Fog in a bottle

Fog in a bottle

Make your own fog

We don't like fog when we're outside, but it's fun to make your own!

What you need:

  • Large bottle
  • Hot water
  • Sieve
  • Ice cubes

How to:

  1. Fill the bottle with hot water.
  2. Pour out the water, leaving around two centimetres in the bottom.
  3. Place the sieve over the mouth of the bottle and put around four ice cubes in the sieve.

What did you notice? You should see a fog start to form. To make it easier to see the fog, put the bottle against a dark background.

What's happening?

Cold air from the ice cubes causes the water vapour in the warm, moist air to condense into water droplets. Just like clouds, fog forms when water vapour condenses into tiny water droplets in the air. The difference is that in fog, the water vapour normally comes from water on the ground such as the sea or lakes. This is why fog forms close to the ground. In clouds, water vapour is present high in the Earth's atmosphere.

Try making a cloud in a bottle. For more exciting weather experiments, visit Weather Labs.

Did you know?

The foggiest place in the world is Grand Banks, Newfoundland, Canada. It has over 200 foggy days per year!

Main image (c) j.o.h.n. walker