User blog comment:SouthWriter/Time Travel and/@comment-or Alternate Universes/@comment-1593341-20100812172013

To Yank on the laws of physics being in flux, the difference between a law and a theory is that a theory while it may have evidence to support it, has not been definitively proven, laws have been definitively proven and are therefore set in stone unless the way the universe works changes.

Special Relativity has recently come into question because a new theory based on the research of some guy at Yale fits within existing laws much better. Its still undergoing peer review before it officially replaces special relativity as the accepted theory, but it shows that even when a theory as entrenched and accepted as Einstein's gets questioned, science is willing to look at something new.