Australian Science Illustrated — Issue 54 2017

78 | SCIENCE ILLUSTRATED

1

Cut out a

piece of felt,

which can

cover the bottom of

the vessel. Glue the

felt to the bottom with

strong glue. Wet the

felt through with

isopropanol. Pour any

surplus liquid onto the

baking plate.

2

Use a large

spoon to fill

the bowl with

dry ice. Make sure that

the surface is as level

as possible, and place

the baking plate on

the dry ice, allowing

the ice to efficiently

cool the plate.

3

Turn the

transparent

vessel upside

down and place it on

the baking plate. Wait

a few minutes for the

dry ice to cool the

baking plate and the

air inside the vessel.

4

Switch off the

light in the

room and use

a flashlight to shine

light on the vessel.

Watch the vapour right

above the plate. After

a few minutes, you can

see clear traces.

Isopropanol is inflammable and

irritates the eyes, so use safety

glasses. The dry ice can cause

frostbite, so do not touch it.

Detect the Invisible

Particles of the Universe

Cosmic rays sleet through us every day. You know this.

And with this (kinda tricky) experiment, you can see them.

A flashlight

A large,

transparent vessel

A large piece

of felt

Isopropanol, also

known as

isopropyl alcohol

About 5 kg of dry

ice (or CO 2 ,

available online)

A baking plate

Safety glasses

A large bowl or

box

YOU WILL NEED: GUIDE:
IT WILL TAKE AN HOUR TO MAKE THE EXPERIMENT.

HOME CHEMISTRY LAB

1

4

2 3

VIDEO GUIDE!

There are dozens of cloud

chamber how-to clips

on YouTube. Here's one

we quite like:

youtu.be/xky3f1aSkB8

HOME CHEMISTRY LAB

EXPERIMENT

LEVEL:

EXPERT!