# Has advanced radiation been detected experimentally?

I would like to know whether there has been an experimental detection of advanced radiation. I seem to recall reading about such an experiment but I can't find any reference to it on the interwebs so I'm starting to wonder whether I imagined the whole episode. IIRC the experiment was roughly like this:-

Light was sent through a magic crystal (my language not theirs ahem) which, they stated, theory indicates would result in advanced radiation. This is normally not detectable, but by passing the advanced radiation through another such crystal the advanced radiation would, they predict, result in normal radiation. They detected this radiation and surmised that advanced radiation is real.

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I have never heard of advanced radiation. Can you please post some links/reference? –  mcodesmart Oct 9 '13 at 12:06
Let me guess, they have a free energy device "almost working" but the big utilities are trying to squash them, so they are looking for a few "advanced" investors? –  Olin Lathrop Oct 9 '13 at 13:11
you are talking of en.wikipedia.org/wiki/Wheeler%E2%80%93Feynman_absorber_theory –  anna v Oct 9 '13 at 16:27
What is advanced radiation? Google doesn't give any obvious results. Is it a term you made up? If so, you should explain. –  DumpsterDoofus Oct 10 '13 at 3:54
To all you skeptics, read Anna V's comment. I can imagine slightly whacky but determined to probe our fundamental knowledge researchers trying to do legitimate research on this topic. Like just about all our physics, Maxwell's equations show absolutely no preference for time direction, so advanced wave solutions where $t\mapsto-t$ are just as legitimate. We always impose causality on Maxwell's equations by throwing away the advanced wave. I'll admit the word "magic" does not bode well, but I have heard it used in the same sense as "black box", "characterized by input/output transformation" ... –  WetSavannaAnimal aka Rod Vance Oct 10 '13 at 6:43