Is it only metals that respond to magnetic forces?
A magnet can affect more than just your metal fridge. In fact, every material has can be affected by a powerful enough magnet.
Asked by: Chris Ormsby, Taunton
Armed with a small magnet and some objects, it’s easy to get the impression that only certain varieties of metal, such as steel, respond to magnetic fields. In fact, every material – wood, plastic, even water – will respond to a magnetic field, if it’s strong enough. That’s because every material possesses a property known as diamagnetism, by which the electrons within the material repel magnetic fields.
Given a sufficiently powerful magnet, this diamagnetic repulsion can produce spectacular effects. In 1997, a team at the University of Nijmegen in the Netherlands used the effect to levitate a frog, using a magnetic field over a million times more powerful than that of the Earth.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.
Subscription offer
Subscribe and save 50% on the shop price. Pay just £16.50 every 6 issues by Direct Debit. Receive every issue delivered direct to your door with FREE UK delivery.