News tagged with quantum gravity

Repulsive gravity as an alternative to dark energy (Part 2: In the quantum vacuum)

(PhysOrg.com) -- During the past few years, CERN physicist Dragan Hajdukovic has been investigating what he thinks may be a widely overlooked part of the cosmos: the quantum vacuum. He suggests that the quantum vacuum has ...

Physics / General Physics

created Feb 01, 2012 | popularity 4.7 / 5 (77) | comments 143 | with audio podcast report

Why we've got the cosmological constant all wrong

(PhysOrg.com) -- Some scientists call the cosmological constant the "worst prediction of physics." And when today’s theories give an estimated value that is about 120 orders of magnitude larger than the ...

Physics / General Physics

created Mar 05, 2012 | popularity 4.5 / 5 (41) | comments 152 | with audio podcast feature

Physicists propose test for loop quantum gravity

(PhysOrg.com) -- As a quantum theory of gravity, loop quantum gravity could potentially solve one of the biggest problems in physics: reconciling general relativity and quantum mechanics. But like all tentative ...

Physics / Quantum Physics

created Jan 03, 2012 | popularity 4.3 / 5 (34) | comments 106 | with audio podcast feature

Physicists search for new physics in primordial quantum fluctuations

(PhysOrg.com) -- Inflation, the brief period that occurred less than a second after the Big Bang, is nearly as difficult to fathom as the Big Bang itself. Physicists calculate that inflation lasted for just ...

Physics / Quantum Physics

created Mar 26, 2012 | popularity 4.6 / 5 (26) | comments 99 | with audio podcast feature

Four reasons why the quantum vacuum may explain dark matter

(PhysOrg.com) -- Earlier this year, PhysOrg reported on a new idea that suggested that gravitational charges in the quantum vacuum could provide an alternative to dark matter. The idea rests on the hypothesis that particles ...

Physics / General Physics

created Nov 28, 2011 | popularity 5 / 5 (67) | comments 124 | with audio podcast report

Revised theory of gravity doesn't predict a Big Bang

(PhysOrg.com) -- The Big Bang theory has formed the basis of our understanding of the universe's origins since it was first proposed in 1927 by Georges Lemaitre. And for good reason: the theory is supported ...

Physics / General Physics

created Jul 12, 2010 | popularity 4.7 / 5 (77) | comments 213 | with audio podcast feature

Einstein equations indicate possibility of black hole formation at the LHC

(PhysOrg.com) -- One of the concerns that has been voiced about the Large Hadron Collider (LHC), is that it could result in the formation of black holes that could destroy the world. While most scientists ...

Physics / General Physics

created Apr 06, 2010 | popularity 4 / 5 (63) | comments 364 | with audio podcast feature

New Law of Physics Could Explain Quantum Mysteries

(PhysOrg.com) -- Since the early days of quantum mechanics, scientists have been trying to understand the many strange implications of the theory: superpositions, wave-particle duality, and the observer’s ...

Physics / Quantum Physics

created Aug 17, 2009 | popularity 4.5 / 5 (98) | comments 162 feature

Physicists investigate fate of five-dimensional black strings

(PhysOrg.com) -- While black holes in four-dimensional space-time are stable and can persist for a long time, their higher-dimensional analogues are usually unstable. One such theoretical analogue is a five-dimensional ...

Physics / General Physics

created Sep 10, 2010 | popularity 4.5 / 5 (36) | comments 14 | with audio podcast feature

Time travel theory avoids grandfather paradox

(PhysOrg.com) -- The possibility of going back in time only to kill your ancestors and prevent your own birth has posed a serious problem for potential time travelers, not even considering the technical details ...

Physics / Quantum Physics

created Jul 21, 2010 | popularity 4.1 / 5 (55) | comments 96 | with audio podcast report

Looking at quantum gravity in a mirror

Einstein's theory of gravity and quantum physics are expected to merge at the Planck-scale of extremely high energies and on very short distances. At this scale, new phenomena could arise. However, the Planck-scale ...

Physics / Quantum Physics

created Mar 18, 2012 | popularity 4.8 / 5 (27) | comments 9 | with audio podcast

Proposed Spacetime Structure Could Provide Hints for Quantum Gravity Theory

(PhysOrg.com) -- Spacetime, which consists of three dimensions of space and one time dimension, is such a large, abstract concept that scientists have a very difficult time understanding and defining it. Moreover, ...

Physics / Quantum Physics

created Dec 16, 2009 | popularity 4.6 / 5 (58) | comments 16 feature

Spacetime May Have Fractal Properties on a Quantum Scale

(PhysOrg.com) -- Usually, we think of spacetime as being four-dimensional, with three dimensions of space and one dimension of time. However, this Euclidean perspective is just one of many possible multi-dimensional ...

Physics / Quantum Physics

created Mar 25, 2009 | popularity 4.7 / 5 (57) | comments 40 feature

Is Everything Made of Mini Black Holes?

(PhysOrg.com) -- In trying to understand how gravity behaves on the quantum scale, physicists have developed a model that has an interesting implication: mini black holes could be everywhere, and all particles ...

Physics / General Physics

created May 18, 2009 | popularity 4.6 / 5 (60) | comments 56 weblog

Gravity might amplify quantum fluctuations, create astrophysical objects

(PhysOrg.com) -- In a new study, physicists have proposed that gravity could trigger a runaway effect in quantum fluctuations, causing them to grow so large that the quantum field’s vacuum energy density could dominate its ...

Physics / General Physics

created May 17, 2010 | popularity 4.6 / 5 (28) | comments 9 | with audio podcast report