Question: what is a white hole

Zoe Vance answered on 21 Mar 2025:

I’m afraid this might be beyond my level of physics to either understand or explain, but we’ll try!

White holes are theoretically the opposite of black holes, some maths that describes how the universe works predicts that they could exist although we don’t yet have any evidence that they do. If they did then they would behave oppositely to a black hole – instead of everything being pulled in and unable to escape they would eject matter and nothing would be able to enter. Some people hypothesise that white holes could be something like the other side of a black hole in another universe but as far as I can tell we don’t even know if they exist in our universe or if they’re just something that could be possible mathematically but doesn’t happen. Pretty cool idea to think about anyway!