And just what are the most powerful magnets in the universe? If a strong enough magnetic field is applied, the magnetic fields of all the iron atoms in all the domains will also align. The current supplied by the battery is spiraling around the nail through the wire creates a magnetic field, because it’s undergoing a centripetal acceleration. This brings us to one of the most powerful magnets mere mortals occasionally encounter in the form of Magnetic Resonance Image (MRI’s). Unfortunately, magnets powerful enough and have a solenoid big enough to levitate a human don’t exist on Earth… yet.