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Originally Posted by Profpat Hi Yeltsin; i believe Einstein changed his mind regarding empty space and later believed in the ether. The only empty space is the Void which is NOTHING. Our space is filled with CBR from the big bang. Radiation is not atoms or mass ( matter ) but rather radiating energy. This part of space is known. Speculation also has strings, quantum foam, etc, being perhaps part of the ether. |
Hi, Profpat.
There's some history here to be noted. You might ask, if electromagnetic radiation is a wave, what is it waving in? So the hypothetical aether was born to account for what electromagnetic waves were waving around. This was at the time of Michelson-Morley and Lorentz, and those guys. Itr was a prevailing notion around the time Einstein was developing special relativity.
Questions arosed about the properties of the aether. The aether had a velocity in space of its own. It had some elastic properties so light could wave in it. Did it pass though the Earth, pass around it, or get dragged around by it?
The speed of light was relative to this aether.
So, anyway, this was not Einstein's aether. Because in relativity the speed of light is independent of inertial frame, rather than in added to the velocity of this aether.
Einstein's idea of an aether was completely different. He asks, what does a region of spacetime devoid of all matter and radiation have?
It has properties. After all, it has dimensionality for one. Spacetime has a geometry. 'Nothing' does not have a geometry. Empty spacetime has a proportionality constant called c, the speed of light. It has curvature. One could go on and on.
So there where two different aethers. One is defunct; one was Einstein's.