Sunrise, Sunset

Posted by: on Jan 29, 2013 | No Comments

This activity is another one which has real visual appeal as well as demonstrating some fascinating science.

Everyone will be amazed to see the different colours produced by something as simple as torchlight shining through a glass of milky water.sun

You Will Need

A clear drinking glass




White card.


Half fill a clear drinking glass with water.

Shine your torch on the glass directly above it. Now shine the torch from the side and hold the card the other side of the glass.

What does the water look like? What colour is the light shining onto the card? Does the torchlight change the appearance of the water?

Now pour approx. 125ml of milk into the glass and mix well.

Take the glass somewhere dark and shine the torch from the side of the glass through the milk. At the same time hold the card on the other side of the glass. Observe what you can see.

What’s Happening?

Torchlight through water will not change the appearance of the water and the light shining on the white card will be white light.

On the other hand torchlight shined through the milky water will look yellow, orange or red and the light shining on the white paper or card will have a similar hue. Be aware however that you may need to experiment with the exact amount of milk you use.

Why? Just like a sunset or sunrise, the light is shining through particles. The atmosphere is full of billions of particles.

When the sun is low in the morning or early evening, its rays must travel through a thicker layer of atmosphere than at other times of the day.

When sunlight hits these particles, the light bounces off them and scatters.

Orange and red light scatter the least, which is why you see these colours in a sunrise or sunset.

Have Fun!

Thanks to, and adapted from