sci.physics.electromag

On Mar 20, 6:17=A0pm, Tom Roberts wrote:
> maxwell wrote:
> > There is almost no connection between Einstein's Special Theory of
> > Relativity (SRT) and his General Theory of Relativity (GRT) apart from
> > the (marketing) fact that they both include the exciting word
> > 'relativity'.
>
> This is plain and simply not true. SR was INSTRUMENTAL in leading
> Einstein to GR, and remains as both:
> =A0 A) the local limit of GR at any point in any manifold
> =A0 B) the solution of the GR field equation for an empty universe
> =A0 =A0 =A0and the topology of R^4.
>
> > SRT is a consequence of Maxwell's theory of electricity
> > and GRT is Einstein's theory of gravity.
>
> Hmmm. Maxwell's theory of electrodynamics is incompatible with SR, but
> the modern version of it is fully compatible with SR. Today we would say
> that SR is a consequence of local symmetries of the universe we inhabit
> (specifically: local Lorentz invariance).
>
> > He wasted the last 40 years
> > of his life trying to unify these two field theories.
>
> This was only "wasted" to those who do not understand what he was doing.
> Yes, he did not succeed in unifying GR and electrodynamics. But in the
> journey there was much to be learned....
>
> > Modern
> > theorists have wasted their own careers in attempting the same but
> > adding the complexity of the quantum.
>
> The modern issues are MUCH more complicated than you seem to think.
>
> Tom Roberts
Tom, I was making a point about the physics, NOT some mathematical
comment about two points that are infinitely close together or
Einstein's mental processes. By introducing the term 'manifold' you
have already left the world of reality (physics) and landed on Plato's
planet of invariant relationships (math). Instead of writing
mathematical gobbleygook like "SR is a consequence of local symmetries
of the universe" why not talk about real phenomena, like electricity.
SR is supposed to work at macro-separations: stop hiding behind
infinitessimals, such as 'local symmetries'. SR is a theory of EM
(check out your history - what do you think Larmor, Poincare & Lorentz
were doing?). It was the universality of c in Maxwell's model of the
aether that led to all this nonsense. Trying to justify a theory of
gravity that only manifests measurable effects with mega masses & then
linking this to the interactions between two microscopic electrons at
LARGE separations is too much of a stretch of the imagination. If you
were right why did Einstein waste 40 years? Incidentally, what did
Einstein learn from all this effort?