Why are there 60 minutes in an hour, according to In Our Time's measurement of time episode?

Kristen Lippincott, former director of the Royal Observatory Greenwich, told Melvyn Bragg the base-60 system goes back to the Babylonians. They liked 60 because it divides by many numbers without a remainder, which mattered before fractions were well handled. She said the choice had nothing to do with lunar observation. It was simply mathematically convenient, and the system built on it survives in degrees, minutes and hours.

• Lippincott listed 60's divisors as including 20, 15, 6, 5 and 3.
• The Babylonians also set the circle at 360 degrees.
• She called the Babylonians the great mathematicians of antiquity.

▸In their words

“The Babylonians were fascinated by numbers and they had what's known as a sexagesimal system, 60-based.” Kristen Lippincott · at 7:57 — open in the transcript →

Source: our own transcription of the episode. The full conversation is on In Our Time (2026-10-12). Read the whole episode summary →

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