Black Crunch jams Universal cycle [Cosmology]

Nature Magazine ^ | 23 Decemeber 2002 | PHILIP BALL

[PatrickHenry]

Space might end up dark, thick and boring.

The Universe is not as bouncy as some think, say two physicists. If a Big Crunch follows the Big Bang, it may get stuck that way for ever¹.

A fluid of black holes would bung up space. There would be nothing to drive another Big Bang, and nowhere else to go. The Universe would be, you might say, stuffed.

In a bouncing universe, all the matter currently flying apart slows until it reverses and falls towards a Big Crunch. Some physicists think this could ignite another Big Bang, in an unending sequence of expansion and contraction.

An idea called M-theory suggests how the switch from crunch to bang could happen². The details depend on the shape of space: whether it is infinite and flat, or finite and curved like the surface of a balloon or a doughnut.

Thomas Banks of Rutgers University, New Jersey, and Willy Fischler of the University of Texas at Austin have considered a flat, infinite space in which particles get ever closer and ever denser.

In a space with such features, the smallest kinks in density are amplified into black holes, the densest objects in the Universe. So the whole of space-time would congeal into a very lumpy soup - a black crunch.

"We don't really know what this fluid is made out of," Fischler admits. But he and Banks argue that it may reach a pressure at which it cannot become any denser. At this point, the speed of sound equals the speed of light. Deadlock results.

No theory can cope with a Big Crunch. Because of this, says Fischler, the analysis that he and Banks have performed remains speculative. And a doughnut-shaped Universe could meet a quite different fate, he adds.

References:

1. Banks, T. & Fishler, W. Black Crunch. Preprint http://xxx.lanl.gov/abs/hep-th/0212113, (2002). |Article|
2. Khoury, J., Ovrut, B. A., Seiberg, N., Steinhardt, P. J. & Turok, N. From Big Crunch to Big Bang. Preprint http://xxx.lanl.gov/abs/hep-th/0108187, (2002). |Article|
[See the original article for links in the footnotes]

[LibWhacker]

Wow, so wrong.

[PatrickHenry]

you dont know that [we won't know the things we aren't meant to know].

This is one of those times where I have faith.

[MacDorcha]

right, and you've been there, so you MUST be the definative source of information on the subject. we cant see or percieve what is beyound our capapbilites to reach and/or detect.
next please.

[Sentis]

MacDorcha wrote"... PROVE the universe exists. the point of God is the unexplaned. we dont know the capabilities of God, nor the standards or boundries there-of. but if we are going to accept that the universe is expanding, what initiated it? "

I see it, I experience it, I can measure it thus it exists.

no need to get into the philosphy of it unlike when you bring in God only philosophy can suffice.

What initiated God? the question is the same. the difference is the universe exists.

[VadeRetro]

right, and you've been there, so you MUST be the definative source of information on the subject. we cant see or percieve what is beyound our capapbilites to reach and/or detect.

Yes. MacDorcha, this is God. Stop trying to shout down the scientists. I did it MY way ...

That is all.

[MacDorcha]

well if its expanding into the quantum, why does the quantum plane exist alongside our percieved plane? if it were expaniding, it would be pushing it away, ans we would not see any. when we see the things though, it proves that there is either a leak, or the quantum exists on both sides of the universal barrier. in which case, it would be like pumping a water balloon... underwater. the univers would be expaning into a greater universe.

[friendly]

What's the universe expanding into?

I believe the universe is infinite in all directions. There is no leading edge of expansion. Space itself expands endlessly. Galaxies exist in all directions infinitely: Look at the Hubble Deep Field North and South.

In a sense there is no Big Bang: The early universe was infinitely denser and hotter. The speed of light also appears to slow down, as one approaches the Big Bang in a recent study of black holes.

This in turn raises the existential question as what "13 billion years ago" really means.

I'll stop my little digression at this point.

[MacDorcha]

ill take your sarcasm as your stepping down.

[Sentis]

MATH isnt a speculation so no need for the disclaimer again you try to play word games :)

[MacDorcha]

i agree with you on that one.

[friendly]

What's the universe expanding into?

I believe the universe is infinite in all directions. There is no leading edge of expansion. Space itself expands endlessly. Galaxies exist in all directions infinitely: Look at the Hubble Deep Field North and South.

In a sense there is no Big Bang: The early universe was infinitely denser and hotter. The speed of light also appears to slow down, as one approaches the Big Bang in a recent study of black holes.

This in turn raises the existential question as what "13 billion years ago" really means.

I'll stop my little digression at this point.

[Scully]

draw a circle on a paper. find halfway between any two points that are exactly opposite the other. center of a flat, round universe. wow, so hard.

You haven't kept up on the latest science news. The Universe (ours, spelled with a capital "U") is neither symmetric nor one-dimensional.

[VadeRetro]

ill take your sarcasm as your stepping down.

I don't see where there's much to discuss, do you?

[MacDorcha]

but you did make a plain statement, without the disclaimer, which i responded to, and you responded to that one. you told me to state something so that people wouldnt assume i knew everything, or that all i said was fact, but my point was, you didn't there.

[PatrickHenry]

The speed of light also appears to slow down, as one approaches the Big Bang in a recent study of black holes.

Huh?

[Sentis]

MacDorcha wrote"so you MUST be the definative source of information on the subject. we cant see or percieve what is beyound our capapbilites to reach and/or detect. "

The wonderful thing about Math is it lets us go places we can't see and percieve things beyond our capabilities.

[MacDorcha]

"I see it, I experience it, I can measure it thus it exists. "


so do dreams. you cant prove that you arent a dream to me, even if i was wide awake, you couldnt prove i wasnt sleeping, not definatelynot to me. we can't prove something like "the Matrix" isnt happening right now. its laughable, but hey, you cant prove it.

[MacDorcha]

only, if it's beyond our realm of perception, how do we know it operates the same way?

[Sentis]

McDorcha wrote "well if its expanding into the quantum, why does the quantum plane exist alongside our percieved plane? if it were expaniding, it would be pushing it away, ans we would not see any. when we see the things though, it proves that there is either a leak, or the quantum exists on both sides of the universal barrier. in which case, it would be like pumping a water balloon... underwater. the univers would be expaning into a greater universe."


It is possible that this Universe is expanding into a greater universe. However higher deminsional physics are not the physics we enjoy at the Macro level and we know that at the quantum level particles do not act or react the way they do on our level.

[Oberon]

Where, precisely, do you think the "center" of the Universe is?

Well, I live in North Carolina, and to hear some basketball fans around here tell it, the center of the Universe is at UNC Chapel Hill.