Why Do We Use 60 Seconds and 60 Minutes in Our Timekeeping System?
Timekeeping has been an essential part of human civilization for thousands of years, with the earliest timekeeping devices dating back to ancient civilizations like the Egyptians and the Babylonians. Dividing time into minutes and hours is fundamental to our daily lives.
However, dividing the day into 24 hours, with 60 minutes in each hour and 60 seconds in each minute, is more than just a random choice. In this article, we will explore the historical and scientific reasons why we use this particular system of timekeeping.
The Babylonians were among the first civilizations to develop a timekeeping system, and they divided the day into 24 hours, each hour into 60 minutes. The ancient Egyptians also adopted the use of base 60 for timekeeping. The use of base 60 is believed to have originated from the Babylonians' mathematical system, which was based on the number 60. The Greeks later adopted this system for various scientific and mathematical calculations.
The Egyptians used a sundial to track the sun's movement across the sky, and they divided the day into 12 hours of daylight and 12 hours of darkness. However, as the length of the day varied throughout the year, the hours also changed. To solve this problem, the Egyptians divided each hour into 60 minutes and each minute into 60 seconds, resulting in a total of 86,400 seconds in a day.
The modern timekeeping system is based on a solar day, the time it takes for the Earth to complete one rotation on its axis. However, the length of the solar day is not constant and varies slightly throughout the year due to the Earth's elliptical orbit around the sun.
In 1967 the size of the second was redefined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom. This definition is based on the properties of cesium atoms, which are incredibly stable and can be used to measure time accurately.
In addition to the historical and scientific reasons for using base 60, there are also practical reasons. Using base 60 allows for easy division and multiplication, as 60 is divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30. That makes calculating time intervals and converting between different time units easier.
Moreover, the 24-hour clock system, based on the division of the day into 24 hours, is widely used worldwide, particularly in the military, aviation, and healthcare industries. The 24-hour clock system is preferred in these industries as it eliminates the confusion between AM and PM and ensures that time intervals are understood.
In conclusion, 60 seconds in a minute and 60 minutes in an hour have their roots in ancient civilizations like the Babylonians and the Egyptians. Using base 60 allowed for easy division and multiplication, and adopting the 24-hour clock system eliminated the confusion between AM and PM. While the use of base 60 may seem arbitrary, it has proven to be a practical and effective way of measuring time, and it will likely continue to be used for many years to come.