Some people check a wristwatch; others use a smartphone app or the position of the sun. But although these methods will tell you what time it is, they won’t reveal your internal time – that is, the ...

The steady tick of a clock usually feels simple and dependable. Something swings or vibrates in a controlled rhythm and marks the passing of each moment. What you rarely notice is the hidden cost ...

Scientists built a tiny clock from single-electron jumps to probe the true energy cost of quantum timekeeping. They discovered that reading the clock’s output requires vastly more energy than the ...