Invented in 1824 by the British physicist William Sturgeon, electromagnets are a fixture of modern life, appearing in loudspeakers, motors, magnetic resonance imaging (MRI) machines, maglev trains, ...

Magnets like this one are great at picking up metal objects like these, but once you pick them up how do you let them go? For that you need a special type of magnet – an electromagnet. Magnetism and ...