Sean Carroll is the name of two different scientists, an evolutionary biologist specializing in the evolution of the developmental process of embryos to adults in animals, and a physicist. The physicist has two Great Courses, one on dark matter and dark energy and one on the physics of time. I started listening to the time course a few days ago.
His third lecture is about human calendars.
In graduate school, I was part of an erratic 1 credit course that ran for three years, in which we used the computer language Fortran to calculate the difference in days between any two dates the professor gave us. He was a tricky guy and we realized that he might well give us two dates that were thousands of years apart. We discovered such oddities as the feeling of outrage and theft felt in some places when Pope Gregory XIII and his astronomers declared that Thursday, October 4, 1582 would be followed the next day by Friday, October 15, 1582. It was clear to many people that the durned Catholic fathers had stolen days from their lives, shortening their life span for no reason.
As Prof. Carroll makes clear, the solar system, with Earth's rotation, its revolution around the sun and Earth's moon gives humans three different time events that are remarkably incompatible in arithmetic terms. Astronomers have worked for thousands of years to create a synthesis of the moon periods, the annual periods and the daily periods that actually fits them, are easy multiples of each other, and are acceptable to civilizations, businesses and governments, not to mention traditions, rivalries and suspicions. Just to give an idea of how controversial and bothersome such an adjustment was to some, the American colonies, as part of Britain, didn't make the adjustment until 1752, nearly 200 years later.
There are something like 60-80 different calendar schemes in use around the world. Human need for regularity and predictability coupled with the actual behavior of our planet and its neighbors have created something of a mess for us and that's no joke.
--
Bill
Main blog: Fear, Fun and Filoz
Main web site: Kirbyvariety
