From sundials and swinging pendulums to vibrating quartz crystals, humans have many ways of measuring the passage of time. But where accuracy is most essential – in global positioning systems and high-speed communication technologies, for example – we rely on atoms, which tick uniformly and are nearly impossible to interrupt. In this brief video, cleverly animated by Dog and Rabbit, the 1997 physics Nobel laureate William D Phillips explains how his team was able to unleash an atomic timekeeping revolution using lasers and mind-bogglingly low temperatures.