Gravity has a secret side. As well as the brute force that holds us to the ground, large masses should also exert a subtle swirling influence when they rotate, a force called gravitomagnetism. It’s so faint that NASA spacecraft called Gravity Probe B has been orbiting the Earth for over two years to accrue enough evidence to have a chance of confirming this force.
Yet in a lab in Austria, Martin Tajmar and his team have already succeeded in detecting a faint signal that seems to be due to this elusive component of gravity. A reason for celebration? Not quite. Puzzlingly, the force they seem to have generated is vastly more powerful than anyone else expected.[..]
In the mid-1980s, Blas Cabrera, also of Standford University, saw Everitt’s work on these gyroscopes and realized that they offered a way to test the theory of superconductors proposed in 1957 by John Bardeen, Leon Cooper and Robert Schrieffer, known as the BCS theory. It says that when the temperature of the material falls below the critical temperature for superconductivity, pairs of electrons overcome their normal repulsion and join into bound systems known as Cooper pairs. Cabrera realized that since the gyroscope’s magnetic field is due to the motion of electrons inside the superconductor, the field could reveal whether those electrons were indeed pairing up. Janet Tate, now of the University of Oregon in Eugene, ran the experiments. She took one of the gyroscopes and spun it at different speeds to measure the resulting field produced by an accelerating superconductor. That’s when the trouble started. Tate found that the magnetic field she measured was stronger than BCS theory predicted.
As the anomaly didn’t affect the performance of the gyroscopes, finding the cause wasn’t essential to the workings of the NASA spacecraft. So, after an initial flurry of interest by physicists, the problem was quietly dropped. “The measurement has remained unexplained for the last 20 years,
