Number 12: The world's simplest electric motor

I saw this astonishingly simple motor described over at the fab proton's for breakfast blog and had to have a go.

All you need is:

• A small stack of 12mm diameter disk magnets (I get mine from emagnets)
• A 1.5V AA battery
• A length of stiff but bendable copper wire
• A penny 

Safety:

The magnets are very strong. Watch out they can fly together and shatter. 

What to do:


1. Stick the magnets onto the negative end of the battery.

2. Place the penny on the top of the battery.

3. Bend the wire so that it balances on the top of the penny whilst the other end only just touches magnets.

4. And watch it spin!

What's going?

When the copper wire touches the magnet a circuit is completed and electricity runs through the wire. When electricity passes through a wire it generates a magnetic field. This then interacts with the magnets at the bottom of the battery (in the same way as opposite poles of a magnet repel each other) and the who thing spins. Hey presto the world's simplest motor.