Caption: To-scale
animation
of a
light pulse
propagating from the
Earth to the
Moon
at the
vacuum light speed c = 2.99792458*10**8 m/s
(exact by definition) ≅ 3*10**8 m/s = 3*10**5 km/s ≅ 1 ft/ns.
The light pulse propagates at
the vacuum light speed
and takes ≅ 1.26 seconds.