Progression of the Perihelion
heimdall
described as the effect of the light-speed of gravity, but
also as the effect of the time dilation and space expansion
(spacetime curvature) nearer the sun.
Undoubtedly, both spacetime curvature and gravity contribute,
but which is more important? Gerber, I think, explained it
entirely as a function of light-speed, but, I understand, his
explanation was wrong although his formula was correct.
Is there a good reference to explaining the motion of the
perihelion, preferably one that introduces just enough mathematics
to get the job done?
Heimdall
greywolf42
heimdall <vze3...@verizon.net> wrote in message
news:b0601654.03052...@posting.google.com...
Yes. An excellent reference for this is Petr Beckmann's "Einstein Plus
Two." And all you need is speed of gravity. (By the way, there are NO
errors in Gerber's work.) Pauli et al dislike Gerber's derivation because
it is not a complete theory of gravity. Not because there are errors in
Gerber's work. (At least no errors have ever been published or noted in
what Gerber actually DID.) GR's results are also the result solely of
finite gravity speed.
greywolf42
ubi dubium ibi libertas
Dharma Fog
[snip]
> Undoubtedly, both spacetime curvature and gravity contribute,
> but which is more important?
Gravity is equivalent to spacetime curvature.
Dirk Van de moortel
"greywolf42" <min...@sim-ss.com> wrote in message news:vd4eur2...@corp.supernews.com...
This nicely qualifies:
http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/AllNeed.html
Title: "And all you need is speed of gravity"
http://groups.google.com/groups?&threadm=7vaq4l$fm4$1...@mark.ucdavis.edu
http://groups.google.com/groups?&threadm=76gd7r$jkv$2...@mark.ucdavis.edu
Dirk Vdm
Tom Roberts
> I have seen the progression of the perihelion of Mercury
> described as the effect of the light-speed of gravity, but
> also as the effect of the time dilation and space expansion
> (spacetime curvature) nearer the sun.
You are confusing two different theories (at least).
> Undoubtedly, both spacetime curvature and gravity contribute,
> but which is more important? Gerber, I think, explained it
> entirely as a function of light-speed, but, I understand, his
> explanation was wrong although his formula was correct.
Again you confuse at least two different theories.
If one wishes to analyze ONLY the advance of the perihelion, one can
follow Gerber and apply Newtonian mechanics with a finite speed of
gravity, and fit the unknown speed of gravity to the observed perihelion
advance and obtain good agreement. That's fine AS FAR AS IT GOES --
because if one tries to apply the same theory to the orbits of other
planets and moons it fails, big time. So this approach is useless, and
nobody has been able to make it work for ALL observations.
In GR, the precession of the perihelion arises naturally for an
elliptical orbit of a test particle around a massive spherical object --
such a geodesic is almost but not quite closed, and for Mercury the GR
prediction agrees quite well with the observations (which are of course
corrected for the influence of other planets, a correction which
significantly exceeds the GR prediction).
In GR, gravitation is merely the geometry of spacetime (one can LOOSELY
say that spacetime curvature "is" gravitation, but that's not really
true). In GR, one cannot unambiguously separate "time dilation" from
"space expansion", as those phrases depend explicitly on one's choice of
coordinates.
Tom Roberts tjro...@lucent.com
greywolf42
Dirk Van de moortel <dirkvand...@ThankS-NO-SperM.hotmail.com> wrote in
message news:0SvAa.21094$1u5....@afrodite.telenet-ops.be...
A true statement is a "fumble?"
1) No one -- including those in your links -- has ever found an "error" in
Gerber's derivation. (Only claimed that it "led to" other errors.
2) The Gerber/Einstein equation contains ONLY v_g {=c}, semimajor axis, and
eccentricity as independent variables.
> http://groups.google.com/groups?&threadm=7vaq4l$fm4$1...@mark.ucdavis.edu
In your first link, Carlip verifies what I said -- that Gerber's assumption
"leads to" dynamical problems. But those "expansions" were never done by
Gerber. (And Carlip himself demonstrated the v_g = c thing).
> http://groups.google.com/groups?&threadm=76gd7r$jkv$2...@mark.ucdavis.edu
The second link merely repeats the claim that Gerber's assumption "leads to"
errors in a complete theory.
Dirk Van de moortel
"greywolf42" <min...@sim-ss.com> wrote in message news:vd7g65p...@corp.supernews.com...
A theory that leads to errors, is a faulty theory.
Specially if the theory leads to *other* errors like you so
eloquently say.
> 2) The Gerber/Einstein equation contains ONLY v_g {=c}, semimajor axis, and
> eccentricity as independent variables.
>
> > http://groups.google.com/groups?&threadm=7vaq4l$fm4$1...@mark.ucdavis.edu
>
> In your first link, Carlip verifies what I said -- that Gerber's assumption
> "leads to" dynamical problems. But those "expansions" were never done by
> Gerber. (And Carlip himself demonstrated the v_g = c thing).
Yeah right, if I create a theory that is later shown to be false,
not by me, but by someone else, my theory is less false. Nice.
>
> > http://groups.google.com/groups?&threadm=76gd7r$jkv$2...@mark.ucdavis.edu
>
> The second link merely repeats the claim that Gerber's assumption "leads to"
> errors in a complete theory.
Trying to beat Ken Seto's Fumble upon fumble?
Or is this Henry Wilson's "Logic is bull" revisited?
Did no one ever even take the trouble to teach you logic?
Dirk Vdm
heimdall
Sorry, I meant "speed of gravity".
heimdall
> heimdall wrote:
> > I have seen the progression of the perihelion of Mercury
> > described as the effect of the light-speed of gravity, but
> > also as the effect of the time dilation and space expansion
> > (spacetime curvature) nearer the sun.
>
> You are confusing two different theories (at least).
>
Let me put it this way. Maybe I can get it right this time.
Consider a class of theories GR(s) where s is the speed with which
gravity propagates. These theories are otherwise identical to GR
so that GR(c) is GR. GR(s) where s > c is inconsistent
with the (very?) strong equivalence principle, but not with the Einstein
equivalence principle.
How close would GR(infinity) be to GR(c) in explaining the precession?
Heimdall
greywolf42
>
> "greywolf42" <min...@sim-ss.com> wrote in message
news:vd7g65p...@corp.supernews.com...
> >
> > Dirk Van de moortel <dirkvand...@ThankS-NO-SperM.hotmail.com> wrote
in
> > message news:0SvAa.21094$1u5....@afrodite.telenet-ops.be...
> > > "greywolf42" <min...@sim-ss.com> wrote in message
> > news:vd4eur2...@corp.supernews.com...
> > > >
{snip higher levels}
> > > > Yes. An excellent reference for this is Petr Beckmann's "Einstein
Plus
> > > > Two." And all you need is speed of gravity. (By the way, there are
NO
> > > > errors in Gerber's work.) Pauli et al dislike Gerber's derivation
> > because
> > > > it is not a complete theory of gravity. Not because there are
errors in
> > > > Gerber's work. (At least no errors have ever been published or
noted in
> > > > what Gerber actually DID.) GR's results are also the result solely
of
> > > > finite gravity speed.
> > >
> > > This nicely qualifies:
> > > http://users.pandora.be/vdmoortel/dirk/Physics/Fumbles/AllNeed.html
> > > Title: "And all you need is speed of gravity"
> >
> > A true statement is a "fumble?"
> >
> > 1) No one -- including those in your links -- has ever found an "error"
in
> > Gerber's derivation. (Only claimed that it "led to" other errors.
>
> A theory that leads to errors, is a faulty theory.
> Specially if the theory leads to *other* errors like you so
> eloquently say.
OK. Now exactly where does Gerber have a "theory?"
> > 2) The Gerber/Einstein equation contains ONLY v_g {=c}, semimajor axis,
and
> > eccentricity as independent variables.
I noticed you couldn't counter the actual physics, could you, Dirk? Three
variables only in the actual equations. Size and (Newtonian) shape of the
orbit -- and the speed of gravity -- explicitly result in the NNPA.of
planets.
And my comment was simply "And all you need is speed of gravity." Einstein
used a broad gravitational theory, and Gerber used only one small piece of a
theory to get to the same point. After all is said and done and all of
Einstein's tensor gyrations are done, the speed of gravity determines the
NNPA of an orbit.
http://groups.google.com/groups?&threadm=7vaq4l$fm4$1...@mark.ucdavis.edu
> >
> > In your first link, Carlip verifies what I said -- that Gerber's
assumption
> > "leads to" dynamical problems. But those "expansions" were never done
by
> > Gerber. (And Carlip himself demonstrated the v_g = c thing).
>
> Yeah right, if I create a theory that is later shown to be false,
> not by me, but by someone else, my theory is less false. Nice.
Except Gerber never HAD a "theory" of gravity.
> > >
http://groups.google.com/groups?&threadm=76gd7r$jkv$2...@mark.ucdavis.edu
> >
> > The second link merely repeats the claim that Gerber's assumption "leads
to"
> > errors in a complete theory.
>
> Trying to beat Ken Seto's Fumble upon fumble?
> Or is this Henry Wilson's "Logic is bull" revisited?
> Did no one ever even take the trouble to teach you logic?
No. This is simply the "can Dirk read a post" effort.
Oriel36
To get the perihelion advance of Mercury joke it is best to return to
the original explanation,an explanation so riddled with errors and
insincerity that it cannot rightly be considered anything other than a
desperate attempt to force wishful thinking into observation,to the
contemporary mind the explanation should be shocking nothwithstanding
that it is impossible to get the mathematics to fit "a result which
is strictly in agreement with observation."
The first line of the explanation has Newton's gravitation laws
replacing Kepler's second law which is strictly derived from the
differences between apparent motion (geocentric) from true motion
(heliocentric).The next line retains the idea of the motion of the
'fixed stars' or the sidereal day in other words which the old
astronomers used as a reference to mark the motion of the primary
planets of the solar system but did so in accordance with the
difference between a day due to diurnal motion of the Earth and the
variation in a day due to Kepler's second law.This difference was a
computation known as the Equation of Time which fundamentally ignores
the sidereal day,in contrast to Newton's codification of the
computation of the Equation of Time into Absolute/Relative time which
makes sense,the author of relativity is all over the place and his
poor astronomical knowledge definitely shows.
"PHĆNOMENON V.
Then the primary planets, by radii drawn to the earth, describe areas
no wise proportional to the times; but that the areas which they
describe by radii drawn to the sun are proportional to the times of
description.
For to the earth they appear sometimes direct, sometimes stationary,
nay, and sometimes retrograde. But from the sun they are always seen
direct, and to proceed with a motion nearly uniform, that is to say, a
little swifter in the perihelion and a little slower in the aphelion
distances, so as to maintain an equality in the description of the
areas. This a noted proposition among astronomers, and particularly
demonstrable in Jupiter, from the eclipses of his satellites; by the
help of which eclipses, as we have said, the heliocentric longitudes
of that planet, and its distances from the sun, are determined."
Principia
The following excerpt from gr is shocking for it remains the standard
today even though it is impossible to give a result of 43 "per
century for Mercury out of a geocentric observation and then give a
figure for the advance for Earth ALSO !.Any intelligent man who
publicly recognises that the supposed validation of gr in 1919 is
bogus is bound to be ostracised even if he is correct,the flaw is so
obvious that only insanity borne from pure indoctrination or
brainwashing will ignore it and it appears to be the case here with
one sole exception.
The answer is not disproof of relativity but why for goodness sake are
men willing to ignore galactic displacements to our local stars of the
Milky Way caused by their rotation around the galactic axis,the
chances are that even if one does recognise these galactic
displacements,which change everything,there is no facility availible
to assimilate the information properly.
Here is the rubbish which you lot adhere so lovingly to,an explanation
so intellectually poor that it stands as a curiousity in its own right
constituting as it does a bad joke dumped on the inhabitants of this
planet.
" According to Newton’s theory, a planet moves round the sun in
an ellipse, which would permanently maintain its position with respect
to the fixed stars, if we could disregard the motion of the fixed
stars, themselves and the action of the other planets under
consideration. Thus, if we correct the observed motion of the planets
for these two influences, and if Newton’s theory be strictly
correct, we ought to obtain for the orbit of the planet an ellipse,
which is fixed with reference to the fixed stars. This deduction,
which can be tested with great accuracy, has been confirmed for all
the planets save one, with the precision that is capable of being
obtained by the delicacy of observation attainable at the present
time. The sole exception is Mercury, the planet which lies nearest the
sun. Since the time Leverrier, it has been known that the ellipse
corresponding to the orbit of Mercury, after it has been corrected for
the influences mentioned above, is not stationary with respect to the
fixed stars, but that it rotates exceedingly slowly in the plane of
the orbit and in the sense of the orbital motion. The value obtained
for this rotary movement of the orbital ellipse was 43 seconds of arc
per century, an amount ensured to be correct to within a few seconds
of arc. This effect can be explained by means of classical mechanics
only on the assumption of hypotheses which have little probability,
and which were devised solely for this purpose.
On the basis of the general theory of relativity, it is found that
the ellipse of every planet round the sun must necessarily rotate in
the manner indicated above; that for all the planets, with the
exception of Mercury, this rotation is too small to be detected with
the delicacy of observation possible at the present time; but that in
the case of Mercury it must amount to 43 seconds of arc per century, a
result which is strictly in agreement with observation."
1920 text
heimdall
I'm sorry, but I didn't understand what you said.
As for the lengthy quotation, I understood it, but it doesn't answer my question.
Basically, I want to know how important the light speed of gravity is
to the magnitude of the progression of the perihelion. If light travelled
at infinite speed in what is otherwise a GR theory, what would the
progression be?
Alternatively, a link to as simple an explanation as possible of the
progression would be helpful.
I am looking for a GR explanation.
Heimdall
dlzc@aol.com (formerly)
"heimdall" <vze3...@verizon.net> wrote in message
news:b0601654.03052...@posting.google.com...
> Oriel36,
>
> I'm sorry, but I didn't understand what you said.
>
> As for the lengthy quotation, I understood it, but it doesn't answer my
question.
>
> Basically, I want to know how important the light speed of gravity is
> to the magnitude of the progression of the perihelion. If light
travelled
> at infinite speed in what is otherwise a GR theory, what would the
> progression be?
The same (my guess). The gravity well for the Sun is established, so it
does not need to propagate further. Mercury's contribution-to / effect-on
this is inconsequential / not-measurable-with-current-technology.
David A. Smith
heimdall
David,
Thanks. Gerber's explanation must have been complete wrong.
The light speed of gravity must have given him an opening to slip
in other assumptions that made his calculations work out to his
empirically determined formula, I guess.
Heimdall
Ken S. Tucker
>I have seen the progression of the perihelion of Mercury
>described as the effect of the light-speed of gravity, but
>also as the effect of the time dilation and space expansion
>(spacetime curvature) nearer the sun.
>Heimdall
Tough question, I have only a bit to add...
In Newtons theory the additional progression of 43 secs is zero,
and excepting perturbations, would be a perfect ellipse,
because F oc 1/r^2, (oc means proportional).
In GR at the location of Mercury, F oc 1/r^(2.000 0002),
approximately.
see this posting...
>From: Tom Salerno
> Subject: Re: ? about Cantor sets
> Newsgroups: sci.math
> Date: 2003-05-28 09:00:58 PST
This F oc 1/r^(2+2E-7) accounts for the progression.
From the point of view of GR, I can't see how the speed
of gravity could vary this formula. However, I wouldn't
rule out a workable theory of gravity based on a
postulate of the limited speed of gravity either.
Asking *what if* questions, or *what causes what*
questions, are actually quite meaningless in GR. GR
is based on Einstein's Law, G_uv = kT_uv, and the
results obtained from it.
I'm satisfied that it works when the speed of
gravity=c, but I haven't worked out otherwise.
For example if c=infinity would G_uv = kT_uv hold?
If someone else has researched this I'd certainly
be interested in there findings...
Regards Ken S. Tucker
Steve Carlip
> Consider a class of theories GR(s) where s is the speed with which
> gravity propagates. These theories are otherwise identical to GR
> so that GR(c) is GR. GR(s) where s > c is inconsistent with the
> (very?) strong equivalence principle, but not with the Einstein
> equivalence principle.
> How close would GR(infinity) be to GR(c) in explaining the precession?
GR(infinity) in this scheme is Newtonian gravity. (The limit is actually
a bit tricky; it's done by Frittelli and Reula, Commun. Math. Phys. 166
(1994) 221.) But this is because your parameter s, which gives the speed
of propagation of gravity, also comes in in many other places that are
not directly related to the speed of propagation. Most notably, ``gravito-
magnetic forces'' depend on s, just as magnetic---even magnetostatic
---forces in electromagnetism depend on c. It's not so easy to decouple
propagation speed from a lot of other factors...
Steve Carlip