Does aether pervade space?

No, aether does not pervade space. In deep space (intergalactic space) there is a near perfect vacuum. Only an atom or two of hydrogen float around here. And a bit of light will be passing through. There is also that pervasive bit of cosmic background microwave radiation. It's everywhere.

In ancient Greece, it was postulated that the aether was the stuff up above the clouds and the sky. Later on when early investigators were looking into what light was, it was suspected to be a wave of some kind. It was also assumed that it had to have a medium through which to travel. The aether was then called the luminiferous aether. But light doesn't need a medium to travel in. When that was finally discovered, the need for the aether vanished.

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First answer by Quirkyquantummechanic. Last edit by Quirkyquantummechanic. Contributor trust: 2271 [recommend contributor]. Question popularity: 5 [recommend question]