Muon and Electron Magnetic‐Moment Anomalies Disagree with Theory

New determinations of $g−2,$ the anomalous magnetic moment, for the muon and electron show small departures from their theoretically predicted values. The muon value, reported by Francis Farley (Royal Military College of Science, Shrivenham, UK) at the Washington APS meeting, is higher than theory. The electron value is lower, according to Arthur Rich of the University of Michigan who recently recalculated (Phys. Rev. Letters 20, 967, 1968) $g−2$ using the data of David T. Wilkinson and H. Richard Crane (Phys. Rev. 130, 852, 1963). New experiments to measure the election g‐factor anomaly are being done by Rich and by Larry Knight of Stanford University and by G. Gräff at the Physics Institute of the University, Bonn.