Magnet Mystery

The big ideas

What the levels teach, in grown-up words.

• Magnets attract iron, steel, nickel and cobalt. Most things, including most metals, are not magnetic. Copper, aluminum and gold do not stick, which surprises almost everyone.
• Every magnet has a north and a south pole. Like poles repel and opposite poles attract. Cut a magnet in half and each piece has both poles again.
• The pull works at a distance and through things. Magnetism passes through wood, glass, plastic, paper and water. That is why a magnet under a table can move a clip on top.
• Iron can be made into a magnet. Inside iron are tiny magnetic regions pointing every which way. Stroking with a magnet lines them up; dropping or heating the nail scrambles them again.
• Electricity makes magnets you can switch off. A coil of wire with a current running through it is a magnet. Scrapyard cranes, doorbells and motors all use electromagnets.
• The Earth is a magnet too. A compass needle is a small magnet that lines up with the Earth's magnetic field, so it points north wherever you are.

Try it at home

Quick experiments that match the game.

1. Fridge magnet hunt. Take a fridge magnet around the house and test twenty things. Sort them into sticks and doesn't stick, and look for surprises like aluminum cans and coins.
2. Paper clip puppet. Put a paper clip on a sheet of card and move a magnet underneath. Try thicker things: a book, a plate, a glass of water.
3. Make a magnet. Stroke a steel needle or nail 30 times in one direction with a magnet, then see if it picks up a paper clip. Drop it on the floor a few times and test again.
4. Floating compass. Magnetize a needle, lay it on a small piece of cork or a leaf floating in a bowl of water, and watch it turn to point north.