[FPSPACE] Scientists Predict How To Detect A Fourth Dimension Of Space
ljk4 at msn.com
Thu Jun 29 13:10:42 EDT 2006
Scientists Predict How To Detect A Fourth Dimension Of Space
Einstein's Theory of Relativity is going to have to defend itself against a
new five-dimensional theory of gravity.
by Staff Writers
Durham NC (SPX) May 26, 2006
Scientists at Duke and Rutgers universities have developed a mathematical
framework they say will enable astronomers to test a new five-dimensional
theory of gravity that competes with Einstein's General Theory of
Charles R. Keeton of Rutgers and Arlie O. Petters of Duke base their work on
a recent theory called the type II Randall-Sundrum braneworld gravity model.
The theory holds that the visible universe is a membrane (hence
"braneworld") embedded within a larger universe, much like a strand of filmy
seaweed floating in the ocean.
The "braneworld universe" has five dimensions -- four spatial dimensions
plus time -- compared with the four dimensions -- three spatial, plus time
-- laid out in the General Theory of Relativity.
From: Floyd Stecker [view email]
Date: Tue, 27 Jun 2006 13:26:21 GMT (926kb)
Testing Relativity at High Energies Using Spaceborne Detectors
Authors: F. W. Stecker (NASA/GSFC)
Comments: pdf file, 13 pages, Text of invitated talk presented at the "From
Quantum to Cosmos: Fundamental Physics Studies from Space" meeting, typo in
(ABRIDGED) The Gamma-ray Large Area Space Telescope (GLAST) will measure the
spectra of distant extragalactic sources of high energy gamma-rays. GLAST
can look for energy dependent propagation effects from such sources as a
signal of Lorentz invariance violation (LIV). Such sources should also
exhibit high energy spectral cutoffs from pair production interactions with
low energy photons. The properties of such cutoffs can also be used to test
LIV. Detectors to measure gamma-ray polarization can look for the
depolarizing effect of space-time birefingence predicted by loop quantum
gravity. A spaceborne detector array looking down on Earth to study
extensive air showers produced by ultrahigh energy cosmic rays can study
their spectral properties and look for a possible deviation from the
predicted GZK effect as another signal of LIV.
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