Do Tachyons Really Exist in Physics?

[nishu1988]

do tachyons exist!

there has been speculated that certain elementary particles like tachyons do exist which disobey the principles of relativity....i.e.they travel with the speed of light...




is that true please help...me to find a satisfactory answer to this topic...

 

[chroot]

Tachyons are particles that move strictly faster than light. No particles with mass may travel exactly the speed of light. Tachyons do not disobey any principle of relativity, but have never actually been detected.

- Warren

 

[nishu1988]

thanx a lot!, well, can you please tell em about quarks and anti quarks!

 

[malawi_glenn]

https://www.physicsforums.com/showthread.php?t=43685

And you may also check out on wikipedia. Search on "standard model" "quark" "anitmatter" and so on. So maybe we can fill in the gasps :)

 

[olgranpappy]

thanx a lot!, well, can you please tell em about quarks and anti quarks!

Quarks and anti-quarks are to be thought of as the real particles which make up nuclei. People who smash particles together really do see quarks and anti-quarks coming out (well, sort of).

But anyways, quarks and antiquarks are a major part of the standard model and are "well-respected" particles.

This is to be contrasted with tachyons which are not to be thought of as real particles. They are not part of the standard model, and no one has ever observed one. Furthermore, they are useless.

 

[Haelfix]

Tachyons can and do exist in a certain mathematical sense. They are often identified with the instability of a quantum vacuum (or rather we've chosen to pick a false vacuum, instead of the real global minima and are doing something that we aren't allowed to do). They can then condense and become 'real' in a sense.

A lot of its the artifact of mathematical machinery, but for instance the higgs mechanism is an example of tachyon condensation, and the real physical situation need not violate causality (unlike the case classically). This is discussed with references on the wiki page on tachyons.

 

[olgranpappy]

Tachyons can and do exist in a certain mathematical sense. They are often identified with the instability of a quantum vacuum (or rather we've chosen to pick a false vacuum, instead of the real global minima and are doing something that we aren't allowed to do). They can then condense and become 'real' in a sense.

A lot of its the artifact of mathematical machinery, but for instance the higgs mechanism is an example of tachyon condensation, and the real physical situation need not violate causality (unlike the case classically). This is discussed with references on the wiki page on tachyons.

But, the Higgs isn't actually tachyonic. It has a positive mass proportional to its vev...

 

[Haelfix]

Yes, the physical particle the Higgs boson is quite real and non tachyonic, but the field at the top of the potential is tachyonic.

Maybe this discussion would help

https://www.physicsforums.com/archive/index.php/t-141793.html

 

[Lakshya]

In a spacetime graph the light goes on 45 degree angle and everything which goes below the speed of light is on one side of the graph and that is our world which we call real. In our world the maximum speed attainable is light. But a theory says that there's another world across the light barrier and in that world the minimum speed attainable is of light. Some people believe that tachyon is a type of particle of that world which we accidently figured out. According to the standard model our world contains many types of particles and in the other world there are also same no. of particles which have opposite properties but still we have only figured out tachyon.

 

[JDługosz]

Also, check out the answer in The Physics FAQ.

 

[Toutatis]

Tachyons do not disobey any principles of physics. In fact, it is by going by the principles of physics that people have thought of these hypothetical particles. The formula is something like this (I don't know how to write such formulas properly on a keyboard, so bear with me): E= (MC^2)/(r 1-(v/c))
Now, if the mass is imaginary (as in, the square root of -1 for example), v must be higher than c. And tachyons, if they do exist, have an a mass of an imaginary unit.
The problem is though, how do one find/make tachyons? They won't come flying out of the blue, and us not being able to make one (yet) doesn't mean that they doesn't exists, it simply means that, well, we aren't able to make one.

 

[olgranpappy]

...and us not being able to make one (yet) ...

Yet?

Let me take this opportunity to unequivocally state that no one will every make a tachyon.

 

[JesseM]

Tachyons do not disobey any principles of physics.

Well, if the principle of relativity is obeyed they'd allow you to send information back in time and thus violate causality, although it's uncertain whether the ultimate laws of physics will respect causality.

The problem is though, how do one find/make tachyons? They won't come flying out of the blue, and us not being able to make one (yet) doesn't mean that they doesn't exists, it simply means that, well, we aren't able to make one.

But they are also not predicted to exist by the standard model of particle physics or by most of the proposed extensions of it like superstring theory, AFAIK.