] =
0.9375c, and (Bv - Av) = (.875c - .25c) = 0.625c, obviously not the same
numbers. Therefore, P *must* conclude that B and C will not meet A at
the same moment. Any disagreements?
However, unless inertial observer A has some reason to conclude that he
is moving relative to the medium of space, he will assume that he is
motionless, that (Cv - Av) = (Bv - Av), since Av is zero and Cv = Bv, of
course, so that A *must* conclude that he will meet B and C at the same
moment.
Now, there is a way around this, namely for the Lorentz transform's
predictions for P's measurements of Bv and Cv to each be wrong by about
25%. Furthermore, we can even declare that the universal curvature of
space in the shape of a hypersphere "mystically" achieves this. But if
you want to claim this, then I have to ask you, how is an extremely
slight curvature (due to 1 km separation) of our 3-D space in the
direction of the 4th dimension going to absolutely destroy the
predictions of the Lorentz transform? In order for this to be true, a
similar phenomenon *must* exist when using just two dimensions, on the
surface of an ordinary 3-D sphere. In other words, when using the
assumptions of the Lorentz transform on an ordinary sphere, show how the
curvature can mess up the calculations of velocity along a straight line
(on the sphere, of course) by even 1%, as compared to similar
calculations for velocities along a straight line on a flat plane. And
remember, this calculation occurs on a very small part of the sphere,
far less than 1 degree. You won't be able to do this, for the simple
reason that this 3rd dimensional curvature has no effect on 2-D
measurements of velocity. The curvature produces other effects, such as
allowing someone to travel in what appears to be a straight line and
return to his starting point, but it doesn't change measurements of
velocity, when that velocity is measured along that apparent straight
line. I could go on, but hopefully that's enough to convince you that
this is not a simple problem that can simply be dismissed, at least not
if we are honest about the problems it presents, and don't simply
declare that "the numbers just work out."
Finally, even if the universe is not closed, anything other than a truly
flat, Euclidean space will probably cause problems. An observer would
have to change directions in order to return in a "saddle-shaped"
universe, but it is quite likely that these changes in direction will
vary depending on our location, so that the path an object must follow
to return to A will vary depending on A's location.
Phil
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D8F6666...@austin.rr.com...
> Paul,
>
> Yours is the first truly scientific response I have seen! All the others
> have been "what's a straight line," "you can't return to the earth
> (never mind what Stephen Weinberg says)," "the universe *might* be
> open," or "the numbers just add up, so there," blah blah blah ...
;-)
[snip]
> Now, there are situations, as Dirk says, where we *expect* two observers
> to predict different results, but those experiments always involve
> differences in space and/or time. Here, where A predicts that B's return
> to A and C's return to A will occur at the same time, all other
> observers *must* predict that B's return and C's return will also occur
> at a single moment in time, if the principle of relativity is to be
> valid. Dirk's other point is that the curvature of space changes P's
> measurements of the velocities of B and C,
My point is that you apply the Lorentz transformation in a way that
is not justified: your universe is not flat and/or your velocities are
not constant. Paul points this out to you and you say thanks.
And then you ignore everything and flatly repeat your error. Again.
You have no idea what you are talking about and you have no
excuse for it since you refuse to read about the very basics because
- like you said - you don't want to "get brainwashed". In this respect
you are no better than josX or Spaceman.
Dirk Vdm
Stephen Speicher
>
> "Phil" <tri...@austin.rr.com> wrote in message news:3D8F6666...@austin.rr.com...
> > to predict different results, but those experiments always involve
> > differences in space and/or time. Here, where A predicts that B's return
> > to A and C's return to A will occur at the same time, all other
> > observers *must* predict that B's return and C's return will also occur
> > at a single moment in time, if the principle of relativity is to be
> > valid. Dirk's other point is that the curvature of space changes P's
> > measurements of the velocities of B and C,
>
> My point is that you apply the Lorentz transformation in a way that
> is not justified: your universe is not flat and/or your velocities are
> not constant. Paul points this out to you and you say thanks.
> And then you ignore everything and flatly repeat your error. Again.
> You have no idea what you are talking about and you have no
> excuse for it since you refuse to read about the very basics because
> - like you said - you don't want to "get brainwashed". In this respect
> you are no better than josX or Spaceman.
>
I think that Phil is an interesting case. He is obviously more
intelligent than the two dolts you mention, yet Phil suffers from
putting on the same blinders as are worn by the other two.
My working hypothesis is that Phil was really motivated years
ago, and he wanted to have some intellectual impact. Somehow he
latched onto what he perceived as a couple of "faults" in
relativity, and he used this as a springboard to make his
"contribution." Unfortunately, by now, he seems so invested in
his thirteen years of effort that he has lost objectivity, and
now, rather than really wanting to discover the way things are,
he is more interested in rationalizing the results of his years
of labor.
Whatever the reason, it's a shame, because, unlike the two
lifeless creatures you mention, Phil has the seeds of a good
spirit in him. Unfortunately, with the path he has chosen, he is
giving expression to the worst within him, and burying the best.
Like I said, a shame.
--
Stephen
s...@speicher.com
Ignorance is just a placeholder for knowledge.
Dirk Van de moortel
"Stephen Speicher" <s...@speicher.com> wrote in message news:Pine.LNX.4.33.020926...@localhost.localdomain...
I had the same feeling: a shame indeed. Wasted intelligence.
I really would have removed him from my fumblepage.
But then I read his reply to Jon:
| "That's all right, because you and John are trying to put
| HONEST bullet holes in my thought experiment, which
| I find unbelievably refreshing after the largely, although
| not entirely (Bilge had some good points) dishonest
| nonsense I've had to answer so far."
I found that as appalling as the weather in Austria.
Being an optimist, I'm afraid that pessimism is more appropriate
for Phil and for Austria.
Dirk Vdm
Phil
[snip]
>
> I think that Phil is an interesting case. He is obviously more
> intelligent than the two dolts you mention, yet Phil suffers from
> putting on the same blinders as are worn by the other two.
>
> My working hypothesis is that Phil was really motivated years
> ago, and he wanted to have some intellectual impact. Somehow he
> latched onto what he perceived as a couple of "faults" in
> relativity, and he used this as a springboard to make his
> "contribution." Unfortunately, by now, he seems so invested in
> his thirteen years of effort that he has lost objectivity, and
> now, rather than really wanting to discover the way things are,
> he is more interested in rationalizing the results of his years
> of labor.
>
> Whatever the reason, it's a shame, because, unlike the two
> lifeless creatures you mention, Phil has the seeds of a good
> spirit in him. Unfortunately, with the path he has chosen, he is
> giving expression to the worst within him, and burying the best.
> Like I said, a shame.
Wow! One of the more difficult things to do is to offer criticism in a
way that can be not only understood, but accepted, by the person
receiving the criticism. This is about as good as I have seen!
Of course, I still think I'm right -- but I'm sure you knew I would
think that before this wrote this. I must admit, however, that while I
*might* believe the things I do because they are correct, it is equally
possible that, as you say, having invested 13 (actually 14) years into
this, I am unwilling to "let go" of my flawed ideas. Furthermore, anyone
else would have to conclude that the odds are much higher that I am
confused, rather than the majority of physicists.
Actually, I would not dare claim for a second that all of my conclusions
are correct, because too many of them have turned out to be wrong over
the years! We'll see. Hopefully I can make at least one or real
contributions. I think I have enough creativity, but in addition to
being creative, a good new idea must also be correct, and it can be very
hard to attain both of those requirements.
The only problem here, is that in setting such a decent tone, it means
I'm going to have to nice to Dirk, too, dang it. Oh well ...
Thanks,
Phil
Jon Hurwitz
I made a simple statement to the effect that you can't *know* the future and
that to predict you have to make assumptions, thinking that it was
uncontroversial; however you found it "ridiculous". I'll be happy to argue
it out in some other thread, but as it clearly won't advance the central
argument of this conversation (as I had hoped it might) I will take the
liberty of dropping it for the time being in order to cut to the chase.
You justifiably point out that I can't just claim that the numbers
mystically match. I wasn't. I was claiming that relativity predicts the
numbers will match.
So here is the chase . . .
I must stick in the proviso here that you shrink the velocities a bit. C is
an object and can't travel at c. How about we halve the velocities? That
should leave your argument intact.
>
> Now, important conclusion #1: As seen and measured by P, the *only* way
> that B and C will meet A at the same moment is if, again as seen by P,
> (Cv - Av) and (Bv - Av) have the same magnitude. If P concludes that
> they do not have the same magnitude, then P must conclude that they will
> not return to A at the same moment. Any problems yet? The question now
> becomes, can this requirement always be met?
>
> Situation 4: P is motionless, A is moving along the positive x-axis at
> 0.25c, and A sends out B and C in opposite directions along the same
> x-axis at speeds of 0.8c, as measured by A. In order for P to predict
> that B and C will meet A at the same time, (Cv - Av) and (Bv - Av)
> *must* have the same magnitudes, where Av, Bv, and Cv are measured by P.
> (The only way for P to get around this would be to assume that the
> distance around the universe is shorter in one direction than in the
> other direction, an assumption which I am rejecting as false.)
Pretty much okay so far
> The
> problem is that the Lorentz transform doesn't work this way. When P
> measures the speeds of B and C relative to himself, he will find that Bv
> = 0.875c, and Cv = 0.6875c, making (Cv - Av) = [.25c - (-.6875c)] =
> 0.9375c, and (Bv - Av) = (.875c - .25c) = 0.625c, obviously not the same
> numbers. Therefore, P *must* conclude that B and C will not meet A at
> the same moment. Any disagreements?
>
You ask for my agreement, but alas you can't have it. We have already hit
major stumbling blocks and differences in the views of the universe as we
are talking about them. I am writing this without even having read where
you go next, which is a bit naughty I admit. I'm sure though, as you have
asked for my agreement as we go along, you won't mind if I chip in at this
point.
You are trying to apply the velocity addition rule where it is inapplicable
and seem to be arguing (from previous posts) that it must be nearly enough
right that you can use it as a first approximation. I have tried
unsuccessfully to explain why small curvatures potentially lead to large
changes in velocity. You agreed but couldn't see how it was applicable. So
I hope by examining in a bit more detail the differences in the relationship
between A and P we can come to a conclusion.
The first thing I need to say is that SR can't model gravity. Do you
remember a couple months or so ago, shortly after I came to this NG two
threads started by John Chelen on rotation and orbits? We went into some
detail and, if memory serves, you got the answers right. (That was in the
salad days of my callow youth,
relatively speaking, when I was so new to all this I kept getting gamma the
wrong way up <g>.) But here you have ignored all that and I am at a loss to
understand why. Don't you remember that in SR the orbiting observer sees
the circumference of the orbit as bigger than the inertial observer sees it?
Indeed he sees it bigger by a factor of gamma. I am going to assume that
you will review this if you need to and I can continue without going back
over the full case.
Look what would happen if I tried to model this as though one of the
observers was inertial and the other was in some sort of 2D orbit --
Minkowskian space is flat and that's the only way we'll get objects coming
back again. Now both A and P can't both be inertial at the same time. So
we must pick one to be the inertial observer. Let's go for A.
A reasons as follows. I feel no force on me because of gravity or or
anything else. So I am inertial. If B, C and P loop round the universe
that must mean they are all in an orbit, even though they look like they are
travelling straight to me. So they must feel a centrifugal and a
centripetal force. Whatever. They are not inertial. If they are not
inertial, they may have to use a different physics to me as I can only be
sure that inertial objects see the world as I do. By reasoning as did
Einstein, he comes to the conclusion that orbiting objects do not measure a
length contraction wrt an inertial frame and that they don't conclude there
is a time dilation. They actually conclude there is a time contraction.
Orbiting objects measure the clocks of inertial objects going faster.
B moves one way at 0.8c, C moves the other way at 0.8c, and P moves at 0.25c
in the same direction as B. A predicts (as you have pointed out) that B and
C will meet each other at A. Please note that he will expect B and C to
complete the circuit of the universe with a length contraction based on
gamma(0.8c). But what about P? P is in orbit and will himself complete the
circuit of the Universe in a length contracted way (according to A) using th
e factor gamma(0.25c). However that's not how A believes P sees it. A
believes P sees a distorted universe, with Guassian curvature, and himself
completing the orbit in a non-length-contracted way, so you CAN'T apply the
standard velocity transforms between P and A.
The addition formula was created for a physics involving length contraction
and time dilation, whereas you need one that works for time contraction and
no length contraction. Now if you want to work out the addition formula
that SR predicts A will believe P must use, then good luck to you. I would
have thought polar coordinates would be your best bet. I can pretty much
predict it won't give numbers anything like the Einstein velocity addition
except when v<<c. However, you can't declare that SR gives the wrong
results on the basis of a formula which is invalid. Actually going back
through the thread, I see that Jan Bielawski has already done it. At first
sight it makes no sense to me whatsoever. I'll have to read it properly
sometime.
> However, unless inertial observer A has some reason to conclude that he
> is moving relative to the medium of space, he will assume that he is
> motionless, that (Cv - Av) = (Bv - Av), since Av is zero and Cv = Bv, of
> course, so that A *must* conclude that he will meet B and C at the same
> moment.
>
> Now, there is a way around this, namely for the Lorentz transform's
> predictions for P's measurements of Bv and Cv to each be wrong by about
> 25%
Or any other combination.
>Furthermore, we can even declare that the universal curvature of
> space in the shape of a hypersphere "mystically" achieves this. But if
> you want to claim this, then I have to ask you, how is an extremely
> slight curvature (due to 1 km separation) of our 3-D space in the
> direction of the 4th dimension going to absolutely destroy the
> predictions of the Lorentz transform?
Sorry, I can't find where this 1km figure comes from. But the answer is:
the same way that when I throw a ball up in the air, the curvature makes it
come down. Okay, I know you can't get this one, because you have linked
Newtonian gravity to SR and are looking for discrepancies against this
bastard model -- an extremely dubious concept. Tell me where the 1km comes
from and I'll try a different way to persuade you. <g>
> In order for this to be true, a
> similar phenomenon *must* exist when using just two dimensions, on the
> surface of an ordinary 3-D sphere. In other words, when using the
> assumptions of the Lorentz transform on an ordinary sphere, show how the
> curvature can mess up the calculations of velocity along a straight line
> (on the sphere, of course) by even 1%, as compared to similar
> calculations for velocities along a straight line on a flat plane. And
> remember, this calculation occurs on a very small part of the sphere,
> far less than 1 degree. You won't be able to do this, for the simple
> reason that this 3rd dimensional curvature has no effect on 2-D
> measurements of velocity. The curvature produces other effects, such as
> allowing someone to travel in what appears to be a straight line and
> return to his starting point, but it doesn't change measurements of
> velocity, when that velocity is measured along that apparent straight
> line. I could go on, but hopefully that's enough to convince you that
> this is not a simple problem that can simply be dismissed, at least not
> if we are honest about the problems it presents, and don't simply
> declare that "the numbers just work out."
>
I hope I've shown why you are very wrong in your declaration that velocity
predictions are not affected for the 2D case. And I never thought this
problem was simple. Trying to figure out in words *why* a non-inertial
obiting observer does not use length contraction even at the limit is still
beyond me. I don't know if you remember but I posted this as a question in
July.
> Finally, even if the universe is not closed, anything other than a truly
> flat, Euclidean space will probably cause problems. An observer would
> have to change directions in order to return in a "saddle-shaped"
> universe, but it is quite likely that these changes in direction will
> vary depending on our location, so that the path an object must follow
> to return to A will vary depending on A's location.
I agree. I never said the calculations would be easy. I just said they
would be different from yours.
Jon
Stephen Speicher
> I must admit, however, that while I *might* believe the things I
> do because they are correct, it is equally possible that, as you
> say, having invested 13 (actually 14) years into this, I am
> unwilling to "let go" of my flawed ideas. Furthermore, anyone
> else would have to conclude that the odds are much higher that I
> am confused, rather than the majority of physicists.
If you would stop and reflect for a moment on what you wrote
above, perhaps you might garner a bit of the sense of amazement
that your words make me feel. Previously you have told at least a
half-dozen knowledgeable people -- some for whom physics is their
profession -- that, basically, they have no idea what they are
talking about in regard to several issues, and yet you yourself
are only 50% sure of the correctness of your views!
If you do not have the confidence of mind to have some degree of
certainty in your understanding, I would respectfully suggest
that you open up your ears to those who have some degree of
certainty, and spend less time lecturing others.
> Actually, I would not dare claim for a second that all of my conclusions
> are correct, because too many of them have turned out to be wrong over
> the years! We'll see. Hopefully I can make at least one or real
> contributions. I think I have enough creativity, but in addition to
> being creative, a good new idea must also be correct, and it can be very
> hard to attain both of those requirements.
>
Yes, indeed. But, perhaps you have approached this whole area of
relativity from the wrong perspective. Perhaps you see relativity
as a canvas upon which you want to paint, rather than seeing
relativity as a well-established field worthy of considerable
effort to learn. Before you make "contributions" you must first
understand thoroughly the way things are, else what is your
"contribution" to be based upon, if not knowledge?
Phil, I have said this to you before, and I'll say it again: you
have no way of realizing just how sympathetic I am to some of
your most general views in regard to science and epistemology. I
submit, however, that you talk a better game than you practice.
If you want to "contribute" _first_ make sure you learn what the
issues are, and why. I'm sorry to say that, in my opinion, you
may have spent too much of those 14 years doing something else
than you should have done. And that should have been, primarily,
first learning.
(I don't mean to say you have learned nothing at all; that would
be silly. Rather, it seems as if you may have arrested your
learning when you started to "contribute," this done earlier than
you should.)
> The only problem here, is that in setting such a decent tone, it means
> I'm going to have to nice to Dirk, too, dang it. Oh well ...
>
I think you are entirely misreading Dirk. Dirk is one of the
nicest and most gracious of people on this group, and he often
goes to a lot of trouble attempting to make people understand
what they themselves may not realize they lack.
Phil
Well let's see. I quoted from Stephen Weinberg:
"(That is, if we set off on a journey in a straight line, we do not
reach any sort of edge of the universe, but simply come back to where we
began.)"
And your response was:
The sentence between parentheses obviously refers to the example of the
surface of the sphere, and not to the actual universe.
Showing that you were either willing to lie to me, or that you were
clueless about 4-D geometry and its place in GR. After I pointed out
that no, Weinberg was indeed talking about our universe (the closed
version of it), you said:
What if the Universe is the analogue of an ellipsoid or a torus, or a
"somewhat less perfect sphere"? What if the Universe is not empty and
the presence of matter disturbs the "perfect sphere"? Do you "simply
come back where you began"?
Which merely dodged the issue, since the closed version of GR is in fact
a hypersphere, i.e., a four dimensional locus of points (although I
realize you probably have no idea what that means). You might as well
have said, "What if all this is just a dream?" -- it really would have
made as much sense.
I then gave a brief description of hyperspheres, and quoted from Bilge
where he said that GR has no problem with the idea of someone traveling
in (what appears to be) a straight line and returning to his starting
point. Then I produced the numbers showing how the two inertial
observers (A and P in your later description) see different results for
the return times of the two spaceships. Your response was:
But Phil, this is so basic. It is relativity of simultaneity. For this
discrepancy to take place, the ships don't even *have* to go "around a
universe". Just suppose that, as seen on Earth, both ships send out a
flash of light at the same time, let's say 2 Earth-minutes after their
departures. Then, as measured on the "the inertial observer", the
flashes will *not* be simultaneous, neither will they be as measured on
the ships themselves. Only Earth will find them to be. That is not a
flaw. That is page one of SR-001. Right?
However, when the two events in question, the return of B to A and the
return of C to A occur not only at the same time as seen by A, but at
the same point, then it is physically impossible for any other observer
to see B and C returning to a single location on A at two different
points in time. Again, either you knew this and were willing to lie to
me, or you forgot it/overlooked it (I refuse to believe that you do not
understand this aspect of simultaneity "SR-001," at least at a basic level).
You then came through with your model of a circle, along with A, P, B,
and C. That was honest and good, although you still claimed at the end
that the disagreement on the return times was a standard example of
simultaneity and SR-001.
After I pointed out the error on simultaneity, you responded with:
But your numbers are wrong and you should know that because it has been
pointed out to you before. You have used the Lorentz transformation and
composed the velocities (P,B) and (P,C) as if all the velocities are
constant, i.o.w. as if the paths are intrinsically straight. But the
paths are not *really* straight, since your space is intrinsically
curved. On a circle the paths are not straight lines. We are free to
*define* them as straight, or *call* them straight because there really
is no other choice, but they still are curved. In that case you cannot
simply use the Lorentz transformation, since the velocities are not
constant. That is page one of SR-001.
Before I get into this one, I want to point out something. You went from
one argument, to another, to another, and then to another. At every step
you claimed that I was wrong, that the "problem" was obvious (although
it changed in every post), that it was basic relativity (again, changing
in every post), that I needed to read the books, I clearly refused to
learn anything, blah blah blah.
Do you seriously consider this to be *scientific* behavior on your part?
Does any of this sound like you ever, from the beginning, had the
slightest idea of what the real problem with my thought experiment
was/is, assuming it has a problem? Would anyone with the sense god gave
an onion, reading this series of posts, conclude that you "play fair,"
that you put scientific honesty and integrity above merely trying to win
an argument, in large measure by cutting your opponent down with a bunch
of general criticisms with no real supporting examples? Dirk, I don't
think that you *always* use lies, distortions, and evasions, but that is
what you have *primarily* done in these posts.
You said that I am just like Josx and Spaceman. *Somebody* here is
acting just like them, putting one bogus and/or stupid argument up after
another in a borderline obsessive attempt to defend his beliefs, but if
you were honest with yourself, you would have to admit that it isn't me.
Because the *only* reason you changed from one argument to another to
another ... is because at each stage, I proved, using honesty and
scientific facts, that your argument did not apply, The *moment* you
figure out what is actually wrong with my thought experiment (in a way I
can understand, of course) I will admit it to everyone, and walk away
the wiser. You can take that to the bank, whether you want to admit it
or not. Does that sound like something that Josx and Spaceman would do?
For that matter, does that sound like something *you* would do? You've
been dishonest or evasive or flat out wrong at *every step* of the way
so far. Give me one reason why I should think that you will change now.
Well, Einstein once said that certain beliefs provide, "a gentile pillow
for the true believer from which he cannot very easily be aroused. So
let him lie there." I need to take his advice and let you lie where you
are, because this pattern of behavior has gone on long enough.
I will mention one or two minor points on your latest argument (the
4th?, the 5th?), and then I will post the remainder to Jon's post. A
plane can be curved through the 3rd dimension into a cylinder as well as
a sphere, and of course a space can be curved through the 4th dimension
into a "hypercylinder" (I don't know if that is the actual term). This
is not what GR predicts for our universe, but it serves to make a point.
In your argument, a plane can support the normal laws of SR, including
the Lorentz transform, just fine, because it has no curvature. But while
it is true that these laws can be valid in a plane, ask yourself, can
the curvature of a plane into a cylinder affect the measurement of
distances, when those measurements are made *along the surface of the
cylinder?* In particular, if a "flatlander" follows along a circle which
is perpendicular to the axis of the cylinder, can the fact that his
world has been curved into a cylinder affect his measurements of
distance or velocity along that circle in any way whatsoever? He can
return to his starting point by traveling along what to him is a
straight line, an effect which *does* result from the 3rd dimensional
curvature, but his measurements of distance and velocity not only will
not, but cannot, be affected by this curvature.
In order for your argument to be valid, all measurements of particles
leaving a radioactive object which is moving at high speed relative to
us would have to be seen by us as having equal velocities *relative to
the radioactive object*. This is the only way that "A and P" can predict
the same results for my thought experiment. Such differences from the
Lorentz transform would have been noticed long ago in measurements of
radioactive materials, so it definitely doesn't exist. But if you try to
go to some physicist and tell him that you have a proof that the
universe is not closed, because "the velocities of particles ejected
from a radioactive object do not obey the Lorentz transform in a closed
universe, but instead must be measured by us as having equal velocities
relative to the radioactive object," you'll get laughed out of the room!
This is just one more in your line of dishonest, bogus responses to my
thought experiment. And I have complete faith that you will promptly
come up with another, if nothing else saying that "I refuse to learn
anything," or whatever. Has it ever occurred to you to THINK about what
my thought experiment really does *and does not* imply, or does the urge
to defend GR at all costs immediately overwhelm you? Have you considered
the possibility of trying to determine whether it is actually true,
instead of merely trying to snowball me with another bogus argument?
Sorry about the harsh tone, but my patience has run out. Honest
disagreement and misunderstanding I can usually handle (except for when
I get stupid -- see Jon's latest post), but this really has gone on long
enough. If you present honest, scientific ideas, arguments, rebuttals,
etc., I will be happy to discuss them with you, but the mindless
arguments, the endless put-downs, in particular the "you're stupid,"
"you don't listen," "you refuse to learn" crap needs to end, now. They
are just one more attempt on your part to win an argument not with
facts, but by cutting your opponent to shreds, and whether you realize
it or not, such techniques contain no scientific value whatsoever.
Phil
Well then, let's see if we can get some facts in here so that I can see
what you're you can give
if we can get some facts in here so that I can see what you're you can
give
>
Jon Hurwitz
If your post to me is anything like this one, don't bother with it. You
have taken eight months to put your current ideas down, yet you expect
everyone to understand them in a week or two. When Dirk doesn't and when he
tries to argue against them (and you have to admit the possibility that you
haven't understood the relevance of his arguments) you call his posts bogus,
mindless and dishonest. I agree that the torus point was more of an
interesting sidelight than an argument (perhaps I only think I understand
it), but his posts to you have never appeared to me to be mindless, bogus or
dishonest. I also have had trouble in understanding where some of the
differences in opinion lie. I too have produced different arguments, which
you claimed to appreciate.
No one has to post anything here. Not you, not me and not Dirk. You posted
because you wanted feedback, and you are getting it. If it isn't what you
wanted, I'm sorry. If what's being said isn't what you expected, I'm sorry,
too. But that's the point of feedback. If it were always what you expected
and wanted, you wouldn't need to solicit it in the first place. I find
almost any feedback at all of some use. That should go double for a wannabe
author.
When something goes wrong, it can always be ascribed to the cock-up or the
conspiracy camp. I suggest you consider inevitable misunderstandings in
this thread to be just that, rather than deliberate evasions and lies. You
imply that Dirk has trivialised your points. And some of them he has. But
he has also said in this thread, "There are some nifty subtleties". And you
have already called one of his points TSTRT. So perhaps you might give him
the benefit of the doubt. Furthermore, this shouldn't be a question of
winning an argument. This should be an exploration of differences in ideas.
You don't have to agree with someone to listen to them. Once again, if all
you are trying to achieve here is to persuade and not to learn, I suspect
you are wasting your time (though probably not mine <g>).
I discuss with you to learn not to win. That doesn't mean I agree, or even
that I will ever agree. I may or I may not. But I can also learn more
about my own views by listening to others than I can by considering them in
isolation. I have posted here from my limited understanding of relativity,
not because these are deeply held beliefs that I want to convert you to, but
because that's what I wanted to discuss, and I thought you did too.
I ask as a favour that you metaphorically count to a hundred before posting
again on this thread. Have a bath, walk the dog, make love, whatever it
takes to make you feel better. If you change your mind then you can post an
apology to Dirk. And if you are very lucky he might accept it.
If your post to him makes *me* this annoyed, I suspect he won't take it too
kindly.
Jon
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D957935...@austin.rr.com...
[snip]
> Well let's see. I quoted from Stephen Weinberg:
>
> "(That is, if we set off on a journey in a straight line, we do not
> reach any sort of edge of the universe, but simply come back to where we
> began.)"
>
> And your response was:
>
> The sentence between parentheses obviously refers to the example of the
> surface of the sphere, and not to the actual universe.
>
> Showing that you were either willing to lie to me, or that you were
> clueless about 4-D geometry and its place in GR. After I pointed out
> that no, Weinberg was indeed talking about our universe (the closed
> version of it), you said:
>
> What if the Universe is the analogue of an ellipsoid or a torus, or a
> "somewhat less perfect sphere"? What if the Universe is not empty and
> the presence of matter disturbs the "perfect sphere"? Do you "simply
> come back where you began"?
>
> Which merely dodged the issue, since the closed version of GR is in fact
> a hypersphere, i.e., a four dimensional locus of points (although I
> realize you probably have no idea what that means). You might as well
> have said, "What if all this is just a dream?" -- it really would have
> made as much sense.
Ha. Apparently (and somewhat surprisingly) you are not aware of
it, but Weinberg and you are talking about a version of a universe
where all matter is evenly distributed on all scales: all matter is
continuously (smoothly) smeared out over that entire universe,
making it a very dull place indeed.
If this is the case and if a critical uniform mass density is reached,
this universe is closed and you "simply get back where you started".
(By the way, for this to be true on a circle you don't even need
any matter: mass density can be uniformly zero.)
But the *actual* universe is not like that. Matter is not smeared out.
There are lumps, making the actual universe a rather interesting
place. In this actual case, if a critical mass density is reached at
some scale (for instance on the scale of [clusters of] galaxies), this
actual universe is closed but you do *not* "simply get back where
you started".
You quoted:
| "On the other hand, if the density of the universe is *greater* than
| this critical value, then the gravitational field produced by the matter
| curves the universe back on itself; it is finite though unbounded, like
| the surface of a sphere. (That is, if we set off on a journey in a
| straight line, we do not reach any sort of edge of the universe, but
| simply come back to where we began.)
So, my original statement:
"The sentence between parentheses obviously refers to the
example of the surface of the sphere, and not to the actual
universe."
stands.
If you really insist, I will add to "surface of a sphere":
- volume of a hypersphere,
provided matter is sufficiently dense *and* uniformly smeared out.
Even in the absence of matter, I will gladly add:
- circumference of a circle or any closed curve,
- location of a point.
But for reasons stated above, I will certainly not add:
- the actual universe.
Perhaps I shouldn't have, but I really thought this was obvious
for someone who has been working on this stuff for 13 years.
I guess you have been working on popularisations only.
Popularisations tend to forget to explicitly mention some vitally
important details. That is why some of us desperately try to
recommend reading *technical* introductions.
Since it took me more than an hour to "hone this message to
razor sharpness", I am afraid I have no other option than to
snip the remainder of your post - essentially unread, sorry.
Dirk Vdm
Phil
That is a nice answer, and it had not occurred to me that you might be
claiming that you cannot return to the *exact* planet you left from, at
least not without "course correction," because of drifts caused by
extremely weak, but still real, gravitational fields from galaxies that
could not be measured and corrected for by the traveler. Okay, that was
an unfair criticism on my part.
Of course, this isn't much better, because it implies that a mere
technological limitation makes the substance of my thought experiment
immaterial. Even our current level of technology, which is good enough
to detect "the great attractor," would probably suffice to get A back to
within a billion light-years of his original location, and in a thought
experiment we can certainly imagine beings who occupy a space this
large, with much better equipment for detecting and correcting for the
drifts caused by these extremely weak fields. I assume you are not
claiming that the undetectable part of these fields (which is the only
part that cannot be corrected for) is going to throw off A's path by 10
degrees or something. And in that case (a retrun to within a billion
light-years if the Lorentz transform does indeed apply) then the results
would still show either A or P to be wrong by an amount far greater than
could be accounted for by mere drift.
Well, all this is academic, because you either take a thought experiment
based on its merits or you don't. The question, given the ability to
return anywhere close to the starting point (an object, not a "point in
space"), is whether A and P will predict the same results. If we have to
imagine this occuring when the universe was so young that matter and
energy were evenly distributed, then we do so, without saying, "But no
spaceships could have existed then," because this is a thought
experiment that tests the compatibility of the PofR with the reality of
a GR closed universe, not a test of technology, including time travel.
If a thought experiment does not violate the laws it proposes to test,
as opposed to laws that limit some aspect of technology, then it is a
valid test.
My conclusion is that you are not interested in actually discussing the
real substance of my experiment, but simply want to attack it, and me,
from any angle that looks promising. Maybe you got into the habit of
always defending yourself, and never acknowledging the merits of "the
other guy's" arguments, when you were up against some of the rabid anti-
SR types on this list. Then again, maybe you just enjoy verbal sparring,
and couldn't care less about new ideas, conclusions, or even insights
into various old ideas. I will be the first to admit that I do not know
with absolute certainty which of those two possibilities is correct.
I'll ask a few questions:
If the Lorentz transform does indeed give the values for B and C as
measured by P, would that potentially cause trouble for the PofR?
Are you confident that even if the LT does give the velocity values,
that it will turn out that my thought experiment is flawed in some other
way, and not just in terms of technology, but at a fundamental level,
where it really matters?
Do you think that my idea that the energy that an object accumulates as
it falls into a gravitational well comes entirely from the medium of
space has any merit?
Would you have any interest in discussing the implications of this idea?
No apology needed, you did exactly what I expected you to do, and
very neatly at that. Of course, you do realize that if my thought
experiment turns out to be correct, that there will probably be some
interest in its "history," including these exchanges.
Phil
Stephen Speicher
> No apology needed, you did exactly what I expected you to do, and
> very neatly at that. Of course, you do realize that if my thought
> experiment turns out to be correct, that there will probably be some
> interest in its "history," including these exchanges.
>
I cannot speak for Dirk or anyone else, but I strongly suspect
most are willing to risk the scrutiny of history in regard to
your postings. Has the possibility occurred to you that, if your
postings are looked at from an historical perspective, the focus
may not be your contribution to physics, but rather from the
perspective of an historical study of megalomania in newsgroups
on the early internet?
Phil
> On Sun, 29 Sep 2002, Phil wrote:
>
>
>>Dirk Van de moortel wrote:
>>
>>
>>>Since it took me more than an hour to "hone this message to
>>>razor sharpness", I am afraid I have no other option than to
>>>snip the remainder of your post - essentially unread, sorry.
>>>
>>>
>>No apology needed, you did exactly what I expected you to do, and
>>very neatly at that. Of course, you do realize that if my thought
>>experiment turns out to be correct, that there will probably be some
>>interest in its "history," including these exchanges.
>>
>>
>
> I cannot speak for Dirk or anyone else, but I strongly suspect
> most are willing to risk the scrutiny of history in regard to
> your postings. Has the possibility occurred to you that, if your
> postings are looked at from an historical perspective, the focus
> may not be your contribution to physics, but rather from the
> perspective of an historical study of megalomania in newsgroups
> on the early internet?
>
Yes, it has occured to me. I sure do hope that won't be the case!
It has also occured to me that no one besides you has said anything
about the medium of space being the source of all gravitational energy
and its implications, and even you just said that it was old news. Maybe
it isn't actually old news at all. Of course, if my thought experiment
on the PofR really is flawed then I will still look stupid on that one,
but all the arguments you guys have come up with so far don't appear
valid to me (I try to be completely honest about it, though I am
probably biased anyway). Bilge said that Dr. Weinberg addressed the
matter of what happens to the energy lost by photons as the universe
expands, but when I asked him if Weinberg also concluded that space
holds at least a trillion times more energy than is contained in all the
matter in all the galaxies combined, more dead silence.
You know, I really could handle it if someone could point me to some
literature adrressing any of these issues, and the literature proved
that I was full of crap. One of the (surprisingly many) advantages of
cancer is that you almost always retain some perspective, at least after
you get done losing your temper! Maybe I should start a new thread or
two on these points and ask if anyone has seen stuff on these matters. I
rrealize I can't always ask you to look this stuff up for me, even
though you do seem to be the master of such things.
Phil
Stephen Speicher
>
> You know, I really could handle it if someone could point me to some
> literature adrressing any of these issues, and the literature proved
> that I was full of crap.
>
Phil, it is not so much that you are "full of crap," (well, that
too) but, mostly ignorant and naive. There are many hundreds of
papers and books to refer you to, but since you do not devote the
time to study basic introductory books like _Spacetime Physics_,
then what is the point of giving you hundreds of technical
references? These sorts of issues are dealt with from a wide
variety of perspectives, much more disparate than you even see
here on this group. However, in the technical literature, such
disparities are respected because of the nature of the approach,
i.e., not pronouncements from ignorance, but speculation from
knowledge.
Look, here are a few I happen to find interesting, for reasons
which are not now important. The first two are technical and will
be difficult for you to follow, but if you persist you can at
least glean a different perspective. The last is not really
technical, and you should find it interesting. I will send each
of these to you by e-mail since I know you do not have access.
Again, these are just a few of many, many hundreds, and most of
these people have some familiarity, at least on a conceptual
level, of the work of the others. This is a state you should
strive for, and it requires education to lead you along the way.
"Spinning strings as torsion line spacetime defects," P. S.
Letelier, _Classical and Quantum Gravity_, 12 (February 1995),
pp. 471-478.
"Space-time defects and teleparallelism," J.W. Maluf and A. Goya,
_Classical and Quantum Gravity_, 18 (23): (Dec 7 2001), pp.
5143-5154.
"The Theory of Everything," R. B. Laughlin and D. Pines,
_Proceedings of the National Academy of Sciences of the United
States of America_, 2000 97: pp. 28-31.
Dirk Van de moortel
"Phil" <tri...@austin.rr.com> wrote in message news:3D96643B...@austin.rr.com...
[snip]
> That is a nice answer, and it had not occurred to me that you might be
> claiming that you cannot return to the *exact* planet you left from, at
> least not without "course correction," because of drifts caused by
> extremely weak, but still real, gravitational fields from galaxies that
> could not be measured and corrected for by the traveler. Okay, that was
> an unfair criticism on my part.
You still don't get the message. Ah well.
>
> Of course, this isn't much better, because it implies that a mere
> technological limitation makes the substance of my thought experiment
> immaterial.
But your thought experiment has no substance. Technology has
nothing to do with anything. I couldn't care less where exactly B
and C return. If they get together, they will do so simultaneously
according to the entire universe, whether it is open, flat or closed,
whether it is empty, lumped, or uniformly filled with smeared out
liquid manure, whether they went in circles or in eights or in three
point fives.
The fact that you insist that there might be a situation where the
simultaneity does not happen for every observer, originates from
your applying a caricature of the consequences of a coordinate
transformation that you do not understand, in a situation that
you do not understand either.
More than once you have been given excellent references to
help you understand. More than once you have been given
more than one good reason why your thought experiment is
fatally futile. But you don't want to get brainwashed, so just
get your book published. Don't forget to mention that you had
to endure some severely dishonest and relentlessly deceitful
resistance going through the process of creating it.
Dirk Vdm
Dirk Van de moortel
"Stephen Speicher" <s...@speicher.com> wrote in message news:Pine.LNX.4.33.020928...@localhost.localdomain...
Couldn't find this one but I guess it's in the same alley as
the second one...
>
> "Space-time defects and teleparallelism," J.W. Maluf and A. Goya,
> _Classical and Quantum Gravity_, 18 (23): (Dec 7 2001), pp.
> 5143-5154.
... which is [Ouch!] *way* out my league :-(
> "The Theory of Everything," R. B. Laughlin and D. Pines,
> _Proceedings of the National Academy of Sciences of the United
> States of America_, 2000 97: pp. 28-31.
A very nice and somewhat humbling experience :-)
I would like to add the beautiful but much too short
http://arxiv.org/abs/gr-qc/0103044
Dirk Vdm
Stephen Speicher
> >
> > "Spinning strings as torsion line spacetime defects," P. S.
> > Letelier, _Classical and Quantum Gravity_, 12 (February 1995),
> > pp. 471-478.
>
> Couldn't find this one but I guess it's in the same alley as
> the second one...
>
At the time of publication Patricio Letelier was associated with
the Isaac Newton Institute for Mathematical Sciences in
Cambridge, UK. The Institute is relatively new (now celebrating
its 10th anniversary) and is a fascinating place. Penrose and
Hawking held a debate there in 1994, somewhat reminiscent of the
famous Bohr-Einstein debates. Princeton University Press
published the essence of the debate under the title "The Nature
of Space and Time," Stephen Hawking and Roger Penrose, 1996. A
fascinating read.
You can check out the Institute's web site at:
Phil
am still looking at them (especially Dirk's), although I have to agree
with Dirk on the relative difficulty of Stephen's suggestions (I do like
that thrid article, however). In any case, these papers refer to quantum
level effects on gravity, whereas the phenomenom that I was thinking
about could, in theory, dump 1,000 solar masses into a very small region
of space in a matter of days, or even seconds. The subject is so
different from my thought experiment that I started a new thread on it,
which will hopefully lead to current papers/ideas, or at least comments
on where I went wrong, on the subject I had in mind.
Thanks again,
Phil
Phil
> "Phil" <tri...@austin.rr.com> wrote in message
news:3D96643B...@austin.rr.com...
>
> [snip]
>
>
>>That is a nice answer, and it had not occurred to me that you might be
>>claiming that you cannot return to the *exact* planet you left from, at
>>least not without "course correction," because of drifts caused by
>>extremely weak, but still real, gravitational fields from galaxies that
>>could not be measured and corrected for by the traveler. Okay, that was
>>an unfair criticism on my part.
>>
>
> You still don't get the message. Ah well.
>
>
>>Of course, this isn't much better, because it implies that a mere
>>technological limitation makes the substance of my thought experiment
>>immaterial.
>>
>
> But your thought experiment has no substance. Technology has
> nothing to do with anything. I couldn't care less where exactly B
> and C return. If they get together, they will do so simultaneously
> according to the entire universe, whether it is open, flat or closed,
> whether it is empty, lumped, or uniformly filled with smeared out
> liquid manure, whether they went in circles or in eights or in three
> point fives.
This answer seems so honest that I am beginning to think that Jon was
right, and that I am just paranoid. Of course, when you include
statements in almost every other post about how stupid I am, I am sure
you can understand how us "thin-skinned" types might become ... ah ...
"confused" as to your honest intention to help others out. Well, live
and learn.
It is true that B and C will always meet "simultaneously." This is a
truism that I think no physics disagrees with. However, it is not
necessarily true that A, B, and C will meet simultaneously. To use
Einstein's train example, the observer in the middle of the train says
that two flashes of light were sent from each end at 7:00 o'clock, and
verifies that they arrived at his location -- A if you will -- at the
same moment in time. Observer P on the tracks says that A's clocks are
not synchronized, that the flashes were sent at different times, that
they took different amounts of time to reach A (since they traveled
different distances, and c is relative to P's IRF, not A's IRF, as seen
by P), but concludes that all these variations canceled each other out
in the end, so that the two flashes of light reached not just each other
simultaneously, but A simultaneously. Had one of the flashes been sent
at a slightly different time, however, then the flashes would not have
reached A simultaneously. More to the point, both A and P predict that
the flashes will be seen by A at the same moment; another way of saying
that the experiment's results are independent of the train's velocity
relative to P, just as claimed by the PofR. Simultaneity in relativity,
therefore, does not mean that everyone sees everything differently. If
A, B, and C, all meet each other at a single point in space during a
single moment in time as seen by one observer, then they must all meet
at a single moment in time as seen by all observers, period. There is no
mechanism in SR or GR that would allow the observer in the middle of the
train to see the flashes as arriving simultaneously, while causing some
other observer to see them as arriving at different times, so that A
could literally see one flash, get off the train and return, and only
then see the next flash. Nope, can't be done.
> The fact that you insist that there might be a situation where the
> simultaneity does not happen for every observer, originates from
> your applying a caricature of the consequences of a coordinate
> transformation that you do not understand, in a situation that
> you do not understand either.
A wonderful example of a general criticism without any actual supporting
examples. I am going to guess that you will not apply any actual numbers
to an actual example demonstrating what you are claiming. The simple
fact remains that under the PofR, both P and A *must* predict the same
results for A's experiment. Either A will predict that B and C will
return at the same time, at least within a thousand years of each other
(and since this is a thought experiment, we ignore the "friction" types
of problems that would make this difficult in actual practice), or he
will predict that they will return at extremely different times,
millions or even billions of years apart. Ditto for P. You
(occasionally) claim that the Lorentz transform will not tell us what P
will measure for the velocities of B and C, given that A appears to have
a velocity of 0.25c as seen by P, and that B and C appear to have
velocities of +/- 0.8c as seen by A, due to "the curvature of space."
But if I successfully measure distances and velocities on a straight
line, how is curving that line into a circle going to change my
measurements of distance and velocity as long as I measure them *along*
the curved line? That's ridiculous, and really *sounds* like (although
it hopefully isn't true) you are simply defending relativity at all
costs, with no regard for reality. Under your theory, the velocities of
B and C relative to A as seen by P would *have* to be equal; there is no
other way for P (or any other observer) to conclude that B and C will
return to A at the same moment in time. If true, however, then measuring
the particles given off by a radioactive sample moving at 0.25c *must*
show that the particles have equal velocities relative to the
radioactive sample, instead of the velocities expected from the Lorentz
transform, if we live in a closed universe, and it simply cannot be that
simple to prove that we do not live in a closed universe. You can't
actually believe that if you go to a physicists and propose this test,
that you will not be laughed out of the room, and for good reason.
> More than once you have been given excellent references to
> help you understand. More than once you have been given
> more than one good reason why your thought experiment is
> fatally futile.
I believe that any honest person would conclude that my responses show
that your claims of "fatal flaws" in my thought experiment do not stand
the test of reality (although they use great debating tricks, such as
claiming that if I just read book x, it will explain why I am wrong --
even though you can't seem to find the evidence in said book yourself),
and so far I can only conclude that you have "relativity religion,"
causing you to make ridiculous claims in its defense, instead of simply
stating, "Look Phil, I don't know why your thought experiment is wrong,
but I have complete faith that it is indeed wrong." That I wouldn't
mind, or even put down! But these ridiculous claims of yours ...
> But you don't want to get brainwashed, so just
> get your book published. Don't forget to mention that you had
> to endure some severely dishonest and relentlessly deceitful
> resistance going through the process of creating it.
I will *not* mention it, because it would be ill-mannered -- even if
it's true. Come on Dirk, you can do better than this. Determine whether
it is or is not true using *valid* techniques of *real* science! Don't
just claim that I am wrong using lines from a bad debate, *demonstrate*
that it is wrong using actual numbers! Or at the very least, given your
inability to do this (assuming you can't, of course), have the decency
to stop telling me how stupid *I* am, since I am not the one who is
failing to come up with any numbers to back up his words.
Phil
Phil
won't show me your other post. That's okay (I think), because I was not
going to add that much to my posts to Dirk anyway -- although I had no
intention of using the same tone, since I believe you are sincere. And
sorry if it bothers you that I think others are occasionally not
sincere, in terms of using what I consider to be debating and political
tricks and maneuvers, instead of real science, in order to cut down
their opponent.
Anyway, the fact that a plane can be rolled into a cylinder with no
effects on distance, angles, etc., should prove that curvature through
"the next" dimension does not necessarily mess up measurements of
distance and velocity. Specifically, if I make measurements on a line,
and then that line is curved into a circle so that the plane of the
circle is perpendicular to the axis of the cylinder, how can this
curvature affect my measurements of distance and velocity, as long as I
make those measurement along the circle? Now place a sphere inside the
cylinder so that the equator of the sphere overlaps the circle; how can
measurements along this circle (which is an assumption of my thought
experiment, by the way) be affected by its curvature around the sphere?
What difference does it make whether I measure along a line in a plane,
or along a line on this equator?
To answer your other question about why I cannot see that this curvature
is similar to what happens with an orbiting observer is harder! However,
I think that to be analogous, we have to have an orbiting observer, and
then have him measure the velocities of objects ejected by another
observer moving along the same orbit, but at a different velocity. The
point here would be to ask, can the measured velocities of B and C (the
ejected objects) be not just different from what we expect from the
Lorentz transform, but different in such a way that they will appear to
have equal velocities relative to A as seen by us. The Lorentz
transform, in normal situations, causes one delta velocity to be higher
that expected from the Galilean simple "addition of velocities," and the
other delta velocity to be lower than expected. I can see how orbiting
observers will see both values expanded, or both contracted, but I
cannot see how they will see one expended and the other contracted, and
by just the right amount to produce Galilean results! In any case, an
orbiting observer really is different, because he knows that he has some
minimum average velocity relative to the medium of space, and so expects
to see weird results. There is no intrinsic reason why A or P should
think that they have some absolute velocity, and so both should simply
assume that they are motionless -- under the PofR, of course.
>> > [snip]
It could be that Dirk has some honest disagreements and
misunderstandings, and simply responds in a way that I find very
offensive, that I view as personal attacks, when he really doesn't mean
them that way. I don't believe that, however, although I will admit that
he has both non-scientific personal attacks, and also some scientific
points. But whether I am simply confused by his style or not, my
patience with his attacks on my intelligence is at an end. It would be
one thing if he backed up his claims with actual examples, but that is
not the case. That makes his attacks dishonest in my book, so I will, at
least somewhat politely, tell him what I really think about his posts
from now on (although that also means being honest when he makes a good
point, which he does on a regular basis).
>
> I discuss with you to learn not to win. That doesn't mean I agree, or even
> that I will ever agree. I may or I may not. But I can also learn more
> about my own views by listening to others than I can by considering them in
> isolation. I have posted here from my limited understanding of relativity,
> not because these are deeply held beliefs that I want to convert you to, but
> because that's what I wanted to discuss, and I thought you did too.
Very intelligent on your part. Sorry if I disappoint you, but I don't
think that I am avoiding either science or a willingness to lose. I
think I have simply had enough of one individual's nonscientific
put-downs. He has come out swinging from post #1 (on this thread). Fine,
I'll take off my gloves as well, and we'll see how much he enjoys it.
Hell, he may be enjoying himself blue at having annoyed me this much!
Who really knows ...
>
> I ask as a favour that you metaphorically count to a hundred before posting
> again on this thread. Have a bath, walk the dog, make love, whatever it
> takes to make you feel better. If you change your mind then you can post an
> apology to Dirk. And if you are very lucky he might accept it.
>
> If your post to him makes *me* this annoyed, I suspect he won't take it too
> kindly.
>
>
> Jon
>
We'll see. Most of what you say is true, but at a fundamental level, you still
trust the guy, and I don't, although I appreciate it when he posts something
really useful, interesting, or helpful. And I must admit that he has
helped me to find the flaws in the kinds of arguments that are likely to
be used against my thought experiment by others. That's been good!
Phil