BRIEF HISTORY OF TIME
Humans have been measuring time for tens of thousands of years.
Since the dawn of our species, we have been using Earth’s rotation to keep track of the day, first by eye, and then with sundials. Our biggest challenge to begin with was being able to tell time in the dark, especially in the depths of winter when the days were short. Solutions included measuring the flow of sand or water, or tracking the length of a burning candle.
The first mechanical clocks didn’t appear until the Renaissance. They used weights to move wheels to strike bells to indicate the hours. Later inventors replaced gravity with springs and spinning wheels with swinging pendulums. In the 20th century, the first quartz clocks were invented, making way for atomic time.