Making a magnet from a piece of iron and a coil or wire, or another magnet, is a simple experiment. An external electric or magnetic field can align groups of atoms in the iron over time so that they take on their own permanent magnetic field. A similar accelerated process stores information on computer hard disks. A special case of magnetism, known as ferrimagnetism, could enable even faster switching of magnetism, leading to massive improvements in the way computers handle information.