Hans Christian Ørsted Electrifies Google

In short, Ørsted was an early discoverer of electromagnetism. According to a very concise account:
Hans Christian Ørsted, one of the leading scientists of the nineteenth century, played a crucial role in understanding electromagnetism. In 1820 he discovered that a compass needle deflects from magnetic north when an electric current is switched on or off in a nearby wire. This showed that electricity and magnetism were related phenomena, a finding that laid the foundation for the theory of electromagnetism and for the research that later created such technologies as radio, television and fiber optics. The unit of magnetic field strength was named the Oersted in his honor.

BONUS: Google Doodle Gallery

For those partial to “Google doodles” (we certainly are), YouTube user Zephopper has put together a compilation video of some of the best from over the years: