Globes are useful for demonstrating the Earth's rotation.
The movement of the Earth can be a highly abstract concept for students, particularly for young children. Earth's rotation is a foundation principle for many branches of science: meteorology, astronomy, physics and geology. Simple experiments can help students understand these fundamental science concepts.
Young Children
For young children, teachers can use globes and a light source, such as a lamp or flashlight, to demonstrate how the movement of the Earth creates day and night. For higher-functioning students, time zones can be discussed as well. A small ball can be added to represent the moon. Young students can also pretend to be the Earth and pretend to rotate and revolve around the sun.
Demonstration
For older students, a more complex model, based on Foucault's Pendulum, can better show the movement of the Earth. Students will need to work in small groups and have the following materials: a quart-sized jar, two rolls of masking tape, a metal washer, a 9-inch piece of string, a ruler, a pencil and a lazy Susan. The students will tie one end of the string to the middle of the pencil and the other to the washer. The students tape the pencil across the mouth of the jar until the washer hangs about 2 inches from the bottom of the jar. The kids put a roll of tape in the middle of the lazy Susan and place the jar atop the roll of tape. The students tilt the jar to start the washer swinging back and forth. Then, they spin the lazy Susan gently. The pendulum will continue to swing back and forth due to the inertia caused by the rotation of the lazy Susan. Teachers can then discuss how this experiment relates to the experiments of Leon Foucault in the 19th century.
Earth Wobbles
For this experiment, students will need a round toothpick, a 2-inch circle from card stock or heavy paper and a ruler. The teacher may want to prepare circles with a small hole in the center. The students put their toothpicks through the hole in the circle so one-fourth inch of the toothpick protrudes through one side. Students will hold the long end of the toothpick, put the other end on a hard surface and spin it like a top. As the circle rotates, its weigh shifts causing it to wobble. The wobbling is due to the circle being imperfect and the hole not being precisely centered. The wobbling of the Earth causes its axis to move in a circular route known as "precession."
Shadow Movement
This activity is intended to show how the movement of the Earth effects the position of the sun, which effects the position and length of shadows. Students working in pairs need the following: a drinking straw, scissors, a ruler, a thumb-sized piece of clay and a flashlight. The students will need to cut a 2-inch section from the straw. They should place the clay on the table or desk, using it to stand the straw straight up. With the lights turned off, the students will move the flashlights in an arcing motion over the straw. The shadows will appear longer when the flashlight is at the sides and shorter when the flashlight is overhead. This is analogous to the movement of the sun and how shadows appear on Earth as it rotates and the position of the sun changes.
Tags: lazy Susan, movement Earth, students will, will need, back forth, Earth rotation, effects position
