Shakes to Seconds (shake to s)
1 shake equals 1×10⁻⁸ seconds exactly.
How to convert shakes to seconds
To convert shakes to seconds, multiply the number of shakes by 1×10⁻⁸. This factor is exact. To go the other way, multiply seconds by 100,000,000.
seconds = shakes × 1×10⁻⁸
Example: 10 shakes = 1×10⁻⁷ seconds.
Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.
About these units
Shake (shake)
Exactly 10 nanoseconds. Coined at the Manhattan Project for nuclear chain reactions, from the phrase 'two shakes of a lamb's tail'.
Physicists on the wartime Manhattan Project needed a handy name for an interval that kept turning up in their chain-reaction calculations, and they settled on the shake. It is defined as 10 nanoseconds, or 10 to the power of minus 8 second. The name plays on the English idiom about something happening in two shakes of a lamb's tail, meaning very quickly.
One step of a fission chain, in which a neutron causes a fission that releases more neutrons, takes roughly one shake, and a whole reaction is typically over within 50 to 100 shakes, according to Wikipedia. The shake was coined in the same circle and for similar reasons as the barn, a unit of cross-sectional area. It is an informal metric unit rather than an SI unit. A shake equals 10,000 picoseconds, and 100 million shakes make one second.
1 shake = 1×10⁻⁸ seconds (exactly).
Sources: Wikipedia: Shake (unit); Wikipedia: Picosecond
Second (s)
The SI base unit of time, defined by the radiation frequency of the cesium-133 atom: 9,192,631,770 cycles per second.
Our word second is a leftover of Latin. Medieval scholars divided a degree, and later the hour, into 60 parts called pars minuta prima, the first small part, and divided those again into pars minuta secunda, the second small part. NIST traces the roots further back: Babylonian and Greek astronomers split the circle into 360 degrees, and around 150 C.E. Ptolemy split each degree into 60 minutes and each minute into 60 seconds. Clocks that could show seconds appeared only in the later 16th century, and Christiaan Huygens's pendulum clock of 1656 was the first able to keep time accurately to the second.
For most of history the second was a fraction of a day, and in 1956 it was redefined as a fraction of the tropical year, a definition the SI took over in 1960. In 1967 the 13th CGPM switched to atoms: 9,192,631,770 periods of the radiation tied to a hyperfine transition of caesium-133. The 2019 SI revision restated this by fixing the caesium frequency at 9,192,631,770 hertz. NIST reports that commercial caesium clocks stay within about a three-millionth of a second per year, and experimental clocks based on other atoms are roughly ten thousand times more precise.
The second is the reference unit for time on this site.
Sources: NIST: the second and the SI redefinition; BIPM: SI Brochure, 9th edition; Wikipedia: Second
Related conversions
- Seconds to shakes (reverse)
- Shakes to minutes
- Shakes to hours
- Shakes to days
- Shakes to weeks
- Shakes to months
- Shakes to years
- Minutes to seconds
- Hours to seconds
- Days to seconds
- Weeks to seconds
- Months to seconds
- Years to seconds
- Milliseconds to seconds
- Microseconds to seconds
- Nanoseconds to seconds
- Decades to seconds
- Centuries to seconds
- Millennia to seconds
See all time units.