Why the Michelson-Morley experiment cannot detect ether?
Michelson-Morley experiment postulated a luminiferous aether that is static.
With the assumption that a celestial object moving in a static medium of luminiferous aether would experience a drag, an aether wind should be detectable. Earth revolves at approximately 30 km/s around Sun, the Sun revolves at approximately 232 km/s around the Galactic center of Milky Way, therefore Earth moving in this static medium should show a significant aether wind with a lower limit of approximately (232-30) 202 km/s and an upper limit of approximately (232+30) 262km/s, or between (552-232-30) 290 km/s and (552+232+30) 814km/s if the movement of Milky Way in space relative to Cosmic microwave background at approximately 552 km/s is considered. If there is such an aether wind at all it should be easily detected with the interferometer. However, in all Michelson-Morley experiments, measurements of such expectations were not detected at all.
However, this is merely a null hypothesis with a null result that static luminiferous aether does not exist. It had only concluded that the postulated aether wind was not found with the assumption of luminiferous aether is a static medium. Neither Albert Michelson nor Edward Morley had ever considered that their experiment had disproven the aether hypothesis, it was the others (such as Oliver Heaviside) who had made the conclusion that aether does not exist at all.
The quote below would be suitable for this place at this point of time.
“Absence of evidence is not evidence of absence.” - Carl Sagan
Watch a video clip on simulating Michelson-Morley experiment in aether wind (http://www.youtube.com/watch?v=Z8K3gcHQiqk) that illustrates if aether wind is present, it would be detected. I hope this would help.
I often wonder how Carl Sagan got to sleep without worrying about the tiger in his bedroom. Obviously, there was no evidence for the tiger but
“Absence of evidence is not evidence of absence.” .
Carl Sagan was not a paranoid, as an atheist he had been rational and his work was always based on logical empiricism. Here is another quote from this very renowned astronomer:
“It is far better to grasp the Universe as it really is
than to persist in delusion, however satisfying and reassuring.” - Carl Sagan
The M-M experiment thingy was not like it had been proven beyond all reasonable doubts, such as the motion of Earth was based on logical positivism that it is an immutable fact it revolves around the Sun.
On unsolved problems with discernable anomalies, Richard Feynman had his say:
"In order to make progress, one must leave the door to the unknown ajar." - Richard Feynman
I think there is a chance that jsaldea12 could be making his last laugh on this issue.
Whatever properties space (by whatever definition) has, it has those properties.
Sticking a new label like "aether" on it achieves nothing and promotes confusion. Relabelling it doesn't alter those properties.
Einstein coined the term "spacetime", in the lecture delivered on May 5th, 1920, in the University of Leyden, Einstein was trying to tell the world what he meant by spacetime.
It was not like a third party trying to interpet what Einstein meant by the word "spacetime", it was the author of "Theory of relativity" who had published his papers since 1905 thru 1915, which had thus began the era of modern physics, and Einstein by himself, not through another party, was trying to tell the world in 1920 with his definitions to clarify what he meant by spacetime.
Other then the 1920 lecture in the University of Leyden, Einstein had also made several notable astute statements on space and time, here are two of them:
“Time and space are modes in which we think
and not conditions in which we live.” - Albert Einstein
“There is no space empty of field.” - Albert Einstein