In 1821, the world famous physicist Ampere proposed the famous molecular current hypothesis. He mathematically proved that the magnetic field of the energized coil is the same as the magnetic field of the strip magnet, which inspires him to regard the magnetism of the magnet as being caused by current. Ampere believes that the nature of magnetism should be attributed to the magnetic effect of current, that is, all magnetic phenomena originate from the motion of current or charge. The molecules of any substance have a molecular current, which is equivalent to a primary magnet. The disordered arrangement of molecular currents makes the whole object non-magnetic, and the molecular currents are regularly arranged to make the object exhibit magnetic properties. The assumption of Ampere is confirmed by modern physics: the magnetic properties of atoms and molecules are caused by the rapid rotation of electrons around the nucleus or around their own axis.