Shadow Play
Everyone and everything has a shadow. Shadows illustrate how three-dimensional objects can be viewed in two dimensions. Younger students can learn about the Suns relative motion in the sky as they experiment with shadows.
Activity One
Begin by asking, Where is the Sun at noon? Depending on the age of the child, responses might be straight up, in the sky, overhead, or in the south. Ask What is a shadow? Accept responses.
Preparation
Divide the class into teams of two or three before going outside.
Materials
Chalk
Outdoor drawing area
Lamp
Action figure and flashlight for each team of students
Experiment
One member is to play statue holding still while the other team members trace the outlines of both the statues feet and shadow on the pavement. When all the tracings are completed, the entire class can examine them. Wait about 3060 minutes, then ask the statues to return to their places (which is why they traced their feet) and hold the same position again.
Analysis
What has changed?
Answer
Students should notice that the length and position of the shadow have changed. Younger children may think that the statue changed position. Ask them to predict where the shadow will be in three hours. Repeat the tracings about once per hour until the end of the school day. Depending on the grade, students may measure the lengths of the shadows or even graph the length versus time of day. Discuss the results.
Activity Two
This activity demonstrates the daily motion of Earth. We perceive the Sun as rising, crossing the daytime sky, and setting. It is actually Earth that moves.
Preparation
Inside the classroom, arrange all the children in a circle around a lamp, which represents the Sun. The teacher should demonstrate and then ask the children to spin. (Young children prefer the term spin to rotate when thinking about Earth's motion.)
Demonstration
To find the proper direction, place your right hand over your heart (the position for reciting the Pledge of Allegiance) and rotate in the direction the fingers point. (As an extension, walk around the lamp to model Earths annual motion around the Sun. Dont try to spin and walk at the same time; it takes 365.25 spins to make a year!)
Analysis
What has changed?
Answer
When children are facing the lamp, it is day. When they are facing away from the lamp, it is night.
Activity Three
Preparation
Replicate the outdoor activity in the classroom by placing an action figure (a 3-inch figure works well) on a piece of paper. Use a flashlight to represent the Sun in the darkened room.
Experiment
Move the Sun across the sky, from rising in the east to setting in the west, through a curved path over the paper.
Analysis
What changes?
Answer
The position of the flashlight mimics the daily apparent motion of the Sun as Earth rotates.
Extension
Students draw pictures of why we have day and night.
Students study how ancient people created stories about what causes day and night.
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