[simpaticoder]

The aether (or just ether) was assumed to be the substance in which light waves waved, just as air is the substance that sound waves. If this substance existed it was likely that the Earth was moving through it at some velocity, and the Michelson-Morley experiment famously showed that this is not so. There were also observations of Jupiter's moons. These null results led to Lorentz' quantification of what would become Einstein's definition of special relativity in 1905.

Our confidence in SR is so strong now that c is defined and length unit defined as the distance light travels during a set time.

[Maxatar]

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.

[simpaticoder]

That hardly constitutes a precise definition

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.

[Maxatar]

> ether is a hypothetical medium for light waves to propagate.

If that's the extent of your definition then it is not at all inconsistent with Einstein's definition of the ether in the lecture I linked to.

>This is a "No True Scotsman" fallacy wherein one redefines the assertion to deal with specific objections.

Imagine using your argument to claim that atoms don't exist because atoms were by definition indivisible structures, and so anyone who argues that atoms are made up of protons, neutrons and electrons is just engaged in a "No true Scotsman" fallacy.

This might be how people on the Internet argue, but it's not how curious people make genuine advances in science.

Note that your definition of ether never said anything about having a definite state of motion so it's not at all clear what exactly you're looking to criticize to begin with. Einstein isn't claiming that the ether has no motion, just that it's motion adheres to Lorenz invariance.

>One can be generous and say he had an intuition about fields

Claiming that it's generous that Einstein had some kind of intuition about fields is so absurdly laughable that I'm not sure there is much more to even discuss on this matter. How generous you must be to recognize that Albert Einstein had some kind of intuition about fields.

It certainly makes me wonder if people read what they write sometimes before hitting the reply button.

[simpaticoder]

I think you need to review the site guidelines about tone and purpose. Moreover, I'd suggest you review the history of quantum mechanics, because Einstein did not invent field theory, just as Newton did not invent or understand the Lagrange or Hamiltonian formulations, nor statistical mechanics, even though his theory provided the foundation of them all. I'm not a historian of physics, or a psychologist, so I will bow out of the conversation. May your clear passion for science continue without making you hostile.

[simiones]

> Moreover, I'd suggest you review the history of quantum mechanics, because Einstein did not invent field theory, just as Newton did not invent or understand the Lagrange or Hamiltonian formulations, nor statistical mechanics, even though his theory provided the foundation of them all.

First of all, physical fields were a concept far before QFT came in the picture, and they are the same concept as QFT's fields. Einstein was definitely familiar with classical field theories, which were prevalent ways of looking at gravitation and electromagnetism far before even quantum mechanics was discovered.

Secondly, Einstein died some time after QFT had become a real theory, so it is very likely that later in life he could have been at least passingly familiar even with some concepts of quantum fields (though of course, not at the time he wrote his GR papers).

[Maxatar]

You're bringing in a bunch of entirely irrelevant topics into this instead of actually addressing the points.

My apologies if pointing that out in clear language goes against site guidelines, it might be rude to point it out but this site does have a problem with people who think they know it all and blurting out something as laughable as it's "generous to say Einstein had an intuition about fields" is in my opinion a prime example of it.

All the best to you.