History of Measuring Time

I found it super fascinating that the Ancient Egyptians counted time by looking at the stars in the sky. It absolutely blew my mind that they were able to divide the sky into 36 sets of stars, with 18 in the day, 12 in the night, and 6 for sunrise/sunset, that’s genius! I feel like this is the kind of stuff I want to teach my students too, just the fact that people have always used math and astronomy to understand the world. Even though I celebrate Lunar New Year with my family, I’ve never considered moon cycles or followed the lunar calendar. I’m pretty used to the Gregorian calendar, so the only difference I know is that the Gregorian calendar starts on Sundays, while the lunar calendar starts on Mondays. In Chinese, Monday literally means “week of one” and Sunday literally means “week of sky,” so starting on Monday and ending on Sunday makes more sense to me. I’ve always seen time in 60s, which I think is such an amazing system. With 60 minutes and 60 seconds, we are able to divide them into halves, quarters, tens, and fifths, which is very convenient for keeping time. The 24 hours makes sense to me, since we sleep 8 hours a day, we are divided our days up into the working hours, relaxing hours, and sleeping hours, all in thirds. We also eat three meals a day, so it is intuitive to me too. The year having 12 months is pretty neat too, but my main complaints are that some months are longer/shorter than ours, and that the year starts in Winter, not in the Spring. I didn’t see months of the year being mentioned in the articles, but all of those timekeeping habits make sense to me because I am so used to them. 

The main inconsistency I see between the articles is the civilizations they credit to our current timekeeping method. MacTutor credited the Sumerians and Babylonians, while Scientific American credited the Ancient Egyptians/Greeks. For the Sumerians, they are theorized to just kind of “know” there are 360 days, while the Ancient Egyptians/Greeks used astronomy to reach the conclusion of dividing up the sky into 24 parts. In the Scientific American article, they mentioned that the base 60 systems and calculations were inherited from the Sumerians and Babylonians, but not much else. So I think that there might be some bias in both articles crediting the civilizations based on geography.

And a last sidenote here… some of the kids nowadays can’t read clocks anymore??? During my summer camp, I had a camper (grade 7) come up to me and ask me for the time. I told her that there’s a clock on the wall, and she said that she couldn’t read it. So I am very motivated to at least make sure that all of my students know how to read a dial clock, even though all phone screens have digital clocks.