functional lightspeed (n.): A curious quirk of relativistics; thanks to time dilation and distance foreshortening, when a lighthugger on a sufficiently lengthy voyage achieves 0.707 lights, the wall-clock time experienced by the crew exactly matches the length of the voyage in the empire-time frame, thus creating the mathematical illusion that the starship is travelling at the speed of light.
While meaningless in practical terms, this has not stopped lighthugger crewers from using it as an excuse to throw a party and hold a “light-barrier crossing ceremony” to initiate those who have never done so before into the Right Honorable and Inebriated Order of the Improbably Celeritous. Such ceremonies include initiation into the “mysteries of the deep black” by the gods of space and stars and their court (played by the oldest Improbables aboard), much drunken horseplay, and the traditional final rite of standing on the foreshield of the lighthugger until one’s nerve cracks, followed by the equally traditional treatment for radiation exposure.
– A Star Traveler’s Dictionary
Hah! That’s pretty darn cool. (Said by someone who never got a chance to become a shellback or join the Order of the Blue Nose, so what do I know, but hey 😛 )