[ To be perfectly frank, Bradbury's not the best guy to ask about this trans-dimensional crap, but he figures she can probably guess that much herself even without him saying it. ]

I don't know what the official theory is, but my guess is that it's because someone else started messing with jumping to other dimensions too. Vulcanus. Guess you could call 'em the "bad guys," at least as far as imPorts are concerned.