Superluminal

Sort of a ps to my last post. "The speed of light was broken again..."

Well, they put a pulse of electromagnetic radiation, they put a beam of light, a laser light into one end of a tube just a few centimeters long, just that long with a gas in it made of metal, the metal cesium, and they measured the pulse going in, and they compared it with a pulse apparently coming out. And the pulse coming out comes out faster than it should, about 300 times faster than it should by what you would expect - Bill Nye, "Speeding Light" July 20, 2000, PBS

So then it seemed in that experiment that c was not just doubled, but was 300 times slower than the signal propagated inside the cesium gas.