On the edge of everything

[Xavier X]

Does anyone know, or can suggest, what you would see or encounter if you could position yourself right on the 'edge' of the universe - what would happen if you stretched out your arm? Physicists may claim that there's no 'edge' but you get my drift.

[fo3nix]

some theories are that there is an edge, but that it's moving at the speed of light. so, even if you were temporarily right next to the edge, you couldn't move your hand out in time.

[burnhal]

oh grief- that question that makes your mind go gaga!!! And if there is an edge- what is it expanding into- surely there cannot be something that is 'nothing'??????

[Xavier X]

Thanks burnhal I suppose that's my point, imagine you were sat on the photon that is defining the 'edge' of the universe and suppose you could reach out, your arm would be beyond the edge - so what would happen to it - would it disappear because it has no frame of reference in which to exist?

[RichiE-RicH]

it is pretty scary thinking about it. Would it be white or black? And its probablt sci-fi but if u wer to reach the edge would ther be like a parrelel universe?

[Zevon]

There isn't an edge, there can't be cos the universe is everything and therefore it cannot have an edge. The imagination is limitless so there is nothing we cannot imagine and the universe is limitless so there is no limit. It defines the limits and therefore has to be outside the limits. Physicists say there is no edge for rather complex, maths reasons but from a philosophical point of view systems go from the smallest to the biggest, the smallest has no lowrer edge and the biggest has no upper edge. the universe is the biggest system so it cannot have an upper edge, otherwise something could theoretically be bigger by excedding that limit. Now that's some ancient Greek Style Logic right there. Not sure if they actually came up with that though, i just thought it now.

[fo3nix]

Zevon: they don't all say that there's no edge.

Xavier: you could thousands of answers here, and they could all feasably be correct. No-one knows. Maybe no-one will ever know?

[jake-the-peg]

We may discover whether or not the universe has an edge.

If there's enough gravity it's closed and you'd travel all the way in one direction and end up where you started like an ant on the inside of a sphere - but in 3 directions.

There are complications in calculating whether or not the universe is closed like this because right now there is something called dark energy that we don't understand that seems to be messing things up a bit but I guess the Nobel prize committee need to be kept in a job so it's as well these things come up.

I think the balance of opinion at the moment is that the Universe is probably not closed like this. You could not reach the edge because it most likely expanded in it's early phase many times faster than the speed of light. (Although objects in the universe cannot break the light barrier as far as we know there's nothing that says the Universe itself cannot .

It's rather anybody's guess what would happen if you could get to the edge - very strange things happen in places like this - we know for example that in extreme gravitational fields concepts like time tend to break down and so therefore moving your hand (which takes time) would too. It's probable that this sort of effect would take place.

But even if somebody came up with a self-consistant theory - how could you ever test it?

[mibn2cweus]

What if you found yourself shaking hands with someone doing the same thing on the opposite side of the universe?

[Zevon]

What if the universe is shaped like a klein bottle, with no edge, inside or outside? Or a mobius strip, same ideas? A 3d and a 2d shape that have no edge.