posted on Oct, 18 2012 @ 02:26 AM
Although quantum theory can explain three of the four forces in nature, scientists currently rely on general relativity to explain the fourth force,
gravity. However, no one is quite sure of how gravity works at very short distances, in particular the shortest distance of all: the Planck length.
If one describes gravity at the quantum level, the bending of light by gravitation becomes energy-dependent – unlike in Newtonian gravity or
Einstein's general relativity," "The higher the energy of the photons, the larger the bending, or the stronger the photon-graviton interaction should
be." Gharibyan suggests that this bending of light according to quantum gravity models may be studied using high-energy accelerator beams that probe
the vacuum symmetry of empty space at small scales. Accelerators could use high-energy Compton scattering, in which a photon that scatters off another
moving particle acquires energy, causing a change in its momentum. The proposed experiments could detect how the effects of quantum gravity change the
photon's energy-momentum relation compared with what would be expected on a normal scale.
Quantum or torsion gravity models predict unusual properties of space-time at very short dis- tances. In particular, near the Planck length,
around 10−35m, empty space may behave as a crystal, singly or doubly refractive. However, this hypothesis remains uncheckable for any direct
measure- ment since the smallest distance accessible in experiment is about 10−19m at the LHC. Here I propose a laboratory test to measure the space
refractivity and birefringence induced by gravity. A sensitivity from 10−31m down to the Planck length could be reached at existent GeV and future
TeV energy lepton accelerators using laser Compton scattering. There are already experimental hints for gravity signature at distances approaching the
Planck length by 5–7 orders of magnitude, derived from SLC and HERA data.
Full paper available here.
edit on 18-10-2012 by ubeenhad because: (no reason given)