Day, night and the sky
Physics · Early Years · The School
The Earth spins
It looks as if the Sun rises, crosses the sky and sets. It does not — WE move. The Earth spins round once every 24 hours, so your side faces the Sun (day) and then faces away (night). Hold a ball with a sticker on it and turn it slowly next to a lamp: the sticker gets day, then night, without the lamp moving at all.
Shadows tell the time
A shadow is where an object blocks the light. In the morning the Sun is low, so shadows are LONG. At midday it is high, so shadows are SHORT. Then they lengthen again. Draw round your shadow three times in one day with chalk and you will have measured the Earth turning.
Never look at the Sun
The Sun is so bright it damages your eyes permanently, and it does not hurt while it happens — which is exactly why the rule matters. Watch shadows instead; they tell you everything about where the Sun is without ever looking up at it.
Stand up with a lamp on the table as the Sun. Face the lamp: that is midday where your nose is. Turn slowly to your left. Your nose passes into shadow — sunset. Keep turning: your face is away from the lamp, which is the middle of the night. Keep going and the light comes back — sunrise. One full turn, one day and one night, and the lamp never moved once.