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The Question

(Submitted November 30, 2004)

Can you explain the Kerr Black Hole in detail please? Also, how can it cause time travel?

The Answer

Thanks for your question. Kerr black holes were postulated by the theorist, Roy Kerr in the 1960s. He postulated that a rotating star could collapse into a black hole with a rotating ring of neutrons at its center rather than the usual singularity. Kerr believed that since there wasn't a singularity at the center, one might be able to travel through the black hole without being crushed by the singularity. Another theoretically possible scenario is that a person could enter the Kerr black hole and exit through a white hole on the other side (a white hole would actually push everything away from it using some form of exotic matter with negative energy), and, in this way, one could travel through spacetime.

While white holes may be theoretically possible, there is absolutely no evidence to support their existence. Many theorists do not believe there is any way to pass through a black hole and that even if it were possible, one would be torn apart by the enormous tidal forces well before reaching the singularity.

Hope this helps,
Georgia & Dirk
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