Is ours an infinite universe?

Question

I struggle with the concept of infinite, having never seen anything that is infinite. Is our universe infinite, with infinite possibilities? or not? or just VERY big?

Answer 1

If this universe were infinite it couln't also be expanding. Think about it: in what could an infinite universe expand? What Space would it be continuously taking up? That of Infinity that contains it? It itself would be Infinity.

(As it is, this universe is finite but expanding, and the further back you go the more finite it was, and the further forward you go the less finite it gets, but it can never be infinite. That which contains it is infinite, for if even that be finite, another space would contain it in turn - and how can space be contained within another space - it can only be the same, one, Infinite Space).

Answer 2

You can look at this infinite universe problem in terms of dimensions.According to Steven Hawking the universe is like the two-dimensional surface of the earth but with two more dimensions (3 space and 1 time).On the surface of the earth a man can start walking and keep walking forever without ever encountering a barrier or boundary even though the earth's surface is finite.He might, because the earth's surface is finite, eventually come across some places again and again.The universe is a four dimensional analogy of this and the idea is known as the No Boundary Proposal.The 4-D universe is very big and finite but in three dimensions the future space traveller can explore the universe in his spaceship and never come to the edge.

The only infinite universe would be an infinity of finite universes like our own-the biggest multiverse.Since we cannot confirm the existence of other universes it's best to apply Occam's razor and not speculate about what we may never be able to verify and instead work with what we know is true or at least testable ie phenomena in our own universe.

So to answer your question the universe is just very big and expanding but to a 25th century astronaut given the task of mapping it it would seem infinite.

Answer 3

Just looking at our nearest planetary neighbours for a second. Remember at school when you learnt about the planets and they were drawn in a line? the big sun at the left hand side of the page all the way across to pluto on the right? They weren't drawn to scale. If they were then, if you had the time and patience to do it it would look someting like this.

If you started at earth, the size of a pea, jupiter, to scale would be 300 meters away and pluto would be 2.5 kilometers away (and about the size of a bacterium). on the same scale, our NEAREST star, proxima Centauri, would be 16000 kilometers away.
If you stood on pluto and looked at the sun (our sun) then it would be the size of a pinhead. We're only talking here about our own solar system!
The universe is so unimaginably huge that we simply cannot comprehend it's size. No human being will ever be able to travel even outside our own solar system because, even at the speed of light (which we're nowhere near achieving) it would take thousands of years. Just reaching the centre of our own galaxy would take longer than man has existed for.
Now here's the mind blowing bit..........We can't even imagine getting outside our OWN solar system...it would take millions of years to travel there.
In our little bit of space..the milky way, no-one knows how many stars there are, probably between 100 and 400 billion and the milky way is only one of 140 billion or so other galaxies many larger than ours

So to all intents and purposes we can say the universe is infinate in size because we are unable to measure it in any way we know.
However..our whole universe may be just a speck of dirt in a giants fingernail.....we just never know.

Answer 4

Nothing can truly be infinite, beyond the universe is something else entirely. Maybe existence of things out there is infinite but not the universe, as that wouldn't allow for other things to exist,which would mean that the posibilities availble were not infinate, which i believe they are.
Sometimes it is best not to dwell on such things as they can have no relivence to your life.

Answer 5

I think you put it very well yourself - "I struggle .....etc".

I have never come across anyone who could define "infinite" to my satisfaction. Oh, it's used colloquially in any number of situations, but I reckon our minds are not sufficiently advanced to encompass the true meaning of the word.

There is no doubt that the universe is very big, but just HOW big seems to be the problem !

I'm not sure that NOMAD is correct, i.e. that there could be something beyond our universe. But I reckon he has a point, in that we shouldn't dwell too much on something it is presently impossible to understand or comprehend !

Answer 6

aah I struggle with the concept 'ours'

Mine is infinite -

when I meditate on never-endingness I get a wavy sort of dissociated feeling so maybe my mind is not geared up for such exercises in imagination which doesn't mean it isn't true just that I am not the right instrument for seeing it.

But if it is still growing it is hard not to imagine it growing into a space and is that space part of it?

Answer 7

I think that we could measure the event of the known universe by multipling the estimated age since the big bang by the speed of light and get a rough estimate to the size of the known universe, then adding in its estimated rate of expansion.

Question is...what are we expanding into.

I dont think we have a frame of refrence to even begin asking this question, nor a means to ever find out.

Answer 8

I love these kind of questions. I too used to drive myself crazy trying to figure out "where does the universe end ? And if it ends there, there has to be something beyond that, and that...Illogical !! When I fell in love 5 years ago and I was in a magical state of mind where I felt like everything made sense, a thought came to me. The universe ends as far as WE take it.

Answer 9

My belief is that Universe we can see, is a part of God.
If there is an end /as in boundary/ to this Universe, this must logically be the end of God and most probably another God is starting its existence near by - having no influence on us.
I comprehend the above as relationship between Micro and Macro worlds. The Micro life say in one brick, is independent of Micro life in another brick. But both bricks are necessary part of Macro life - say the house and people and the cat living in it.
Do we have microscope powerfull and accurate enough to detect life on one atom of a brick?

Answer 10

If we can ever know what is after this
Let us assume this Universe is in a BIG SPHERE so we need t know what is there outside this sphere till then it is infinite