How to Make a Sundial: A Fun STEM Activity for Kids

Have you ever wondered how people told time before clocks and watches? One way was by using a sundial. A sundial is a simple device that uses the sun's position in the sky to tell the time. In this blog post, we'll learn how sundials work and how to make your own. This is a great STEM activity for kids of all ages, and it's a fun way to learn about the sun and the Earth's rotation.

How Sundials Work

Sundials work by using the shadow of an object to track the sun's movement across the sky. The shadow of an object will always point in the opposite direction of the sun. So, if you know where the sun is in the sky, you can use the shadow of an object to tell the time.

The most common type of sundial is called a horizontal sundial. A horizontal sundial is a flat surface with a stick or rod sticking up from it. The stick or rod is called the gnomon. The gnomon casts a shadow on the flat surface, and the position of the shadow indicates the time of day.

The position of the sun in the sky changes throughout the day. At sunrise, the sun is in the east. At noon, the sun is in the south. And at sunset, the sun is in the west. The shadow of the gnomon will move across the flat surface of the sundial as the sun moves across the sky. The position of the shadow will tell you the time of day.

How to Make a Sundial

Making a sundial is a fun and easy project that you can do with your kids. Here are the materials you will need:

• A flat surface, such as a piece of cardboard or plywood
• A stick or rod, such as a dowel or a pencil
• A protractor
• A compass
• A marker

Instructions:

1. Draw a circle on the flat surface. The circle should be about 12 inches in diameter.
2. Mark the center of the circle. This is where you will place the gnomon.
3. Use the protractor to draw a line from the center of the circle to the edge of the circle. This line will represent the 12 o'clock position.
4. Use the compass to draw a line from the center of the circle to the edge of the circle. This line will represent the 6 o'clock position.
5. Use the marker to draw lines from the center of the circle to the edge of the circle at 1-hour intervals. These lines will represent the 1 o'clock, 2 o'clock, 3 o'clock, and so on positions.
6. Place the gnomon in the center of the circle. The gnomon should be pointing straight up.
7. Take your sundial outside and find a spot where it will get direct sunlight. The sundial should be placed on a flat surface, and the gnomon should be pointing towards the North Pole.
8. Watch the shadow of the gnomon as it moves across the sundial. The position of the shadow will tell you the time of day.

Conclusion

Sundials are a simple but effective way to tell time. They are a great way to learn about the sun and the Earth's rotation. And they are a fun and easy project to make with your kids.

So what are you waiting for? Make your own sundial today!