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 behind every tick. Timekeeping works only because something ...

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 clock uses to function. This measurement process also ...