Table-top experiments unlock quantum realm predicted by Dirac equation. Trapped ions masquerading as high-speed particles have been used to confirm a bizarre 80-year-old prediction of quantum mechanics. Quantum particles racing at close to the speed of light were first predicted to jitter violently as they moved — a phenomenon known as the Zitterbewegung — in 1930, by the father of quantum mechanics, Erwin Schrödinger. The prediction was based on the Dirac equation, developed by British physicist Paul Dirac in 1928, which merges quantum mechanics with special relativity to describe how particles such as electrons behave. "The motion is particularly unexpected...