Sasha is joined by science communicator BILL NYE and historian of technology DAVID ROONEY to discuss a concept that measures, slices, defines, and controls our lives more than any other.


BILL NYE: So the Vatican astronomers came up with the following rule, which is just amazing. They realized that by adding a leap year every four years, which had been going on, I guess since the 12th century, which is a pretty good innovation by adding a leap year every four years. They were adjusting for this, the spin of the Earth not quite lining up with the orbit of the Earth around the Sun. And we all say 365 days, some of us say 365 and a quarter days, but it’s really much closer to 365.24 days. It’s 100th of a day off, about 11 minutes. So by adding a leap year every four years, you’re adding about 11 minutes too much time. Now it’s okay for a while, but after 1600 years, yeah, things were not lining up. And everybody noticed. So here’s the rule they came up with in fifteen hundred seventy freakin’ two, all right: In order to be a leap year, a century has to be evenly divisible by 400. So year 1600 was a leap year. The year 1700 was not 1800 was not 1900 was not 2100 will not be, but 2000 was. So the next adjustment is in something like 3080… set your clocks.

Historian of technology DAVID ROONEY: We’re always watching the clock, we can’t have our lunch break until the clock allows us to, we can’t eat when we’re hungry, we’ve got to wait until the clock tells us it’s one o’clock or whatever that feels like. We think it’s something from the industrial period when we all moved to towns and cities, and we moved into factories, and we started becoming wage slaves. But it’s much, much older. So ancient Rome got its first public sundial in the year 263 BCE, so like 2200 years ago, and it was the first public sundial. It had been looted in a military campaign on the island of Sicily. And they’ve had this sundial in Sicily, and the military leaders of Rome, cut it down, brought it back to the heart of Rome, the Roman Forum, put it up on a really tall column that looked over the people of Rome.

And the people of Rome hated it. Because then as now it was there to show military might but it was also that just as our clocks are to divide our day up, to kind of keep us in order through the day. So here’s this quotation. I love this. A character in a place says “The gods damn the man who first discovered the hours, who first set up a sundial here, he’s smashed the day into bits for poor me. It’s cut and hacked my day so wretchedly into small pieces. When I was a boy, my stomach was the only sundial, it was by far, the truest. But now, what there is to eat isn’t eaten unless the sun says so. In fact, this town is so stuffed with sundials that most people crawl along, shriveled up with hunger.”

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