Day and Night

Principle

How are day and night created? Day and night are "created" by the rotation of the earth around its own axis, with day on the side facing the sun and night on the side facing away from the sun. This simple Sun, Earth, Moon model is used to model how day and night are created.

The pupils can use the model to try out for themselves how day and night are created by rotating the earth model on its axis while it is illuminated by the torch representing the sun. In one place, it is always daytime when that place is illuminated by the sun. Since the earth is round, there are always places in shadow where it is night. Since the earth rotates, day and night always alternate in every place. This rotation is also responsible for the time zones.