I remember once seeing those NIST guys one evening at Dogfish Head Alehouse across the street talking physics and neutrinos. To measure time between two events,

I remember once seeing those NIST guys one evening at Dogfish Head Alehouse across the street talking physics and neutrinos. To measure time between two events, something needs to move faster than those events to perceive it. After a few beers, you'll be left with the check.