Rewriting general relativity? Putting a new model of quantum gravity under the microscope

Aug 24, 2009
Scientists are trying to figure out to what extent a new theory of quantum gravity will reproduce general relativity -- the theory that currently explains, to very high accuracy, how masses curve spacetime and create the influence of gravity. Credit: Image copyright American Physical Society, Illustration: Carin Cain

Does an exciting but controversial new model of quantum gravity reproduce Einstein's theory of general relativity? Scientists at Texas A&M University in the US explore this question in a paper appearing in Physical Review Letters and highlighted with a Viewpoint in the August 24th issue of Physics.

"If it ain't broke, don't fix it," sums up fairly well how many scientists have viewed Einstein's theory of general relativity. The theory, which Einstein developed in the early 20th century, says that matter curves spacetime, and it is this curvature which deflects massive bodies - an effect that we interpret as the influence of gravity. The theory has been tested to extremely high accuracy and without it, our satellite global positioning system would be off by about 10 km per day.

Despite the success of general relativity, one of the most important problems in modern physics is finding a theory of quantum gravity that reconciles the continuous nature of gravitational fields with the inherent 'graininess' of quantum mechanics. Recently, Petr Hořava at Lawrence Berkeley Lab proposed such a model for that has received widespread interest, in no small part because it is one of the few models that could be experimentally tested. In Hořava's model, Lorentz symmetry, which says that physics is the same regardless of the reference frame, is violated at small distance scales, but remerges over longer distance scales

The team at Texas A&M, which includes Hong Lu, Jianwei Mei and Christopher Pope, report their investigations into how the modifications proposed in Hořava's theory will broadly affect the solutions of general relativity. One aspect of their study is that it leads to an important caveat, described by Horatiu Nastase in a Viewpoint commentary in Physics. Lu et al.'s calculations, explains Nastase, suggest that Hořava's model only reproduces on unobservable scales, "larger than the size of the Universe".

Lu et al.'s paper is an important contribution to testing the Hořava model and shows that a good deal of work remains to understand its full implications.

More information: http://link.aps.org/doi/10.1103/PhysRevLett.103.091301; Download PDF (free)

Source: American Physical Society

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OregonWind
1 / 5 (1) Aug 24, 2009
"Scientists at Texas A&M University in the US explore this question in a paper appearing in Physical Review Letters and highlighted with a Viewpoint in the August 24th issue of Physics."

Also

Division of Applied Mathematics and Theoretical Physics, China Institute for Advanced Study, Central University of Finance and Economics, Beijing, 100081, China


And

DAMTP, Centre for Mathematical Sciences, Cambridge University, Wilberforce Road, Cambridge CB3 OWA, United Kingdom

NeilFarbstein
2.3 / 5 (4) Aug 24, 2009
call it son of relativity...no..cousin of relativity.
HenisDov
1 / 5 (7) Aug 25, 2009
The Basic Implications Of E=Total[m(1 D)]
http://www.the-sc...age#3108
a recapitulation


A. Its essential statement

"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."

E = Energy content of the universe
m = mass content of the universe
D = distance, Total = in all spatial directions, from the point of Big-Bang, of singularity's energy-mass superposition

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 initial inflation, followed by the ongoing expansion, of what became the galactic clusters.

At 10^-35 seconds, D was already a fraction of a second above zero. This is when gravity starts. This is what started gravity. At this instance starts the energetic space texture, starts the straining of the space texture, and starts the space-texture-memory, gravity, that most probably will eventually overcome expansion and initiate re-impansion back to singularity.


B. Some of its further essential implications beyond Einstein-Hubble and re classical-quantum physics

And again and again : "On The Origin Of Origins"
http://www.the-sc...age#2753

1. It promotes commonsensical scientific critical thinking beyond Einstein-Hubble.

The universe is the archetype of quantum within classical physics, which is the fractal oneness of the universe.

Astronomically there are two physics. A classical Newtonian physics behaviour of and between galactic clusters, and a quantum physics behaviour WITHIN the galactic clusters.

The onset of big-bang's inflation, the cataclysmic resolution of the Original Superposition, started gravity, with formation - BY DISPERSION - of galactic clusters that behave as classical Newtonian bodies and continuously reconvert their original pre-inflation masses back to energy, thus fueling the galactic clusters expansion, and with endless quantum-within-classical intertwined evolutions WITHIN the clusters in attempt to delay-resist this reconversion.

2. There is no call, no need, for any dark energy. The energy of the universe is conserved. The mass of the universe is conserved in the form of energy, the energy fueling the clusters expansion. At the next universal singularity, at the next D = 0, there will again be E = m for a small fraction of a second...just wait and see...

Following Newton (1) gravity is decreased when mass is decreased and (2) acceleration of a body is given by dividing the force acting upon it by its mass. By plain common sense the combination of those two 'laws' may explain the accelerating cosmic expansion of galaxy clusters and the laws that drive it, based on the E/ m/ D relationship suggested above..

3. There is no call, no need, for a Higgs Particle.

The resolution of energy-mass superposition is reverted when D = 0. Shockingly sad, but must be soberingly faced rationally.


C. Its implications re the origin and nature of life beyond Darwin, re selection for survival

For Nature, Earth's biosphere is one of the many ways of temporarily constraining an amount of energy within a galaxy within a galactic cluster, for thus avoiding, as long as possible, spending this particularly constrained amount as part of the fuel that maintains the clusters expansion.

Genes are THE Earth's organisms and ALL other organisms are their temporary take-offs.

For Nature genes are genes are genes. None are more or less important than the others. Genes and their take-offs, all Earth organisms, are temporary energy packages and the more of them there are the more enhanced is the biosphere, Earth's life, Earth's temporary storage of constrained energy. This is the origin, the archetype, of selected modes of survival.

The early genes came into being by solar energy and lived a very long period solely on direct solar energy. Metabolic energy, the indirect exploitation of solar energy, evolved at a much later phase in the evolution of Earth's biosphere.


Dov Henis
(Comments from 22nd century)
Updated Life's Manifest May 2009
http://www.physfo...ic=14988&st=480&#entry412704
http://www.the-sc...age#2321
Slotin
3.4 / 5 (5) Aug 25, 2009
There are some objections concerning the Horava's model of gravity.

http://arxiv.org/abs/0905.2751
Alexa
2.3 / 5 (3) Aug 27, 2009
And here we can find good introduction into subject
http://physics.ap...es/v2/71
KBK
1 / 5 (1) Sep 11, 2009
Look up Einstein's Unified theory published in 1928. There you will find torsion tensors, ie Relativity thrown out and Maxwell's full equations put back in-right where they should be.

It was a successful, workable, and engineerable theory.

Which is why it was basically--erased.

It also appears as if Physorg is enacting a selected form of bias and premeditated crushing of opinions and thoughts they don't like. Ie, they have politicized the site. I am limited to 1000 characters. For example, there is a post in this comment area that far exceeds my own 'given' capacity.

This makes the political censoring quite obvious, does it not?

It makes you wonder who is running this site.

Obviously--someone does not like what I say. I'm not rude, I just bring up points in science they don't like to hear. I push at the dogma of science, as intelligent and thinking people should.

If they don't like what I say, then obviously--I'm saying the right things.

Think about it.
KBK
3 / 5 (2) Sep 11, 2009
The point being-is that the current dogma of science can and many times does pose a greater danger to the forward progress of man than religion.

Science flows from people, and there is nothing that intrinsically makes scientists less dogmatic than any given religious nutbar. This is basic psychology, 101. They just many a time.... hide it better.

Danger, Will Robinson, Danger.
vantomic
not rated yet Oct 20, 2009
good call KBK, i see that HenisDov is allowed over 1000 words and he/she is spitting out pseudoscience (against the guidelines of physorg)...an explanation is in order physorg of why this person gets special treatment.

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