When a micro black hole is created for a pico-second by colliding two super-heavy isotopes in the linear particle collider and then sending several atto-second pulses of laser light into it to test it's stability communication between two separate universes is created. The atto-second laser pulses are detected by an alien civilization that is at about the same technological level as us. Time in the separate universe progresses at a different rate then in our own and 100 thousand years passes for them in the amount of time that it takes to repeat the same collision experiment in our universe. When the experiment is repeated the alien civilization is technologically ready and stabilizes the new black hole by accelerating nuclei of their devising into the hole on their end. This allows them to communicate with us. Unfortunately, the communication causes the wave-function of both the universes to collapse because a measurement is made from outside. The collapse simply forces all matter and light to take a stance, ie everything loses it's wave nature very briefly. Because of this many things begin to go wrong, for instance cancer starts popping up all over the place because cells stopped functioning perfectly for a short period of time. Next astronomers notice that the sun is expanding at a much faster rate than it should be, estimating that Earth will be consumed in only two thousand years at this rate and human life will be incinerated within one hundred years due to a instability created within the center of the sun.
For better communication larger black holes are created in space and worm holes are made by aligning them in the correct orientation. The two civilizations can now freely move back and forth between each different universe. Many different species of life are observed. New types of space craft and as it turns out two new types of intelligent aliens exist in the other universe. We learn about how the two species learned of each other and how they set up an intergalactic government in order to keep peace.
Our heros, a human physicist and an alien, determine that the best route to solving these problems is to make further communication with the other universe (whose time now moves at the same rate as ours because the collapse of both our universes wave-functions normalized us to the same physics). Together the two civilizations share each other's knowledge, of which the aliens have much more than us so we learn a great deal. It is determined that what needs to be done is to stabilize both universes by entangling them and separating them by creating two black holes that merge, and by merging they collapse themselves entangling each universe to the other and sending us off on our own journey of discovery again.