Chalk Sundials
A CSUMB student checks the accuracy of a chalk sundial at noon.
Whenever we talk about time in my cinema classes, I love to talk about light and outer space. Throughout the world, humans have used shadows to tell time - determined by the earth’s relationship to the sun. Some cultures used Sundials.
An image of a sundial from ancient Egypt, in the linked the article 8 different types of Sundials.
Materials:
Chalk (sidewalk chalk works best!)
A compass or the compass app on your phone.
Process: (see gallery above for each step in order)
Take a look at some images of old sundials for inspiration and pick your colors of chalk.
Draw a circle.
Mark out the four directions.
Make a circle in the center of the sundial and mark it “Stand here.”
Working with a partner - one student stands in the center of the circle. The other student draws a line from the center of the sundial through the center of the shadow.
Mark the time that this shadow was cast.
Estimate where the other times will be in relation. ie: where will the shadow be noon?
Come outside and check? Did you guess correctly? If not correct (and continue to decorate!) your sundial.
