Paradox lost. Even though the magnet feels a torque in one reference frame but not in the other, it doesn’t spin in either, as the torque simply feeds the magnet’s “hidden” angular momentum. Credit: Preston Huey/Science/AAAS

Purported Relativity Paradox Resolved

by Adrian Cho on 25 January 2013, 3:50 PM

You can rest easier now: A purported conflict between the century-old theory of classical electrodynamics and Einstein’s theory of special relativity doesn’t exist, a chorus of physicists says.

Last April, Masud Mansuripur, an electrical engineer at the University of Arizona in Tucson, claimed that the equation that determines the force exerted on an electrically charged particle by electric and magnetic fields—the Lorentz force law—clashes with relativity, the theory that centers on how observers moving at a constant speed relative to one another will view the same events. To prove it, he concocted a simple “thought experiment” in which the Lorentz force law seemed to lead to a paradox, which he described in Physical Review Letters (PRL). Now, four physicists independently say that they have resolved the paradox in comments in press at PRL.

“Masud is completely convinced that he’s right, but he’s not,” says Stephen Barnett, a commenter from the University of Strathclyde in Glasgow, U.K.

Read more: Purported Relativity Paradox Resolved – ScienceNOW.

Home           Top of page