Magnetism is a force that either pulls magnetic materials together or pushes them apart.
Iron and nickel are the most common magnetic materials. Electricity is also magnetic.
Around every magnet there is a region in which its effects are felt, called its magnetic field.
The magnetic field around a planet or a star is called the magnetosphere.
Most of the planets in the Solar System, including the Earth, have a magnetic field.
Planets have magnetic fields because of the liquid iron in their cores. As the planets rotate, so the iron swirls, generating electric currents that create a magnetic field.
Jupiter’s magnetic field is 30 times stronger than that of the Earth, because Jupiter is huge and spins very quickly.
Neptune and Uranus are unusual because, unlike other planets’ magnetic fields, theirs are at right angles to their axis of rotation (the angle at which they spin).
Magnetism is linked to electricity, and together they make up the force called electromagnetism.
Electromagnetism is one of the four fundamental forces in the Universe, along with gravity and the two basic forces of the atomic nucleus.
Magnetism is the invisible force between materials such as iron and nickel. Magnetism attracts or repels.
A magnetic field is the area around a magnet inside which its magnetic force can be detected.
An electric current creates its own magnetic field.
A magnet has two poles: a north pole and a south pole.
Like (similar) poles (e.g. two north poles) repel each other; unlike poles attract each other.
The Earth has a magnetic field that is created by electric currents inside its iron core. The magnetic north pole is close to the geographic North Pole.
If left to swivel freely, a magnet will turn so that its north pole points to the Earth’s magnetic north pole.
The strength of a magnet is measured in teslas. The Earth’s magnetic field is 0.00005 teslas.
All magnetic materials are made up of tiny groups of atoms called domains. Each one is like a mini-magnet with north and south poles. When material is magnetized, millions of domains line up.
Some animals seem to detect the Earth’s magnetic One of the world’s strongest magnets is field and use it to help at the Lawrence Berkeley National them find their way when Laboratory, California, USA. Its field is they migrate. Birds which 250,000 times stronger than the Earth’s have this built-in compass include swallows, geese and pigeons.