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Tachyons
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Hypothetical faster-than-light particles with imaginary mass.
Hypothetical particles with imaginary mass that always move faster than c. They'd allow causality violations and none have been observed; imaginary mass in field theory signals instability instead.
Used as a concept in string theory.
Relativity forbids ordinary matter from reaching c, not hypothetical particles that were always faster.
In more detail
Tachyons are hypothetical particles that always travel faster than light. They are not observed, and their existence would create causal paradoxes in relativity.
Real-world uses
- Tachyons appear in theoretical discussions about the limits of relativity.
- They are not part of established physics.
- Physicists consider tachyons in theoretical discussions, but no experiment has found a faster-than-light particle.
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Frequently asked questions
Have tachyons been found?
No. Experiments have found no evidence for them.
Why are they a problem?
They could allow signals to travel backward in time, which leads to causal paradoxes.
Do tachyons violate relativity?
They would, in some respects, which is why they are considered only as a theoretical possibility, not a physical reality.
Related topics in Relativity
Particle accelerators and relativity · Mass–energy in nuclear reactions · Relativistic electromagnetism · Equivalence principle · Gravitational time dilation · Gravitational redshift