Posted on 08/04/2006 4:26:21 AM PDT by PatrickHenry
The question of what happened before the Big Bang long has frustrated cosmologists, both amateur and professional.
Though Einstein's theory of general relativity does an excellent job of describing the universe almost back to its beginning, near the Big Bang matter becomes so dense that relativity breaks down, says Penn State physicist Abhay Ashtekar. "Beyond that point, we need to apply quantum tools that were not available to Einstein."
Now Ashtekar and two of his post-doctoral researchers, Tomasz Pawlowski and Parmpreet Singh, have done just that. Using a theory called loop quantum gravity, they have developed a mathematical model that skates right up to the Big Bang -- and steps through it. On the other side, Ashtekar says, exists another universe with space-time geometry similar to our own, except that instead of expanding, it is shrinking. "In place of a classical Big Bang, there is in fact a quantum Bounce," he says.
Loop quantum gravity, one of the leading approaches to the unification of general relativity with quantum physics, was pioneered at the Institute of Gravitational Physics and Geometry at Penn State, which Ashtekar directs. The theory posits that space-time geometry itself has a discrete "atomic" structure, Ashtekar explains. Instead of the familiar space-time continuum, the fabric of space is made up of one-dimensional quantum threads. Near the Big Bang, this fabric is violently torn, and these quantum properties cause gravity to become repulsive, rather than attractive.
While the idea of another universe existing prior to the Big Bang has been proposed before, he adds, this is the first mathematical description that systematically establishes its existence and deduces its space-time geometry.
"Our initial work assumes a homogenous model of our universe," Ashtekar acknowledges. "However, it has given us confidence in the underlying ideas of loop quantum gravity. We will continue to refine the model to better portray the universe as we know it and to better understand the features of quantum gravity."
***
Abhay Ashtekar is holder of the Eberly family chair in physics and director of the Institute for Gravitational Physics and Geometry in the Eberly College of Science. He can be reached at ava1@psu.edu.
The finding reported above was published in Physical Review Letters in May 2006. The research was sponsored by the National Science Foundation, Alexander von Humboldt Foundation, and the Penn State Eberly College of Science.
The Big Dig?
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LOL! Well, did time exist? ...and for the umteenth time,
how did something explode from nothing?
The Big Cigarette came after.
Cosmic foreplay???
I fervently believe in the Big Bang theory.
God spoke and BANG, the universe came into existence.
That is my only remaining hold on Religion. That some intelligence got the ball rolling. After that, I do not see it.
God retired?
And for the umpteenth time, there was no "explosion." Spacetime expanded rapidly.
Note to lurkers: sirchtruth will be back with his inane question on the next such thread. No matter how many times he's given an answer he isintrinsically unable to actually assimilate any new data and appears to be stuck, educationally, somewhere in grade school.
Then you're not looking outside of that little box you've created...
"He went out for a beer and never came back" Bingo from.....
"Venus on the Half Shell"
Why, the Big Whizz, of course!
First, the brakes failed...
I have difficulty grasping loopy quantum gravity but I do understand God spoke and it stood fast.
Didn't Adam Sandler play him in a movie?
No I crawled out of the little box that the clerics tried to confine me in.. ...You got it backwards.
LOL! Yea, to some elitist, superior intellect I guess my questions are quite "inane," thanks for noticing!
Alex, I'll take wisdom for 500!
So, in other words, you prefer your myth better? I guess you were there!
It sure takes a lot of faith, to believe the crap all the "educated" people bring us. At least they keep us talking with their daily revisions.
Well, the book does say he created the universe.
Then the Big Bang is described very accurately.
Seems pretty simple to me.
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