• Question: Is there such thing as a white hole.

    Asked by 257sptm42 to Ollie, Angus, Christine, Guy on 5 Mar 2018.
    • Photo: Guy Rixon

      Guy Rixon answered on 5 Mar 2018:

      13.8 bilion years. See https://www.space.com/24054-how-old-is-the-universe.html for a discussion.

      It’s only fairly recently that we’ve had a reliable value for the age. 15 years ago, everybody got different values depending on how they measure it.

    • Photo: Alexander Burke

      Alexander Burke answered on 5 Mar 2018:

      The maths and physics on paper (theoretically) says that white holes should exist. White holes are a solution to Einstein’s equations where Einstein’s equations describe how gravity works. White holes are defined as the time reversal of a black hole – so whereas black holes are objects in the universe which suck in things, white holes are objects which spit things out! You can never enter a white hole, they are a one-way ticket: You can leave but you can never return. In a way, white holes are even stranger than black holes! White holes have never been observed in our universe and I highly doubt they will ever be discovered by humans. To see them, you would need to travel backwards in time to observe them, or enter a spinning black hole and be spat out at the other end. Even when you are spat out by the white hole you would need a pretty good camera to catch the exact moment you cross the white hole boundary. This is because once you leave that part, you can never return to it!

      White holes are cool. Really really cool.