• Question: How dense is a black hole? And, if you were 'sucked in' what do you think would happen?

    Asked by to Thomas, Simon, Daniel, Clara on 13 Mar 2014. This question was also asked by .
    • Photo: Simon Albright

      Simon Albright answered on 13 Mar 2014:

      No one really knows how dense a black hole is. According to our equations they are infinitely small and infinitely dense, but it might be that we just can’t accurately describe them.

      If you fall into a black hole you won’t really notice anything, you’ll just go flying in and get squished into a volume smaller than an atom. Although you’d die long before that through a process called “spaghetification” which is when you get stretched out because the gravity at your feet is much stronger than the gravity at your head. Although most black holes are surrounded by super heated clouds of material that are falling into them so you may find you get cooked and incenerated before you get spaghettified… Isn’t physics fun!!!

      But what’s really interesting is what someone a long way away from you would see! There’s a theory called General Relativity (GR) which was developed by Einstein. GR tells us that anything really heavy changes the rate that time passes which we know to be true. GR has to be taken into account for SatNav systems to work because clocks in space run very slightly faster than those on earth. This means that if someone is watching you fall into the black hole as you get nearer they will think your moving slower, and the nearer you get, whilst being incinerated and spaghettified, you gradually slow down until, just at the edge of the black hole, you appear to stop completely.

    • Photo: Thomas Elias Cocolios

      Thomas Elias Cocolios answered on 13 Mar 2014:

      Spaghettification is really a cool concept! Not one that I would like to experience though!

      The other thing that happens is that light gets progressively trapped in the black hole as well and even the light that can live from it is very much slowed altogether. As such, an external observer would actually never see you disappear, but rather see you keep on falling for ever and ever, always closer to the event horizon. (when in fact you are already feeding the black hole’s bolonaise sauce!)

    • Photo: Daniel Roach

      Daniel Roach answered on 14 Mar 2014:

      The problem with black holes is that words like ‘density’, ‘time’ and ‘space’ don’t really have any meaning! Once you’ve crossed the event horizon of a black hole, you’ve left the rules of our ‘normal’ universe behind.

      I can’t imagine it would be very nice, though… having a gravitic incline across your body would pull all your organs apart, squeeze you into a sausage, then separate that sausage into … urrgggh!

    • Photo: Clara Nellist

      Clara Nellist answered on 19 Mar 2014:

      Like the others have said, we don’t know how dense black holes, but we do know that they can get more massive by eating other things around them! They absorb other stars and anything else around them until they become ‘supermassive black holes’! This is also the name of a song by the band Muse. There are many scientist that agree that there is a supermassive black hole at the centre of our galaxy, with a mass about 4.3 million times that of our sun!

Comments