[Closed] If the universe isn't infinite...

the matrix

It's circular innit?

Nothing. No space, no time, just nothing

Chuck Norris

another universe

another universe

And on the other side of that one?

Infinite universes?

all the socks and spare change i've lost over the years i assume as i've looked everywhere!

I've been trying to figure out what a void is, but I just can't get my head around it. Oh well, no matter.

Space isn't a vacuum if that helps. So maybe at the edge of space there is a proper vacuum, or maybe there is nothing, as in, no reality. You couldn't go there, because there is nothing there. Same as asking what comes after the edge of your computer screen.

It's circular innit?

You mean spherical? I'm not sure, something says it might be doughnut shaped, but please don't ask me why.

..then what's on the other side?

MBUK

..then what's on the other side?

Take a strip of paper, twist it one half turn then join the two ends.

[img] [/img]

You've just made a [url= http://en.wikipedia.org/wiki/M%C3%B6bius_strip ]Möbius strip[/url]

If you were travelling along the surface of this paper then you could travel all over it, to the exclusion of everything else. (i.e. there is no [i]other[/i] side)

So now imagine that, but in four (or more) dimensions...

Seriously though - it is impossible for the universe to go on for infinity, just as it is impossible for it to stop as surely there has to be 'something'.

And if it does stop and there is absolutely nothing on the other side, a sense of being absolutely nothing, how can the universe expand into it?

And another thing - how can we use biiiiiiiig binoculars and see back in time to the big bang?

It's a glass bubble - holding everything in, otherwise it'd all just fall out!

The universe and the planets are just atoms making up a really big chair leg.

Doesn't the Möbius strip have edges? (In which case, there's surely got to be something beyond the edge). Or is this a four-dimensional perception breakdown?

mastiles_fanylion - Member

The universe and the planets are just atoms making up a really big chair leg.

hope its not an ikea one!

Just outside the edge of the universe there's a car park, a BFO Argos, a KFC and probably a Carpet Right.

I'd just take it as infinite.

Unfortunately we aren't equipped as a species to imagine 4D surfaces!
Graham's Möbius strip or the inside of a sphere for a closed 2D surface are about the best examples that can easily be imagined.

But the original question is flawed - there [i]can't[/i] be another side unless the universe exists within a higher dimensional space. If the universe is everything, then there is no other side for anything to be on.

Harry_the_Spider - Member
Just outside the edge of the universe there's a car park, a BFO Argos, a KFC and probably a Carpet Right.

You forgot Nando's......!!!!

hope its not an ikea one!

The new life springing forth will follow their leader GÅD

GrahamS, mobius strips are too easy, check out a klein bottle.

Seriously though - it is impossible for the universe to go on for infinity, just as it is impossible for it to stop as surely there has to be 'something'.

And if it does stop and there is absolutely nothing on the other side, a sense of being absolutely nothing, how can the universe expand into it?

And another thing - how can we use biiiiiiiig binoculars and see back in time to the big bang?

The universe currently has a finite size, which is fairly simple to work out, although you do have to make a few assumptions. Assumptions withholding, the universe will never reach infinite size. Stuff in reality doesn't tend to reach infinite anything, as it's more a mathematical concept. Reality has physical limits.

If there is nothing on the other side, surely it should be easy for the universe to expand into it. Much harder if there was something, surely? Really though, who knows. Go get a degree in astrophysics and come back and tell me.

The whole looking back in time thing only works if you can move faster then the speed of light. We can't do this normally, so how about we assume we can use worm holes or something to move huge distances very quickly. So you move out 100 lightyears away from earth, in the space of a few seconds. You then get a mega powerful telescope, and look back at earth. The light that has left earth 100 years ago is just reaching you now. So you can see, with a birds eye view, what happened 100 years ago. Simples.

If there is nothing on the other side, surely it should be easy for the universe to expand into it.

This (without Shakin Stevens)..

[img] ?w=252&h=200[/img]

Yeah, but you could build an extension on to the house, assuming there aren't trees in the way.

I fear this analogy may have already gone to far.

But if the universe is expanding, it has to be expanding into something. At least, that's what normal human logic tells us. My opinion is that normal rational thought can't really be applied to the concept of the universe.

The expansion of the universe - surely - would erase the existence of the house's exterior wall and outside impediments (trees). A wall would appear further away, the house would have three bedrooms and IKEA furniture would sprout out of nothingness - and disintegrate four months later.

Doesn't the Möbius strip have edges? (In which case, there's surely got to be something beyond the edge). Or is this a four-dimensional perception breakdown?

Yeah, it only really represents one metaphorical dimension. It's a struggle to imagine what a two-dimensional version would look like, never mind our own 3-dimensions + time + whatever unknown dimensions we are subject to but haven't yet discovered.

My opinion is that normal rational thought can't really be applied to the concept of the universe.

Yeah, also our level of education and understand holds us back a lot. Might as well ask what neutrinos smell like or something. Nothing wrong with trying though.

Yeah, it only really represents one metaphorical dimension. It's a struggle to imagine what a two-dimensional version would look like, never mind our own 3-dimensions + time + whatever unknown dimensions we are subject to but haven't yet discovered.

KLEIN BOTTLE. It's a 4 dimensional mobius strip embedded in 3 dimensions.

[img] [/img]

RealMan - Member
Yeah, but you could build an extension on to the house, assuming there aren't trees in the way.

And another thing - how can we use biiiiiiiig binoculars and see back in time to the big bang?

We can't?

KLEIN BOTTLE. It's a 4 dimensional mobius strip embedded in 3 dimensions.

I so want to understand what that means...

We can't?

Theoretically, you could (I think - just). Do you read anything I write? 😉

Well yes, you can build an extension because there IS something outside the house...

Yes, but what does a neutrino smell like? The other side of the universe is not something we are really able to understand I think. It's fairly simple to accept there is nothing there, and hence it is easy to expand into it. All depends on your idea of nothing, though.

And another thing - how can we use biiiiiiiig binoculars and see back in time to the big bang?

Because there are still radio waves emanating from the big bang, and becuase there are certain events, like collapsing and exploding stars which have certain similarities to the start of the universe. At least I think that's what PBC said...

Camo, have a look here.

http://en.wikipedia.org/wiki/Klein_bottle

I think it's actually 2 mobius strips combined, to make a 4 dimensional object that exists in 3 dimensions. Or something.

TRIPLE KLEIN. Don't look at it too hard, it starts to hurt your brain.

[img] [/img]

RealMan, I have looked.

I kind of get the no right or left and no boundaries concept, but isn't there still an outside?

Theoretically, you could (I think - just). Do you read anything I write?

I do. But I disagree.

You [i]can[/i] use a big telescope to magnify the image of a very distant, say 100,000 light years away. And yes you are looking at a 100,000 year old image of that star.

but you can't look back to see the big bang, because (unless the universe is expanding faster than light) the light from the big bang is at the very edge of the universe so you'd have to leave the universe to observe it.

Not in any mathematical definition of the word. Think of a hollow sphere (like a football). It's got an inside, and an outside. A klein bottle on the other hand, doesn't. If you put your finger on the surface anywhere, you can draw your finger along the surface to anywhere on it. You can't do that with a football.

[img] [/img]

...then what's on the other side?

Being thick at the proverbial two short planks, has its advantages here, by answering this question 'I don't know' I am able to get on with my life in blissful ignorance 😉

camo16 - Member

And on the other side of that one?

Turtles all the way down ????

I kind of get the no right or left and no boundaries concept, but isn't there still an outside?

This is why I like the Möbius strip - it's a simpler metaphor.

We naturally expect a piece of paper to have two sides. But a Möbius strip demonstrates that isn't always the case - it only has one side, because the plane is twisted through another dimension.

but you can't look back to see the big bang, because (unless the universe is expanding faster than light) the light from the big bang is at the very edge of the universe so you'd have to leave the universe to observe it.

Yes, that's why I said "I think - just". But I have a feeling the universe does expand quicker then the speed of light, so you would be able to. And theoretically, you could put a completely 2 dimensional mirror against the edge of the universe, then look at that through a telescope, to see the big bang (if the light from the big bang had only just reached the edge).

This is why I like the Möbius strip - it's a simpler metaphor.

Yeah, but the klein bottle is a cooler metaphor 😀

Space isn't a vacuum if that helps. So maybe at the edge of space there is a proper vacuum, or maybe there is nothing, as in, no reality. You couldn't go there, because there is nothing there. Same as asking what comes after the edge of your computer screen.

🙂 Beautiful.

We naturally expect a piece of paper to have two sides. But a Möbius strip demonstrates that isn't always the case - it only has one side, because the plane is twisted through another dimension.

So (and here I'm inviting sighs and 'what are you, a numpty?' comments) the point of the möbius strip and klein bottle is to emphasise how such concepts as direction, edges and boundaries can become blurred/meaningless?

And, therefore, that while the universe may not be infinite it might have no edges?

** Baby steps being taken here **

Big Bang

😆

We don't know.

The expansion of the universe is not an outward expansion it is the growing of distance between objects in the universe over time.

Therefore it does not have to expand into anything other than its self. Thats if it is expanding, which might not be the case, it may just look like it is and actually be smaller that it measures.

Big Bang
😆

🙄 Feel free to offer your own competing theory dd.
It's the best model we have so far in our limited understanding.

It's the best model we have so far in our limited understanding.

😆

So some things in the universe are small and some are far away [i]at the same time[/i]?

Obviously dd, some people's understanding is more limited than others. 😉

I know G! There's no need to feel bad about it mate. 😉

I don't.

I will always have that faint hope that one day you might read a book 😛

the universe expands from all points, everything gets further away from everthing else, its the 3d equivalent of the 2d surface of a ballon being inflated. Draw a face on a balloon then blow it up and the features expand away from each other. Because of this the big bang occurred not just in the distant "edge" of space but everywhere in the universe is the point of the big bang. Physicists just try to observe the BB at great distances as the further you look the more back in time it is, nothing to do with the big bang being far away.

The surface of the balloon theory like the mobius strip is an aid to understanding the no edge theory of 3d space too, as this is beyond human comprehesion unfortunately, well mine anyway.

Interesting replies all.

I had this down as a philosophy question, but the beard strokers have been clearly outnumbered by the physics guys...

** determines to print thread off and digest, whilst stroking beard earnestly ••

Is the Klein bottle really a bottle? Can it hold anything? If the inside and the outside are all linked then won't stuff just fall out?

Is the Klein bottle really a bottle? Can it hold anything? If the inside and the outside are all linked then won't stuff just fall out?

Have a look at it, there's plenty of pictures here already. It's pretty obvious you can hold stuff "in" it, and maybe even drink out of it. A straw would help though.

I assumed it held aftershave. 😀

...an infinite amount of aftershave?

😯

http://www.kleinbottle.com/

http://www.kleinbottle.com/drinking_mug_klein_bottle.htm

http://blog.blazingangles.net/whatsthis/2007/08/never-spill-your-drink-again.html

I expect to purchase a Klein Bottle one day, primarily because I want to be able to accidentally spill my drink right onto the table outside of the Klein Bottle drinking glass, expecting the drink to appear inside of the glass nonetheless. I'm just hoping that the zero-volume property won't prevent me from drinking from the glass which, by definition, will always be empty.

I almost bought one the other day, purely because they are awesomely nerdy.

.then what's on the other side?

[img] [/img]