User blog comment:PitaKang/Funday Monday 3: What would an interstellar civilization look like?/@comment-4758513-20130430022547/@comment-4758513-20130430233425

Exotic matter has been proven before. Dark matter and the Higgs Boson are two technical forms of exotic matter. And this is just the wikipedia article. Another one I read made no mention of exotic matter at all, although that one is probably less accurate.