Mind Fuck: Day 13

Today I found out... The ancient Egyptians divided the time between sunrise and sunset into twelve periods, and that between sunset and sunrise into another twelve, the origin of our twenty four hours.  Their hours actually had variable length, since sunrise and sunset varied throughout the year, and the astronomers of ancient Greece – in around 150 BC – decided that this was too complicated, so decided that all hours should be of the same length.  They used the ancient Babylonian system of dividing things into 60s to develop ‘first divisions’ (or minutes as we call them) and ‘second divisions’ (or seconds as we call them). Sexagesimal measurements as they called them were used as 60 as it was one of the most versatile and divisible numbers.