A magnetic field is invisible, but it can be detected using a magnetic compass. A compass contains a small bar magnet on a pivot so that it can rotate. The compass needle points in the direction ...

A permanent magnet is always magnetic. It has an invisible magnetic field. Only certain materials, such as iron, feel a magnetic force. Permanent magnets can come in lots of different shapes and ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. How the universe got its large magnetic fields has remained one of the stickiest outstanding ...