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.
Can you point to an example of "different properties under different conditions."
I'm trying to think of something, like how time slows down or speeds up in altitude. (very minute) I don't remember the name of the experiment, but it was where they flew clocks around the world from different directions.
Please share with us your expert basis for distinguishing speculation from fact.
You can tap into it via gravity wells. But don't get caught. The Force Police are almost as bad as the Time Cops.
Black hole singularities.
For an individual with such strong opinions on the matter, you seem remarkably hazy on the details.
But his self-esteem is good.
I don't know why evo's use this example because it's so bad...anyways we know the effects of gravity we see it and feel them constantly every second. We can see it's cause and effect.
Nonsense. We can prove in mathematics that an evolutionary dynamic must exist in biology, the "theory" is to what extent that necessarily existing dynamic is responsible for speciation. Evolution is mathematics (general systems theory) applied to biology in the same way calculus is applied to physics. Would you argue that physics is somehow exempt from calculus if it was convenient for you, or were you unaware the evolution in biology is applied theoretical mathematics?
Do you know what a "scientific theory" is? From your response, I would say you don't.
Wow, that statement really worked for ya didn't it? Quite an edification.
Got anymore brillant insights, Sherlock?
I saw a recent study on inner city youth, in which they drew an inverse correlation between self-esteem and performance on standardized tests. The conclusion they drew was rather euphemistially phrased, but translated, it was essentially 'some people are too stupid to realize how stupid they are'.
Of course, I am just recalling an amusing anecdote; in no way is this relevant to the present instance. All FReepers are above average.
We can see it's cause
What is its cause?
Humbled, I am.
I'm sorry, I forgot it was Friday night. Have another drink, and do not pay any attention to me.
:)
Whether you agree or not that evolution is a science puts no LESS fact into the theory that Man evolved.
There, fixed it for you.
I saw a recent study on inner city youth, in which they drew an inverse correlation between self-esteem and performance on standardized tests. The conclusion they drew was rather euphemistially phrased, but translated, it was essentially 'some people are too stupid to realize how stupid they are'.
Our prisons are filled with people with high self esteem.
ANOTHER entry in my potential tagline list! And that one is pithy enough to be put into use when I am ready to switch (my current tag is a paraphrase from Coyoteman).
Check my profile in about 10 minutes...
It was given that name derisively by one of its early detractors.
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