Why can you travel between universes?

I am a fan of this movie and even I had to read the prequel comic to get every thing. I had never seen a "Sliders" type movie, and to be honest I wish they would remake this, but plan a trilogy around it.

Anyway, according to the prequel comic, they use the power of a collapsing black hole to pierce through the fabric of their universe, based on a similar concept ins string theory that suggests that gravity is are made of closed strings, unlike everything else that made of open strings. The idea is that the closed string of gravity can leave our universe, because its not tied to the "Membrane" that is our universe.

Now in the movie "The One", They use the power of a collapsing black hole, and shape that energy into a traverse-able microscopic wormhole. The "Window" they have is the time between Initiation of collapse when the first pierce in the fabric occurs and the point in which gravity becomes so intense it pinches off the new micro universe and the hole closes.

The Machine breaks down the matter in the stream into a microscopically thin strand, combined with the fact that the open-looped strings that make up the matter in the stream has to "Arc" from universe to universe using the micro-wormhole as a medium, its no wonder the experience is....painful to say the least.

Now the ability to predict these blackhole collapses come from the fact that they have a deep understanding of what the precursor signs of a star becoming a black hole.

Other then that, you just need a telescope to find these "Candidates" and send that information to the Quantum Tunnel machine. And to be honest, you don't even need a Time machine or faster then light communication to know. You look at a star that's in the process of becoming a black hole that's 101 light years away. you observe that it has maybe a 100 years left of life based on a keep understanding of stellar physics. However you must also take into account that the star is 101 light years away. So some quick math tells you that the star in actuality has 1 year of life left in it.

Now this is just general math, in the comic, they had the ability to determine down to the second, when the singularity forms, and how long that singularity takes before it "pinches" off from the "mother" universe. This process I'm sure is automated and given over to a computer to observe the stars, but based on that, it could be done.