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Member (Idle past 5876 days) Posts: 109 From: Bozeman, Montana, USA Joined: |
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Author | Topic: Universe Race | |||||||||||||||||||||||
cavediver Member (Idle past 3674 days) Posts: 4129 From: UK Joined: |
The balloon don't fly because everything would be getting farther apart and it is not. Galxayes have colided and are going to colide. I don't think the balloon is a good example at all. It creates too many problems. And yet just about every cosmologist uses this analogy... so who's understanding do you think is screwed? Do you really think that you should be dismissing this analogy out of hand, becuase you have found problems with it? Do you not think that a better attitude would be to ask for clarification because you are confused about the possibility and actuality of galactic collisions? You have completely misunderstood the cone analogy - there is no interior to the cone. It is exactly the same situation as with the balloon - all that exists is the surface.
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Rahvin Member Posts: 4046 Joined: Member Rating: 8.3 |
No I am trying to think of it as baking a cake in a cone type baking pan. A cone is the normal analogy given for the expansion of the big bang. In doing that everything would be in the bottom. But it could only produce so much. It would be limited to the amount of volume of the cake dough in the bottom of the baking pan. Until the matter that is the cake batter changes phases. When you break down atoms and even subatomic particles, you can squeeze an aweful lot into a small area...especially when area itself was smaller.
Just as the universe would be limited to the volume of pure energy that could be contained in something the size of a pea. "Pure energy" is a poor term. There really isn't any such thing - energy, scientifically described, is the ability to perform work. You can say that a beam of light posesses energy, or that the light's energy was transferred into heat when it struck an object, but "pure energy" is a misnomer popularized by science fiction. The answer, ICANT, is basically "we don't know what state matter was in in that barest fraction of a second, becasue our math stops working. We do know that matter and energy can't be created, we do know that the matter in the Universe does exist, we do know that it existed as a quark-gluon plasma after the unknown moment and before T=1810^-16, and we do know that the Universe is smaller as you approach T=0.
The balloon don't fly because everything would be getting farther apart and it is not. Galxayes have colided and are going to colide. You neglect to consider gravity, which is the major force in play at such scales, as well as the fact that all of the gravitational interactions even before stars formed and supernovae afterwards cause things to move in all manner of different direction. We've done computer models based on exactly this scenario, ICANT, and what we see is eerily close to what we observe in the Universe. There's been a lot of time for the cat to tangle this ball of string. The balloon model is relatively accurate. Not perfect, certainly, but it works for describing that space expands, not matter.
I don't think the balloon is a good example at all. It creates too many problems. It's your comprehension that is the problem, ICANT.
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Taz Member (Idle past 3322 days) Posts: 5069 From: Zerus Joined: |
ICANT writes:
Ok, let's give this another try. The balloon don't fly because everything would be getting farther apart and it is not. Galxayes have colided and are going to colide. Suppose we have a balloon that is already inflated. On the surface of the balloon there are hundreds of ants crawling around. The surface area of the balloon increases as the balloon itself continues to inflates. The general distances between the ants increase over time as the balloon continues to inflates. However, some ants will inevitably bump into each other. Added by edit. Small ants represent stars. Big ants represent galaxies. And if you want to get more specific, the parasites that reside on the ants represent planets and asteroids, and other planetary bodies. Edited by Taz, : No reason given.
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cavediver Member (Idle past 3674 days) Posts: 4129 From: UK Joined: |
Probably naively I would think that each Planck volume (is there such a thing? - in any case, I'm trying to refer to the smallest unit of space) could only contain a single fundamental "something", whatever that might be, whether quarks or superstrings or whatever. Yes, you can have a Planck volume. There's not quite a google of them in a pea. If each volume has a string mode and that string mode has the Planck energy, then that's about 10^107 J. That pea has to contain the observable universe, which has a visible mass of about 10^52kg, so say a total mass of 10^54 to be safe, and that gives an energy of 10^71 J. Conclusion: our pea is actually rather uncramped...
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ICANT Member Posts: 6769 From: SSC Joined: Member Rating: 1.7 |
Hi Paul,
Paulk writes: THere were no stars in that volume. Stars did not exist then. Matter didn't exist then. Stars formed much later. Son Goku told me HereSon Goku writes: 13.7 billion years ago the whole universe was about the size of a pea. I am having a real problem here. Son says the whole universe was about the size of a pea. That means everything in the universe had to be in some form at the point Son is speaking about. Mass and energy can not be created so all the mass and energy had to be there in the form of Pure Energy. I was suggesting to Son Here ICANT writes: If we go back in time to T=0 we have a mass between 5 and 7 billion light years in diameter. I have no idea what shape it would be. But I would assume it was probably pretty much the shape of the universe today. Son was assuring me the universe was about the size of a pea. I am just trying to sort out what I thought I had learned here. God Bless, "John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."
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PaulK Member Posts: 17828 Joined: Member Rating: 2.5 |
quote: It certainly doesn't mean that there had to be stars there ! The mass/energy would have existed in exotic forms that can only exist under such extreme conditions. Which doesn't include normal matter.
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Percy Member Posts: 22508 From: New Hampshire Joined: Member Rating: 5.4 |
But as we go back in time our pea becomes smaller and smaller. Going by your figures, the observable universe would still fit easily in something the size of a proton, but as we continue back in time we eventually progress to where each point in Planck space has the Planck energy. What then? Is this where current theory breaks down? Or is something else responsible?
--Percy
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ICANT Member Posts: 6769 From: SSC Joined: Member Rating: 1.7 |
Thanks Taz,
That sounds a lot better. Although the ants would not be affected by the laws of physics. God Bless, "John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."
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cavediver Member (Idle past 3674 days) Posts: 4129 From: UK Joined: |
Is this where current theory breaks down? Exactly, though 'current theory' will be highly modified well away from that scale, becoming more and more exotic as T=0 is approached.
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cavediver Member (Idle past 3674 days) Posts: 4129 From: UK Joined: |
Nice one, Taz. I always forget to the add the ants. Mind you, they will be VERY slow ants, or that balloon is bloody big...
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ICANT Member Posts: 6769 From: SSC Joined: Member Rating: 1.7 |
Hi cavediver,
cavediver writes: Conclusion: our pea is actually rather uncramped... How much gravitational pull would be necessary to suck the universe into something the size a of pea? God Bless, Edited by ICANT, : No reason given. "John 5:39 (KJS) Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me."
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cavediver Member (Idle past 3674 days) Posts: 4129 From: UK Joined: |
How much gravitational pull would be necessary to suck the universe into something the size a of pea? If there is sufficient density in the Universe (and ignoring the cosmological constant) then the Universe will collapse back to something the size of a pea and beyond. In terms of 'gravitational pull' (which is highly misleading) then as the Universe starts shrinking, the matter in the Universe will be closer together and so the gravitational attraction will grow, this will cause the Universe to shrink further, and so the 'pull' grows yet more. There will be no difficulty shrinking the Universe in this scenario, it will be a runaway effect.
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onifre Member (Idle past 2981 days) Posts: 4854 From: Dark Side of the Moon Joined: |
Hi ICANT,
How much gravitational pull would be necessary to suck the universe into something the size a of pea? Alot... How much gravitational force do you think is beyond the event horizon of a black hole? After the Big Bang 90% of the nuclei were hydrogen(the rest was helium,), all other elements came after stars blew up into supernovas. All the matter that is present today in this universe was created after the first star was created so you don't need to imagine this universe compressed to the size of a pea. Now, how many hydrogen nuclei can you fit into a pea? All great truths begin as blasphemies
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Taz Member (Idle past 3322 days) Posts: 5069 From: Zerus Joined: |
caverdiver writes:
We always have to remember that the surface of the balloon represents space itself, not space and matter. Although I did get a laugh out of imagining a bunch of ants crawling around on the surface of a balloon.
Nice one, Taz. I always forget to the add the ants. Mind you, they will be VERY slow ants, or that balloon is bloody big...
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Taz Member (Idle past 3322 days) Posts: 5069 From: Zerus Joined: |
caverdiver writes:
As a thought experiment with my buddies back in the old days, we decided that the only conceivable way we could save the universe from flying apart and become a cold almost empty place is through time travel. We could start sending back in time stars... whole galaxies and whole clusters. Not too much, though. Just enough to create a balance between gravity and the universal expansion and eventually create a static universe. In such a universe, we would have untold trillions of years to come up with a way to deal with the eventual heat death.
If there is sufficient density in the Universe (and ignoring the cosmological constant) then the Universe will collapse back to something the size of a pea and beyond.
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