This letter was written by Richard Dawkins, and given to his daughter when she turned 10. Richard Dawkins is a respected scientist and author.
To my dearest daughter,
Now that you are ten, I want to write to you about something that is important to me. Have you ever wondered how we know the things that we know? How do we know, for instance, that the stars, which look like tiny pinpricks in the sky, are really huge balls of fire like the Sun and very far away? And how do we know that the Earth is a smaller ball whirling round one of those stars, the Sun?