Today we talked about why keeping track of the seasons would be important to hunter-gatherers (need to know when plants will be ready to harvest and when animals will be migrating) and the different ways people have kept track of time. We talked about the ‘calendar’ recently discovered in Scotland that is thought to be 10,000 year old! Holes were found in the ground that marked the position of the moon throughout the year. In Peru, they’v recently discovered the oldest known solar observatory, Chankillo, in the Americas (photo on the left taken on June Solstice). 13 towers mark the position of the setting sun from the June to December Solstice. We also talked about sun dials, water clocks, candle clocks and the ‘cosmic engine’ created by Su Song, a Chinese polymath around 1000AD. One interesting thing I learned while putting the slideshow together, is the word ‘calendar’, comes from the Romans. A Roman prient would call out each month when it was a new month, and the 1st day of the new month was called the Kalends, from calare – meaning to call out.
We watched the following SciShow on the History of Time in class.
And then the kids made a pocket sundial and a star clock, which allows them to tell the time by observing the orientation of the big dipper in the sky. Both of these activities are from the Universe at Your Fingertips DVD. Here’s a slightly different version of the pocket sun clock activity. The sun clock is shown below, you hold it so the string is pointing North and the shadow falls on the time. For daylight savings time you have to add an hour. And the big dipper star clock can be found here.
The activities only took a few minutes to put together so then I had the kids work in groups of 2 or 3 and fill out one of the Big History Project activities where they compare ancient civilizations. Each group picked one civilization, Rome, Greece, Egypt, etc. and filled out a table, time span, where its located, what crops they grew, animals they domesticated, difficulties they had (dry land, volcanoes, etc) and what they’re famous for. Once they had their table filled out, they swapped information with another group so they would have information on two different civilizations. This is a nice lead in to the Museum exhibit project they’re going to complete this month. Again working in groups or by themselves, they’l research one civilization and give a presentation to the class at the end of the month. They can either do as the Big History Project activity recommends and build a mini museum exhibit or do a slideshow stressing why the civilization was ‘Great’.