Posted on 02/03/2007 7:49:37 AM PST by aculeus
A new cosmological model demonstrates the universe can endlessly expand and contract, providing a rival to Big Bang theories and solving a thorny modern physics problem, according to University of North Carolina at Chapel Hill physicists.
The cyclic model proposed by Dr. Paul Frampton, Louis J. Rubin Jr. distinguished professor of physics in UNC's College of Arts & Sciences, and co-author Lauris Baum, a UNC graduate student in physics, has four key parts: expansion, turnaround, contraction and bounce.
During expansion, dark energy -- the unknown force causing the universe to expand at an accelerating rate -- pushes and pushes until all matter fragments into patches so far apart that nothing can bridge the gaps. Everything from black holes to atoms disintegrates. This point, just a fraction of a second before the end of time, is the turnaround.
At the turnaround, each fragmented patch collapses and contracts individually instead of pulling back together in a reversal of the Big Bang. The patches become an infinite number of independent universes that contract and then bounce outward again, reinflating in a manner similar to the Big Bang. One patch becomes our universe.
"This cycle happens an infinite number of times, thus eliminating any start or end of time," Frampton said. "There is no Big Bang."
An article describing the model is available on the arXiv.org e-print archive and will appear in an upcoming issue of Physical Review Letters.
Cosmologists first offered an oscillating universe model, with no beginning or end, as a Big Bang alternative in the 1930s. The idea was abandoned because the oscillations could not be reconciled with the rules of physics, including the second law of thermodynamics, Frampton said.
The second law says entropy (a measure of disorder) can't be destroyed. But if entropy increases from one oscillation to the next, the universe becomes larger with each cycle. "The universe would grow like a runaway snowball," Frampton said. Each oscillation will also become successively longer. "Extrapolating backwards in time, this implies that the oscillations before our present one were shorter and shorter. This leads inevitably to a Big Bang," he said.
Frampton and Baum circumvent the Big Bang by postulating that, at the turnaround, any remaining entropy is in patches too remote for interaction. Having each "causal patch" become a separate universe allows each universe to contract essentially empty of matter and entropy. "The presence of any matter creates insuperable difficulties with contraction," Frampton said. "The idea of coming back empty is the most important ingredient of this new cyclic model."
This concept jolted Frampton when it popped into his head last October.
"I suddenly saw there was a new way of solving this seemingly impossible problem," he said. "I was sitting with my feet on my desk, half-asleep and puzzled, and I almost fell out of my chair when I realized there was a much, much simpler possibility."
Also key to Frampton and Baum's model is an assumption about dark energy's equation of state -- the mathematical description of its pressure and density. Frampton and Baum assume dark energy's equation of state is always less than -1. This distinguishes their work from a similar cyclic model proposed in 2002 by physicists Paul Steinhardt and Neil Turok, who assumed the equation of state is never less than -1.
A negative equation of state gives Frampton and Baum a way to stop the universe from blowing itself apart irreversibly, an end physicists call the "Big Rip." The pair found that in their model, the density of dark energy becomes equal to the density of the universe and expansion stops just before the Big Rip.
New satellites currently under construction, such as the European Space Agency's Planck satellite, could gather enough information to determine dark energy's equation of state, Frampton said.
A copy of the paper may be downloaded at http://arxiv.org/abs/hep-th/0610213
Source: University of North Carolina at Chapel Hill
Right. We are looking at the range and can't see the delta of the domain.
Poppy cock.
Alternatively, we can see only what we have imagined.
I still say there is no possible way primitive man could have built the Grand Canyon without the help of technologically advanced aliens.
Source: University of North Carolina at Chapel Hill
People actually work over there?!? That's news in and of itself.
"bereshith" (in beginning) has no definite article. That doesn't prove that it means "in a beginning".
I'm not sure what is new in this theory. I thought this is pretty much how we thought it worked.
It's obvious that scientists have no answer for the biggest question of all. And they can not have an answer for it, since there is no way to experience any supposed "big bang".
They can only draw up theories and then talk about them without end.
Deep space is not nothing, it is deep space seething with virtual particle-anti particle pairs. Virtual particles have energy as a prerequisite. You see the problem here?
The philosopher's concept of absolute nothingness is a figment of the philosopher's imagination, derived by imagining subtracting away everything definite until nothing is left, whereupon the philosopher says, "Nothing remains". To my knowledge, there is no concept in physics that corresponds to this notion of absolute nothingness.
Of course, nothingness also appears in mathematics in many guises: the number zero, the zero function, the empty set, etc. But we're talking about physics, not mathematics. Even the most ardent platonist is usually willing to concede that mathematics is not identical with physics.
So by 'nothingness' in my original post, understand me to be referring to whatever physicists would consider to be nothingness. And, again, if the physical is all there has ever been, that's what nothingness would be (so to speak).
I agree.
As far as God is a concern of ours, he is everywhere in everything and this is his universe and every creature too. Whether he also has other universes would not be our business for a long time to come if ever.
There's no such thing as "dark energy." It's only a hypothetical mathematical construct for various *models* of our universe (and a poor one at that).
So according to this new model...God is simply a bystander watching from the wings....waiting....waiting...here it comes...the right moment...is almost here....
"LET THERE BE LIGHT!...Yeah, that's the ticket. Let there be light."
Riiiight.
If our equations come out with nothingness, it's because we are only looking at a small part of reality, IMO.
It's probably my fault (to write quickly while short on sleep is to court unclarity), but that's not quite what I meant.
One little problem with mathematics being the language of creation is that while some physics is fairly well described in some math--to a part in ten million or so--a lot of math doesn't describe anything in physics.
Back to basics: there are three dimensions--time, people, and dinner. Look it up.
What is your take on this?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.