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]

[MacDorcha]

i thought thought conveyance was the point of language. in which case, it shouldnt matter to anyone what i present myself as, at least, anyone who knows what im trying to proev by doing this. i couldnt care less for the people who think its not right to write like this. they can get over it.

[MacDorcha]

no, because you blew me off with that statement. you told me to do something. it wasnt a request, or even a helpful hint. you read that, and think of how it sounds in your head. you practically slapped me.

[Aracelis]

To RadioAstronomer from MacDorca: "ok, i was being nice.... now you can shove it."

Gentlemen (not you, MacDorka), the word "priapism" leaps to mind.

[Moonman62]

Nobody has the answers to those questions. Current observations indicate a universe that will expand forever, anyway.

The vast majority of cosmologists though, still "prefer" a universe that will eventually contract, so they are coming up with theoretical ways the universe will contract, but still explain the observed acceleration of the universe's expansion.

[MacDorcha]

im going to try to get some shut eye for the time. got work in 4 hours. i dont mind a debate, but dont treat me like a kid, or i will get pissy. and before anyone says how that proves how childlike i am, imagine someone walking up to you, telling you you have no clue what you're talking about, and then patting you on the head like you're a child. now try imagining what you would do if it were possible to not be offended.

[RadioAstronomer]

it wasnt a request, or even a helpful hint

I used the word suggest, not demand. And yes it was a helpful hint. There is far more you can learn from a math book than a few equations I could post late at night on a message board.

I am sorry you got offended. I was not intending such.

[MacDorcha]

ok, it's cool then. apology accepted. sorry i flew off, but as you see, im not accpted for thinking differently here.

[LibWhacker]

im going to try to get some shut eye

I'm surprised your parents let you stay up so late.

[MacDorcha]

the word "priapism" leaps to mind

clever. now that we know you have a fixation of sorts...

[MacDorcha]

it's 320 am. i work for my car and my eductaion. i do as i wish

[LibWhacker]

You're cranky when you're sleepy. You should be in bed, young man!

[MacDorcha]

i didnt attack you. im not cranky. i am pissed that the second some one mentions an alternate idea, it's not accepted just because it's new. it's people like you who kept the world thinking the world was flat, almost 150 years after it was proven that other ideas may be right.

[MacDorcha]

if we all agree, no one is thinking.

[LibWhacker]

I'm just messin' with 'ya . . . :-)

Speaking of cars . . . Are you familiar with this place?

[LibWhacker]

You're not having trouble here because your ideas are new, but because you're wrong. But that's okay. We all had to learn.

Study hard in school, young feller . . . and DO NOT resist doing things the professor's way. There is plenty of room for creativity once you learn the fundamentals.

[PatrickHenry]

I see that I didn't miss much since my last placemarker.

[Physicist]

you mean side-angle-side?

No...

10 cubed root...

Oh, dear.

[Physicist]

oh, and btw. i proved gravity, not air-resitance. lock th device in a vacuum. it will still stop, and it will never reach the same height without assitance. the force down is greater than the force out or up.

Oh, my.

Is this not also true of the gravitational force on the moon? Why doesn't it stop?

[Doctor Stochastic]

The radius is not part of the circle. You should learn some elementary geometry. Be careful not to confuse a circle with a disk.