Our Universe: A Quantum Loop
April 25th, 2006“There are two classical branches of the universe connected by a quantum bridge. This connects the former collapse with the current expansion.” While Abhay Ashtekar and his colleagues, Tomasz Pawlowski and Parampreet Singh, may not have come with a completely new theory, what they have done is create a systematic way, through quantum equations, to look back in time to the birth of our current universe.
Ashtekar’s team from Pennsylvania State University’s Institute for Gravitational Physics and Geometry published a Letter in Physical Review Letters on April 12th, detailing what was found, and shedding a little more light on what actually happened at the time the universe began expanding.
“The idea of a bounce has been around for a while,” Ashtekar explains to PhysOrg.com, “and it has been looked at in many contexts. One of them is String Theory.” He continues: “The pre-Big Bang cosmology considered the idea that a branch of the universe existed before the Big Bang, and in the Ekpyrotic scenario, a `brane’ collides with another `brane,’ causing a bounce.”
What makes the PSU explanation different, says Ashtekar, is the fact that while it was assumed that there might possibly be something before the Big Bang, a systematic determination of what that might have been was missing. Additionally, “one never had systematic equations that are determinate, leading from the pre- to post-Big Bang branches of the universe.”
Ashtekar and his colleagues use Einstein’s quantum equations from Loop Quantum Gravity (LQG), an approach to the unification of general relativity and quantum physics. LQG does not presuppose the existence of a space-time continuum. Ashtekar and his fellow team members find that quite likely there is a classical universe, one that looks and behaves pretty much like our currently universe, on the other side of the Big Bang, which he describes as more of a Big Bounce. In these classical universes, spacetime is a continuum and Einstein’s theory of general relativity is mostly accurate. But between these two classical universes, Ashtekar says, is a point at which general relativity doesn’t apply. “We know that on the quantum level the theory of general relativity breaks down,” he explains, “and this quantum bridge, which lasts for such a small period of `time,’ connects the two branches of the universe.”
Using the collapse of stars as an example, Ashtekar explains how the pre-Big Bang universe retracted and became smaller until it bounced out and began expanding again in what we recognize as our universe: “Stars like our sun are in equilibrium. There is a radiation that push outward against gravity, which tries to collapse. When the star runs out of fuel, the radiation reduces, and there is nothing to stop the collapse. For stars with three times the mass of our sun or less, when it gets to a certain point, the neutrons repulse each other and they become neutron stars or pulsars.” He pauses and then continues to explain that in larger stars, stars with more than three times the mass of our sun, the crushing gravity causes the star to continue its collapse, becoming a black hole. “The forces of nature, which we understand well, just aren’t enough to stop that collapse.”
The universe, says Ashtekar, acts in much the same way. The pre-universe collapses-in on itself. However, a new kind of repulsive force comes into play because of the quantum properties of the geometry itself. “No matter how heavy, how much mass,” says Ashtekar, “this repulsive force still wins out. When the universe reached a point of high Planck density, [named after Max Planck, the founder of quantum mechanics] the repulsive force bounced it out.” Ashtekar’s team created the first detailed calculations that show classical behavior in the universe before the epoch of the Big Bang. “This is the time when quantum physics and relativity must be combined, and at this point the new physics causes a Big Bounce. And we find the equations that tell us that before this Big Bounce, there was a classical universe.”
While different scenarios abound as to what is on the other side of the Big Bang, no one had definitively predicted a classical universe. “The fact that there is a classical universe on the other side of the bounce, rather than a sort of quantum foam in which the space-time geometry fizzles out, was so surprising to us that we had to run more tests for several months to make sure it wasn’t a fluke. And the result was robust.”
Ashtekar does admit one limitation to the equations on which this idea is based: “We start by assuming that the universe is homogeneous and isotropic. It is an approximation done in cosmology, even though we know that the universe is not exactly like that. So the question is how to make the model more and more realistic. And this is an ongoing work.”
“All of this offers a solution to long-standing problems,” says Ashtekar. “We can show that spacetime was classical before the Big Bounce, and became classical again surprisingly close to after the bounce. We showed that there is no quantum foam on the other side, but that there is a classical branch connected by quantum geometry. And the coherence of these results shows that quantum geometry effects play a crucial role in understanding the true nature of the Big Bang.”
Ashtekar also adds that this work, as he and his colleagues continue to probe the Big Bounce and work toward overcoming the limitations of their equations and models, will contribute to better understanding quantum gravity, and developing a more complete theory. “Our work has some essential features of a theory of quantum gravity,” he says. “It gives us confidence in our underlying ideas.”
By Miranda Marquit, Copyright 2006 PhysOrg.com
Jun 09, 2009 |
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It's too bad that knowing universally can't exist outside of the current/western cognitive-system, or the certainty & knowing of the yoga tradition might be worth contemplating...
A Commonsensible Epilogue, And A Prologue To Life Evolution
Origin Of Gravity And Formation Of Life
Should be
(1 plus D)
!!!
http://www.scienc..._feeding
A Commonsensible Epilogue, And A Prologue To Life Evolution
Origin Of Gravity And Formation Of Life
http://www.scienc..._feeding
**The onset of big-bang's inflation started gravity, followed by formation of galactic clusters that behave "classically" as Newtonian bodies while continuously reconverting their shares of pre-inflation masses back to energy, and of endless intertwined evolutions WITHIN the clusters in attempts to resist this reconversion.
Astronomically there are two "physics", a "classical physics" behaviour of and between galactic clusters, and a "quantum physics" behaviour within galactic clusters.**
A. "Heavyweight galaxies in the young universe", at
http://www.scienc...universe
New observations of full-grown galaxies in the young universe may force astrophysicists to revise their leading theory of galaxy formation, at least as it applies to regions where galaxies congregate into clusters.
B. Some brief notes in "Light On Dark Matter?", at
http://www.physfo...ic=22994&st=0&#entry373127
- "Galaxy Clusters Evolved By Dispersion, Not By Conglomeration"
- Introduction of E=Total[m(1 D)]
- "Dark Energy And Matter And The Emperor's New Clothes"
- "Evolutionary Cosmology: Ordained Or Random"
- "%u201CMovie%u201D Of Microwave Pulse Transitioning From Quantum To Classical Physics"
- "Broken Symmetry" Is Physics' Term Of Biology's "Evolution"
- "A Glimpse Of Forces-Matter-Life Unified Theory"
C. Commonsensible conception of gravity
1. According to the standard model, which describes all the forces in nature except gravity, all elementary particles were born massless. Interactions with the proposed Higgs field would slow down some of the particles and endow them with mass. Finding the Higgs %u2014 or proving it does not exist %u2014 has therefore become one of the most important quests in particle physics.
However, for a commonsensible primitive mind with a commonsensible universe represented by
E=Total[m(1 D)], this conceptual equation describes gravity. It does not explain gravity. It describes it. It applies to the whole universe and to every and all specific cases, regardless of size.
2. Thus gravity is simply another face of the total cosmic energy. Thus gravity is THE cosmic parent of phenomena such as black holes and life. It is the display of THE all-pervasive-embracive strained space texture, laid down by the expanding galactic clusters, also noticed within the galactic clusters in the energy backlashes into various constructs of temporary constrained energy packages.
3. "Extrapolation of the expansion of the universe backwards in time to the early hot dense "Big Bang" phase, using general relativity, yields an infinite density and temperature at a finite time in the past. At age 10^-35 seconds the Universe begins with a cataclysm that generates space and time, as well as all the matter and energy the Universe will ever hold."
At D=0, E was = m and both E and m were, together, all the energy and matter the Universe will ever hold. Since the onset of the cataclysm, E remains constant and m diminishes as D increases.
The increase of D is the inflation, followed by expansion, of what became the galactic clusters.
At 10^-35 seconds, D in E=Total[m(1 D)] was already a fraction of a second above zero. This is when gravity started. This is what started gravity. At this instance starts the space texture, starts the straining of the space texture, and starts the "space texture memory", gravity, that may eventually overcome expansion and initiate re-impansion back to singularity.
D. Commonsensible conception of the forces other than gravity
The forces other than gravity are, commonsensibly, forces involved in conjunction with evolution within the galactic clusters:
http://royalsocie...?id=4770
The farthest we go in reductionism in Everything, including in Life, we shall still end up with wholism, until we arrive at energy. Energy is the base element of everything and of all in the universe. At the beginning was the energy singularity, at the end will be near zero mass and an infinite dispersion of the beginning energy, and in-between, the universe undergoes continuous evolution consisting of myriad energy-to-energy and energy-to-mass-to-energy transformations.
The universe, and everything in it, are continuously evolving, and all the evolutions are intertwined.
E. PS to "On Cosmic Energy And Mass Evolutions"
As mass is just another face of energy it is commonsensible to regard not only life, but mass in general, as a format of temporarily constrained energy.
It therefore ensues that whereas the expanding cosmic constructs, the galaxies clusters, are - overall - continuously converting "their" original pre-inflation mass back to energy, the overall evolution WITHIN them, within the clusters, is in the opposite direction, temporarily constrained
energy packages such as black holes and biospheres and other energy-storing mass-formats are precariuosly forming and "doing best" to survive as long as "possible"...
F. From "Strings Link the Ultracold with the Superhot"
http://www.scienc...Superhot
"Perfect liquids suggest theory%u2019s math mirrors something real.
When the universe was very young, and still superhot from the aftermath of the Big Bang, plasma should have been the only state of matter around. And that%u2019s what scientists at Brookhaven expected to see when they smashed gold ions together at 99.99 percent of the speed of light using a machine called RHIC (for Relativistic Heavy Ion Collider). RHIC physicists thought the ion collisions would melt the gold%u2019s protons and neutrons into a hot plasma of quarks and gluons at a temperature of a trillion kelvins, replicating conditions similar to those a microsecond after the birth of the universe. But instead of a gaslike plasma, the physicists reported in 2005, RHIC served up a hot quark soup, behaving more like a liquid than a plasma or gas."
G. The expectation of Brookhaven scientists was a bit unrealistic
The "aftermath of the Big Bang" lasted much less than 10^-35 seconds. This is evidenced by the fact that "Gravity Is THE Manifestation Of The Onset Of Cosmic Inflation Cataclysm":
http://www.the-sc...age#1950
and
http://www.the-sc...age#1982
With all respect due to the scientists at Brookhaven it is unrealistic to expect that they can recreate the state of pre big-bang energy-mass singularity. Commonsense is still the best scientific approach.
H. PS To "Gravity Limits Link Ultracold And Superhot": Our Inability To Create Singularity
a. From "Strings Link the Ultracold with the Superhot"
A new truth always has to contend with many difficulties,%u201D the German physicist Max Planck said decades ago. %u201CIf it were not so, it would have been discovered much sooner.%u201D
b. IMO gravity is attempted reversal of inflation
To me, a simple uninformed one, E=mc^2 is a derived formula, whereas E=Total[m(1 D)] is a commonsensical descriptive concept.
I intuitively regard both the ultracold and superhot liquids as being in a confined space and "striving but unable" to overcome D, to render D=0.
I also intuitively regard our accelerated collisions smashups as attempted "reverse inflations" in the sense that Newton's law of universal gravitation seems to me as "reverse inflation".
I. An epilogue and a prologue
Here ends the basic story of Energy, Mass, Gravity and Galaxies Clusters. For us, humans, this is the prologue to the story of Life's Evolution, briefly presented in "Updated Life's Manifest May 2009".
Dov Henis
(Comments from 22nd century)
http://blog.360.y...Q--?cq=1
Updated Life's Manifest May 2009
http://www.physfo...ic=14988]http://www.physfo...ic=14988[/url]&st=495&#entry412704
http://www.the-sc...age#2321
EVOLUTION Beyond Darwin 200
http://www.physfo...ic=14988]http://www.physfo...ic=14988[/url]&st=405&#entry396201
http://www.the-sc...age#1407
That is, the Universe appears to be open and not closed. For there to be another Big Bounce the Universe must be closed and not open.
Ethelred