| When you
look at a magnified view of the magnetic crystal in this exhibit,
youll see a pattern made up of light and dark areas. The light
areas indicate regions in which atoms have south poles facing up,
and the dark areas have north poles facing up. Regions of atoms
that are aligned the same way are called domains.
If you turn a nearby magnet so that the poles switch direction,
youll see the domain patterns change: The domains that are
aligned with the magnetic field of the magnet grow larger. This
happens because atoms bordering these domains reverse their polarity.