A light-year (LY) is a unit of distance measurement based on the travel of light energy, undisturbed in a vacuum, over the course of one Earth year.

History and specifics[]

A light year is about 9.5 quadrillion meters long.

The first mention of light-years in Star Trek was in the pilot episode "Where No Man Has Gone Before", referring to the half light-year (0.5LY) that the Valiant traveled past the galactic barrier. The episode also made use of light-days as a unit of measure for the journey to Delta Vega.

Appendices[]

References[]

• TOS episode & Star Trek 8 novelization: Where No Man Has Gone Before

External link[]

• Light-year article at Wikipedia, the free encyclopedia.