fasterthanlight

Faster-than-light (FTL) refers to hypothetical methods of travel or communication that exceed the speed of light in vacuum. In physics, the speed of light is a cosmic speed limit for information and matter with mass, according to special relativity, and accelerating toward or beyond c leads to infinite energy requirements. Because of these constraints, no experimental demonstration of true FTL has been achieved.

Theoretical concepts commonly discussed in physics and science fiction include: warp drives that bend or warp spacetime (such as the hypothetical Alcubierre drive); traversable wormholes that provide shortcuts through spacetime; and tachyons, hypothetical particles that would travel faster than light. Some approaches claim to permit effective or apparent FTL without violating causality, but they remain speculative and face significant technical and physical challenges. Additionally, certain quantum effects produce apparent superluminal signals (e.g., phase or group velocity in some media), but these do not enable faster-than-light information transfer.

FTL remains unsupported by empirical evidence. It raises paradoxes such as causality violations in some frameworks, and most physicists consider it unlikely for macroscopic objects. In fiction and popular culture, FTL concepts are widely used to enable interstellar travel or rapid communication, often with speculative technologies like hyperspace, warp drives, or wormholes.

Notes: The term "fasterthanlight" is sometimes encountered as a stylized spelling or username in online communities and projects dealing with space, science fiction, or gaming, but it is not a scientific term by itself.