• Question: what do you think a black hole or a wormhole is?

    Asked by ragustinh to Dean, Jess, Luisa on 24 Jun 2010 in Categories: .
    • Photo: Luisa Ostertag

      Luisa Ostertag answered on 24 Jun 2010:

      I don’t really know about these things. But I am sure Dean and Jess will be able to help you better with this question.

    • Photo: Jessica Housden

      Jessica Housden answered on 24 Jun 2010:

      A black hole is something that is so heavy it sucks everything towards it, and even light can’t escape it’s garvitational pull. It would have once been a very very big star, which, when it had finished nurning all it’s fuel collapsed in on itself. However, as it was so big, it collapsed in on itself – called gravitational collapse. Only very big stars can do this (our Sun wont). Black holes are pretty awesome, especially as time does very funny things as you get close to one. There is an ‘event horizon’, basically the point of no return. once you go beyond this, nothing can escape – not light, not radio signal.

      If you imagine space as a fishing net. If you put a very very heavy object in one place, it would create a ‘well’ in the net that things would fall into and not have enough energy to get out of. That is a bit like a black hole, with the net representing the gravity field in Space.

      Now imagine that the net (the Universe) was not flat to begin with, but curved and different shapes. It might be possible for the very heavy object to make the net dip down so it touches the other side. Theoretically, this is a wormhole; although not one that would last for any time at all. For the wormhole to open long enough for anything to go through it, negative energy density would be required, which scientists do not understand much about. The only other problem, is whilst theoretically they could exist; scientists don’t yet know what would trigger them to start in the first place!

    • Photo: Dean Whittaker

      Dean Whittaker answered on 24 Jun 2010:

      A black hole is what we call a singularity. So there’s no volume, but there is mass. A black hole is what happens when gravity pulls everything in and squashes it so much that it shrinks to nothing. Steven Hawking did a lot on black holes and he worked out that they radiate a little bit (kinda like glowing a little but you can’t see it). This explains how they can exist, because of some complicated physics. I’m not really an expert on black holes but they’re fascinating objects and we’ve observed them at the centre of most galaxies!

      Wormholes are a theoretical thing. We’ve never seen one but they’re a concequence of all the smart maths that Einstein did in coming up with theory of relativity. Space isn’t flat. So if you imagine the universe is curved just like the earth, then you can either go around the long way (around the globe), or you could create a hole going through the middle of the earth and get there quicker. Unfortunately drilling such a hole wouildn’t be very cost effective here. But the same could happen for the whole universe. So travelling to our nearest star might have a shortcut. The wormhole would be that tunnel that goes through the middle instead of round the outside.

      It’s all very complicated and difficult to explain!

Comments