BETA ZEN
Light-second
Texto da Wikipédia (en), licença CC BY-SA. O BETARUBI mostra o verbete inteiro nesta página — a leitura não continua fora do site.
The light-second is a unit of length useful in astronomy, telecommunications and relativistic physics. It is defined as the distance that light travels in free space in one second, and is equal to exactly 299792458 m.