Peter.D.Riley

International bestselling award-winning author Facebook Twitter

Taking science education across the world

Our future depends on exploring all the frontiers of science, on innovative technologies based on these explorations and on the development of scientific literacy in all peoples through science education.

Science Around Us – Clouds 1 – Why Are Clouds White

A group of small clouds passing by

Clouds are made up from millions of tiny water droplets that float in the air. The sunlight that shines onto them is a mixture of the rainbow colours which makes the light white. This white light shines onto the droplets and they behave like millions of tiny mirrors reflecting the white light in all directions. The reflection of the light makes the clouds appear white.

Pippa gathered some equipment and materials to make a model cloud.

Pippa in her kitchen lab

She poured some olive oil into the water. In this model the water represents the air and the oil represents the material (the water droplets) in the cloud.

The oil and water ready to be mixed

Pippa stirred up the oil and water. As oil and water do not mix, the oil began to form tiny droplets in the water.

Pippa stirred up the oil and wate

As Pippa stirred the droplets became smaller and smaller until they behaved like the water droplets in a cloud and reflected the white light in the kitchen in all directions.

Pippa’s model cloud

How do clouds stay up in the air?

The billions of water droplets that make up a cloud are smaller in diameter than a hair on your arm. If you could scoop up part of the cloud shown in the first picture and put it in a box measuring one metre square (or about the size of a kitchen fridge) and measure the weight of all the water droplets in it you would find they weighed about as much as one baked bean. This means they weigh very, very little and any upward movement in the air (such as wind or rising air from the warm ground) will keep them in the air.

Next topic – Clouds 2 – How are clouds made?



If you liked this, you might like to receive my newsletter where I keep parents and teachers like yourself informed about...

  • Fun and exciting lesson plans you can download freely from my site.
  • Videos, presentations and other classroom materials to compliment my books.
  • Teaching-related articles on my site with tips and ideas useful to you.

You'll receive no more than one or two emails per month and your address will never be sold or passed on to anyone else. You can unsubscribe at any time by simply clicking the unsubscribe link in the email. My mailing list is securely managed using mailchimp.com.

My Books

Follow the links below to find out more about my books and book series, as well as downloadable resources for teachers and parents using my books.

Books for Primary Schools
Books for Secondary Schools

Books and Resources for Teachers

Contact Me

I can be contacted in the following ways. If you have a picture for the Natural World Photo Gallery or the Science Exhibition Gallery, please send it by email.