A particle which always moves faster than the speed of light.
Such particles are hypothetically possible, but none has ever
been observed, and their actual physical existence is now
considered more than a little doubtful. Also see luxon and
tardyon. a hypothetical faster-than-light quantum particle,
which has not been proven to actually exist a hypothetical
particle that travels at superluminal velocities a hypothetical
particle that travels faster than the speed of light and has
imaginary mass a theoretical particle that always travels faster
than light a theoretical particle that can travel faster than
the speed of light a type of subatomic particle that exists only
at faster-than-light velocities a [theoretical] particle that
moves faster than light. A tachyon (from the Greek (takhÃºs),
meaning "swift, fast") is any hypothetical particle that travels
at superluminal velocity. The first description of tachyons is
attributed to German physicist Arnold Sommerfeld, but it was
George Sudarshan, Olexa-Myron Bila