[KholdStunner]

i was recently reading a book called 'The Universe In A Nutshell' by: Steven Hawking. He said that the universe DOES end somewhere. He knows this because if the universe was infinit then that means everywhere we look there would be a star, and the night sky would be as bright as the sun.


so in other words if the universe went on forever then there would be a star EVERYWHERE we look. But there isnt. So the universe must end at some point

[Macroscopic]

It wouldn't be any different than now. The light from all the stars wouldn't all reach us. Also it could be infinite by folding over on itself, so when you go far enough you reach your original point. Like the surface of the Earth; it seems like you're going in a straight line, but you're actually going in a circle.

[KholdStunner]

actually there r no theories that even imply that that could be possible. the universe could be flat, spherical or curved, like a horse saddle. Those r the only theories that scientists accept. Ive never heard of an over-lapping universe. how would that be possible? the shape of the universe depends if its at critical density. if its below critical, above critical, or ON the critical density point. i forget what shapes go with what but i THINK i remember its this:

-if its above critical then its shape is spherical
-if its on the critical density its shape is flat
-if its below critical density its like a horse saddle

-like i said, im not sure which shape goes with what, but those r the possibilities.

[ydoaPs]

universe in a nutshell is old pop-sci. it isn't as simple as sphereical or saddle. above critical=+curveature, below=-curvature. if you haven't heard that the universe could be infinite and curved in on itself, then you may want to try harder.

[Cadmus]

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i was recently reading a book called 'The Universe In A Nutshell' by: Steven Hawking. He said that the universe DOES end somewhere. He knows this because if the universe was infinit then that means everywhere we look there would be a star, and the night sky would be as bright as the sun.


so in other words if the universe went on forever then there would be a star EVERYWHERE we look. But there isnt. So the universe must end at some point

I think that you must have misunderstood what he wrote. I say that because it cannot be correct, I think. If the Big Bang appears to be 14 billion years old, and there is a limit to the speed of light, then any light from a distance greater than a certain distance will not be reaching us. What good are godzillions of stars if they are so far away that their light does not reach us?

[KholdStunner]

the universe isnt expanding faster than the speed of light, so the light would have reached us by now, no matter where the star is.

[Cadmus]

KholdStunner said:

the universe isnt expanding faster than the speed of light, so the light would have reached us by now, no matter where the star is.

I think that you are working under an arbitrary assumption, which discounts the popular idea of inflation.

For you to make this statement, I believe that you must accept the idea of the Big Bang, 15 billion years ago. However, if the universe is only 15 billion years old, then how could it already be infinite in size and filled completely with stars?

[KholdStunner]

EXACTLY. it isnt infinit, thats what im trying to say. IT ENDS. it couldnt be infinit in size, thats what im trying to say. If its expanding from the big bang then it CANT be infinit.

[Macroscopic]

KholdStunner said:

Ive never heard of an over-lapping universe. how would that be possible?

It's based on the idea that space is curved. If space is curved than it has to be. I like the idea because, as I said in my signature, I can't understand how the universe could be infinite or how it could be finite, and this idea solves that problem.

[Cadmus]

KholdStunner said:

EXACTLY. it isnt infinit, thats what im trying to say. IT ENDS. it couldnt be infinit in size, thats what im trying to say. If its expanding from the big bang then it CANT be infinit.

I am afraid that I don't follow how it cannot be infinite in size because it is expanding from the big bang.

[ecoli]

I see one immediate problem with the way we teach the big bang theory.

The way it was explained to me, is that it was a small rubber ball sized...well...ball, floating in space. It was Incredibly dense, inside is all the matter that is still in the universe today, if not in the same molecular form as today.

Ok, given this. is it actually a ball floating in space, or is it not floating in anything? Remove the space around the ball...you are just left with the ball...nothing outside. Is that a more accurate picture.

Oh dear...i think I've just created more questions then answers.

[Macroscopic]

KholdStunner said:

it couldnt be infinit in size, thats what im trying to say. If its expanding from the big bang then it CANT be infinit.

Space wasn't created at the big bang. Space is three dimensions, and an explosion couldn't create a dimension, no matter how big it is. The big bang didn't make space, so you can't say that space isn't infinite because of the big bang.

[Cadmus]

Macroscopic said:

Space is three dimensions, and an explosion couldn't create a dimension, no matter how big it is.

How do you know this?

[Macroscopic]

Cadmus said:

How do you know this?

How could it be possible for an explosion to make a dimension? An explosion is just a physical event, how could it create a dimension?

[Cadmus]

Macroscopic said:

How could it be possible for an explosion to make a dimension? An explosion is just a physical event, how could it create a dimension?

Space at the time of the Big Bang can be conceptualized as a point. Upon the bang, space expanded linearly, etc., etc. Linear motion of space upon the bang constitutes a dimension, does it not?

[Macroscopic]

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Originally Posted by Macroscopic
How could it be possible for an explosion to make a dimension? An explosion is just a physical event, how could it create a dimension?

Linear motion of space upon the bang constitutes a dimension, does it not?

What's your point?

[Cadmus]

Macroscopic said:

What's your point?

The point is the linear dimension did not exist before the big bang, and did exist after the big bang. Therefore, it is possbile to consider that it, and other dimensions, came into existence with the big bang. This statement is contrary to your statement. My point is that I think that your statement in the earlier post is not necessary.

[Macroscopic]

Cadmus said:

The point is the linear dimension did not exist before the big bang, and did exist after the big bang.

What is this 'linear dimension'?

[The Holy Mol]

I think that space is infinite. Space is just the void that our planet and every detectable and as of yet undetectable 'thing' resides in. It's like an ant climbing around on a leaf that's drifting in the current with a large tree in an infinite ocean. The ant is the human species, the leaf is earth, the tree is the universe and the ocean is space.

I think that the matter inside of space is finite--to an extent. There may be an infitine number of other trees floating around out there.

I think that just being able to somehow detect the edge of our own universe will be a big accomplishment. So far the trend is that the further back we look the newer everything is. Soon there's only going to be dust, which is hard to detect without an energy source being emitted from behind it.

If not for the space dust and innumerable other objects and debris and phenomenon, our sky would already shine like daytime. I read this somewhere, a search on star formation or something should give some info.

[soulestada]

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so in other words if the universe went on forever then there would be a star EVERYWHERE we look. But there isnt. So the universe must end at some point

This is called Obler's Paradox. I think that maybe if the universe is infinite, then maybe there are stars that are hundreds of billions or trillions of ly away, and that maybe their light has not reached us yet.