A shadow is a place light did not reach
At noon, a neem tree makes a dark patch on the ground. Step into it, and the strong, bright light stops.
Step 1 of 4
- A lamp, an object, and a wall stand in a row.
- Light leaves the lamp and travels straight.
- The object blocks the rays, or light paths, that hit it.
- The dark patch on the wall is the shadow.
The new word
- Opaque — stops light completely. No light gets through it.
- Transparent — lets light pass. Translucent — lets some through, so its shadow is faint.
The rule
An outline is the line round a shape.
A dark shadow needs light, something opaque, and a surface behind it. Take any one away and it goes. A shadow shows only the outline of the object, not its colour.
| What | An example |
|---|---|
| Something making light | The Sun, a torch |
| Something opaque | A tree, a tumbler |
| A surface behind | A wall, the ground |
Now try it. Switch each part on and off. When is there a shadow?
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