In a grandfather clock, a pendulum swings back and forth and this periodic motion is maintained using the energy stored in its suspended weights. This is done with the help of the escapement mechanism, which converts the gravitational energy of the weights into impulses that drive the pendulum, which then moves the clock’s gears, which move its hands.

A group of researchers recently designed a quantum version of the pendulum clock. According to their new study, published in Physical Review A, this quantum pendulum clock can operate autonomously and is more accurate than previous quantum clocks.