Creation of celestia out on the fringe

[Realitycheck]

This is the way I understand new growth of the universe. Matter congregates into dense enough patches that they start reacting together until it gets dense enough to start a fusion process.

 

However, this doesn't seem to make sense out on the fringe, since logically, the fringe should be the least filled with matter. Since matter should be so sparse out on the fringes, then the chances of matter congregating in dense enough patches out on the fringe in order to promote star building should be infinitely small.

 

What is the explanation of this paradox?

 

Unless it is dark matter that accumulates, rendering the Big Bang Theory a myth, or at least as we know it.

[Klaynos]

The fringe of what? In intergalatic space there are few stars...

[Reaper]

This is assuming that the Universe has an edge. There is the possibility that it may not have one.

 

In the edge of the galaxy, there are not a lot of stars out there, if this is what you mean. Most stars are either in the center of the galaxy or in the arms.

[Realitycheck]

Yes, according to the Big Bang Theory, the universe should have edges, the outermost parts of its expansion in all directions.

 

I kind of jumped to a conclusion too soon regarding the dark matter. I was thinking that maybe the dark matter was already there as the rest of the universe may expand into it, or something like that. Then, we have collisions between matter that create stars out on the sparsely populated fringes of the universe. The common model doesn't really make sense, in that respect.

[Reaper]

Yes, according to the Big Bang Theory, the universe should have edges, the outermost parts of its expansion in all directions.

 

Not exactly. Some models regarding the shape of the Universe predict an edge. If the universe is negatively curved or is flat, then an edge is a possibility. Current data from the COBE, WMAP and other observations strongly indicate that the Universe is flat because the temperature fluctuations are uniform and differ by very tiny amounts. link: http://www.berkeley.edu/news/media/releases/2000/05/09_maxima.html

 

 

I kind of jumped to a conclusion too soon regarding the dark matter. I was thinking that maybe the dark matter was already there as the rest of the universe may expand into it, or something like that. Then, we have collisions between matter that create stars out on the sparsely populated fringes of the universe. The common model doesn't really make sense, in that respect.

 

Well, dark matter is part of the Universe itself, so I don't see how it can expand into it. We really don't know what is outside the Universe. I don't think we really have enough data to say what is happening at the edge (if there is one) because all observations take place within the observable universe.

 

My speculation is that even if it does have an edge, it shouldn't make a difference because if the Universe is flat, all the matter would probably not collapse to a central point. It should be densely populated by stars even at its edge.

[Realitycheck]

This really sounds like more of a big joke than anything. How do you explain this flat universe if we see stars of unlimited distance in every direction? Of course, I've always said that anything could happen in California.

[Klaynos]

Nice posts Lockhead. The definition of the word universe means everything taht we can interact with so anything beyond an edge, if it does have one, which I think most (but not all by far) think it does not, cannot be interacted with, if it can, it is infact part of the universe and we're back to looking for an edge...

 

We cannot see stars at unlimited distance in every direction. After a certain distance/time many say it is impossible, the dark ages... Although there was a claim recently by a group to have seen a galaxy older than any previousely seen.

[Jacques]

Agentchange told: How do you explain this flat universe if we see stars of unlimited distance in every direction?

Flat doesn't mean flat like a sheet of paper in cosmology. Flat mean that the space is not curved. Someone else can explain more than me, but try wikipedia.

[Realitycheck]

I understand your points, though I don't really understand the concept of a flat universe yet. My main issue is with the lack of matter, or rather, the presence of matter required to build showing up in the least likely places for it to be. Without hard data on the extent of the universe, it is kind of hard to put the pieces together.

[lucaspa]

This is the way I understand new growth of the universe. Matter congregates into dense enough patches that they start reacting together until it gets dense enough to start a fusion process.

 

However, this doesn't seem to make sense out on the fringe, since logically, the fringe should be the least filled with matter. Since matter should be so sparse out on the fringes, then the chances of matter congregating in dense enough patches out on the fringe in order to promote star building should be infinitely small.

 

What is the explanation of this paradox?

 

Unless it is dark matter that accumulates, rendering the Big Bang Theory a myth, or at least as we know it.

 

1. Matter congregating thru gravity to start fusion (making stars) is not the growth of the universe. When we speak of the universe gaining in size, we mean that space itself is expanding.

 

2. Way, way, back, the universe was nearly uniform in density of matter. This occurred at the end of inflation about 10^-30 seconds after the Big Bang. At that point, the universe was a meter in diameter. There were quantum fluctuations that created points of higher density that started the condensation to stars and galaxies. http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec25.html

 

So you can see that the expansion after that carried these condensations out to the "edges" of the universe. There is no "fringe" the way you are thinking of it.

 

So there is the explanation of your "paradox".

 

This really sounds like more of a big joke than anything. How do you explain this flat universe if we see stars of unlimited distance in every direction?

 

"Flat" is a cosmological term. It refers to the 4D shape of the universe in Riemann geometry: http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec21.html (halfway down the page)

 

There is a "closed" universe whose 3D analogy is a sphere. There is an "open" universe whose 3D analogy looks like a saddle. A "flat" universe has a 3D analogy of a plane.

 

This also refers to the amount of matter in the universe. A high mass universe is "closed" or has "positive curvature". Right now it looks like the universe is "open" or "negative curvature".

 

There is NOTHING "outside" the universe. When we speak of expansion, we are usually thinking of matter expanding into space. But you have to remember that the expansion of the universe is spacetime expanding. So space is expanding.

 

By the logic of the BB, there must be an "edge" to the universe in that there must be a place where "space" ends and there is nothing "beyond". However, when cosmologists speak of "finite" or "infinite", they are speaking whether the universe is "open" or "closed".

 

You must remember to use the words the way cosmologists are, not put your own definition to them. I think you would benefit by reading this article in Scientific American. You can purchase the digital version online:

 

7. Lineweaver CH and Davis TM Misconceptions about the Big Bang, Scientific American 36-45 March 2005. http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0009F0CA-C523-1213-852383414B7F0147