Question

What is Tachyon particle?

Answer 1

Tachyon is a hypothetical particle that travels faster than light particles. But they are not recognised by physics because it doesn't respect the laws of physics. If such particle would be used practically, then it would violate the laws of physics. Thus it is hypothetical and can never be practical.

Answer 2

A tachyon or tachyonic particle is a hypothetical particle that always travels faster than light. Most physicists believe that faster-than-light particles cannot exist because they are not consistent with the known laws of physics.