Dear MEL Topic Readers,
The ancient reason there are 60 minutes in an hour
In 1793, the revolution-minded French Republic introduced a 100-sec/100-minute/10-hour/10-day
week decimal time system, which lasted only a year or so. Why do we use the sexagesimal
system for time and day while using the decimal system for most other
measurements? In fact, 60 is convenient for divisions as it can be divided by one,
two, three, four, five, six, 10, 12, 15, 20, 30, and 60 without fractions or
decimals, while 10 can be divided only by one, two, five, and 10. Long ago, the
Sumerians, who lived in Mesopotamia from around 5300 BCE, started using a writing
system, including a number system based on the concept of 60. The Babylonians,
who came after the Sumerians in the region, used timekeeping, presumably based
on 60. Also, ancient Egyptians divided the night into 12 hours around the time
they built pyramids, and later, they used sundials and water clocks. Then, by
the Roman period, hours and half-hours became standard time units there. In the
meantime, the Babylonians figured it took around 360 days for the sun to return
to the same position in the sky, the concept of a year, which is easily divided
by 12 months of 30 days each. They also came up with 12 zodiac signs, which were
later organized by the ancient Greeks. Around the same time, the Chinese zodiac
with a 12-year sexagenary cycle was established during the Han Dynasty. Indeed,
the sexagenary system and the cycle of 12 seem to have been convenient for many
civilizations.
Read the article and learn why an hour is divided into 60 minutes.
