Question

I do not understand how Michelson and Morley got the conclusion that the ether doesn't exist just from the fact that it doesn't move.

Answer 1

@Fifciol

Answer 2

It could simply be that the ether exists but it doesn't move.

Answer 3

there's evidence that light has two quantities(of waves and masses), of course,.. but didn't Einstein study the photoelectric effect after the Michelson-Morley experiment? so...i'm just curious how 'they' got the conclusion... (oh, wait... does Einstein's theory on the photoelectric effect support the idea that light doesn't need the ether?)

Answer 4

The ether is just a physical model to unificate waves as they move in some medium. Take for the example this situation:
You would observe that relative to you water wave is moving faster than if the car were standing still, and in all mediums that mechanical waves are propagating, you would observe the change in velocity relative to you. So you've defined the way of describing the medium.
it was said that the speed of light remains the same in any reference frame , that means if you could measure that the speed of light is changing in some reference frames you'd abolish the theory. And this is exactly what Michelson and Morley tried to do. But the experiments prove the validity of this property of light, so the medium of propagation of the light could be simply deleted and what the hell you need it, it gives you nothing.