πͺ Space and stars π Sights in the sky
Shadows
π In short
A shadow is a dark area that forms when something blocks light. When you stand in the sun, your body blocks some of its light, and your shadow appears on the ground in your shape, following you wherever you go!
π€© Did you know?
- If the light source is very small, the shadow is sharp with clear edges.
- See-through things like glass don't make a dark shadow.
- A lunar eclipse happens when the Moon moves into the Earth's shadow.
- At night the whole Earth is in its own shadow!
π Find out more
π Why do shadows form?
Light travels in straight lines and can't bend around things. So when something that isn't see-through is in its way, there's an area behind it that light can't reach: the shadow.
π Long and short shadows
In the morning and evening the Sun is low, so your shadow is very long. At midday the Sun is high, so your shadow is short, under your feet.
π‘ Shadow clocks
Long ago people used shadows to tell the time, with a stick called a sundial. In Islam, the times of the Dhuhr and Asr prayers are known by the length of objects' shadows.
π― Shadow theater
With your hands in front of a lamp, you can make shadows on the wall that look like a rabbit, a bird or a dog. The old shadow puppet theater came from this idea.
𧩠Test yourself
1 When is your shadow shortest?
2 Why do shadows form?
3 Which picture shows βShadowsβ?
πͺ Discover more
π· Picture sources: Wikimedia Commons
- Afshin10 Β· CC BY-SA 4.0
