An effect that far exceeds what would be expected under Einstein’s theory of General Relativity has been produced in a laboratory. The fact that the effect — the gravitational equivalent of a magnetic field — is one hundred million trillion times larger than what General Relativity predicts has raised the eyebrows of more than a few researchers. But Martin Tajmar (ARC Seibersdorf Research GmbH, Austria) says that three years and 250 experimental runs have gone into this work, and encourages other physicists to examine and verify it.
If confirmed, the new findings could be a key result in the search for a quantum theory of gravity. We know that a moving electrical charge creates a magnetic field, and General Relativity assumes that a moving mass likewise generates a gravitomagnetic field, one that should, by the tenets of GR, be all but negligible. To test this, Tajmar and colleague Clovis de Matos (European Space Agency HQ, Paris) used a ring of superconducting material rotating 6500 times per minute. From an ESA news release:
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).
The result: acceleration sensors placed close to the spinning superconductor show an acceleration field that seems to be produced by gravitomagnetism. In other words, a superconductive gyroscope seems to be capable of generating a gravitomagnetic field, making it the gravitational counterpart of the magnetic coil used in Michael Faraday’s classic experiment of 1831. In that groundbreaking work, Faraday moved a magnet through a loop of wire and observed electric current flowing in the wire, thus demonstrating electromagnetic induction.
Despite being far vaster than what General Relativity predicts, the effect is nonetheless just 100 millionths of the acceleration due to Earth’s gravitational field. It could, nonetheless, represent a breakthrough in engineering acceleration fields. “If confirmed, this would be a major breakthrough,” says Tajmar, “it opens up a new means of investigating general relativity and its consequences in the quantum world.”
Further research and confirmation of these findings will be a fascinating process to watch. The results were presented on March 21 at ESA’s European Space and Technology Research Centre in the Netherlands. The two papers to study right now are:
Tajmar, Martin, F. Plesescu, K. Marhold, and Clovis J. de Matos, “Experimental Detection of the Gravitomagnetic London Moment,” submitted to Physica C and available here.
Tajmar, Martin and Clovis J. de Matos, “Local Photon and Graviton Mass and its Consequences,” submitted to International Journal of Modern Physics D, available here.