Video narration
Why can one place have day while another has night? Try a flashlight and a ball. The flashlight stands for the Sun, and the ball stands for Earth. Shine the light at the ball: only the side facing it is bright. That side has day. The side turned away is dark-night. Now mark one spot and turn the ball. As Earth rotates, the spot moves into the light: day. Then it turns away: night. Keep turning, and the pattern repeats. Here's the turn: the Sun is not switching day and night on and off. Earth's rotation changes which side faces the Sun. Different places are on different sides of the ball, so day and night happen at the same time in different places. So why can one place have day while another has night? Earth rotates. Each place faces the Sun for day, then faces away for night.