Professor Kip Thorne of CalTech wrote a remarkable book, “Black Hole and Time Warps: Einstein’s Outrageous Legacy.” According to Thorne, time for a particle just above the event horizon of a black hole slows to a crawl because of gravitational time dilation. (For more information on gravitational time dilation see http://www.search.com/reference/Time_dilation#Gravitational_time_dilation_tests.)
A particle hovering just above such a black hole might travel between galaxies in a short time. Consider two galaxies separated by 1000 light years. Each galaxy has a super massive black hole at center. As gravity pulls the two black holes toward each other, a particle just above the event horizon of one of the black holes might travel to the other galaxy in a short period of time as measured by clocks in its reference frame. For instance, the particle might travel to the other galaxy in ten years as measured by a clock just above the event horizon. (I haven’t worked the equations.)
As long as the particle moves away from the black hole before both collide with matter from the other galaxy, it might survive the intergalactic voyage.
Theoretically, this leads to the possibility that a spacecraft might make the intergalactic leap!
We can simulate on a computer the natural phenomenon of a particle traveling between galaxies in a short time as measured by its clock.
