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The Earth spins

Space and time · level 1, lesson 2 of 6

A question to start

When you ride a merry-go-round, the trees and houses seem to spin past you. But they are standing still. Could the Sun be doing the same thing?

The idea

Yes. The Sun stays where it is. It is the Earth that turns, like a spinning ball.

  • The Earth spins round once every day.
  • The side of the Earth facing the Sun has day.
  • The side facing away from the Sun has night.

As the Earth turns, your home is carried from the night side into the light: the Sun seems to rise. Later you are carried into the dark again: the Sun seems to set.

Sundaynight

Worked examples

1. One turn. The Earth turns once in a day, so you get one daytime and one night-time.

2. Two places. When it is day in Canada, it is night on the other side of the world, in places like India.

3. A ball and a lamp. Shine a lamp on a ball in a dark room. Turn the ball slowly. A sticker on the ball goes into the light, then into the dark: day, then night.

Try it

  1. Does the Sun move round the Earth each day, or does the Earth spin?
  2. Which side of the Earth has day?
  3. How long does the Earth take to spin round once?
  4. When it is midday in your town, is it day or night on the far side of the world?
Answers
  1. The Earth spins.
  2. The side facing the Sun.
  3. One day.
  4. Night.

Common mistake

"At night the Sun goes out." The Sun is always shining. At night your side of the Earth has turned away from it.

Where it leads