Question: How do magnets work? :D

Alan Winfield answered on 16 Mar 2011:

I think that the best way to understand how magnets work is by making an electromagnet. Get an ordinary nail and some insulated copper wire. Wrap the copper wire around the nail – perhaps 10 times – making a coil. If you now a compass and put it on the table near the nail+coil and connect the ends of the wire to a battery, you’ll see the compass needle move to point toward the electromagnet (instead of the North pole). Basically the current flowing through the wire and the coil creates a magnetic field – but it’s only temporary – if you disconnect the battery (which you’ll have to do anyway because the wire will get hot) the magnetic field disappears. What’s really interesting is that electro- magnetism works both ways. If you take a permanent magnet and move it through a coil of wire then you induce a current into a wire. One of my scientific heroes Michael Faraday worked all of this out in the 1820s: ideas that led to motors – which turn electricity into movement – and dynamos – which turn movement into electricity.

So electricity and magentism are very closely connected. It’s the connection between them that led to one of the most amazing inventions ever (in my humble opinion) – radio. Another great Victorian called James Clerk Maxwell worked out the (very hard) maths called electromagnetic theory – which I had to learn when I was a student. Without electro- magnetism we wouldn’t have radios, TVs, satellites, sat nav, WiFi or mobile phones (and quite a few other things besides).

Hope this answer helps:)