Me: Ooh I know this one... Right. To explain this we need a roundish yellow thing. Yup, that balloon will do.. And a little round blue thing.. A poker die? Well it's kind of square isn't it? Never mind, we'll pretend it's round. And blue.
Me: OK now, you see this little diamond on the die? Pretend that's our whole country. And the die is our whole planet, which goes around the sun once a year, like this.. and turns around itself once a day, like this.
Me: Now. Watch carefully. In the daytime we face the sun, like this, and at night-time we turn away from the sun, which is why it goes dark. Then next day we face it again, so we're in daylight again. See? So you tell me, where did the sun go?
Lyddie: *Looking out of window* Behind a cloud?
Me: Nooo, look. We're pretending the sun is this balloon. Watch again - keep your eye on it as the little diamond goes from day... to night.... And where did the sun go?
Lyddie: Into the sunset?
Me: OK watch the balloon very closely. The balloon is the sun. The diamond turns away from it and where does the sun-balloon go?
Lyddie: It's hiding?
Me: No, look, it hasn't gone anywhere. The balloon is still here, in front of your face, isn't it? It was the diamond on the die that moved, not the balloon.. Oh never mind. I'm not explaining it very well, probably. *Gives up and puts them both down*.
Lyddie: So where does the sun go?
Me: Nowhere really, it's us that's moving away from it. It's not actually moving.
Lyddie: *Looks at floor* Neither are we.
Lyddie: Let's make some soup.
Me: Yes, let's.