The Secret of Time: Why a Clock Has 60 Minutes? The Cosmic Power of 60 ⏳

In the modern world, we predominantly use the **base-10 (decimal) system**: 10 fingers, grouping in tens. Yet, when you look at a clock, we suddenly abandon this system: one hour is **60 minutes**, and one minute is **60 seconds**. In geometry, a circle measures **360 degrees**. These numbers are not simple decimal units like 10, 100, or 1000; they are multiples of 60. The ubiquity of these peculiar numbers is the result of a scientific choice made over 4,000 years ago, forming the bedrock of modern technology and mathematics: the **Sexagesimal System (Base-60).**

1. The Mesopotamian Legacy: Why Choose 60?

The origin of the base-60 system traces back to the **Sumerians** and **Babylonians** who lived in Mesopotamia around 2000 BCE. The Babylonians used a mixed system, but the power of 60 was key. Why did they choose a relatively large number like 60? The answer lies in its exceptional **divisibility**.

While the number 10 is only divisible by 1, 2, 5, and 10, the number **60 is divisible by 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60**—a total of **12 different integers**. This incredible capacity for easy division made 60 perfect for ancient applications in trade, weighing, and especially **astronomy**. Being able to easily divide a number into halves, thirds, quarters, fifths, or sixths provided immense practical convenience during an era when handling complex fractions was cumbersome.

2. The Standardization of Time Measurement

The division of the day into 24 hours, and the division of the hour into 60 minutes, is a system directly inherited from Babylonian astronomy, transmitted through the Greeks.

Days and Hours

* **The Day:** The Babylonians, and later the Egyptians, divided the day into 24 equal parts (12 for daylight, 12 for night). The number 24 aligns well with 60 and possesses many divisors. * **Minutes and Seconds:** The idea of dividing an hour into 60 minutes and a minute into 60 seconds showcases the mathematical strength of the Mesopotamian tradition. Because 60 is perfectly divisible by both small integers (2, 3, 4, 5, 6) and larger ones (10, 12, 15, 20, 30), it allowed time to be measured in precise and practical fractional segments. This sexagesimal subdivision was crucial for tracking celestial movements with the accuracy required for ancient astronomical predictions.

3. 360 Degrees and the Astronomical Link

To understand why a circle is divided into 360 degrees, we again turn to ancient astronomy. The Babylonians, while studying the Sun’s annual journey across the sky (the ecliptic), noticed that the Sun completed a full circle in approximately 360 days.

The number **360** is six times 60 and is one of the numbers with the most divisors of any number close to its size (it has 24 different divisors). This number harmonized perfectly with both their calendar (360 days) and their foundational numbering system (60). Thus, dividing a circle (a full rotation) into 360 equal parts provided an elegant solution that suited both astronomical observations and the mathematical need for divisibility. This system was adopted by Greek mathematicians, notably Hipparchus and Ptolemy, ensuring its survival into the modern era.

4. The Enduring Place of 60 in Modern Technology

Although modern computing and engineering primarily rely on binary and decimal systems, all systems requiring precise timekeeping, angular measurements, and global navigation still rely on our **Sexagesimal heritage**. When charting the course of an aircraft, deploying a satellite, or tuning a global time signal, the precision and flexibility of the base-60 system remain indispensable.

As we count the seconds and minutes in our daily lives, we are unknowingly utilizing a legacy of mathematical genius spanning four millennia. The number 60, a practical and aesthetically brilliant solution to the needs of ancient civilizations, continues to govern the stopwatch of the modern world.