Keeping time is easy, keeping precise time is hard, but a new type of clock based on atomic nuclei has pushed time-keeping precision to new levels.

One of the world’s most famous astronomical clocks looms over a side street in the old city of Prague, with a complex astronomical dial, multiple myths, and a recent scandal — all worth investigating.

All living creatures are affected by the cycles of celestial objects. Humans have always been locked into the rhythms of sunrise and sunset, the phases of the Moon, and the seasons. We left some of ...