Cloud emerging from bottle.

Cloud in a bottle

Cloud emerging from bottle.

You can hold your very own cloud in your hands – here’s how:

1. Find and empty a plastic fizzy drinks bottle – one of the flexible PET bottles, 2 litres if possible.

2. Put cold water into the bottle, to a depth of between 1 and 2 cm (about half an inch).

3. Light and then blow out a match, and then drop it into the bottle. As it falls, it will leave a little smoke in the air. [Yes, do ask an adult to do it if you are young!!?]

4. Twist on the cap. Now squeeze the bottle hard and hold it like that for about ten seconds.

5. Quickly release, and you will see a cloud form inside the bottle. Squeeze again and it disappears.

6. Repeat step 5 again and again, admiring the transient existence of your own cloud. When you are done, open the cap and gently squeeze the bottle to set free your cloud.