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by Maxatar
658 days ago
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That hardly constitutes a precise definition, but at any rate the lecture I linked to goes over the history and I quote, once again from Einstein himself: >The next position which it was possible to take up in face of this state of things appeared to be the following. The ether does not exist at all... >More careful reflection teaches us however, that the special theory of relativity does not compel us to deny ether. We may assume the existence of an ether; only we must give up ascribing a definite state of motion to it This is about half way through the lecture before Einstein touches on general relativity. Towards the end he is quite adamant that a theory of the ether is necessary to fully appreciate general relativity. With that said I do not want to fall into an argument from authority, certainly much of what we understand about relativity today along with its implications differs from its original formulation, but I present the lecture because I think a lot of people don't quite have the appreciation or historical understanding of what the ether was or wasn't, they just read about how the Michelson-Morley experiment proved that it can't exist along with sensational views that the experiment represented some kind of embarrassment or catastrophe in physics and the ether became a fall-guy of sorts that we must entirely rid ourselves of. But if you read through the actual primary sources you get a very different picture of how physics progressed bit by bit. |
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It is precise enough for our purpose: ether is a hypothetical medium for light waves to propagate. Moreover it would need to have no interaction with ordinary matter, or else it would cause planets' orbits to decay.
only we must give up ascribing a definite state of motion to it - Einstein
This is a "No True Scotsman" fallacy wherein one redefines the assertion to deal with specific objections. I hesitate to criticize Einstein, of course, but in this case it's not clear that "ether" minus motion means anything. One can be generous and say he had an intuition about fields, however fields aren't ether, either.