Tachyon physics?

Question

ok i herd about this particle called a tachyon that travels faster then speed of light but i thought nothing can go at the speed of light please explain to me

Answer 1

The Captain pretty much has it right.

Philosophically, I wouldn't be quite so dogmatic and absolute about some of the statements, but there is no evidence that tachyons exist.  Just because something appears to be allowed by an equation doesn't mean it exists.  On the other hand, scientists shouldn't be overly quick to dismiss such things as nonsense--Schrodinger threw out the Klein-Gordon equation because he thought its solutions were nonsense because it was predicting anti-matter and pair production and stuff that wasn't understood yet.  Keep a skeptical, but open mind.  And let scifi have its fun.  Greg Benford's "Timescape" is a good novel about using tachyons to communicate with the past.

Answer 2

Light limit is more "stable" version of physics, than tachyons one. Tachyons are highly hypothetical, i.e. very basic laws, including causality, should be revised.

Answer 3

Einstein proposed that a universe could exist where all matter moved in excess of light speed, such an object is called. a tachyon. Because this came from the great man science had a look at the idea and actually carried out experiments to detect a tachyon at the fringes of out universe, none were detected.

Answer 4

And where did you hear about this tachyon, Star Trek Voyager? No matter, there are less reliable sources anyway. Why is it that someone can come out with something stupid and you just never hear the end of it? THERE IS NO SUCH THING AS A TACHYON. OK? Things that have mass, such as you, can not traval at or above the speed of light. The speed of light is sort of like those signs on the freeway - you know, speed limit 70 or whatever - ONLY light means what it says and the universe, sort of the big cop that is everywhere, makes sure that that limit is never broken. Let me repeat that so it is perfectly clear - never broken.

As for tachyons, as I heard the story someone was looking at one of the equations from relativity  and said something like "what if there existed particles that have regular mass ONLY when they travel faster than light but that have imaginary rest mass?"

The equation is: M = M0 / SQRT[1 - (v^2/c^2]

M0 = rest mass

c = speed of light

v = speed of particle

So when v = 0, M = M0 ... obvious since this is the rest mass

When v < c, M > M0 and as v -> c the bottom of that equation gets smaller and smaller and the mass gets larger and larger. And at the speed of light you are dividing by 0 and that is a no-no.

Now suppose we want regular mass for speeds greater than c, what happens? Well if v > c, 1 - v^2/c^2 is negative and you end up with the square root of a negative number (an imaginary number). So in order to make M real, you just make the rest mass M0 imaginary. And there is the tachyon. Imaginary rest mass but real mass when it moves faster than light which it must do to exist. I can not vouch for the accuracy of this and I am too tired to look it up but this is what I recall as being the origin of the tachyon.

Answer 5

tachyons are pure hypothetical. according to einstein, nothing can travel faster than the speed of light, however, modern science may prove this incorrect, as described in http://news.bbc.co.uk/2/hi/science/natur...

Answer 6

They are theoretical