At the beginning of the nineteenth century, electricity and magnetism had been seen as two entirely different forces. This all changed thanks to Hans Christian Oersted's lucky lecture.

Oersted had been using a strong battery in one of his lectures, and as he concluded his talk he placed a current-carrying wire over a compass. To his surprise, the compass began to move quickly from the north direction to the east directon, as if it were in the presence of an intense magnetic field. Oersted reversed the flow of the electric current and the compass promptly began pointing west.

As soon as Oersted announced his discovery, physicists all over Europe duplicated the experiment and quickly realized that electricity and magnetism were two aspects of the same force. Today we refer to this force as electromagnetism, thanks, in part, to Oersted's lucky lecture.