The Universe, according to theory at least, should not exist. Theoretically, the birth of the Universe should have produced equal quantities of particles and antiparticles. Why the current Universe is so heavily skewed in particles’ favor is an enduring mystery—one whose solution remains all the harder to find because of antiparticles’ tendency to go and collide with particles. In a cryogenic, superconducting vacuum trap, physicists at Northwestern University in the US succes