DIY Sunny Sundial

Build your own ancient time-telling device using a stick and the sun! You'll learn how the Earth's rotation creates moving shadows to track the hours of the day.

Materials

• straight stick or drinking straw (1)
• paper plate (1)
• bucket of sand or pebbles (1)
• small rocks for marking (12)

Safety

• Protect work surface. Materials may stain clothing.
• Adult supervision required for children under 8.

Steps

1. Choose your base: Either find a patch of dirt, use a paper plate, or fill a bucket with sand or pebbles.
2. Prepare your gnomon: If using a paper plate, have an adult help you poke a hole exactly in the center and insert your stick or straw.
3. Position your sundial: Place the base in a sunny spot. Tilt the stick slightly toward the North (if you are in the Northern Hemisphere) or toward the South (if you are in the Southern Hemisphere).
4. Set your timer: Set an alarm to remind you to go outside every hour, starting at 7:00 AM.
5. Mark the hours: Every hour, look at where the shadow of the stick (the gnomon) falls on the ground or plate. Use a rock or sidewalk chalk to make a mark at the tip of the shadow.
6. Label your dial: Once you have marks for the whole day, use chalk or a marker to draw lines from the stick to each mark (like spokes on a wheel) and write the corresponding hour number next to each line.
7. Test your clock: The next day, place your sundial in the exact same spot and direction. Look at where the shadow falls to see what time it is!