Just a Second... - NaturPhilosophie
What Does a Second Look Like? 1/60 minute. 1/3,600 hour. 1/86,400 day. 1/1 hertz. The duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of a 133 55Cs caesium isotope corresponds to one second. But what does it look like?