As some accounts have it, the stones were first noticed in around 2500 BCE by a shepherd in Magnesia, in what is modern-day Turkey. He observed that they clung to the nails in his shoes.The stones were made of naturally magnetic iron ore. They were probably already familiar to the Chinese, who used lodestones — a form of magnetite — to first tell fortunes and later make navigational compasses. It would take until the 20th century for scientists to uncover a second type of magnetism. Astonishingly, researchers announced last week that they had confirmed discovery of a third.
“The idea that there has been a third type of magnetism and we haven’t noticed it, really captures people’s imaginations,” says Felix Flicker, a Bristol University researcher who studies magnetism and author of The Magick of Matter, which draws parallels between scientific phenomena and wizardry. Other forms, he thinks, may be awaiting discovery.
As well as adding mystique to a phenomenon that has long fascinated humans, this new form, called altermagnetism, could lead to more energy-efficient computation. With data centres thought to account for around one per cent of global electricity consumption, even a modest efficiency improvement could have a large environmental impact.