I want to know how the world started

Dear Mister Rogers,
I want to know how the world started. I think a star exploded and then it got all the pieces of the star and made the world. Sometimes I see a shape, like a circle all around us. It makes me think that a star exploded because there looks like there's a circle around us and when you look at stars they look like circles, too.
 - Benjamin, age 4

Dear Benjamin,
Many things about this world are hard to understand-- even for scientists. Since no one was living on earth when the world started, people have tried for a long time to imagine what that was like. They try to look and listen carefully for clues about how things began, but they also imagine. Imagination isn't just something children need for pretending-- it's part of the work of grown people like scientists, too [...] (p. 60)

Dear Mister Rogers: Does it ever rain in your neighborhood? (1996). New York: Penguin Books.