Contents
Key Stage 2
Meaning
Light is what we can see with our eyes and dark is when there is not enough light to see things clearly.
About Light and Dark
- Light can be very bright or it can be very dark.
- When light is very bright it can hurt our eyes. Light from the sun is very bright and we shouldn't look at the sun because it can cause people to go blind.
- When there is not enough light to see we say it is dark. At night time it is very dark which is why it is hard to see.
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| No-one can see because there is no light so the room is dark. | The man can see the light bulb because light from the bulb goes into the man's eyes. The boy cannot see the light bulb because his eyes are closed. |
Key Stage 3
Meaning
Light is a wave that transfers energy and information.
About Light
- Light is a transverse wave.
- Light can travel through a vacuum as well as through any transparent solid, liquid, gas.
- The speed of light through a vacuum is 300,000,000m/s.
- Transmitted - Light can pass through a medium.
- Absorbed - The energy transferred by light can be taken in by an opaque material.
- Reflected - Light can bounce of a surface. This can be either Diffuse Reflection or Specular Reflection.
- Refracted - Light can change direction when it changes medium.
Medium
- Light can travel through a transparent medium but it does not need a medium to travel through as it can pass through a vacuum.
- Light can travel through any transparent solid, liquid, gas.
- Light travels most quickly through a vacuum.
- Light travels most slowly through solids.
Colour
Light can be divided into 7 colours:
- Red
- Orange
- Yellow
- Green
- Blue
- Indigo
- Violet