Talk:Exotic Matter Manipulation/@comment-24053170-20160130094822/@comment-26322734-20160930223120

Actually, tachyons do defy the laws of physics. The idea of tachyons in the first place came from the idea that Einstein's equation can be reversed -- if nothing can go faster than light, then there can be something that can ONLY go faster than the speed of light. The thing is, it defies the laws of physics because, by the principle of general relativity, nothing with mass goes faster than light. Period.

Tachyons are thought to have something called "negative mass", which allows them to move at superluminal speeds, which defines them as "exotic matter" by definition. No baryonic matter has negative mass, so anything with "negative mass" is exotic matter.