| Minutes (min) | Microseconds (µs) |
|---|---|
| 1 Minute | 60000000 µs |
| 2 Minutes | 120000000 µs |
| 3 Minutes | 180000000 µs |
| 4 Minutes | 240000000 µs |
| 5 Minutes | 300000000 µs |
| 10 Minutes | 600000000 µs |
| 20 Minutes | 1200000000 µs |
| 25 Minutes | 1500000000 µs |
| 50 Minutes | 3000000000 µs |
| 100 Minutes | 6000000000 µs |
| Reference | Minutes (min) | Microseconds (µs) |
|---|---|---|
| A blink of an eye | 0.00166667 min | 100000 µs |
| One heartbeat at rest | 0.0138333 min | 830000 µs |
| Half of a football match | 45 min | 2.7 × 109 µs |
| A full day | 1440 min | 8.64 × 1010 µs |
The minute is a unit of time equal to 60 seconds, or one sixtieth of an hour. Its symbol is min. It is not an SI unit but is accepted for use with the SI, and it is one of the very few sexagesimal survivals in ordinary modern life.
The division of the hour into sixty parts comes from Babylonian astronomy by way of Greek and Islamic scholarship. Sixty is a highly composite number, divisible by 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30 and 60, which means halves, thirds, quarters, fifths and sixths of an hour are all whole numbers of minutes. A decimal hour of a hundred parts would give clean halves, quarters and fifths but no exact third, and a third of an hour is a quantity people actually use.
For centuries the minute was a theoretical division rather than a measured one, because no clock could show it. Mechanical clocks with only an hour hand were normal until the seventeenth century, and it was the pendulum, developed by Christiaan Huygens from Galileo's observation of isochronism, that first made minute-level accuracy ordinary. The minute hand followed the pendulum, not the other way round.
The French Republic tried to abolish it. The decimal time introduced in 1794 divided the day into ten hours of a hundred minutes, each of a hundred seconds. It was mandatory for less than two years, failed because every clock in the country would have needed replacing, and remains the clearest demonstration that metric reform succeeds only where the existing units are genuinely inconvenient.
Modern use is universal and unremarkable. Appointments, cooking times, journey durations, sports periods and billing increments are all in minutes, and the unit sits at a natural human scale: long enough to be a meaningful span of activity, short enough to be planned around without further subdivision.
Its sixtieth-part logic is shared with the circle, and the two meet in navigation. A minute of arc of latitude is one nautical mile, and a ship covering one nautical mile in one minute of time is travelling at sixty knots, which is why an old rule of thumb converts between distance and time on a chart without arithmetic. Music divides time the same way. Tempo is given in beats per minute, from a funeral march near 60 to dance music at 120 or more, and the metronome that Maelzel patented in 1815 fixed that convention in print. In both fields the minute is short enough to feel and long enough to count.
One minute equals 60 seconds, one sixtieth of an hour, or about 0.000694444 days.
The microsecond is a unit of time equal to one millionth of a second, or one thousandth of a millisecond. Its symbol is µs, written with the Greek letter mu, and the form us appears where that character is inconvenient to type.
It sits below the threshold of human experience entirely. Nothing a person does or perceives happens on this scale, so the unit belongs wholly to instruments. Light travels about three hundred metres in a microsecond, roughly the length of three football pitches, which sets a hard floor on how fast any signal can cross a room, a circuit board or a continent.
Satellite navigation depends on measuring it accurately. A receiver works out its position from the arrival times of signals from several satellites, and an error of one microsecond in that timing translates into a position error of about three hundred metres. This is why the satellites carry atomic clocks and why the system corrects for relativistic effects: the clocks in orbit run measurably faster than clocks on the ground, by about thirty-eight microseconds a day, and without that correction navigation would drift by kilometres within hours.
Electronics works comfortably at this scale. The switching time of a power transistor, the pulse width in radar, the interval between samples in high-speed data acquisition and the response of an analogue-to-digital converter are all quoted in microseconds. A microcontroller running at one megahertz completes one instruction cycle per microsecond, which makes the unit the natural currency of embedded timing.
Physics and chemistry use it for processes that are fast but not extreme. Muons produced in the upper atmosphere have a mean lifetime of about 2.2 microseconds, and the fact that they reach the ground at all is a direct experimental demonstration of time dilation. Some fluorescence decays, gas-phase reactions and shock-wave phenomena also occupy this range.
Audio engineering encounters it in digital sampling. At the standard rate of 44,100 samples per second, one sample lasts about 22.7 microseconds, and the timing jitter that degrades converter performance is measured in fractions of that.
One microsecond equals 0.000001 seconds, 0.001 milliseconds, or 1000 nanoseconds.