What if a white hole and a black hole of identical size, mass and rotation(same magnitude, opposite direction) meet each other head on?

The white hole would try to push away the black hole and the black hole would try to suck in the white hole, and since they have identical properties, wouldn't the forces cancel out and form a stable system? How can General Relativity explain such an interaction?

Also what would happen to a particle placed midway between such a system?

And what would happen if they had the same rotation(direction and magnitude)?

  • $\begingroup$ Possible duplicates: physics.stackexchange.com/q/30406/2451 and links therein. $\endgroup$
    – Qmechanic
    Commented Oct 23, 2016 at 8:39
  • $\begingroup$ @Qmechanic that question addresses ollision but mine is interaction and fate of a particle between such a system. $\endgroup$ Commented Oct 23, 2016 at 9:20
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    $\begingroup$ This is an interesting question. +1 I wonder about the possibility of having a white hole and a black hole near each other in space, especially since white holes violate some of the laws of thermodynamics. I wonder whether the tools of black hole thermodynamics would even apply to such a system. $\endgroup$
    – Anon
    Commented Oct 27, 2016 at 3:05

1 Answer 1


The white hole is also a hole in space-time and would probably have equal gravity as the black hole. So both holes exert gravity pull on each other. The white hole also has a repelling horizon which pushes. So with just taking these forces into account, a particle placed in the middle might be pushed against the black hole and swallowed.

Such white hole repelling force might seem to be some kind of a new force of physics, and we might not quite know how it works. And if the white hole repel, and if there is symmetry, as it often is in physics, would there be some extra pull besides gravity from the black hole?

Anyway even without these strange forces, energy and matter streaming out of the white hole might also push the particle in the middle against the black hole.

A black hole white hole binary might also resolve the stability issue of wormholes. A wormhole is calculated to be incredibly unstable and would easily collapse, and need a kind of opposite energy to keep the "funnel" open. Exotic matter is one proposal to keep wormholes open. But a binary with oppositely directed wormholes might provide the perfect opposite energy which might stabilize both wormholes, so black and white (worm)holes might then stabilize each other. If wormholes exist in space they might then be such opposite black/white binaries, the white hole would then light up, and the black hole would be far more difficult to observe, as it is a dark wormhole entrance.

I researched the black hole in the center of our galaxy called Sagittarius A*, and could not find a single evidence of it being a black hole, but a dozen of observations pointed at it being a white hole, isn't that odd?

And in the galactic center we could really need a new force, as the orbiting stars does not seem to behave according to Kepler and Newtonian mechanics, as most stars have about the same speed around the galactic center, about 220 km/s, like our Sun. So we postulated dark matter to solve this, but dark matter is both hard to find and hard to distribute correctly in the models. So maybe dark matter is not matter, but instead a strange force with tremendous energy?

  • $\begingroup$ How can a white hole have gravity? $\endgroup$ Commented May 7, 2020 at 2:30
  • $\begingroup$ It is a hole in spacetime, a gravity well, in this way both ends of a wormhole, the white hole and the black hole has strong gravity even without normal matter. $\endgroup$
    – Enos Oye
    Commented Jul 22, 2020 at 14:26
  • $\begingroup$ But a hole in space-time can only be created by normal matter or energy. $\endgroup$ Commented Jul 27, 2020 at 18:14

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