Light Years & Light Nano-Seconds
A light nanosecond — the distance light can travel in a billionth of a
second — is about 1 foot (about 30 cm).
Radar uses this fact to measure how far away something like an airplane is. A radar antenna sends out a short radio pulse and then waits for it to echo off an airplane or other target. While it’s waiting, it counts the number of nanoseconds that pass. Radio waves travel at the speed of light, so the number of nanoseconds divided by 2 tells the radar unit how far away the object is!
By a similar reasoning: PI Seconds is a Nano-Century!
