Banned because such a thing might not be provable via the Almighty, tried and true SCIENTIFIC METHOD, but science doesn't know everything (and will never know everything). There are certain things people consider "supernatural" that I personally know beyond a shadow of a doubt, exist. With that being said, although I don't know of any alternate universes or worlds, I can't completely rule such a thing out as a possibility.
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"I got to keep you on your toes. When you think I'll zig, I'll zag. Then when you think I'm gonna zag, I do zag, just to mess you up for the next time, when I might zig" - Lorelai Gilmore