User blog comment:SouthWriter/Time Travel and/@comment-or Alternate Universes/@comment-1375165-20100813023819

I don't think that its right to say that any scientific law is "set in stone". By definition science can't "definitively prove" anything. Even such vital things like the LAW of Gravity and the first LAW of thermodynamics can be violated in certain cases and don't hold everywhere. A theory is just less accepted than a law.