Space

[Yai]

There are a few things I just can't understand about 'space'. What was here before the big bang ? Why did the big bang happen ? Why is 'space' here in the first place ? How can there be no edges to space, ie. how could you just fly forever and ever and never stop, just keep going further out and never reach an end ? (When I say space, I don't mean the universe, I know that that's constantly expanding, but is expanding into 'space'.) My head hurts :(

[bernardo]

What was here before the big bang? There wasn't anything "before" the big bang, because the big bang was the point at which time started.

Why did the big bang happen? Why not? Life would be much more boring if it hadn't happened.

Why is space here in the first place? Where else would it be?

How can there be no edges to space? Space is a bit like the surface of the earth: if you carry on travelling, you end up just going round and round, and keep finding places you've been to before. The surface doesn't need any "edges" because it wraps around on itself. Space is a bit like that as well: if you go out into outer space and keep going for zillions of years, you will eventually come back to Earth. Thus it is possible for the Earth to have a surface of a limited size (and it is possible for space to have a limited size) without necessarily having any edges or boundaries.

The universe isn't expanding "into" space, because "space" is an essential ingredient of the universe itself. If you zapped the universe out of existence, there wouldn't be any empty space left, because that would itself be a sort-of universe. Otherwise it would be like having the surface of a balloon still existing even after the ballon itself has been popped.

[robber1]

People more intelligent than us have ideas regarding all of this, but the true answer must simply be "no one knows". I understand when you say that your head hurts when you think about it, because its normal. The whole thing is beyond human comprehension. Maybe in the future we will gain more knowledge to help us solve this.

[woofgang]

Stephen hawking's books are really helpful, even though I can only read then one sentence at a time, he seems to be able to explain things clearly

[Quizmonster]

Click http://map.gsfc.nasa.gov/m_uni.html for a website that might help. Once there, there are lots of links, coloured red or green, that deal with some of your points.

[Yai]

Thanks for the answers, particularly bernardo. So, if space wraps round like you described, and if the universe is constantly expanding, isn't the universe one day going to have to stop ? Also, earth has a limited size and it is inside space, which also had a limited size, so what is space inside of ?

[TommyC]

The truth, as Robber has already indicated, is that in fact, no one really knows the fully accurate answers to all these questions, because tied up inexorably with this topic (and many others) is the simple truth that even the most brilliant scientists (and evolutionists, and doctors) don't actually know quite as much as they think or pretend that they know. But to suggest or admit this simple fact openly is tantamount to heresy for some people. The "best guess" based on available evidence (often very little) is often all we have to go on with questions like these, and all indications from the available eveidence are that, to all intents and purposes, space is in fact, "infinite", (at least as far as our frail and limited minds are capable of grasping), and the universe is indeed "expanding" at the speed of light into it. Where that leaves the "location" of space and its exact makeup is open to further interpetation...!!

[bernardo]

So, if space wraps round like you described, and if the universe is constantly expanding, isn't the universe one day going to have to stop ?
Not necessarily. If you carry on blowing up a balloon, it just gets bigger and bigger, indefinitely. The surface of the ballon is like space. Imagine the balloon has lots of bits of stuff stuck onto it, like grains of sand. They are like the galaxies in the universe. As the ballon expands, the grains of sand get further and further apart. As the universe expands, the galaxies get further apart.

Also, earth has a limited size and it is inside space, which also had a limited size, so what is space inside of ?
The balloon is a two-dimensional surface curved around within a three-dimensional space. The universe is a three-dimensional surface curved around a four-dimensional hypershere. Elsewhere, unknown to the grains of sand on the balloon, there may be an entirely different balloon somewhere else in the same space. There may be other universes in a higher dimension of space. One theory is that the universe is only one "bubble" in a boiling froth of millions of other bubbles. Each one is a different universe, and they make up a multiverse. Some of the individual bubbles within the froth may last a long time; others may pop or combine with each other.

[incitatus]

Tommy- a word or two about how science works. science is a model that allows you to make predictive statements. it is constantly refined, but no one doing science properly would say that they fully beleived what they were saying was the absolute truth, because science does not deal with absolute truths. Because there arent any. What it does deal in is prediction and testing. So the current "rubber sheet" model of the expanding universe allows us to make accurate predictions about the way the universe works. As such it is more correct than newtons universe, and very much more correct than the idea of angels pushing globes arround. that isnt to say that the angels dont push the globes around, but at the moment they are behaving as though they were a rubber sheet. It could all be the pixies. So we have a developing model. This doesnt seem to satisfy many people, all of whom want "the truth" (which doesnt exist) and so they come out with bitter little statements like yours. The way scientists deal with a conflict of ideas is to test the opposing theories till one of them fails. I would be interested in hearing your cosmogenic theory.

[Waterwolf]

One small question, Incitatus. Forgive me if I'm missing something really obvious here, but surely there must be some absolute truths? I mean, either the 'rubber sheet' model of the universe is or isn't correct, even if science cannot ultimately prove it either way. (Understand that it's not my intention to attack science in this post.) Surely there is a description of the universe that corresponds to 'the truth', even if we can only test theories about what that description is?

[incitatus]

but you said it yourself, wolfy, an absolute truth requires proof. and proof is impossible outside of mathematics. only disproof can be managed. And even if you find a perfect model it will not fit at all levels because the universe itself is inconsistent, and at the smallest level varies according to wether you are looking or not.