John Smith wrote:
Why has ether become synonymous with "kook?"

From Wikipedia:
"Einstein in later years proposed calling empty space equipped
with gravitational and electromagnetic fields the "ether",
whereby, however, this word is not to denote a substance with
its traditional attributes. Thus, in the "ether" there are to
be no determinable points, and it is meaningless to speak of
motion relative to the "ether." Such a use of the word "ether"
is of course admissible, and when once it has been sanctioned
by usage in this way, probably quite convenient."

Ives was the first to positively measure the effect of speed on clock
rates. He wrote in 1940 in a paper in Science:

"I have considered the popular claim that the ether has been "abolished"
[...]. Reverting to experimental findings I have reviewed the experiment
of Sagnac, having in mind the claim that the ether can not be detected
experimentally. I have asserted that, in the light of the experimentally
found variation of clock rate with motion, this experiment does detect
the ether."
--
73, Cecil http://www.w5dxp.com