Would an anti-matter magnet attract iron?
Assuming it was possible to create a magnet made of anti-matter, would it attract or repel anti-matter iron / normal Iron? Would you have anti-magnetism or is magnetism the same in an antimatter universe as it is here if so why?
Dave - It is a wonderful question. The main difference we know about antimatter is it's got the anti-electrons with the opposite charge to normal electrons, so a positron has the opposite charge to a normal electron, and magnetism is all about charge. It's actually a sort of minor alteration, a minor tweak to the normal electric field which is due to relativity. So Einstein's specialty of relativity predicts magnetism, and it's actually part of the way he worked out the theory in the first place. And so, antimatter has got perfect normal charges. It behaves normally, just in the opposite direction. So, an antimatter magnet would behave - as far as I can work out, exactly the same as a normal magnet. So it would attract both antimatter iron and normal iron. Chris - The difference being of course if it touched the antimatter. Dave - Yeah. It would get immense amounts of energy released. Although the question which nobody knows the answer to is whether it would be attracted or repelled by gravity. So whether it would fall downwards or upwards, nobody knows. No one has been able to measure that yet.