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.
Eh? In order to measure space, you can go from one point to another. If you didn't hit anything on the way, you went through that distance of space.
Now obviously if the universe is empty than you can't really measure it, but then it's moot anyway because neither you nor I would exist.
show off!
good slaunchwise pun!
"Toto, I don't think we're in the backroom anymore" placemark
Didn't those things within the singularity exist or were they suddenly created?
Before the Big Bang?
There was bumping, and thumpin,
and someone said , "Was it god for you?"
Then some idiot just had to light a cigarette.
My understanding (and IANA physicist) is they did not exist but were created at the time.
Were the componets of which they were comprised exist before the sudden expansion of time space.
How would you locate a point in empty space? IOW what's you're frame of reference?
I'm not sure of the question. Of what components are space and time comprised?
What does Planned Parenthood have to do with a scientific theory?
Programmer's analysis of "Prime:" 1 is prime, 2 is prime, 3 is prime, 5 is prime, 7 is prime, 9 is... a feature, 11 is prime, 13 is prime...
I'll go out on a limb here and say "space and time."
Alas, I am afraid the Big Bang is based on strong observational evidence for an expanding universe. That evidence consists of the cosmological redshift, and the cosmic microwave background. Do you have some alternative explanation for these phenomena?
The components, shall we say, of the matter that took shape as the universe expanded. Did they arise from nothingness or were they contained in their entireity within the singularity?
You gotta love this place. Every nook and cranny of the Bell Curve is well represented.
I see. Factual information really causes you a problem, doesn't it? I see you can't even answer why you posted what you did.
Of course, we now have to deal with the "cult" of astonomy, the "cult" of physics, the "cult" of chemistry.
So many "cults," so little time.
That is in contention to be added to my Tag List!! (LOL)
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