Planck constant 6.626070040 x [10.sup.-34] kilogram kg [m.sup.2]/s Speed of light
299,792,458 m/s meter in a vacuum Elementary 1.6021766208 x [10.sup.-19] ampere charge ampere seconds Boltzmann 1.38064852 x [10.sup.-23] kelvin constant kg [m.sup.2] ([s.sup.2] kelvin) Avogadro 6.022140857 x [10.sup.23]/ mole; used with constant mole [R.sub.[infinity]] to measure h, then define kg Rydberg 10,973,731.568508/m used with [N.sub.A] to constant measure h, then define kg Hyperfine 9,192,631,770/s second splitting of cesium Luminous 683 candela steradian candela efficacy [s.sup.3]/(kg [m.sup.2]) Fine-structure 1/137.035999139 none, but its value is constant related to the other constants
Now given that the speed of light is
299,792,458 metres per second then it is highly unlikely we will ever visit this far-off planet.
The "speed of light" in free space is more properly denoted [c.sub.0] and since 1983, has been defined as
299,792,458 metres per second.
I think they had meant to say "speed of light", which everyone knows is
299,792,458 m/s.
A meter is defined as the distance light travels in 1/299,792,458 seconds, which fixes c to the value
299,792,458 m/s.
Gezari [1] reported a difference of 200 [+ or -] 10 m/s to the known value (c =
299,792,458 m/s according to [1]), which is in accordance with the speed of the observatory on the earth to the retro-reflector on the moon.