
I learned it today – understanding length in metres
Speed of light =299792458m/s 0r approx 300000km/sec Second= 9192631770 cycles of the standard caesium 133 atom(55) transition (electron vibration pulse)- in future optical clocks because of less uncertainty Metre= the length of the path travelled by light in a vacuum during a time interval of 1/299792458 of a second Pm=Picometer unit of length equivalent to […]