Sidewalk Chalk Sundial (Do This on a Sunny Day!)

I got this great idea from FamilyFun magazine! A Sidewalk Chalk Sundial teaches kids how to keep time the way ancient civilizations used to do! You’ll need to do this on a bright sunny day for best results. Grab your sidewalk chalk and get ready to be amazed at how much your child’s shadow changes throughout the day.

The Lesson:

Your child is learning the same principles that ancient Egyptians and Babylonians used to create early sundials. When it’s bright outside, your body blocks the sunlight, casting a shadow.

Your shadow changes all day. It’s longer when the sun is low on the horizon, early in the morning or just before sunset, and shorter at midday, when the sun is high in the sky. Even though it looks like the sun is moving, it’s actually the earth that’s rotating on its axis. At night, it’s dark out because our part of the earth is no longer facing the sun.

Project Directions:

1. On a day forecast to be sunny, head out in the morning with your child and to a flat, paved area that gets good sun exposure most of the day. Stand still and have him or her use sidewalk chalk to trace the outline of your (or a friend/sibling’s) shadow. Mark the spot where you were standing and write down the time next to the shadow or in a journal.

2. Set a timer for an hour. When it goes off, head to the same spot and have your child trace the shadow again in a different color.

3. Repeat several times through­out the day to record how your shadow’s position and shape shift.

Adapted from Whatever the Weather by Annie Riechmann and Dawn Suzette Smith by arrangement with Roost Books, Copyright © 2016 by Annie Riechmann and Dawn Suzette Smith.