Tachyons

Tachyons are hypothetical particles proposed in physics that always travel faster than light. According to some theories, they would have imaginary mass and could potentially violate causality, meaning cause-and-effect relationships might break down. However, there’s no experimental evidence that tachyons exist, and their existence challenges our current understanding of physics. They remain a speculative concept used mainly in theoretical discussions about faster-than-light phenomena and the limits of relativistic physics.