ATOMIC clocks are the basis of GPS devices, they define the official length of the second and recently played a role in tracking subatomic particles that seemingly travelled faster than the speed of light. Now this "ultimate" timekeeper has a rival: a new method for making nuclear clocks suggests such devices could be 60 times as accurate as their atomic rivals.
A nuclear clock has not yet been made but the idea would be to use the atomic nucleus like a tuning fork. A nucleus will jump to a higher energy state, then fall back down, and jump up again, only if it is hit with a very specific frequency of light. Tuning a laser so that it prompts these jumps is a way to set its frequency with a phenomenal level of precision. The frequency can then be used like a clock's tick to keep time.
