Multiverse theory (split from, "Where Does Space End? It Must End Somewhere!")

[mpmcd101]

Hi Everyone, this is my first time on here, but I love the subject and so would like to share my thoughts, although I'm not sure it's going to answer the question.

 

It depends on whether you believe in the multiverse theory or not. Personally I do. I think it's more then likely that the big bang happened many many times before and after the one that created our own universe and is still happening over and over again like bubbles in boiling water. Our own universe, although very very big, has an edge, a skin if you like, that is expanding. It now seems that it is expanding faster, the further out you go, giving rise to the question why? The answer (so far) seems to be dark energy. I'm not sure I like that idea. That's not to say that it's impossible, but I might be able to explain the faster expansion in a way that doesn't call for a mysterious new entity, but uses good old fashioned gravity.

 

If you accept that we are not living in a space that has only one universe, but that there are in fact a huge number of other universes out there, it would follow that as each of them expands, their edges would get closer and closer to each other. This would exert a pulling force on the matter nearest the two leading edges, leading to a more rapid expansion as the two edges get closer. Instead of inventing a new force to push from inside, this way, gravity can still be the main protagonist, acting in the same way as it always has, by pulling from the outside.

 

The only problem I have with the multiverse theory is when they say that each of the other universes must be filled with "other" versions of us, all with slightly different variations. Every possibility that can be realised, is happening somewhere on one of the other earths in another universe. I really don't see why that should be so. I think it's much more likely that the inhabitants of any other universe would have nothing what so ever to do with anything we might recognise. There may be millions of other earth like planets, but there is no other earth, no other you or me. Why should there be a potentially infinite number of universes all filled with the same people, except in one I might be a billionaire and in another I might be tramp. Just doesn't make any sense to me.

 

So, where does space end? I don't know. Our space ends on the skin of our universe bubble and will continue to expand indefinitely. In this way, we both have an end, an edge, but that edge is also continually growing, and so not a static position where you can say, here is where it stops.

 

If you believe in the multiverse, what is each universe in and how big is this medium?

 

I love the beautiful purpley orange picture of the tendril like formations and distribution of the galaxies in our own universe, and I don't see why this same picture could not apply to the distribution of universes in the multiverse. Nature loves the fractal repetition patterns seen everywhere from humble cauliflower to the distibution of galaxies. It seems likely that this would continue on ad infinitum.

 

 

[Ophiolite]

mpmcd101, welcome to the forum.

 

If your hypothesis is correct how do you account for this? The expansion of our universe appears to be proceeding at an equal rate in all directions. That would require a remarkable coincidence of other universes at just the right distance and with just the right mass to generate such an equality of expansion. I don't see how this could occur by chance. Perhaps you do and will explain.

[Strange]

It now seems that it is expanding faster, the further out you go, giving rise to the question why? The answer (so far) seems to be dark energy. I'm not sure I like that idea. That's not to say that it's impossible, but I might be able to explain the faster expansion in a way that doesn't call for a mysterious new entity, but uses good old fashioned gravity.

 

I wouldn't say dark energy was the answer. Dark energy is just the name given to whatever the, currently unknown, answer turns out to be.

 

If you accept that we are not living in a space that has only one universe, but that there are in fact a huge number of other universes out there, it would follow that as each of them expands, their edges would get closer and closer to each other. This would exert a pulling force on the matter nearest the two leading edges, leading to a more rapid expansion as the two edges get closer. Instead of inventing a new force to push from inside, this way, gravity can still be the main protagonist, acting in the same way as it always has, by pulling from the outside.

 

Isaac Newton. Shell Theorem. In other words, no.

http://en.wikipedia.org/wiki/Shell_theorem

 

Our space ends on the skin of our universe bubble and will continue to expand indefinitely.

 

Current cosmological models do not have such an edge for the universe.

[hypervalent_iodine]

!

Moderator Note

mpmcd101,

I have moved your post into its own thread on account of how old the one you posted in was and because you were introducing your own speculations. Please take a moment to review the rules of this part of the forum (here: http://www.scienceforums.net/index.php?app=forums&module=forums&section=rules&f=29)

[mpmcd101]

Hello Ophiolite, thank you for the welcome.

 

Yes of course you are right, it would require a remarkable coincidence, but could it not depend on where we are positioned in the soup? As with the picture of the distribution of galaxies, there are hubs of tightly packed clusters, we may well be in the middle of one of these, that might go some way to explain the seemingly even push/pull of the expansion. However, This is all viewed from the perspective of a 3 (or 4 if you include time) dimensional space. If we were to take in string theories need for 11 (is it) dimensions, then the possibility of being completely surrounded by other outside influences gets very great. And, how ever small the force, this could not help but have at least some effect.

 

The same coincidence would have to be true of dark energy if were to be the driving force of the expansion, as in that the distribution of this energy would have to be equal and without fluctuation in all directions to provided an equal push in all directions.

[Ophiolite]

But since the universe is considered to be isotropic and the dark energy is internal, then that is not a problem.

 

Cosmology, like other universes, lies outside my area of competence. However, I strongly suspect that to render your hypothesis plausible you would need to produce some mathematical description of conditions that satisfied observation. My limited knowledge suggests this would be a major challenge.

[mpmcd101]

I have always wished that I could do the maths needed to understand and prove or disprove various hypothesis but sadly that is well beyond me. But thanks for at least taking some time to read and consider my musings LOL

And, to Hypervalent Iodine, Thanks for your advise, I did later create a new thread myself for this for the reasons you stated. It's my first post here and I was not sure of the procedure, and as it was the earlier post that sparked my post, I was not sure what to do as I wanted to reply, but then got rambling a bit in my own direction LOL

[mpmcd101]

Hello Strange,

 

Thanks for your info. I read the link and if I understood it correctly then it could be much better way of explaining what I was trying to express LOL

 

 

 

 

Isaac Newton. Shell Theorem. In other words, no.

http://en.wikipedia.org/wiki/Shell_theorem

 

 

"Current cosmological models do not have such an edge for the universe".

 

I'm a bit at odds with this bit though. Given that we accept the big bang as the beginning of our universe, there must have been an outer edge to the bang debris that later became gas clouds, then stars and planets etc., the fact that it has expanded far beyond what we can readily observe, does not mean that that edge has disappeared, no?

[Strange]

I'm a bit at odds with this bit though. Given that we accept the big bang as the beginning of our universe, there must have been an outer edge to the bang debris that later became gas clouds, then stars and planets etc., the fact that it has expanded far beyond what we can readily observe, does not mean that that edge has disappeared, no?

 

First of all, you seem to be thinking of the big bang as an explosion which threw stuff out into space. That is not accurate. A better way to think of it is that the universe was very hot and dense, then it expanded and cooled. So it was the whole universe that expanded, and everything in it that moved apart.

 

There are two possible explanations for why the universe does not have an edge. The simplest one is that the universe is infinite; therefore there is no end and no edge. The alternative explanation is that the universe is finite but unbounded. As an analogy, think of the surface of the Earth, it has a finite area but no "edge". Extend that to 3 dimensions and that might describe the universe.

 

As it is, we don't know if the universe is infinite or not. (And probably can't know.)

[Airbrush]

 

First of all, you seem to be thinking of the big bang as an explosion which threw stuff out into space. That is not accurate. A better way to think of it is that the universe was very hot and dense, then it expanded and cooled. So it was the whole universe that expanded, and everything in it that moved apart.

 

In the multiverse model, many if not an infinite number of big bangs may have occurred, and are occuring even now. Those big bangs, our's included, have a finite size, reside within a "bulk" of infinite dimensions, and therefore you can compare it to an explosion that has an outermost edge. Which is the same as saying our big bang was "very hot and dense, then it expanded and cooled".

 

"The multiverse (or meta-universe) is the hypothetical set of infinite or finite possible universes (including the universe we consistently experience) that together comprise everything that exists: the entirety of space, time, matter, and energy as well as the physical laws and constants that describe them. The various universes within the multiverse are sometimes called parallel universes or "alternate universes"

 

http://en.wikipedia.org/wiki/Multiverse

Edited December 5, 2014 by Airbrush

[mpmcd101]

 

First of all, you seem to be thinking of the big bang as an explosion which threw stuff out into space. That is not accurate. A better way to think of it is that the universe was very hot and dense, then it expanded and cooled. So it was the whole universe that expanded, and everything in it that moved apart.

 

There are two possible explanations for why the universe does not have an edge. The simplest one is that the universe is infinite; therefore there is no end and no edge. The alternative explanation is that the universe is finite but unbounded. As an analogy, think of the surface of the Earth, it has a finite area but no "edge". Extend that to 3 dimensions and that might describe the universe.

 

As it is, we don't know if the universe is infinite or not. (And probably can't know.)

I don't think of the big bang as throwing stuff out into space, I think of it as creating space, and the "stuff" flowing into that new space. Before then, for our universe at least, there was no space/time. I also know that it was a very hot dense state that later cooled as it expanded. (Just because I can't do the math, doesn't mean I don't read and watch documentaries), I am aware of most of the current theories. This is more about whether I believe them or not, and if not, then what I might offer as an alternative, unsupported by the math as they may be.

 

Both of the possibilities you put forward for the none existence of an edge to our universe, make sense and I can see how both might work, I just don't believe them.

 

I was watching a documentary a few weeks ago about Dark Energy. I got thinking again. Dark Energy could be thought of as a 5th force, created at the time of the big bang, that is weaker than gravity. It is the force responsible for creating space. In the early universe, it was impeded by gravity, not stopped, but much reduced. Now, at the further reaches of the universe where matter is much less densely packed, gravity is much weaker, so much so, that dark energy is now stronger than gravity in those regions, and so is able to create more space at a greater rate than in the regions where gravity is still stronger than dark energy. It is not a "pushing" force, repelling matter, it is just now able to do it's job of creating more space, hence the faster expansion the further out you go.

Edited April 21, 2015 by mpmcd101