Magnets have been around since the beginning of Earth. That’s because Earth itself is like a giant magnet. It has a north and south pole and a spinning liquid iron core that creates a magnetic field.
The Sun, Saturn, Jupiter, Uranus and Neptune all have stronger magnetic fields than Earth. Mars, Mercury and Venus have weaker magnetic fields and the Moon has hardly any magnetism at all.
Earth’s magnetism is really important for animals like birds and whales. This is because they use the Earth’s magnetic field to find their way during migration.
Magnets throughout history
The first magnet discovered on Earth was a stone made of iron called lodestone.
When the lodestone was shaped into a needle and placed on a leaf on water, it would always point in the same direction. This is what led to the invention of the compass.
The Vikings, ancient Greeks and Chinese are all known for using compasses.
The south pole of a compass is attracted to the north pole of the Earth, this is why the compass needle always points to the north.
William Gilbert was the one who found out that Earth is a giant magnet. He also found out that if you rub a magnet on an iron object in the same direction, it makes the iron a permanent magnet. He also discovered that if you heat a permanent magnet the magnetism is lost.
Have a look at some of these devices that all use magnets:
- Toothbrushes, microwaves, televisions and computers use magnets.
- Refrigerator doors, credit cards and medical devices like MRIs use magnets. MRIs are machines that can scan and create pictures of our entire body.
- Modern trains use magnets to lift them off the ground so they float.