Pioneering Computer Scientist Grace Hopper Shows Us How to Visualize a Nanosecond (1983)

Human imag­i­na­tion seems seri­ous­ly lim­it­ed when faced with the cos­mic scope of time and space. We can imag­ine, through stop-motion ani­ma­tion and CGI, what it might be like to walk the earth with crea­tures the size of office build­ings. But how to wrap our heads around the fact that they lived hun­dreds of mil­lions of years ago, on a plan­et some four and a half bil­lion years old? We trust the sci­ence, but can’t rely on intu­ition alone to guide us to such mind-bog­gling knowl­edge.

At the oth­er end of the scale, events mea­sured in nanosec­onds, or bil­lionths of a sec­ond, seem incon­ceiv­able, even to some­one as smart as Grace Hop­per, the Navy math­e­mati­cian who invent­ed COBOL and helped built the first com­put­er. Or so she says in the 1983 video clip above from one of her many lec­tures in her role as a guest lec­tur­er at uni­ver­si­ties, muse­ums, mil­i­tary bod­ies, and cor­po­ra­tions.

When she first heard of “cir­cuits that act­ed in nanosec­onds,” she says, “bil­lionths of a sec­ond… Well, I didn’t know what a bil­lion was…. And if you don’t know what a bil­lion is, how on earth do you know what a bil­lionth is? Final­ly, one morn­ing in total des­per­a­tion, I called over the engi­neer­ing build­ing, and I said, ‘Please cut off a nanosec­ond and send it to me.” What she asked for, she explains, and shows the class, was a piece of wire rep­re­sent­ing the dis­tance a sig­nal could trav­el in a nanosec­ond.

Now of course it wouldn’t real­ly be through wire — it’d be out in space, the veloc­i­ty of light. So if we start with a veloc­i­ty of light and use your friend­ly com­put­er, you’ll dis­cov­er that a nanosec­ond is 11.8 inch­es long, the max­i­mum lim­it­ing dis­tance that elec­tric­i­ty can trav­el in a bil­lionth of a sec­ond.

Fol­low the rest of her expla­na­tion, with wire props, and see if you can bet­ter under­stand a mea­sure of time beyond the reach­es of con­scious expe­ri­ence. The expla­na­tion was imme­di­ate­ly suc­cess­ful when she began using it in the late 1960s “to demon­strate how design­ing small­er com­po­nents would pro­duce faster com­put­ers,” writes the Nation­al Muse­um of Amer­i­can His­to­ry. The bun­dle of wires below, each about 30cm (11.8 inch­es) long, comes from a lec­ture Hop­per gave muse­um docents in March 1985.

Pho­to via the Nation­al Muse­um of Amer­i­can His­to­ry

Like the age of the dinosaurs, the nanosec­ond may only rep­re­sent a small frac­tion of the incom­pre­hen­si­bly small units of time sci­en­tists are even­tu­al­ly able to measure—and com­put­er sci­en­tists able to access. “Lat­er,” notes the NMAH, “as com­po­nents shrank and com­put­er speeds increased, Hop­per used grains of pep­per to rep­re­sent the dis­tance elec­tric­i­ty trav­eled in a picosec­ond, one tril­lionth of a sec­ond.”

At this point, the map becomes no more reveal­ing than the unknown ter­ri­to­ry, invis­i­ble to the naked eye, incon­ceiv­able but through wild leaps of imag­i­na­tion. But if any­one could explain the increas­ing­ly inex­plic­a­ble in terms most any­one could under­stand, it was the bril­liant but down-to-earth Hop­per.

via Kot­tke

Relat­ed Con­tent:

Meet Grace Hop­per, the Pio­neer­ing Com­put­er Sci­en­tist Who Helped Invent COBOL and Build the His­toric Mark I Com­put­er (1906–1992)

The Map of Com­put­er Sci­ence: New Ani­ma­tion Presents a Sur­vey of Com­put­er Sci­ence, from Alan Tur­ing to “Aug­ment­ed Real­i­ty”

Free Online Com­put­er Sci­ence Cours­es 

Josh Jones is a writer and musi­cian based in Durham, NC. Fol­low him at @jdmagness

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