No more Valentines: New induction detectors see no monopoles

On St. Valentine's Day two years ago, Blas Cabrera's magnetic‐monopole detector at Stanford, unattended on that Sunday afternoon, recorded a current jump in its superconducting detection loop that corresponded precisely to the induction one would expect if a Dirac monopole had passed through it. “Having now expanded our monopole search almost a hundredfold with a larger, more sophisticated detector,” Cabrera told us two years later to the day, “we've seen nothing comparable.”