Science fiction often portrays robots on the extreme ends of the spectrum: helpful and ready to learn and serve, or dangerous and preparing to take over jobs—and perhaps the world. Luckily, that fiction isn’t the reality. The evolution of robotics has only just begun....

Engineers at the University of California, San Diego have demonstrated a new and more efficient way to trap light, using a phenomenon called bound states in the continuum (BIC) that was first proposed in the early days of quantum wave mechanics. Boubacar Kanté, an...