What are tacieons?

Question

OK I can't Spell it. But I still don't know what they are?
All I've heard is they can travel faster than the speed if light.
Were do they come from?
How do we know they exist?
Any help here?

Answer 1

I can spell it. "IT" There ya go. Tachyons are not theoretical in the future, where I come from. :)

Answer 2

Back in the 1970s, some guys were playing around with Einstein's equations and had the brainstorm to think, "What if we plug in something with an imaginary mass?" And by imaginary, they meant a multiple of the square root of negative one. (Imaginary numbers are very useful, even if they seem to make no sense.)

By assuming an imaginary mass in the equations, they found that such a particle would get more massive as it went slower (as opposed to real masses, which get bigger as they go faster), reaching the "rest" mass at infinite speed. Just as a real mass can't reach light speed from below without becoming infinitely massive, an imaginary mass can't slow down to light speed without becoming infinite (if still imaginary).

Unfortunately, we can't ever directly detect tachyons (which is what these guys decided to call particles of imaginary mass), because they're of a different "causal type" and can't interact directly with normal matter. They should be able to interact with light, just as normal matter does, but without the ability to directly manipulate them, no one's figured out how to design an experiment that would prove or disprove the existence of tachyonic matter.

Answer 3

You're looking for "tachyons" (..pronounced tacky-on..) These are nothing more than theoretical particles that can never travel SLOWER than the speed of light. No such particle has ever been observed, but sci-fi writers love to use 'em as the means to time travel.