Is the universe infinite?

[OneArmedScissor]

Ok... I just got into a long discussion with a friend of mine as to whether or not the universe is infinite or finite.

 

I said it was sort of a mixture of both. Like a sphere inside itself. Or something you see off in the distance, but no matter how fast you run or travel, you'll never get to it.

 

His argument was that the universe was infinite... That it goes forever with no ends, etc.

 

Basically, my whole point was that it was neither, but shared properties of each (infinite and finite). His whole argument was that, "since you can never get to the end of it, that means it's infinite."

 

Anyways, any inputs would be appreciated!

[infamous]

Ok... I just got into a long discussion with a friend of mine as to whether or not the universe is infinite or finite.

 

I said it was sort of a mixture of both. Like a sphere inside itself. Or something you see off in the distance, but no matter how fast you run or travel, you'll never get to it.

 

His argument was that the universe was infinite... That it goes forever with no ends, etc.

 

Basically, my whole point was that it was neither, but shared properties of each (infinite and finite). His whole argument was that, "since you can never get to the end of it, that means it's infinite."

 

Anyways, any inputs would be appreciated!

These questions may never be answered with any absolute precision but the standard model views our local universe as a finite sphere. Nevertheless, our local universe may be contained within a larger megauniverse which may be infinite in nature. Hopefully this defination does not confuse things for you.

[C1ay]

The Big Bang model of the universe is finite. I personally believe the big bang universe is just an event in an infinite universe. We'll likely never know the real answer.

[OneArmedScissor]

I understand all that completely. But what pissed me off more than just about anything through the whole argument, would be that he would make these ridiculous claims/speculations. Whenever I would ask him how he came up with this, and that there is no evidence to support these claims at all, etc., he would just be like "yeah but you can't prove me wrong because you don't know".......................................................

I hate arguing with people like this. Why should it be my responsibility to prove you wrong when there is no evidence to support your claim in the first place? Most annoying thing ever.

[Harzburgite]

I hate arguing with people like this. Why should it be my responsibility to prove you wrong when there is no evidence to support your claim in the first place? Most annoying thing ever.

Unless you are practicing your debating skills the best policy is to avoid such people. There are plenty like that on forums such as this. (Remember to do as I say, not as I do :) )

[C1ay]

Why should it be my responsibility to prove you wrong when there is no evidence to support your claim in the first place? Most annoying thing ever.

It's not. It's the burden of the one making a claim to prove it. As the critic it is your responsibility to point out the holes in his proof once he provides one. It doersn't sound to me like you are arguing with a scientist.

[EWright]

The Big Bang model of the universe is finite. I personally believe the big bang universe is just an event in an infinite universe. We'll likely never know the real answer.

 

I'm sorry, but the Big Bang model does not predict a finite universe.

[C1ay]

I'm sorry, but the Big Bang model does not predict a finite universe.

You are saying the big bang universe has no boundary?

[EWright]

You are saying the big bang universe has no boundary?

 

No, big bang cosmologists say the big bang universe has no boundry. Certainly you've heard the comparative metaphore of an ant walking on the 2 dimensional surface of an expanding balloon. In those two dimensions, the baloon has no boudries. This is then applied to the third dimension, when referring to the infinite properties of the universe. It is generally difficult for most people to understand or conceive of in three dimensions.

 

As for the shape of the universe: flat, spherical, or hyperbolic. It is generally believed to be flat and infinite. The shape of the universe will ultimately decide its fate -- whether it expands for ever (the leading theory due to dark energy and an increasing rate of expansion) or collapse (if gravity can overcome dark energy and draw all matter back into a singularity via a 'big crunch').

[C1ay]

No, big bang cosmologists say the big bang universe has no boundry. Certainly you've heard the comparative metaphore of an ant walking on the 2 dimensional surface of an expanding balloon. In those two dimensions, the baloon has no boudries. This is then applied to the third dimension, when referring to the infinite properties of the universe. It is generally difficult for most people to understand or conceive of in three dimensions.

 

As for the shape of the universe: flat, spherical, or hyperbolic. It is generally believed to be flat and infinite. The shape of the universe will ultimately decide its fate -- whether it expands for ever (the leading theory due to dark energy and an increasing rate of expansion) or collapse (if gravity can overcome dark energy and draw all matter back into a singularity via a 'big crunch').

So you are saying that conclusions from WMAP suggesting the universe to be 156 billion light-years wide are incorrect? Do you also disagree with claims that the universe has a finite quantity of matter?

[Buffy]

So you are saying that conclusions from WMAP suggesting the universe to be 156 billion light-years wide are incorrect? Do you also disagree with claims that the universe has a finite quantity of matter?

Its the issue of the definition of "boundary": current cosmological models say its isomorphic which colloquially means "same everywhere" which translates into "everyone anywhere in the universe perceives they are at the center". No one is "near the edge." Paradoxically to we 4-dimensional beings--who oft times have a hard time even with 3 dimensions--this still means there is no "boundary" but it *is* finite and it *does* have a "measurable" diameter!

 

Go figure!

 

Cheers,

Buffy

[EWright]

So you are saying that conclusions from WMAP suggesting the universe to be 156 billion light-years wide are incorrect? Do you also disagree with claims that the universe has a finite quantity of matter?

 

I'm saying what the concensus among most cosmologists seems to be. I did read the 156Gy diameter article in SciAm a year ago and found it very interesting. But cosmologists need to then decide if they want to use this figure or the 13.7Gy figure that is most often quoted.

 

In either case, it doesn't matter. If you are going to say that the universe is finite, then you must be able to say what it is expanding into. But by definition, the universe is all that there is. It may be that what is beyond the observable universe is very different than what we see (though unlikely if you use the bb model). But in both cases it is believed, as I understand it, that the universe is still believed to be infinite in size in the sense that it wraps back around on itself and if you travel in a straight direction you will end up back where you began (after a very long voyage). If you do so, you may aquire 156Gy (plus added expansion) on your odometer, but according to bb theory you will not encounter an 'edge' of the universe as you do. And because the universe is expanding, and given the time it will take you to make the hypothetically plausible trip, you will not be able to return to the same "point" and that section of the universe will have likely changed so much in the given time that you will not recognize it. (We can say the Earth is xx,xxx miles around, but you will not find an 'edge' in your travels around the world.)

 

Let me stress that I am expressing the ideas of bb theorists as I understand them to be. This does not mean that my own theory agrees with them. It does, however, support the evidence they site and explains many of the events that the bb theory does not.

[C1ay]

I'm saying what the concensus among most cosmologists seems to be. I did read the 156Gy diameter article in SciAm a year ago and found it very interesting. But cosmologists need to then decide if they want to use this figure or the 13.7Gy figure that is most often quoted.

 

In either case, it doesn't matter. If you are going to say that the universe is finite, then you must be able to say what it is expanding into. But by definition, the universe is all that there is. It may be that what is beyond the observable universe is very different than what we see (though unlikely if you use the bb model). But in both cases it is believed, as I understand it, that the universe is still believed to be infinite in size in the sense that it wraps back around on itself and if you travel in a straight direction you will end up back where you began (after a very long voyage).

Because you can go around something and end up where you started, it cannot be infinite. If it were infinite you would never get around it.

[EWright]

Because you can go around something and end up where you started, it cannot be infinite. If it were infinite you would never get around it.

 

Your preaching to the choir, my friend. I didn't say I buy into the infinite universe idea per se. But the big bang model does not call for a finite universe. Take that up with bb theorists as well as the rest of the things they can't explain. I take issue with the theory too. It is your perception or interpretation that defines it as infinite (not the bb model itself), and in the context you describe, I would agree with you.

[tatwood106]

If there was no time or space before the Big Bang and the entire universe was a singularity then What did the singularity exist in? It had to be somewhere didn't it? If not space then what? If there was no space and time till after the big bang does place or when even apply?

[arkain101]

Well, just by reading your title it noticed some issues.

 

Infinite can imply a number of meanings. Infinite is size, infinite it time, infinite in speed.

 

 

My thoughts on this;

 

I find it difficult to comprehend anything existing, even existence itself, if it was not infinite. To suggest it is not infinite, leaves two unknowns before and after its existence. In fact, unknowns is not even a strong enough word.

 

However, you are referring to the universe. And I am going to assume you are referring to the current state that we observe the universe.

 

The universe will go through many changes, it always goes through changes. There may be possible states of the universe that you and I would not consider a universe, such as a singularity, or somthing to this kind of effect.

 

What I can propose is that the source of the universe as we see it today, the deepest, and most fundamental source, is infinite in the sense that it always was, always is, and always will be.

 

This most pure, deep, fundamental source, I consider should be unchanging. That is because if it, itself goes through changes, then it itself can not -as far as I can determine- be considered as the most fundamental ever lasting region of existence. If the essence of the most fundamental were able to transform, then I suppose we would be left with no fundamental identity, which would cause us to look deeper or conclude nothing lasts forever, and what does exist, is entirely random and chaotic needing no source.

 

However, it is difficult to imagine anything existing without a source, and respectfully difficult to think of a source requiring no preceeding source.

 

Because it is difficult to provide proof, I can for the most part only provide my own view. And my own view prefers a fundamental source, and that it be infinite, in how long it lasts, in how far it can reach, expand, or shrink. Infact, one of the only ways to warp our minds around this concept is to exclude these limitation types of ideas like time, and size and scale. Then, replace them with a conceptions of being, now, am, is, and are.

[arkain101]

If there was no time or space before the Big Bang and the entire universe was a singularity then What did the singularity exist in? It had to be somewhere didn't it? If not space then what? If there was no space and time till after the big bang does place or when even apply?

 

Oh I had just realized that this topic is actually a revival from 2005.

 

In response to you Tatwood, I suggest the following.

 

 

Imagine mankind never developed the ability to see, yet still managed to become quite intelligent socialists. I suppose we would require a low preditor environment to survive, :( , hah, but that is besides the point.

 

If we never conceived the idea of visual space, where would we consider anything exists, not to mention the universe.

 

This is actually a very useful though experiment to 'see' things in a different 'vision'.

 

We would very unlikely have formulated the idea of a universe, since we would never see any stars or horizons, or anything for that matter. However, given that we had the minds we do now minus our visual perception, it is expected we would still formulate the idea of something existing, what do you think that would be?

 

Ask yourself, Would it be any less true than the world we have come to "SEE" and "KNOW" as we are now, as visually able humans?

 

Ask yourself ,How true is visual perception? and does it have any more superiority over a definition of existence?

 

And furthermore, how true are any of our conceptions that define the universe and existence?

 

It is likely that things, otherwise known as reality can exist in all places, at all times, and it is our perception that has confined us to assume that it does not, therefore providing us with the very issue your provide here for us in your post.

 

Reality has truth on more than one level and those truths are not always true for each individual level. Reality has unique 'truths' to each respectful level.

 

This tells us that reality is both unified and separated at the same time, the choices of which are defined by the observer. It also tells us that reality is extended beyond our perceptions in many ways, and has truths entirely unknown to us.

 

This means the universe both exists, and does not, depending on the limits and restrictions that an observer places on the potential the universe contains.

 

In this respect, the universe is over, and beginning, and right now, all at the same time, but the only truth of which is more or less true is held in the observer itself.