Why universe can be infinite

Cosmologist call our Universe finite but unbounded. Einstein showed that spacetime was created with our Universe(though he did not know this at the time). The Universe does not exist within a separate space, it IS spacetime. The estimates I have seen is that the Universe is currently about 43 billion light years in size but this gets kind of weird because there are no edges(that's what unbounded means, no boundaries). The even weirder thing is we can currently see all of it, even though we see it as approximately 28 billion light years in size(the photons we see were released from the material ~13.5 billion years ago but that is from both sides of any straight line drawn through Earth). It has grown substantually since then, we just can't see it in the present and some of it has passed over the light horizon by now(IE the stretching space between us and them means we are traveling faster than light relative to them and vice versa). IOW if you started travelling in any direction at the speed of light(the Universes speed limit)you would never reach the farthest galaxies we can currently see as they are receeding from us faster than light(at the present moment, despite appearances of their current speed). The weirdest thing of all is that every atom in your body was once at the exact position of the Big Bang and that is true for every atom in the Universe. And what we see 13.5 billion years ago/away spread out over the sky once occupied a space smaller than a hydrogen atom. Just sayin'.

Grumpy

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Small scale infinity.

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:crazy:

 

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The universe is not infinite.

Infinity + 1 = infinity

 

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Careful. That is 'true' in abstract axiomatic mathematical sense/construct.

The universe is not so 'constructed/abstracted' in reality.....so your expression there can say nothing definite 'physically' about the universal state regarding finity or infinity of 'extension' in real (not abstract) energy-space context(s) that may turn out to be 'singular' or 'plural' energy-space context(s).

That is yet to be determined.

Cheers!

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the Universe is infinite

because energy and matter are infinite

for the Universe to be other wise is not reasonable

 

IMPO . . . . . the total universe (energy) is probably infinite . . . and the material (matter+less energy/observable) portion of the universe is finite and 'bounded' by the "outer" quasi-interface (~ 13.8 bly) existing near the 'energy-only' and the 'matter+less energy' transition front.

(For James: IMPO may = "In My Professional (or Philosophical) Opinion")

 

@RealityCheck

That's similar to what I commented previously in this thread.​

 

It would be interesting to know IMO how then the "material" portion of the universe which is finite 'connects' to the infinite energy-only portion of the universe and how indirectly.

 

My apologies and respect, Big Chiller!

I was just 'surfing through' and billvon's "infinity + 1= infinity" expression caught my eye in passing. So I stopped and made the cautionary remark that I did.

I aknowledge your priority and give credit to you unreservedly for the salient point made. Kudos!

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Cheers.
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@RealityCheck

Don't sweat it no apology required I appreciate your input similar to mine in this or other threads.

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​

 

BC . . . sorry, I can't 'speculate' here (Prom) and I can't 'self-promote' (AN and JamesR) . . .but have a look at Alternate Theories (Sciforums) sometime . . .

 

The Universe MUST be infinite. There is no wall at the "edge." Saying that there is an end to the Universe is like saying the Earth is flat!

 

Well, we have a pretty good idea that it is finite - not due to any mathematical construct, but just because there is a limit to how far _anything_ can propagate from a point in time 14 billion years ago. (Even accounting for expansion.)

 

The term universe is of the object the universe. It's like saying "galaxy" only larger in scale. A galaxy is a component of a universe, like a solar system is a component of a galaxy.

So when you say the universe is infinite, it's like saying a galaxy is infinite.

What you really mean is that the VOLUME of space is infinite, but the object the universe is finite (but expanding) and it resides in the infinite volume of space.

So, with a finite universe in an infinite volume of space, do you think a universe object orbits a more massive body, along with other universes that orbit that body, like a large scale galaxy????

 

IMPO (professional or philosophical): The universe is infinite. The 'volume' of the universe is 'space' that is permeated by extremely high-energy, and an expanding portion of that 'space' contains matter (observable mass) within a lower energy state. The all-permeable high-energy is the source for creation of mass via interim production of virtual mass (virtual particles) from whence (VPs) a small portion becomes 'permanent', observable, and interactive mass, from whence derives gravity. This is a 'continuous creation' (not a Steady-State) scenario that is compatible with a cosmological constant and continuous creation of CMBR. A Big Bang is not required, but is permissible. This is a 'speculative hypothesis' that is described elsewhere in Sciforums.

Mod Note: If this post is inappropriate on this thread (it is only in response to preceding posts), please feel free to move it to another location, e.g., Alternative Theories, Pseudoscience, or other . . .

wlminex

 

The Universe is FINITE but unbounded. Just like nature abhors a complete vacuum, it does not allow infinities. Infinity is a concept, not a reality(heck, humans have a lot of such concepts that cannot be found in nature).

The Universe is finite because it had a beginning in both time and space. And while it may continue in time from now on, that is not ever an infinity as there is still time it hasn't reached yet. It is also finite in size, space is expanding and it has not reached the limits of that size.

To understand unbounded you must first realize that every particle of the Universe began it's existence at the very center of the Big Bang and to it's perspective it has never moved from that center(local movement excepted). All of the rest of spacetime is expanding away from it in both space and time. This is true no matter where you are in the Universe. So no matter where you are, the Universe is all around you and the lengths to all the oldest things you can see are 13.7 billion light years away in all directions. They are also 13.7 billion years in your past, a great illustration of why you cannot separate space and time(spacetime).

Grumpy

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Have you an argument in support of this contention?

Or this one?

Or this?
You've given three statements of belief, without offering any argument in support of them and presenting them as if they were facts. At present, your reader has no reason to give these statements any serious consideration.

 

The arguement is long and technical but Stepen Hawking makes it in terms most people can understand in "A Breif History of Time" if you are interested. I certainly didn't rely on my own understanding, as I lack the breadth of education to make the arguement.

I assume you have heard of the Big Bang theory(not hypothesis)? Time and space began at that event, therefore neither are infinite(nor will they ever be).

You do understand what "singularity" means, right? It means every particle occupying the same place at the same time. When the expansion occurred the motion of all particles was RELATIVE to the observer(as they are to this very day), no matter which particle he is perched upon. It isn't Euclidian, but that type of geometry does not take into account time any more than a two dimensional geometry can take into account for the third dimension. Our observation gives us the impression that we occupy the very center of a sphere some 27 billion ly in diameter, but since we started out at exactly the same point in space and time as every other observer they see the exact same thing no matter what their relative position to us is.

These are not statements of belief, they are statements that reflect the best of our current understanding and are consistent with the evidence we currently have. I did not come up with these explanations, they have been produced by the finest minds who have studied for lifetimes these very things. Your argument is not with me, but with Hawkings, Einstein, Rees, Hubble, et al.

Grumpy

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The problem with saying that time and space began is that you are automatically eliminating the possibility and probability that the universe is part of a larger object that existed prior to the big bang. If and when evidence is produced that the universe is part of a multiverse, what will you call the time before the big bang, negative time?

The big bang occurred 13.5 billion years ago, so the duration of expansion has been 13.5 billion years. That doesn't mean time began 13.5 billion years ago any more than than it did by saying that you've been timing a sponge's expansion, and it has been expanding for 13 minutes, so time began for the sponge 13 minutes ago. Time didn't begin at the start of expansion, the stop watch started at the time of expansion!

 

As none of these people are here, supporting your claims, those claims remain unsupported. I see no reason to accept your contention that the universe cannot be infinite.