Had no idea who he was until this morning. One would think that someone who’s made significant contributions to the field of electromagnetism would be more well-known. Today is the day of his birth.
Thus the study of electromagentism was born, and it’s the basis of a lot of modern life: it led to the development of electricity generators and transformers. Remember that next time you flick a light switch.
As with many great discoveries, it happened by accident. In 1820, Ørsted, a professor of natural philosophy at the University of Copenhagen, was preparing an evening lecture when he noticed that a compass needle moved away from magnetic north and pointed to the wire whenever current flowed from the battery.
Perhaps even more surprisingly, the compass needle pointed in the opposite direction when you flipped the battery round.
With an invisible current creating an invisible field that moved a physical needle, this caused quite a stir at the time. In London, the Royal Society gave him a medal, and he was also made a knight of the Prussian Order of Merit, of the French Legion of Honor, and the Danish Order of the Dannebrog. On his death in Copenhagen in 1851, he was given a state funeral.