• Question: what will happen if you get sucked up in a black hole

    Asked by ziarniaf to Rochelle, Julia, Jon F, Beth, Adrian on 21 Jan 2016. This question was also asked by chanel, starlucy3000, emiridesu, saphireroks.
    • Photo: Jon Farrow

      Jon Farrow answered on 21 Jan 2016:


      The technical term for what happens to something when it approaches a black hole is “spaghettification”. Seriously!

      Crossing over the edge of a black hole (crossing the event horizon) would look really weird. Most of the weirdness comes from the extreme mass of a black hole.

      As you approached, you’d get spaghettified. This is because the gravity at your feet would be so much stronger than at your head that you’d get stretched. (Reminder that the strength of gravity depends on distance between masses). This is the same principle behind how the moon raises tides on Earth, but to an extreme level.

      The other really weird thing comes from this thing called gravitational time dilation. This theory, proposed by Einstein and confirmed many times over, says that time runs slower the closer you are to a large mass. The effect is pretty small on a planet like Earth, but it’s noticeable. In fact, if the GPS satellites didn’t take this effect into consideration, they’d lose accuracy at a rate of a few meters every day. The fact that your phone knows where you are to within a few meters proves that “low clocks run slow”. So as you approached the black hole, time would run slower and slower for you, until the moment you reached the very edge, when it would basically stop.

      The OTHER really weird thing that would happen is that if your friend was watching from far away, you’d change colour. You’d become redder and redder and eventually disappear. This is called gravitational redshift and it happens because the light from you has to “fight” against gravity as it moves out towards your friend and it loses energy, so it becomes redder.

      If you want to read and/or watch more about this, check out these links!
      http://www.bbc.com/earth/story/20150525-a-black-hole-would-clone-you

      http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/fall_in.html

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