Admiral Grace Hopper Explains the Nanosecond (1983) [video]
The foot has been criticized for being an arbitrary measurement with no real relation to a repeatable physical distance.However, it turns out that a foot is within 2% of the distance light travels in a nanosecond!Because of this, the foot becomes really convenient when talking about latencies. For example, if something is 6 inches away from the cpu on a motherboard, the lowest possible latency to reach that is 0.5 nanoseconds.Time to push for the adoption of feet everywhere /s