A sundial is a device that uses the sun, and the shadows, to tell time. As the earth rotates, the shadows made from a fixed object move in a predictable pattern that can be used to tell time. We have archaeological evidence that these types of "clocks" have been used for at least 3,500 years! Even though we have digital clocks all around us today, sundials are a great way to have fun, tell time, and get outside to observe the world around us!
But, to understand a sundial, we have to understand shadows. Here's a great video to help explain what a shadow is, and why they change throughout the day:
Here's a great lesson that uses sidewalk chalk, and your own shadow, to see the pattern of shadows that is made as the earth rotates around the sun!
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