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

From: Mike Helland (mhelland_at_techmocracy.net)
Date: 07/23/04 

Date: 22 Jul 2004 23:18:14 -0700

Eric Gisse <fsegg@uaf.edu> wrote in message news:<kgu0g01jbetlpfv8fjiq8caaraf3b365r6@4ax.com>...

> >In the list of predictions that confirm General Relativity there are:
> >
> >1. Gravitational lensing
> >2. Gravitaitonal red***
> >3. Mercury's orbit
> >
> >To make Newton's theory match the observed results of these
> >experiments, isn't it simple enough to assign mass to a photon?
>
> No.
>
> Massed exchange particles have very limited range. EM interactions go
> out to infinity as far as we can see.

Not trying to change the subject here, but this is quite an ironic
statement.

Based on the assumption that EM interactions go out to infinity
requires that we must also assume that the universe is finite in size
and age (the Big Bang theory).

Not important to this discussion, of course, but insightful
nonetheless.

> >My second question is, how exactly do we measure the distance from,
> >say, Mercury to the Sun? Do we do it using photons? The more explicit
> >the answers are, despite their obviousness, would be appreciated.
>
> Radar. We can find the distance from Earth to Mercury using radar, and
> then find out the distance from Earth to the Sun some other way.
>
> >Finally, thinking purely in Newtonian physics here, if we measure
> >distance using a photon, and if the photon can be lensed/reshifted by
> >gravity, doesn't that imply that our measurements of distance are
> >themselves warped, a natural consequence of the mechanism used as a
> >measuring stick? In that case, could we transform the measured
> >distances to attempt to get a value for the absolute distance between
> >the bodies?
>
> 1) Yes. That is one of the things GR does.
>
> If you are thinking in Newtonian terms, there is a whole host of
> things that happen to photons in reality that do NOT happen to photons
> in Newtonian mechanics. The Newtonian view does not work.
>
> 2) 'Absolute' distances between objects don't exist, so no.

Agreed on both points. As Uncle Al pointed out I shoudn't say
"Newtonian" because thats not quite what I have in mind, though it can
be accurately described as non-relativistic. And the fact that we're
able to come up with a value for absolute distance does not mean that
absolute distance must physically exist. I agree with #2 but I don't
think its a fatal flaw.

> >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?
>
> There is a section on this type of thing in MTW. It is in Chapter 40.
>
> Newton's laws work fine using SR (I can't speak for sure for GR).
>
> GR's postulates are as simple as they get, why would you try a
> reformulation of them to kludge Newtonian dynamics into working
> alongside Relativistic dynamics?
>
> I see you seem to prefer Newton, but accept GR/SR predict things that
> Newton can't. Why are you keeping Newtonian ideas close by when they
> obviously do not work?

Take a look at new ideas of space and time in physics. For example,
from Julian Barbour, among others, change is primary and time is
something we deduce from it.

If this is true then a system with lots of change means that we have a
system with lots of time. To me this adequately describes time
dilation without Relativity. I think the assumption that space-time is
a background, fixed or unfixed, for phenomena is unnecessary and
problematic and should be removed. That basically amounts to removing
the postulates of Relativity from our view of the universe.

This is why I'm keeping non-Relativistic ideas (such as those of
Leibniz, as well as Newton to a lesser degree) close. Because I think
it should be determined more carefully that they do not infact work.
I'm wierd like that. 

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