In modern society, the most common number system is decimal, that is, based on the number 10. Most likely, this system has found its distribution among people because of the ease of use when counting on the fingers. The first human civilizations, which divided the day into shorter periods of time, used different number systems, mainly duodecimal (12) and hexadecimal (60). Consider in the article the question of why there is 60 minutes in an hour.
Sundial of Ancient Egypt
Most historians believe that the first human civilization, which began to divide the day into smaller parts, was Egyptian civilization. At the dawn of the formation of their culture, the Egyptians used sundials to determine the current time. The first sundial was a simple pole, which was installed in an open sunny place. The length and direction of the shadow cast by the pole, the Egyptians determined what time it was.
Many historical evidence says that before 1500 BC, more complex sundials appeared in ancient Egypt, which were a T-shaped bar located on a flat surface. This instrument was calibrated in such a way that the entire time between sunrise and sunset was divided into 12 equal intervals. This invention can be considered a prerequisite for the further popularization of the use of the duodecimal system of calculating time, which makes it possible to understand why it takes 60 minutes in an hour , 60 seconds in a minute, and 24 hours in a day.
Thus, many scientific inventions of the ancient Egyptians indicate that they had duodecimal as the dominant number system. Subsequent generations of sundials led to the gradual establishment of a unit of time, which is now known as one hour. It is also known that the duration of the Egyptian hour was not constant, it varied throughout the year, for example, in the summer season, the hour was longer than in winter.
Day and night
Since ancient times, people have noticed that there are two time periods that fundamentally differ from each other. In the first the sun shines (day), in the second there is only darkness (night). Ancient people considered these periods to be two different natural phenomena, that is, at that time the concept of the day did not yet exist. Without the use of a sundial, it was very difficult to separate the night period into separate parts in comparison with the daytime.
Over time, people began to divide day and night into 12 parts, which is the beginning of establishing the concept of the day and the presence of 24 hours in them. Despite the development of astronomical knowledge, the ancient Egyptians did not establish a constant duration of one hour. The Greeks did this for the first time, for which it was necessary to use fixed time intervals for theoretical calculations.
Temporary Standards of Antique Greece
The philosophers of ancient Greece began to divide the day into 24 hours, of which 12 hours were day and 12 hours at night during the autumn and spring equinox. Despite this scientific concept, ordinary people continued to use the hour with a varying duration for several centuries. The standard of one hour became constant only with the advent of the first mechanical watches at sunset of the Middle Ages (approximately in the XIV century).
The Six Decimal Number System of the Ancient Babylonians and Sumerians
To understand why the hour is 60 minutes, and not 100, which would seem to be more convenient for a person, one should turn to a more ancient era than Ancient Greece. Greek astronomers used the technique that was created before them by the civilizations of Mesopotamia: the Babylonians and Sumerians, to study celestial bodies. So, the ancient Babylonians used a six-decimal number system for astronomical calculations. Why they chose precisely the number 60 as the basis of their numerical system is not currently known. However, it should be noted the mathematical advantage of the number 60, which consists in the fact that it has 12 divisors: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60. A large number of divisors makes it easy to count the fractional parts whole. It should be noted that 60 is the smallest number, which is divided into the first 6 numbers: 1, 2, 3, 4, 5 and 6. This information allows us to explain why 60 minutes is in 1 hour.
In our world, the six-decimal number system has lost its position, but it continues to be used to measure geometric angles, geographical coordinates and time intervals.
Eratosthenes, Hipparchus, Ptolemy and geographical coordinates
The Greek astronomer and mathematician Eratosthenes, who lived in the III-II centuries BC, used a six-decimal number system to divide the circle into 60 equal parts, to develop a mathematical system to describe the geographical latitudes of our planet, the spherical shape of which was already known at that time. One century later, another Greek astronomer Hipparchus changed the horizontal lines of the latitude of the Earth, making them mutually parallel in accordance with the geometry of the planet. He also introduced the concept of longitude, dividing the entire globe into 360 equal parts by lines that began at one pole of the Earth and ended at another.
Subsequently, Ptolemy, who lived in the 2nd century AD, expanded and deepened the work of his predecessors and divided the degrees of geographical longitude and latitude into smaller parts. The first division of one degree Ptolemy called minutae primae - the first minute, which began to be called just a minute. The scientist called the second division for minutes minutes minutae secundae - the second minute. She began to be called a second. All these works contain the answer to the question of why there is 60 minutes in an hour.
Minutes and seconds
The concept of minute and second in the six-decimal number system began to be actively used only a few centuries after the work of Ptolemy. Prior to this, time intervals were divided in half, by 3, by 4, in some cases by 12 parts, but they were never divided into 60 parts. Only with the advent of the first mechanical watch was the concept of 1 hour and 60 minutes established in it.
Thus, the general answer to the question why in an hour exactly 60 minutes, and in a minute 60 seconds, lies in the historical development of astronomy in different human civilizations of antiquity, the scientific achievements of which were recorded in modern society.