How Current Loops and Solenoids Curve Space-time
Date: Monday, January 11, 2016 @ 00:11:31 EST
by Andre Fuzfa/University of Namur, Belgium/December 15, 2015
The curved space-time around current loops and solenoids carrying arbitrarily large steady electric currents is obtained from the numerical resolution of the coupled Einstein-Maxwell equations in cylindrical symmetry. The artificial gravitational field associated to the generation of a magnetic field produces gravitational redshift of photons and deviation of light. Null geodesics in the curved space-time of current loops and solenoids are also presented. We finally propose an experimental setup, achievable with current technology of superconducting coils, that produces a phase shift of light of the same order of magnitude than astrophysical signals in ground-based gravitational wave observatories.
Somehow, studying gravity is a contemplative activity: physicists restrict themselves to the study of natural, pre-existing, sources of gravitation. Generating artificial gravitational fields, that could be switched on or off at will, is a question captured or left to science-fiction.
However, the equivalence principle, at the very heart of Einstein's general relativity, states that all types of energy produce and undergo gravitation in the same way. The most widespread source of gravitation is the inertial mass, which produces permanent gravitational fields. At the opposite, electromagnetic fields could be used to generate artificial, or human-made, gravitational fields, that could be switched on or o at will, depending whether their electromagnetic progenitors are present or not...
Full paper: http://arxiv.org/pdf/1504.00333v3.pdf