Abacus

What particle would that be?

Ice

http://www.howstuffworks.com/news-item6.htm

Jesse

Ice, no particles or information travelled faster than light in those experiments (read the last sentence of the article)--it has always been known that certain properties of waves can appear to move "faster than light" in some sense, in a way that does not violate relativity. See this thread for more on these types of experiments:

http://www.iidb.org/vbb/showthread.p...threadid=37729

And as I said there:

Answerer

I thought particles like tachyons travel faster than the speed of light. Okay, I know they have not been discovered yet.

Jesse

Tachyons are not ruled out by relativity, but as you say they have not been discovered. Also, if the relativistic notion of the equivalence of different reference frames is correct, then two slower-than-light observers armed with tachyon transmitters and travelling away from each other at a sufficient fraction of light speed could send messages back in time--observer A could send some information to observer B using tachyons, then observer B could beam the same information back to him using tachyons, and observer A would recieve observer B's message before he sent the original message. For this and other reasons, most physicists seem to think that tachyons will never be found, and that perhaps they will end up being forbidden by the laws of physics.