what are tachyons/tachions?

Question

i know that they have something to do with time travel,but what are they actually?do they exist?

Answer 1

Tachyon, hypothetical elementary particle that travels only at speeds exceeding that of light.

According to the theory of relativity, the speed of light is the limiting velocity for all ordinary material particles. Particles having nonzero rest mass can approach, but not reach, the speed of light, since their mass would become infinite at that speed. On the other hand, particles with zero rest mass, such as the photon, must always travel at the speed of light; they cannot be brought to rest or even slowed down. Theorists have argued that since nothing in principle prohibits the existence of a third class of particles that travel only at speeds exceeding that of light, such particles, called tachyons may exist although no evidence for them has been found. In the terminology of the theory, the particles that travel only at the speed of light are called luxons, and those that travel at lesser speeds are called tardyons.

Like the original theory of relativity, the theory of tachyons has several aspects that appear to contradict common sense but that are fully self-consistent. For example, a tachyon must have an imaginary (in the mathematical sense) rest mass, or proper mass, and it must travel faster rather than slow down when it loses energy.

Answer 2

A tachyon (from the Greek ταχύς {takhús}, meaning "swift") is a hypothetical particle that travels at superluminal velocity. The first theoretical description of tachyons is attributed to physicist Arnold Sommerfeld; however, the concept has recurred in a variety of other contexts, such as string theory. Many strange properties have been attributed to tachyons, which also play a role in some popular science fiction

Answer 3

Tachyons are only hypothetical; they have never been proven to exist. They are particles that travel faster than light. The existence of tachyons was first theorized by German physicist Arnold Sommerfeld, but it was two men named George Sudarshan and Gerald Feinberg who gave the particle its name. Interestingly, the tachyon can never slow to the speed of light or below; it travels only at speeds greater than light. In classical physics, nothing can travel faster than light.