: Stop me if I'm wrong, but aren't white holes basically the time reversals of black holes? If so, wouldn't it be possible for a wormhole to exist between two universes that were the time reversals of each other? : Think of a cassette tape. While you listen to one side, which grows increasingly closer to it's end, the other is rewinding. Yet, they are both moving in the same direction. Viola! Time reversal. Wouldn't it be possible for two perhaps parallel universes to be doing something similar to this, thus allowing white holes to exist in one? It's just a thought. : If you have time, read my other post on this page, and visit my website, too (http://www.angelfire.com/ut/skydivingelephants), or my other website whose link is below.

Well, a worm hole between two parallel universes could not exist, according to quantum mechanics, but to get to a parallel universe, You would have to travel back in time and make another decision to go up the other branch. I am not sure If time could run backwards unless there was a tunnel between a black hole in the past and one in the future, and if all time coexisted. www.geocities.com/blackhole_14