Nanosecond

A nanosecond (ns) is a unit of time in the International System of Units (SI) equal to one billionth of a second, that is, $1/1 000 000 000$ of a second, or 10$−9$ seconds.

The term combines the SI prefix nano- indicating a 1 billionth submultiple of an SI unit (e.g. nanogram, nanometre, etc.) and second, the primary unit of time in the SI.

A nanosecond is equal to 1000 picoseconds or $1/1000$ microsecond. Time units ranging between 10$−8$ and 10$−7$ seconds are typically expressed as tens or hundreds of nanoseconds.

Time units of this granularity are commonly found in telecommunications, pulsed lasers, and related aspects of electronics.

Common measurements

 * 0.001 nanoseconds – one picosecond
 * 0.96 nanoseconds – 100 Gigabit Ethernet Interpacket gap
 * 1.0 nanosecond – cycle time of an electromagnetic wave with a frequency of 1 GHz (1 hertz).
 * 1.0 nanosecond – electromagnetic wavelength of 1 light-nanosecond. Equivalent to 0.3m radio band.
 * nanoseconds (by definition) – time taken by light to travel 1 foot in a vacuum.
 * nanoseconds (by definition) – time taken by light to travel 1 metre in a vacuum.
 * 8 nanoseconds - typical propagation delay of 74HC series logic chips based on HCMOS technology, commonly used for digital electronics in the mid-1980s.
 * 10 nanoseconds – one "shake", (as in a "shake of a lamb's tail") approximate time of one generation of a nuclear chain reaction with fast neutrons
 * 10 nanoseconds – cycle time for frequency 100 MHz (1 hertz), radio wavelength 3 m (VHF, FM band)
 * 10 nanoseconds – half-life of lithium-12
 * 12 nanoseconds – mean lifetime of a charged K meson
 * 20–40 nanoseconds – time of fusion reaction in a hydrogen bomb
 * 30 nanoseconds – half-life of carbon-21
 * 77 nanoseconds – a sixth (a 60th of a 60th of a 60th of a 60th of a second)
 * 96 nanoseconds – Gigabit Ethernet Interpacket gap
 * 100 nanoseconds – cycle time for frequency 10 MHz, radio wavelength 30 m (shortwave)
 * 294.4 nanoseconds – half-life of polonium-212
 * 333 nanoseconds – cycle time of highest medium wave radio frequency, 3 MHz
 * 500 nanoseconds – T1 time of Josephson phase qubit (see also Qubit) as of May 2005
 * 1,000 nanoseconds – one microsecond