Night and day

There are key facts and figures to get to grips with when understanding night and day. We decided to create a video for teachers to use in the classroom which pulls them all together and here it is. You can pause the video at certain points to reiterate specific concepts in class.

Here are the main science points mentioned in the video:

• Light travels in straight lines.
• It reflects off planets and the Moon – this is why they are visible to us.
• Stars make their own light.
• The Sun is a star.
• The Earth spins on its axis anti-clockwise, once every 24 hours.
• The Sun reaches its highest point at midday in the south (assuming you are in the northern hemisphere of the Earth) and then sets in the western sky. It rises again in the morning in the east and eventually reaches its highest point again in the south, the whole cycle taking 24 hours to complete. This is all because of the Earth’s spin.
• A shadow is formed when an object (or person) blocks light – we see the absence of light opposite to the light source.
• A shadow cast by a stationary object blocking sunlight will move in the opposite direction to the Sun. It will also change size as the Sun rises and sets in the sky.
• A sundial is a clock that casts a shadow and the direction of the shadow tells you your local time.
• If the Earth was spinning clockwise we would see the Sun rise in the west and set in the east – like on Venus.

We often use this video along with the resources Spinning Earth and Human Sundials to help explain these tricky concepts.

How would you use this video and the resources?