User blog comment:Gmx0/Why Alternate History/@comment-Multiverses are impossible./@comment-174.89.114.18-20100317134223

Because this is about science, I'll come in here. Quantum mechanics DOES NOT state that alternate realities have to exist. The Multiverse interpretation is one of several possible theories to explain the wave phenomena of particles, and one of the less plausible ones at that.

In any case, this website is about creating entertaining and researched works of fiction, there's no need to defend whether any of this can actually happen. But that's just my take.