csmyth3025 said:

Isn't it amazing that a thought experiment generated a century ago based on the scientific understandings of the time produced a new way of looking at the world that, to this day, remains the "gold standard" against which alternate theories are tested. Even more amazing is that all the astronomical observations, particle accelerator experiments, and advancements in particle physics theory have been unable to clearly establish a better way of looking at the (macro) world.

Eventually someone may well produce a "better way of looking at the world", but I suspect that it will build on and extend the work of Einstein in much the same way that Einstein extended the work of Newton into realms that Newton could only speculate about.

Chris

Isn't that how all theories begin, with an idea and setting up the experiments that will prove that idea correct.

Einstein little throught experiment did not begin the process of Special and General relativity.

The limitation of C as a max velocity was first hinted at by Maxwell equations on electromagnetic, Maxwell originally saw the fact that the velocity of light would be independent of an object Velocity. Just as Planck saw the first sign in the crack of the physics of his day, Maxwell was unsure what his equation meant, he even went as far as coming up with an alternate theory of Ether to explain his result, which didnot pan out.

Einstein saw that Maxwell equations,and Lorentz and Fritz contractions hints to something special about the Veolcity of light and its relationship to Space and time.

General Relativity, like special Relativity had its seeds that came before Einstein, Reimanns and even Gauss suspected that Gravity was a Geometric property of space, Einstein added to it by including time, but if it was not for Reimanns Tensors equations, Einstein would not have had the tools to express his theory.

Maybe the reason that all these astronomical observations, particle accelerator experiments, and advancements in particle physics theory, fails to come up with something better, is the fact that Einstein nail it on the head. Special and General Relativity may be like the laws of Thermodynamic , an undeniable truth of the nature of the universe. Both theories invoke Symmetries that most other theories of Physics follow. The symmetries of space and time that give raise to conservation of momentum, and Energy.

General Relativity fails when it come to the extremely small where quantum interactions begin to make a major different, examine a small enought region of space time and the uncertainty principle show that the energy in that region turns the smooth space time into a foam of roaring chaos, the Quantum Foam of Wheeler. Also just like most field theories, GR fails as we approach the radius of a point. The fact that QR doesnot specify a minium distant is sign that it is incomplete.

Special Relativity was incorporated into Quantum mechanics, but General Relativity haven't. Problem is that we donot understand how to incorporate it, string and M theory hope to, but generally ignore it when dealing with the Quantum world. So the incorporation lies with the various Quantum theories of Gravity that are attempting to show what space time is like on a quantum scale, whether it an collection of loops, triangle, spin foams,Twistor and spinor obritals.

And you are correct, these theories assume Relativity is correct, and are looking at the smallest region that predictions of Relativity can be applied, so we can Quantumize Space time. I believe when the right method of Describing Space time on at the Quantum level is found, we'll be able to promote Both special Relativity and General to the status of scientific laws and it will put to rest our doubts about Einstein. Maybe it well also tell us a little more about the Reality of Quantum Mechanics..