|
Sun Clocks
 Before there were clocks and wrist watches, the Sun helped people tell the time of day. With a few simple materials, you can make a sun clock. (Do this activity on a sunny day.)
What You Need
• 1 small flower pot
• 1 paper plate
• 1 chopstick (or pencil)
• Modelling clay
• 1 felt pen
What to Do
1. Put the flower pot upside-down on the paper plate.
2. Stick the chopstick through the small opening in the flower pot.
3. If necessary, use modelling clay to secure the chopstick in place. It should not wobble.
4. In the morning, place your clock in a place where it will be in the Sun all day. (If you are up early enough, put your clock out before sunrise.)
5. At each hour of the day, make a mark on the paper plate where the shadow from the chopstick falls. By the end of the day, you will have a clock set by the Sun.
How it Works
A “day” is the time it takes the Earth to rotate once. As the Earth rotates, the shadow cast by the chopstick falls in a different place. The length of the shadow also changes. At noon, when the Sun is at its highest point in the sky, the shadow is short and pointed toward the north. Later in the day, when the Sun is in the west, the shadow will be longer and directed to the east.
|
|
