Since its debut in Elihu Thomson's 1886 article "Novel Phenomena of Alternating Currents," the Thomson jumping ring apparatus has been a popular and captivating demonstration of magnetic induction. The components are quite simple. There is a solenoid, an iron core, and a ring. The demonstration usually begins with the professor saying something along the lines of, "An alternating current introduced to the solenoid will create a changing magnetic field, which induces a current in the ring in such a way to oppose the changing flux of the magnetic field responsible for the creation of the ring current. This will make the ring jump!" The professor then turns a switch, the ring is instantaneously launched into the air, and a classroom of students is amazed. The behavior of the demonstration is then attributed Lenz's law and the lecture moves on.