Summary

A basic equation of electricity and magnetism is wrong, one scientist claims. The classic formula for the force exerted by electric and magnetic fields—the so-called Lorentz force—clashes with Einstein's special theory of relativity, says Masud Mansuripur, an electrical engineer at the University of Arizona in Tucson. Others doubt the claim but have not found a flaw in the simple argument that challenges century-old textbook physics.