nanosecond

nanosecond

(1) One billionth of a second. Used to measure the speed of logic and memory chips, a nanosecond can be visualized by converting it to distance. In one nanosecond, electricity travels approximately a foot in a wire. Admiral Grace Hopper was famous for handing out strands of "telephone wire nanoseconds" to her audience whenever she lectured about technology. Holding the wire turns the unreal concept of a billionth of a second into reality.

Even at 186,000 miles per second, electricity is never fast enough for the hardware designer who worries over a few inches of circuit path. The slightest delay is multiplied millions of times, since millions of pulses are sent through a wire in a single second. In addition, today's chips contain more than a quarter mile of wire traces (current-carrying pathways). Future chips are expected to contain several miles of circuit paths. See space/time, jiffy and ohnosecond.

(2) The time between a traffic light turning green and a New York City cab driver blowing his horn.

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(unit)

nanosecond - (ns) 10^-9 seconds; one thousand millionth part of a second. This is the unit in which the fundamental logical operations of modern digital circuits are typically measured. For example, a microprocessor with a clock frequency of 100 megahertz will have a 10 nanosecond clock period.