Is the universe infinite or finite?

[Aupmanyav]

We need to REDEFINE existence or non-existence in light of Quantum Mechanics. It is not a question that can be answered with a simple yes or no.
This is EXISTENCE OR NON-EXISTENCE, whatever you choose to call it.
YOU (me too) are creatures of Quantum fluctuations. Every thing is that only, even the whole universe or all universes (if there are more than one).

 

[firedragon]

We need to REDEFINE existence or non-existence in light of Quantum Mechanics. It is not a question that can be answered with a simple yes or no.
This is EXISTENCE OR NON-EXISTENCE, whatever you choose to call it.

No. Read the OP. It is "Is the universe infinite or finite?"

 

[Aupmanyav]

A related question is whether there is any universe or not?
Or it is something only in our minds?

 

[viole]

This question comes out of curiosity to find the arguments of those who make both sides of the word "or". If this is a false dichotomy I would like to hear the other options to this as well.

A few atheists have been making a similar argument to "the universe is infinite" in this very forum when discussing the Kalam Cosmological Argument, which is the reason for this thought experiment if I may put it that way. Now before anyone derails the thread saying "this is a strawman" let me make it clear that this is not an atheists position in general, but a few do make this positive claim, thus what are the philosophical or/and scientific reasonings for this?

What philosophy? That is a scientific claim.

If relativity (general) is true, and observations of large scale flatness of the Universe are correct, then the Universe is infinite in extension. It would be also if large scale curvature were negative.

Ciao

- viole

 

[firedragon]

A related question is whether there is any universe or not?

Irrelevant.

But anyway you can do your rhetoric. I am no one to stop you. Have at it.

Cheers.

 

[viole]

If there was a beginning according to the Big Bang model, can the universe still be infinite?

Of course. When you hear "our universe was very small at the BB", they mean "our observable universe was very small at the BB".

Ciao

- viole

 

[ChristineM]

You meant Omega? OK OK. No problem. That was just a clarification. There is no need to get offended.

Who is getting offended? More frustrated at having to repeatedly repeat myself.

So bottomline is you are saying the universe is not infinite with a beginning but infinite in expansion.

No, i am saying, as i said in my first post that it is unknown. But feel free to think you are thinking for me

 

[RestlessSoul]

A related question is whether there is any universe or not?
Or it is something only in our minds?

So each mind is a universe in itself?

Or there is only one mind, and one universe, but one which is experienced subjectively by it’s various components?

I think the universe is a dream within a dream within a dream. And for there to be a dream, there has to be a dreamer; it follows that the dreamer must exist beyond or outside the dream, therefore beyond time and space. This dreamer we may choose to call God. And we may choose to think it benign.

Of course I cannot prove any of this, using science or anything else. Better minds than mine are coming close I think, and may one day do so. But probably not to the satisfaction of their fellows. So it goes on.

 

[firedragon]

Who is getting offended? More frustrated at having to repeatedly repeat myself.




No, i am saying, as i said in my first post that it is unknown. But feel free to think you are thinking for me

Thanks. Have a good day.

 

[viole]

Firedragon, what is the Kalam Cosmological Argument?

That is what Christians (and Muslims, etc. ) use when they realise that the evidence of their respective beliefs tenets is zero.

Ciao

- viole

 

[Tiberius]

If the universe is finite, what lies beyond the boundary?

A finite universe doesn't need to have a boundary. The surface of the Earth is not infinite, yet there is no boundary to it.

 

[Polymath257]

I am talking about this universe. If you wish, the multiverse "idea" could be discussed in a new thread.

In the context of a multiuverse, the natural question is whether the multiverse is infinite or not.

What about the entropy of a cyclic universe?

Think of the Borthe gorde vilenkin theorum. It says that the past eternal cyclic models are simply ruled out. Please provide an explanation to the conflict of cyclic universe model and the problems of thermodynamics.

Entropy is a statistical property. While it is far more probable that it increases, it *will* decrease if there is infinite time. The amount of time for it to cycle is around the Poincare recurrence time, which is finite.

So any proof based on thermodynamics (which is statistical mechanics) ignores that statistical property of things like entropy, temperature, and pressure.

Also, any such exclusion result has assumptions. It is quite possible for those assumptions to be wrong and for exceptions to arise because of that.

 

[Fallen Prophet]

Right. Got it. No energy or material in God's kingdom, only clouds.

That is not what I said at all.

Hey! You're that "prowling" guy who "polices" other RF members.

Way to stick to your brand bro!

You came in and offered nothing.

I believe that Chaotic Space is filled with energy and matter unorganized. It is chaotic.

God's Kingdom is organized - everything spiritual and physical - including the Earth and us.

Thanks for wasting my time!

 

[firedragon]

In the context of a multiuverse, the natural question is whether the multiverse is infinite or not.

Sure. Its interesting to discuss this in another thread and I can learn something.

Entropy is a statistical property. While it is far more probable that it increases, it *will* decrease if there is infinite time. The amount of time for it to cycle is around the Poincare recurrence time, which is finite.

So any proof based on thermodynamics (which is statistical mechanics) ignores that statistical property of things like entropy, temperature, and pressure.

Also, any such exclusion result has assumptions. It is quite possible for those assumptions to be wrong and for exceptions to arise because of that.

Let me try and explain my question. A cyclic universe should have reached thermodynamic equilibrium because of increase of entropy, but it has not. The universe might reach the minimum protocol for entropy exchange because it could also decrease the size of cycles. If the total effect could mean the arrow of time reverses. The idea of a cyclic universe leaves the BGV theorem aside. In fact it rules the cyclic universe out. Also consider the so called "space traveller" who if keeps travelling at a critical or non-critical increase in speed he will achieve the speed of light eventually. This according to the BGV model makes the past eternality an impossibility. It also makes eternal inflation with no beginning an impossibility.

Please do explain what your position is since you proposed the cyclic universe.

 

[RestlessSoul]

A finite universe doesn't need to have a boundary. The surface of the Earth is not infinite, yet there is no boundary to it.

A surface is a boundary, surely?

 

[ratiocinator]

A surface is a boundary, surely?

You misunderstand the analogy. The (2-dimensional) surface of the Earth has no boundary (you can't fall off the edge) and yet is finite. It is possible that the 3-dimnesional space of the universe is also finite but without boundary. Basically, in principle, if you travelled a very long way (further than the size of the observable universe) you might end up back where you started, rather than encountering a boundary.

 

[wellwisher]

This question comes out of curiosity to find the arguments of those who make both sides of the word "or". If this is a false dichotomy I would like to hear the other options to this as well.

A few atheists have been making a similar argument to "the universe is infinite" in this very forum when discussing the Kalam Cosmological Argument, which is the reason for this thought experiment if I may put it that way. Now before anyone derails the thread saying "this is a strawman" let me make it clear that this is not an atheists position in general, but a few do make this positive claim, thus what are the philosophical or/and scientific reasonings for this?

One practical problem with an infinite universe and a cyclic universe is connected to the second law. The second law states that the entropy of the universe has to increase. While an increase in entropy will absorb energy.

For the second law to be satisfied, universally, the usable energy of the universe has to be decreasing over time, since energy needs to go into entropy, which itself has to increase over time. Energy is being bled off into increasing entropy.

The energy being constantly bled off and lost by the universe, into entropy, will be conserved, but not in a net reusable way by the material universe, since the entropy of the universe has to net increase. The universe is not a perpetual motion machine as many seem to claim. The second law suggests a one time occurrence with a finite self life. The universe is like a living thing that ages due to the second law.

The question then becomes, what is nature of the energy stored within entropy? We know that it is not net reusable by the universe, due to the second law. Entropy is considered a state variable meaning any given state of matter has a specific entropy value that is measurable. Water at 25C and 1 Atmosphere, has a fixed amount of entropy that is always the same. In that respect, the energy within entropy is similar to specific information about a very specific state. We can retrieve some of energy in entropy, by simply changing the state; go to water at 20C and 1 atmosphere. However, we cannot get the entropy energy back while also leaving the state unchanged.

The living state, in general, and the brain, in particular ,generate a lot of entropy. The energy within that entropy, if conserved, would mean your essence or your many states of life and being; soul, are conserved by the universe within the universal entropy pool. The energy for that data storage come at the expense of the universe aging.

 

[RestlessSoul]

You misunderstand the analogy. The (2-dimensional) surface of the Earth has no boundary (you can't fall off the edge) and yet is finite. It is possible that the 3-dimnesional space of the universe is also finite but without boundary. Basically, in principle, if you travelled a very long way (further than the size of the observable universe) you might end up back where you started, rather than encountering a boundary.

Yes, I understand that. I also understand that the surface of the globe has potentially an infinite number of co-ordinates on it’s surface.

I’m not saying the universe has to have a boundary, because I have no idea if that’s true or not; but everything in the observable universe, including the surface of a globe, does have limits, which are definable by context.

For a form to be without limits, it must be without a centre. And it must be unmeasurable.

In your scenario above, one returns to one’s starting point by following the boundary.

 

[ratiocinator]

For a form to be without limits, it must be without a centre.

You seem to have slipped from boundary to 'limits' - not sure if you mean the same thing. The surface of a globe doesn't have a centre.

In your scenario above, one returns to one’s starting point by following the boundary.

No. You don't need an actual globe, in a third dimension, in order for the surface to make logical (mathematical) sense all by itself. The same could be true of the universe if it's closed in that way.

And it must be unmeasurable.

Don't get this at all. Why and in what way 'measurable'?

 

[firedragon]

A surface is a boundary, surely?

Whats a surface in the universe?

The earths sphere analogy is taken to express the horizon and radii of the universe taken into many equations like the hot Big Bang model. That does not mean you should take it so literally as if the universe is a globe like the earth with an earth crust and one could think of digging into earth as a boundary.