Could black holes be portals to other universes?

There is a long history to the idea that black holes may connect with other regions of the Universe, or other universes entirely, but this is purely speculation.

By Dr Alastair Gunn

Asked by: Stuart Laws, by email

Some physicists have attempted to combine quantum mechanics with the General Theory of Relativity and concluded that black holes may not contain a ‘singularity’, the point at which density becomes infinite. This would open up the possibility that black holes are shortcuts to other universes. Actual tunnels through space-time, called ‘wormholes’, may be a better bet for traversing between universes. But although they’re predicted by Einstein’s theories, no wormholes have yet been discovered, and there are doubts that they could occur naturally at all.

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