Ørsted's compass discovery was no lecture-hall accident
A popular story says Hans Christian Ørsted stumbled on electromagnetism mid-lecture when a wire twitched a compass. In fact he had been hunting for a link between electricity and magnetism since 1818 and was baffled by his results. His 1820 paper showing a current deflects a needle set off a revolution leading to the telegraph.
Ørsted was born in 1777 in Rudkøbing, a small Danish town, and caught the science bug helping in his father's pharmacy. He and his brother Anders, a future prime minister, largely taught themselves at home before both excelled at the University of Copenhagen. His doctorate in 1799 was on the philosophy of Kant, whose belief in the unity of nature would shape his physics. Alessandro Volta's announcement of the electric battery in 1800 drew him to experiments, and in Germany he met Johann Ritter, who also suspected electricity and magnetism were related.
At first he thought magnetism radiated outward from a live wire, the way heat and light do. Further experiments three months later showed the magnetic field actually circles the wire. Britain's Royal Society gave him the Copley Medal, and the French Academy awarded him 3,000 francs. André-Marie Ampère quickly turned the finding into a mathematical law of forces between currents, and Pierre-Simon Laplace suggested an electric telegraph almost at once, although a commercial one took nearly two decades.
In 1824 he became the first person to produce metallic aluminium, if impure, by reacting aluminium chloride with a potassium-mercury alloy and boiling off the mercury, leaving small tin-like lumps. Humphry Davy had predicted the metal but failed to isolate it. Ørsted thought little of his success, published it in an obscure Danish journal, and in 1827 handed the research to his friend Friedrich Wöhler.
He was also the first to extract piperine, the compound that gives black pepper its bite, and the first modern writer to name the thought experiment. He founded what became the Technical University of Denmark and the precursors of Denmark's meteorological institute and patent office, and counted Hans Christian Andersen among his close friends. A unit of magnetic field strength is named the oersted, and Denmark's state energy company took his name as it switched to offshore wind.
Source: Hans Christian Ørsted
