2 ms·
432 Hz is (by definition) once every 21279240 + 5/24 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground sta
by jacobolus 10y ago
432 Hz is (by definition) once every 21279240 + 5/24 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. Super aesthetically critical number right there.
- Intermernet 10y agoBut only at zero Kelvin. Once you punch that Caesium 133 up to room temperature you need the extra 8Hz to achieve aesthetic purity. On really hot days, you need to go to 440.1 or even 440.2.