A measurement of positronium’s energy levels confounds scientists

Positronium is positively puzzling. A new measurement of the exotic “atom” — consisting of an electron and its antiparticle, a positron — disagrees with theoretical calculations, scientists report in the…

To live up to the hype, quantum computers must repair their error problems

Astronaut John Glenn was wary about trusting a computer. It was 1962, early in the computer age, and a room-sized machine had calculated the flight path for his upcoming orbit…