Ultra Precise Quantum Logic Clock Puts Old Atomic Clock to Shame

The quantum-logic clock, which detects the energy state of a single aluminum ion, keeps time to within a second every 3.7 billion years. The new timekeeper could one day improve GPS or detect the slowing of time predicted by Einstein’s theory of general relativity.

Chen-wen Chou says the clock allows him to know within 1 nanosecond how long it's been since he got laid.