• Question: How long do you think it is until humans can travel to the centre of the universe? or do you think it will never be possible?!

    Asked by lucasjacobs to Meeks, Pete, Stephen, Steve, Tom on 18 Jun 2010 in Categories: .
    • Photo: Tom Hartley

      Tom Hartley answered on 17 Jun 2010:

      Again, this is a physics question, and I am not so sure about the answer, so you should listen to the other scientists. I am goinf to have a go at answering, because I love thinking about this sort of thing, but I don’t know much (if any) more about it than you .

      My understanding is that we are already at the centre of the Universe, and (confusingly) so is everywhere else. Since the big bang, the universe has been expanding, but all points are moving away from each other. So from any position (say the Earth) if you look at the stars they are all moving away from us (which you can tell, because their light is slightly redder than would be expected – this is called Doppeler Shift). But you would see the same phenomenon from any other place.

      This is a bit like a balloon being blown up. If you put dots on the balloon, before you blow it up, you will see that as it is inflated they all move away from each other, and there’s no place you could call the centre.

      I think this explanation also depends on the fact that the balloon is curved. However, somewhere else on this site, I read Meeks say that the universe is flat like a piece of paper (although in 3 or more dimensions). If this is true, then the analogy breaks down.

      Also, if the universe had an edge then you could say the centre was the place furthest from the edge, and then maybe we could get to that place.

      So my understanding is that three things are linked: the shape of the universe (whether “flat” or “curved”) the size of the universe (whether finite or infinite, with no edge) and the centre of the universe.

    • Photo: Marieke Navin

      Marieke Navin answered on 17 Jun 2010:

      That’s a tough one because where is the centre of the Universe?! Interstellar travel is going to be hard because of the vast distances and we can’t go very fast. It depends if we ever discover a way to do it, such as travelling down wormholes which is the stuff of science fiction at the moment…

    • Photo: Stephen Curry

      Stephen Curry answered on 17 Jun 2010:

      Based on our current understanding of physics (afaik), nothing can travel faster than the speed of light. Given that the universe is many millions (billions?) of light year across, it would seem to be impossible for a single individual to live long enough to survive the journey.

      Of course that assumes that we had the technology to get up to light speed. For comparison, the space shuttle gets up to about 7500 m/s after launch. Light travels at 300,000,000 m/s.

      However, I have heard talk of ‘worm-holes’ in space-time that might provide a short-cut from one side to the other but I’m not sure if they really exist.

    • Photo: Pete Edwards

      Pete Edwards answered on 18 Jun 2010:

      Hi Lucas
      This answer may give you a nosebleed 🙂 but we don’t think of the universe as having a single point as a centre. I know that whenever you see pictures of the birth of the universe in a Big Bang you see everything coming from a single point – but this isn’t what we think actually happened. At the Big Bang the whole of the universe came into existence. Everything we can see (and the bits that we can’t) began at the same time! So if our universe is infinite it was born infinite with no centre or edges. It’s true to say that we sit on the Earth at the centre of the visible universe – the bit that we can see – but most cosmologists believe that what we can see is only part of the whole thing!

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