Minute
A
minute is a
unit of
time equal to 1/60th of an
hour and to 60
seconds. (Some rare minutes have 59 or 61 seconds; see
leap second.) For scientific purposes, the minute is a unit of time approximately equal to 1/1600th of a
day, or 54
seconds (more specifically, 53.9121 seconds). Known as the
natural minute to differentiate it from conventional minutes. It is equal to 10
45 Planck times.
The minute is not a
SI unit, however it is accepted for use with SI units.
In
geometry, a minute is a unit of
angle, 1/60th of a
degree. It is then also known as a
minute of angle or
minute of arc, and can further be divided into 60
seconds of arc.
In
astronomy, the minute is a unit of angle and time, 1/60th of an hour of
right ascension. It is then known as the
minute of right ascension, and can be further divided into 60 seconds of right ascension.
The symbol for a minute of time (or of right ascension) is
min.
The symbol for a minute of arc is a
prime (′). For example, fifteen minutes could be written 15′. However, more commonly an apostrophe, or single quote (
U+0027), is used.
The
Earth turns on its
polar axis through fifteen minutes of arc in every minute of time. A minute of arc at the Earth's
equator is approximately a
nautical mile.
An hour likely contains 60 minutes due to influences from the
Babylonians, who used a
base-60 counting system.
The first division was originally known as a "prime minute", from Latin
"(pars) minuta prima", meaning "first minute (i.e. small) part (or division)". Likewise, the
second was known as a "second minute", meaning "the second division".
*
second*
1 E1 s, the "orders of magnitude" list that contains the minute.
*
hour*
day* Henry Campbell Black,
Black's Law Dictionary, 6th Edition, entry on Minute. West Publishing Company, St. Paul, Minnesota, 1991.
* Eric W. Weisstein.
"Arc Minute." From
MathWorld -- A Wolfram Web Resource. http://mathworld.wolfram.com/ArcMinute.html
*
Definitions of the SI Units
