Towards a new test of general relativity?
Experiment in ARC Seibersdorf research
23 March 2006
Scientists funded by the European Space Agency believe they may have
measured the gravitational equivalent of a magnetic field for the
first time in a laboratory. Under certain special conditions the
effect is much larger than expected from general relativity and could
help physicists to make a significant step towards the
long-sought-after quantum theory of gravity.
Just as a moving electrical charge creates a magnetic field, so a
moving mass generates a gravitomagnetic field. According to Einstein's
Theory of General Relativity, the effect is virtually negligible.
However, Martin Tajmar, ARC Seibersdorf Research GmbH, Austria; Clovis
de Matos, ESA-HQ, Paris; and colleagues believe they have measured the
effect in a laboratory.
Their experiment involves a ring of superconducting material rotating
up to 6 500 times a minute. Superconductors are special materials that
lose all electrical resistance at a certain temperature. Spinning
superconductors produce a weak magnetic field, the so-called London
moment. The new experiment tests a conjecture by Tajmar and de Matos
that explains the difference between high-precision mass measurements
of Cooper-pairs (the current carriers in superconductors) and their
prediction via quantum theory. They have discovered that this anomaly
could be explained by the appearance of a gravitomagnetic field in the
spinning superconductor (This effect has been named the
Gravitomagnetic London Moment by analogy with its magnetic
counterpart).
Small acceleration sensors placed at different locations close to the
spinning superconductor, which has to be accelerated for the effect to
be noticeable, recorded an acceleration field outside the
superconductor that appears to be produced by gravitomagnetism. "This
experiment is the gravitational analogue of Faraday's electromagnetic
induction experiment in 1831.
It demonstrates that a superconductive gyroscope is capable of
generating a powerful gravitomagnetic field, and is therefore the
gravitational counterpart of the magnetic coil. Depending on further
confirmation, this effect could form the basis for a new technological
domain, which would have numerous applications in space and other
high-tech sectors" says de Matos. Although just 100 millionths of the
acceleration due to the Earth's gravitational field, the measured
field is a surprising one hundred million trillion times larger than
Einstein's General Relativity predicts. Initially, the researchers
were reluctant to believe their own results.
Gravitomagnetic induction of gravitational fields
"We ran more than 250 experiments, improved the facility over 3 years
and discussed the validity of the results for 8 months before making
this announcement. Now we are confident about the measurement," says
Tajmar, who performed the experiments and hopes that other physicists
will conduct their own versions of the experiment in order to verify
the findings and rule out a facility induced effect.
In parallel to the experimental evaluation of their conjecture, Tajmar
and de Matos also looked for a more refined theoretical model of the
Gravitomagnetic London Moment. They took their inspiration from
superconductivity. The electromagnetic properties of superconductors
are explained in quantum theory by assuming that force-carrying
particles, known as photons, gain mass. By allowing force-carrying
gravitational particles, known as the gravitons, to become heavier,
they found that the unexpectedly large gravitomagnetic force could be
modelled.
"If confirmed, this would be a major breakthrough," says Tajmar, "it
opens up a new means of investigating general relativity and it
consequences in the quantum world."
The results were presented at a one-day conference at ESA's European
Space and Technology Research Centre (ESTEC), in the Netherlands, 21
March 2006. Two papers detailing the work are now being considered for
publication. The papers can be accessed on-line at the Los Alamos
pre-print server using the references: gr-qc/0603033 and
gr-qc/0603032.
For more detailed information, please contact:
Dipl-Ing Dr Martin Tajmar
Head of Business Field Space Propulsion
ARC Seibersdorf research GmbH
A-2444 Seibersdorf
Austria
Phone: +43 (0)5 05 50 31 42
Fax: +43 (0)5 05 50 33 66
Email:
Web: http://ilfb.tuwien.ac.at/~tajmar
Dr Clovis J. de Matos
General Studies Officer
European Space Agency ESA-HQ
Advanced Concepts and Studies Office - EUI-AC
8-10 Rue Mario Nikis
75738 Paris Cedex 15
France
Tel: +33 (0)1 53 69 74 98
Fax: +33 (0)1 53 69 76 51
Email:
http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html
--
Mario
http://mario.silent-tower.org/
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