Where does the unphysical particle called a Tacion fit into Superstring theory?

Question

Where does the unphysical particle called a Tacion fit into Superstring theory?

Answer 1

I guess if you could spell it, you'd look it up, right? ;)

It's "tachyon" (I had to look it up, too:).

Last I heard, it was an embarassment- a bit of a fly in the ointment.

Answer 2

Tachyon particle is theoretical particle which comes out of the math of superstring theory. The problem is that it is suppose to be faster then light. Since relativity said nothing can be faster then light, the presence of the particle in superstring is a bit of a problem for string theorist.