How Do Tachyons Work?

[Anonymous]

yo,
ive been learning about physics(and time travel) on my spare time and i have come across tachyons many a time. i dont quite understand them. can someone help me and give me some info on how htey work and such? and why are they so crucial in the physics of time travel?
ZERO
i know that they travel interdimensionaly or something like that

 

[Anonymous]

Well, tachyons doesn't really work. They are only a theory. Einstein said that it is impossible for something to accelerate from normal speeds to light speed. But there was nothing in his theories that said it was impossible to move faster than light. The problem is just the things that did, would have to always have moved faster than light, and they can never slow down to under light speed.

So someone suggested there might exist particles that could do these things, and they call them tachyons. And since they travel faster than light, they might be a way of getting information back in time. Which would be handy for time travel.

 

[NilesCalder]

The fundamental problem with Tachyons is that since they only exist in an FTL state, and we can't detect anything exists in an FTL state (as far as I know) we can never detect them.

Of course Tachyons could just be Tardons with a negative energy...

Niles "sh'yeah, right" Calder

 

[Anonymous]

It is possible to interact with tachyons, just as it is possible for tardyons to interact with photons (travelling at the speed of light, as they would.) A number of years ago I attended a theoretical physics colloquia in which the speaker was postulating that neutrinos may be tachyons. People had been performing experiments in order to try and determine the mass of the neutrino. (Actually the measured quantity was the square of the neutrino mass.)

When all of the results were combined, the weighted average for the square of the mass was negative, with the 1 sigma limits not taking it above zero. Most folks used this as good evidence that the neutrino mass was thus zero (as it was assumed that it would have a real mass.) This guy used this as a starting point. "What if it really does have a negative value of m^2?" If true then it would be a tachyon. He then presented the calculations showing what the physical consequence of this would be. The peculiar thing was that it would still behave in a fashion consistent with our (current) measurements of it.

 

[NilesCalder]

This guy used this as a starting point. "What if it really does have a negative value of m^2?" If true then it would be a tachyon. He then presented the calculations showing what the physical consequence of this would be. The peculiar thing was that it would still behave in a fashion consistent with our (current) measurements of it.

That would imply Neutrinos have a negative energy right? Negative mass = negative energy? If that were so (since Neutrinos are, like, the most common stuff in the universe or something) it would be relativly easy to create an Alcubirre-Vandenbroeck style Warpdrive.

Next stop Alpha Centuri!

Niles "Make It Sew" Calder

 

[rynner2]

Niles "Make It Sew" Calder

..or should that be:- Niles "Make It Sew" Singer-Calder ?

A colleague recently sent me this . It is legible enough, I think (I tried to keep the file size down), and should be of interest to those who don't mind equations and are happy with complex (or 'imaginary') numbers.

And always remember the First Law of Everything -

To every expert there is always an equal and opposite expert.

 

[Anonymous]

That would imply Neutrinos have a negative energy right? Negative mass = negative energy? If that were so (since Neutrinos are, like, the most common stuff in the universe or something) it would be relativly easy to create an Alcubirre-Vandenbroeck style Warpdrive.

Next stop Alpha Centuri!

Niles "Make It Sew" Calder

Sorry, I should have said m_0^2, i.e. the square of the rest mass. When combined with gamma^2 (i.e. sqrt(1-v^2/c^2)) the negative signs disappear and we're left with a relatively "normal" relativistic particle. (Though one for which v>c !! )

 

[Xeyes]

Hello.

I thought recently that it was agreed that Neutrinos have a very small positive mass! and helps scientists to find alot of the missing mass of the universe?

 

[Anonymous]

Xeno,
You're quite right. This presentation on the implications of tachyonic neutrinos was from ~1991. Even though it looks as if neutinos have a real rest mass (helps explain a *lot* of things) it is still interesting to see that people have been playing the good scientific game of "what if?"