The nanolight-second, how far light moves in a nanosecond, turns out to be an everyday-sized unit of length. It is about 29.979 cm, or 11.803 inches. I find it suprising that it is so close to the Imperial unit foot.

The calculation: By a slight adjustment of definition, a light-second is 299792458 metres. "Nano" means billionth (a thousandth thousandth thousandth), so a nanolight-second, or light-nanosecond, is 0.299792458 m, or 29.9792458 cm.

If there were a more convenient name for this unit of length (one that wasn't five syllables), I might even start using it in everyday talk to be even more confusing! How about len (Light Nano) or nel (Nano Light)? Hmm... hard decision. Oh well, until the revolution I'll be saying nanolight-second anyway.