Re: Photon Mass, Measuring Distance, and Mercury's orbit

From: Mike Helland (mhelland_at_techmocracy.net)
Date: 07/22/04 

Date: 22 Jul 2004 11:15:46 -0700

Bjoern Feuerbacher wrote:
> Mike Helland wrote:
> > Bjoern Feuerbacher wrote:
> >
> >>Mike Helland wrote:
> >>
> >>>In the list of predictions that confirm General Relativity there
> >
> > are:
> >
> >>>1. Gravitational lensing
> >>>2. Gravitaitonal red***
> >>
> >>I'm quite sure that GR does not predict red *** ;-)
> >
> >
> > http://archive.ncsa.uiuc.edu/Cyberia/NumRel/EinsteinTest.html
> >
> > See "Gravitational Redshift" partway down the page.
>
> *sigh* Are you unable to understand a joke?

Oh, haha, I see now.

> > Recall that the gravitational constant itself is not exactly
accurately
> > known:
> > http://en.wikipedia.org/wiki/Gravitational_constant
>
> Err, *no* constant of nature is "exactly accurately" known (with the
> exception of the speed of light, since its value was simply
*defined*).

Poor choice of words on my part, "not quite accurately known" would
have been better.

> >>>It seems to me that the possibility of using this value, derived
> >>>from
> >>>the reverse transformation to compensate for gravitational
> >>>redshifting/lensing, we could use different values in calculating
> >>>Newton's Law. Perhaps this approach might lead to computing
> >>>Mercury's
> >>>orbit more accurately than Newton's Law, with far simpler axioms
> >>>than General Relativity?
> >>
> >>If you think that this works, feel free to present your
calculations.
> >
> >
> > In order to do this I would need to know with the utmost detail how
the
> > measurements of distance are performed.
>
> AFAIK, there are different methods used. Most probably use
triangulation.

Triangulation requires known distances, does it not? So are there any
measurements of distance independent of prior measurements of distance?

I'll post on sci.astro as you recomended.

> >>I, for one, don't see how "warped" measurements of Mercury's orbit
> >>could explain its perihelion shift.
> >
> >
> > Lets say that the actual distance between two bodies where the
> > gravitational redshift of one is very great is much shorter than
the
> > measurement of that distance says so.
>
> *How* much shorter? Are we talking about deviations of 0.1% or more
> like 10% or 100% here?

It obviouslly would vary with the masses and distances involved. In the
case of Mercury+Sun it could be far more noticable than Earth+Sun or
Earth and close by objects for that matter.

> > If we plug in the shorter the distance to Fg = G(m1*m2)/d^2 it
could be
> > that where the effects are great enough, the calculuation of a
> > noticeably greater Fg is a result, and thus, a greater pull on
Mercury
> > than we had thought, and maybe a quicker advancement of the
perhelion?
>
> A greater pull on Mercury would not mean a quicker advancement of
> the perihelion. As long as the force goes with 1/d^2 only, there is
> *no* advance of the perihelion at all. Remember Kepler's first law?
It
> says that the planets move on elliptical orbits. *No* change of the
> perihelion at all. Kepler's laws hold as long as the force depends
only
> on 1/d^2.
>
> That the perihelion *does* advance in reality is caused by the force
on
> Mercury being *not* only dependent on 1/d^2 (due to the gravitational

> influence of the other planets, and some GR effects).

I think you misunderstand the empirical evidence.

Newtonian Gravity *does* show an advancement in the orbit, however, it
shows the *incorrect* value. Its too little.

There is a windows program on my website at:

http://www.techmocracy.net/science/gravity.zip
runtimes:
http://www.techmocracy.net/science/vfp8.exe

That implements Newton's Theory of gravity and shows that with certain
distances and masses, orbits do indeed advance there perihelion. Anyone
that has computed Newton's Law should see that.

Have you?

> > Again, I'm just thinking out loud, but it does appear to be an
> > interesting suggestion worth pursuing, hence my specific questions.
>
> Well, since you did not even know that for a force which goes as
1/d^2,
> there is *no* advance of the perihelion at all, you seem not to be
> qualified to discuss this, sorry...

<q>
Since almost two centuries earlier astronomers had been aware of a
small flaw in Mercury's orbit around the Sun, as predicted by Newton's
laws. As the closest planet to the Sun, Mercury orbits a region in the
solar system where spacetime is disturbed by t he Sun's mass. Mercury's
elliptical path around the Sun shifts slightly with each orbit such
that its closest point to the Sun (or "perihelion") shifts forward with
each pass. Newton's theory had predicted an advance only half as large
as the one actually observed. Einstein's predictions exactly matched
the observation.
</q>
http://archive.ncsa.uiuc.edu/Cyberia/NumRel/EinsteinTest.html

I don't think qualifications should be called into this discussion, but
if they are, you are quite obviouslly wrong, and unqualified to insult
me. Fortunately, I forgive you. 

--
Mike Helland
http://www.techmocracy.net/science/time.htm
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