"tachyons"

[RAMAN]

i just want to know about tachyons as a layman right from the beginning

[iNow]

Have you checked the wiki?

 

http://en.wikipedia.org/wiki/Tachyon

[RAMAN]

Is it possible that is something faster than light

[ajb]

Is it possible that is something faster than light

 

It is completely consistent with special relativity to have a particle that travels faster than light. However, if such a particle i.e. a tachyon exists it cannot be slowed down to the speed of light or below.

 

In quantum field theory tachyons are usually unstable and decay into non-tachyonic states.

 

So, I would say it is unlikely that tachyons are physical.

[timo]

It is completely consistent with special relativity to have a particle that travels faster than light.

Wouldn't tachyons seem like an obvious way to break causality (unless you put the additional constraint that tachyons do not interact with anything )?

[Kyrisch]

Wouldn't tachyons seem like an obvious way to break causality (unless you put the additional constraint that tachyons do not interact with anything )?

 

I don't think so, because they move in a linear path through time, just backwards?

[ajb]

Wouldn't tachyons seem like an obvious way to break causality (unless you put the additional constraint that tachyons do not interact with anything )?

 

Is the maximal speed of light a consequence of causality or is causality a consequence of the maximal speed of light?

 

Either way, yes causality would need to be examined very carefully if tachyons exist. It looks like relativity by itself does not rule them out, but QFT does.