Oh, well then, it doesn't exist. Al Michelson and Ed Morley, back in 1887, did this experiment that disproved the existence of ether (or aether, if you prefer). N.B.: they did this at Case Western Reserve University, the graduate alma mater of, ahem, moi.

(If you want to know about it, do a websearch for "Michelson-Morley Experiment" and you'll find all sorts of information. I'd do it for you, but then you'd never learn.)