This decimal clock was made by Pierre Daniel Destigny in Rouen, France, between 1798 and 1805. | DeFacto, Wikimedia Commons // CC BY-SA 4.0 Everybody knows that there are 24 hours in a day, 60 minutes ...

Many stop lights at street intersections display a countdown of the remaining seconds before the light changes. If you’re like me, you count this time in your head and then check how in sync you are.

For thousands of years, we’ve divided days into 24 hours, hours into 60 minutes, and minutes into 60 seconds. But why do we have to do that? Here’s the story of the one gloriously failed attempt to ...