The Universe

[docklands77]

According to my limited knowledge of astronomy, the universe is finite. So, could someone explain to me, when you are travelling in your spaceship and arrive at the 'end' of the universe, what is on the other side? Please don't say its like a mobius strip! Layman's explanation also would be widely appreciated.

[Gef]

Easy answer to give - the universe is infinite!

[lisaj]

... however, since gravity drops off at an inverse exponential rate with a linear increase in distance, it follows that it (gravitaional attraction between two objects) becomes small, but never zero. This would imply that the universe will eventually slow down, stop and begin to contract again at an ever increasing rate. With regards to its size, it's as good as infinite as far as mankind is concerned, irrespective of mathmatical precision: it's so ridiculously, incomprehensibly large!

[rekstout]

As time, as we know it, can only exist within the context of this universe, if one did move beyond the extent of the universe, time would cease to exist - so you wouldn't be able to percieve anything beyond it. Just an idea.

[DavidUK]

lisaj - that's what was thought, but I believe that some recent measurements have shown that the rate of expansion is increasing not decreasing, although no-one can understand how this can be.

[Andromeda]

Rekstout, love your answer. Not an angle I had previously thought of. David, I think it is all to do with whereabouts we are in the Universe life cycle. Relatively speaking if we are close still to the 'big bang' then the force of that will be fueling the increasing rate of expansion. Whether or not this will finally top out, and then slow down the expansion enough to start contraction depends on the type of universe we are in. There is some lovely mathematics that shows what would happen. This is of course I you believe the big bang theory. There is still some evidence to suggest the steady state theory, although I believe this is being discredited now.

Andy

[docklands77]

but...... what's outside this massive universe? if the universe is an expanding balloon, whats on the other side? can anyone explain this by way of analogy?

[Mintox]

plus we would die trying to find out as it would take soooo long to get there.

[rogersaurus]

GRRR! As negative as TW (and other Answerbankers in the past) are about the human race (we are all stupid, we are all evil, we bring death and destruction everywhere we go etc.) it is likely that we WILL know the answers sometime in the future (not us personally, but our decendants) and then people like TW will have to accept that we aren't completely useless and our existence isn't pointless, and hopefully all this over-dramatic negativity towards the human race will stop. We primative, pathetic beings (ahem) managed to knock up a piece of kit called the Hubble telescope which has enabled us to view star systems millions of light years away, towards the edges of the universe. I see the universe as both finite and infinite, depending upon your definition of the universe. If you classify it as the extent of matter (stars, planets etc.) then it is finite and expanding. If you regard the vacuum of space as a physical component of the universe, then this may well be infinite (where you would include 'dark matter' in this is subjective). After all, if there is nothingness beyond the edge of the universe, would this not be viewed as more vacuum, more empty space, an extention of the boundries of our universe? If there is a physical boundry, do other universes lie beyond it? We don't know, YET.

[docklands77]

one of my theories on this is this. if we did actually find out what is beyond the universe, we might also discover why we are here, who is "god" etc. etc. so i think it might be possible that we will never find out.

[TheHitMaker]

Er, the way I've always understood it the universe contains everything - by definition. Therefore there is nothing outside it - neither time, distance or objects - nothing. Whether it is infinite or not is irrelevent - there is nothing outside it, 'cos if there was, then the universe would get bigger to include it.

[rogersaurus]

Great point TheHitMaker. The dictionary definition is "everything that exists, everywhere" (Dictionary.com).

[thoma?]

my theory is that at the edge of the univers, there is a nether region where nothing exists. in this nether region, there are an infinate number of universi(plural?). each universe is encapsulsted inside a wall. using the big bang theory, i say that the reason that the universe imploded before exploding was because the universi grew to big, and started to compress each other back to the big bang stage. I think the last bit needs some work, but thats my idea. comments?

[xyzzyplugh]

How could it expand - if it's infinite?

[Andromeda]

xyzzyplugh - good question. I've often wondered about that. But from observation and calculation it is shown that distant objects are receding from us faster than nearer ones - e.g the Universe is expanding. So is our posit that the universe is infinite wrong? If we take TheHitMakers excellent point, then it is indeed irrelevant. Erm, I think I need more help at this point. I seems to have argued myself into a certainty of a winter death for the universe rather than a big crunch. Hmm.

Andy

[docklands77]

does it really matter or not whether it is expanding or not? surely at the edge of the universe i would still be able to continue in my very fast spaceship? the other thing that is bothering me is - what is inside a vacuum? if there is nothing, does anyone know what that "nothingness" consists of?

[xyzzyplugh]

inside a vacuum is a dustbag, unless you own a Dyson.