Unidentified scratchpad
An extension to a joke about measurement
- 1 times the speed of light in vacuum (such that the speed of light in vacuum is 1 times this unit)
- of the frequency of radiation corresponding to the transition between the two hyperfine levels of the unpertubed ground state of the cesium-133 atom
- cal
- of the energy transferred in vacuum when a system absorbs or emits exactly one photon of monochromatic electromagnetic radiation of frequency .