Who's to decide how long is one second? What's the standard? Who's to decide how fast the digital numbers jump? Who's to decide how fast the second hand turns? Then i went to wiki it...
Under the International System of Units, the second is currently defined as
| “ | 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 the caesium 133 atom.[1] | ” |
This definition refers to a caesium atom at rest at a temperature of 0 K (absolute zero). The ground state is defined at zero magnetic field. The second thus defined is equivalent to the ephemeris second, which was based on astronomical measurements. (See History below.
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