Isaac Newton was a famous scientist from England. He lived long ago. He did important work in math. He also studied light. And he studied how things move.

Newton's first law says a still thing stays still. A moving thing keeps moving the same way. That is true unless a force acts on it.

Newton's third law says one thing can push on another. Then the second thing pushes back. It pushes back just as hard. It pushes in the opposite direction.

Push a heavy thing and a light thing. Use the same force on each. The heavy one speeds up less than the light one.

Newton said that everything pulls on everything else. He called this pull gravity.

The Earth pulls on the Moon with gravity. That pull keeps the Moon going around the Earth.

Newton told a story about an apple. In the story, he watched it fall from a tree.

Newton shone sunlight through a glass prism. He saw a band of colors. White light is made of all the rainbow colors. Newton showed this.

Newton made a telescope that uses a mirror. His first one was only about six inches long.

Newton wrote a famous book about how things move. It is called the Principia. It was published in 1687.

Queen Anne made Newton a knight in 1705. Newton lived to be 84 years old. He is buried in Westminster Abbey in London.

Words to know

• force: a push
• gravity: a pull
• telescope: far-seeing tube
• Principia: Newton's book