Day and Night
≈ 15 minEarth is always slowly spinning, like a top. It makes one full spin about every 24 hours — and that one spin gives us one day and one night.
The Sun can only light up the half of Earth facing towards it. On the side facing the Sun it is day; on the side turned away it is night. As Earth keeps spinning, your part of the world turns towards the Sun (sunrise), then later turns away again (sunset).
Worked example. When it is daytime here in South Africa, it is night-time on the opposite side of the Earth. Both places share the very same Sun — they are just facing different ways as the Earth slowly spins.
What causes day and night on Earth?
About how many hours does Earth take to spin around once — that is, one full day and night?
It is daytime on the side of Earth that faces the Sun. What do we call the time on the side that faces away from the Sun?
A friend says: 'The Sun moves across the sky because the Sun travels around the Earth every day.' Is this idea correct, or a common mix-up?