Is the universe infinite or finite?

krasnichuk said:

This has been something I've pondered on before. In believe that the universe is a finite size. Yet I often question what would be beyond the edge of the universe? I came across the idea one night of adding the idea of time into this equation. I'm not going to lie I was on some a psychoactive drug, but it seemed to make a lot of sense then and strangely enough a lot of sense now. Just a little less comprehensible. The idea was that since time can be considered a fourth dimension you would only ever have something happen once at that particular point in time. Now the idea was if you were to go beyond the edge of the universe would it be possible to fall back or go forward (in the sense of being able to go forward quicker than you normally would) to a point in time to a pre-existing state of the universe or yet to happen state of the universe.
It's just an idea, but I hate that I'm probably not going to find the answer in this lifetime

Click to expand...

I believe time is variable and constant.

For example, take time as a vector; as a time unit passes, another dimension or universe is created, where a new, different future can happen, therefore time actually makes the universe live in the past, present and future.

steve001 said:

3. Time the 4th dimension is not a spacial dimension but a coordinate of time; hence the term Spacetime.

Click to expand...

No, this is a common misconception. Time is a 4th variable (people call it dimension) on a 4 variable function (4 dimensional function f(x;y;z;t) like in physics), but that doesn't mean there can't be other variables in a 4 dimensional function. For example, a 4 dimensional SPACE can be f(x;y;z;w). Five dimensions: f(x;y;z;w;r) or whatever letter you want.

In algebra you learn how to project spaces/surfaces of higher dimensions into an n-1 dimension. It's the common example of a 3 dimensional cube projecting a 2 dimensional square on a sheet of paper (shadow of a 2 dimensional cube). Same thing with 4 dimensions, a hypercube would be seen as a cube if it's "shadow" were to be projected on a sheet of paper.

From
The History Channel.
Parallel Universes

Premiere Date: 11/18/2008

Some of the world's leading physicists believe they have found startling new evidence showing the existence of universes other than our own. One possibility is that the universe is so vast that an exact replica of our Solar System, our planet and ourselves exists many times over. These Doppelganger Universes exist within our own Universe; in what scientist now call "The Multiverse." Today, trailblazing experiments by state of the art particle colliders are looking for evidence of higher dimensions and Parallel Universes. If proof is found, it will change our lives, our minds, our planet, our science and our universe.

This was a very interesting show. And appears downloadable from iTunes. A must see if you are really interested
The Universe — Season 3 Episode Guide — History.com

The 1st Post on this thread states.....

"Discuss. Please don't just post Google answers, try to discuss it here."

I would believe that means use your own words/knowledge....
Correct me if I misunderstood...:yabbem:

Jerry

nikokapo said:

I believe time is variable and constant.

For example, take time as a vector; as a time unit passes, another dimension or universe is created, where a new, different future can happen, therefore time actually makes the universe live in the past, present and future.




No, this is a common misconception. Time is a 4th variable (people call it dimension) on a 4 variable function (4 dimensional function f(x;y;z;t) like in physics), but that doesn't mean there can't be other variables in a 4 dimensional function. For example, a 4 dimensional SPACE can be f(x;y;z;w). Five dimensions: f(x;y;z;w;r) or whatever letter you want.

In algebra you learn how to project spaces/surfaces of higher dimensions into an n-1 dimension. It's the common example of a 3 dimensional cube projecting a 2 dimensional square on a sheet of paper (shadow of a 2 dimensional cube). Same thing with 4 dimensions, a hypercube would be seen as a cube if it's "shadow" were to be projected on a sheet of paper.

Click to expand...

That's theoretical. We have no firm proof that other spacial dimensions do indeed exist beyond the 3 we know of. In the Universe we live in there are 3 spacial dimensions plus the coordinate of time that describes where and when your are or where. Other dimensions of space according to the experts exist as essentially dimensionless points.

lasersbee said:

The 1st Post on this thread states.....

"Discuss. Please don't just post Google answers, try to discuss it here."

I would believe that means use your own words/knowledge....
Correct me if I misunderstood...:yabbem:

Jerry

Click to expand...

Jerry, it's alright, he has posted useful information. What I really meant with that was that I wasn't looking for a definite answer for myself, as in: Don't post a Google result showing me "Is the universe infinite?"

I should read more into the multiverse theory, I have read something about it but I don't remember much.

No problem Niko... I wasn't saying the info wasn't useful...
I just went by what you posted and I understood...
No foul... no injury...

Jerry

steve001 said:

From
The History Channel.
Parallel Universes

Premiere Date: 11/18/2008

Some of the world's leading physicists believe they have found startling new evidence showing the existence of universes other than our own. One possibility is that the universe is so vast that an exact replica of our Solar System, our planet and ourselves exists many times over. These Doppelganger Universes exist within our own Universe; in what scientist now call "The Multiverse." Today, trailblazing experiments by state of the art particle colliders are looking for evidence of higher dimensions and Parallel Universes. If proof is found, it will change our lives, our minds, our planet, our science and our universe.

This was a very interesting show. And appears downloadable from iTunes. A must see if you are really interested
The Universe — Season 3 Episode Guide — History.com

Click to expand...

Sounds like thinking toward what I was alluding to before.
For quite some time, I have thought if you could dream or imagine it, that and more is real somewhere!
-Glenn

TIME has meaning only to you finate creatures of creation. Only YOU have a beginning and an end.

HMike

Mike, so does Heaven and Earth...

Time has a lot to do with this "expansion". The Big Bang was not an explosion, right?
It is only best described as a.. big bang.

For instance, concerning the duality properties of matter, and things like superposition, it has been suggested that matter can exist outside of time.

I personally understand it like this:

When two particles are in superposition to one another, each does whatever the other does. If you spin one, the other spins accordingly- instantaneously. This is where it gets a bit sketchy,

In order for the "spin" information to travel from one particle to the other instantaneously, the particles must be acting as if they were not separated at all. The information travels "back" to when the particles were together, (loss of time) and then travels forward in time to reach the other particle, (gain in time) forcing the particle to behave in a reaction time equal to zero.

This theory implies that all matter in the universe is somehow connected. That without time, there could be no separation of particles.

If this is all sounding nuts, don't worry- I think it is too. Its just that my thoughts are so limited to seeing time as a constant that has always been there, and the fact that I can't fully understand infinity.

I can't wait to take my quantum theory class next year!

Meatball said:

Mike, so does Heaven and Earth...
Time has a lot to do with this "expansion". The Big Bang was not an explosion, right?
It is only best described as a.. big bang.
For instance, concerning the duality properties of matter, and things like superposition, it has been suggested that matter can exist outside of time.
I personally understand it like this:
When two particles are in superposition to one another, each does whatever the other does. If you spin one, the other spins accordingly- instantaneously. This is where it gets a bit sketchy,
In order for the "spin" information to travel from one particle to the other instantaneously, the particles must be acting as if they were not separated at all. The information travels "back" to when the particles were together, (loss of time) and then travels forward in time to reach the other particle, (gain in time) forcing the particle to behave in a reaction time equal to zero.
This theory implies that all matter in the universe is somehow connected. That without time, there could be no separation of particles.
If this is all sounding nuts, don't worry- I think it is too. Its just that my thoughts are so limited to seeing time as a constant that has always been there, and the fact that I can't fully understand infinity.
I can't wait to take my quantum theory class next year!

Click to expand...

Don't try to bend the spoon. That is impossible. Only try to realize that there is no spoon -- The Matrix

IIRC Stephan Hawking said that postulating on other universes and/or the "time" before the Big Bang is useless. The laws of physics could be (and probably were/are) different in other universes. You can admit and postulate about their existence, but trying to understand how they work is an exercise in futility.

You don't need parallel universes and or the multi-verse to find possible replications of our solar system and/or even our "world." There are enough "worlds" in this universe for the law of infinite variation to replicate conditions here.

Peace,
dave

It just becomes difficult to even ask to right question. For instance,

Can we even as this question? (Is the univerese finite or infinite?)

For all we DO know, the question is entirely irrelevant. Seeing as there is hardly a single definition for "universe" and how there may be only SOME parts of it, that can be considered finite or infinite.

This is stuff, I don't think that we even CAN know.

Would it help us to know? Probably not, in my intial opinion.

any black hole would create a rip in space-time, which theoretically would form another universe. these universe could be traveled to by launching something/someone through that black hole at light speed.

theory stated.

Has anyone here seen "The Elegant Universe" narrated by Bryan Greene?

As soon as I saw the first part on NOVA a few years back, I immediately searched eBay for the whole three part DVD series.

Humanity's ability to understand is limited. It is very possible (likely, even) that there are many, many things that we are incapable of wrapping our head around at this stage of our evolution.

Disclaimer: the folowing paragraph is NOT intended to turn this into a religious discussion. I am only bringing this up as an example.

The Jehovah's Witnesses came to my house one morning and were giving me their sales pitch. During the conversation, I told them that I have real issues believing or understanding certain parts of Christianity and the Bible that are paranormal by my definition. Their response was one of the best I've ever been given and it really put things into perspective for me since I had never thought about it like this before:

They asked me what I did for a living. I'm an IT professional and a computer technician. I also have a degree in electronics engineering that I don't really use at work.

they said "OK, so it's like this: If you were to ask us how a computer works or a complex electronic device, we wouldn't be able to answer. To us it seems like magic, but that's because we can't understand it with the knowledge we have right now."

Hmmmm... I'm still not a religious person, but I have to give them props on a good answer..

The same applies to this discussion. We as mere humans are not likely to be able to fathom the true intricacies and inner workings of the universe at this stage of our evolution, and probably not ever. Our collective intellect is about as significant as the smallest grain of sand on a neverending beach in the grand scheme of things. Much of it may as well be magic as far as we're concerned.

I love those kinds of specials, and the articles in Popular Science too.

EF - that was cool, and I think quite on target.

The question of finite or infinite is entirely relevant in cosmology because it give a direction to research. It guides the researcher in the search for physical components that can support or deny a position. Philosophically, the debate may be moot as there is no conceivable means of experiencing something infinite but the philosophical concept can also create a myopic view toward something of infinite size restricting us to a finite existence. In terms of infinite we can look at something as simple as limit theory in calculus. In an example of a limit we could define a function such that as a number x approaches infinity the function would result in some whole number such as 2. The limit would be 2 but it is the limit not the actual result given any number x as x only approaches infinity and gets closer and closer to infinity as the function gets closer and closer to 2. For some, this is a very difficult concept to comprehend because we humans have no experience in our daily lives of infinity but we know in mathematics it does exist. The paradigm of finite can limit many in the quest for knowledge.

Now, back to the physics. All that is and ever will be is currently in our universe. That is a concept of finite but we know space is expanding. The distance between the stars and galaxies is increasing not because of inertia left over from the big bang but because the volume of space is expanding carrying the stars and galaxies along like the waves of the ocean or more closely the wake of space-time expansion. Big Bang inertia is meaningless as the Big Bang happened everywhere at the same time and all of the universe was was involved in the singularity at the moment of the Big Bang. As the volume of space increases it leaves more room for more space to expand and as such, the rate of expansion is increasing.

We can be sure our universe is bounded because it had a beginning and an age (13.7 billion years old) but the size of the universe is increasing toward infinity. If the acceleration cannot be stopped by gravity the universe will continue to expand indefinitely, slowly cooling over the millennia until it is nothing but space getting infinitesimally closer to absolute zero.

The fate of the universe plus the existence of other universes and dimensions relies on gravity. Current string theory with super gravity theory folded in defines 11 dimensions of existence. The issue is no one can really define gravity. We know it is associated with mass but we do not really know why as we only see the fields of gravity. From a quantum perspective this is very troubling. Quantum mechanics requires highly defined quantum states operating in a probabilistic environment. No particle has been found for gravity although the graviton is theorized. Every field in physics has a related particle responsible for that field. Once the secrets of gravity are unlocked, the relationships between the various dimensions, strings, membranes and other strange objects of string theory will solidify and the fate will truly be known. It will tie quantum mechanics and relativity together. Gravity is the key. The debate rages.

I think the universe is infinite.

Here's a tidbit: Some scientists believe they will be able to create their own universes in accelerators given enough energy. The universes will experience their own big bang and expand into full fledged universes every bit as complex as our own. The neat thing is these universes will not expand in our universe, they will be creating their own space in their own universe never to affect us. If that ever happens we will know the multiverse is infinite as you can create more if you can create one.