User blog comment:VonGlusenburg/Alternate universes, probability and alternative outcomes/@comment-1777104-20120816175000/@comment-1630894-20120817003532

Anything is possible, but often requires alterations in the fundamental laws of our universe. For the sake of drawing the line here, anything that is impossible to occur in our universe is impossible. This includes magic, zombies, superheroes, and humans doing what we simply cannot do.