Vanquishing infinity: Old methods lead to a new approach to finding a quantum theory of gravity

Aug 17, 2009
In the 1940s, Richard Feynman devised a graphical method for carrying out calculations. Bern et al. use different kinds of diagrams that permit large calculations. Owing to their resemblance to the work of artist Piet Mondrian, these graphical computational devices are sometimes referred to as Mondrian diagrams. Credit: Adapted from Bern et al., Phys. Rev. D 76, 125020 (2007)]

Quantum mechanics and Einstein's theory of general relativity are both extremely accurate theories of how the universe works, but all attempts to combine the two into a unified theory have ended in failure. When physicists try to calculate the properties of a quantum theory of gravity, they find quantities that become infinite -- infinities that are so bad they can't be removed by mathematical gambits that work in other areas of physics.

Now, Zvi Bern, John Carrasco, and Henrik Johanssen at UCLA, Lance Dixon at the Stanford Linear Accelerator Center, and Radu Roiban at Pennsylvania State University have found a way to carry out a new set of gravity calculations with the help of an older theory that has been known since the 1980s to be finite.

Their new results are reported in Physical Review Letters and highlighted in a commentary by Hermann Nicolai at the Max Planck Institute for Gravitational Physics in Potsdam, Germany, in Physics.

Previous attempts at removing the fatal infinities in calculations collapsed when researchers discovered that you would need an infinite number of parameters. The problem stems from the point-like and thus infinitesimally small fundamental particles in the theories, so some physicists have developed as a possible approach: instead of point particles, the fundamental entities are vibrating loops of string. But string theory is beset with its own difficulties, as it lays out a "landscape" of possibilities with an astronomical number of scenarios.

The new paper by Bern et al. shows that by combining desirable aspects of string theory and point-like particles, they can use cancellations in the calculations - done with the help of graphical computational methods called Feynman diagrams (and later elaborations) - to escape the problem of infinities. While not a solution to the problem of quantum gravity, nor a result that knocks string theory aside, the findings of Bern et al. show that theories thought to be dead ends may still show the way forward.

More information: Phys. Rev. Lett. 103, 081301 (2009), link.aps.org/doi/10.1103/PhysRevLett.103.081301

Source: American Physical Society

Explore further: When parallel worlds collide, quantum mechanics is born

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Alexa
Aug 18, 2009
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mattytheory
1 / 5 (1) Aug 24, 2009
Hindsight is always 20/20. And, correct me if I am wrong, but the purpose of science is to explore EVERY possibility, right? If so, then the opposite (what you are suggesting) is not science.
HenisDov
1 / 5 (2) 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