What does tachyon mean?
A tachyon is a hypothetical particle that travels faster than light. Ordinary matter is believed to be unable to pass through the speed of light, so the idea of a tachyon is not that such a particle accelerates beyond light speed, but that it has always traveled faster than light and may possess unusual energy and momentum properties. No tachyon has been experimentally confirmed, and proposals concerning them remain speculative, although the term has played an important role in discussions of relativity, causality, and the apparent reversal of cause and effect. In science fiction, tachyons frequently serve as faster-than-light carriers of messages or other information. The word can refer either to a hypothetical particle or, more loosely, to a faster-than-light signal. Its specialized theoretical associations distinguish it from the everyday vocabulary of speed and keep its use largely confined to physics, popular science, and speculative fiction.
nounA hypothetical particle that travels faster than light. In theoretical physics, tachyons are proposed to exist always below the speed of light and have never been experimentally confirmed.
- A hypothetical particle or signal that travels faster than light, used chiefly in theoretical physics and science fiction.
"The observation was dismissed as evidence of an imaginary tachyon rather than a new form of matter."
"The model predicts a tachyon, although no such particle has been detected experimentally."
"The message was transmitted by tachyon, allowing the crew to receive it before it was sent."
The plural is used for hypothetical particles collectively or for multiple supposed faster-than-light signals.
"The experiment searched for tachyons without detecting any."
A tachyon's name comes from Greek for “swift,” making it a particle that would earn its name by outrunning light itself.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does tachyon come from?
The English term combines the Greek ταχύς (tachys), meaning “swift” or “fast,” with the suffix -on. It was developed in the twentieth century as a scientific name for a hypothetical faster-than-light particle. Related English words such as tachometer, tachycardia, tachylite, and tachypnea also draw on the same Greek element, although they developed independently in different technical fields.
How tachyon is actually used
This is primarily a specialized term used in physics and science fiction. It is usually pluralized as “tachyons” and can also function attributively, as in “tachyon communication.” The word does not ordinarily appear in everyday speech.