Rear Admiral Grace Hopper is famous both as a computer pioneer and for, at the time of her retirement (at age 79), being the nation's oldest active military officer. Hopper worked on early computers, and is widely credited with popularizing the term "computer bug" after she found a moth stuck inside a relay in Harvard's Mark II computer in 1947. (Thus "debugging" became the term for fixing computer problems....) You can see the first computer bug (they kept the moth!) at the Smithsonian, in the American History museum.
In this 1986 interview with David Letterman, Grace Hopper displays her grace and wit, and explains the concept of a nanosecond, using Bell System telephone wire cut into 30cm lengths -- 30cm is the maximum distance light can travel in a billionth of a second. Here's a representative quote:
"When an admiral asks you why it takes so damn long to send a message via satellite, you point out to him that between here and the satellite there are a very large number of nanoseconds. [Waves the wire at the sky.]"
She also gets into picoseconds! Enjoy:
You can read more about Hopper from Wikipedia.