Make your own sunset

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Sunlight contains all the colours of the rainbow (red, orange, yellow, green, blue, indigo, and violet). Red light has the longest wavelength and blue the shortest. As sunlight passes through the atmosphere, blue light is scattered in the atmosphere more than the longer wavelengths. Red light is scattered the least.

 

When the Sun is close to the horizon, sunlight has to pass through up to 40 times more air than when the Sun is overhead. The large amount of blue light scattered in the atmosphere makes the Sun look red.  Sunsets tend to be redder than sunrises because there is more pollution and dust in the atmosphere than in the morning.

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You can easily make your own sunset by following these instructions.

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1. Get hold of a transparent container with flat sides.

2. Fill the container with water.

3. Shine a white LED light through the container and look at the light through the water. You will see that the light looks white.

4. Add a drop of milk to the water in the container, stir, and look at the light through the water again. You might see that the light looks more red or yellow. If not, keep adding drops until you see the effect. If you can't see the light, you might have added too much milk. If so, tip some of the water out and add some more water to dilute.