Hans Christian Ørsted

The young H. C. Ørsted

Ørsted was born in Rudkøbing in 1777. As a young boy he developed an interest in science while working for his father, who owned the local pharmacy.[3] He and his brother Anders received most of their early education through self-study at home, going to Copenhagen in 1793 to take entrance exams for the University of Copenhagen, where both brothers excelled academically. By 1796, Ørsted had been awarded honors for his papers in both aesthetics and physics. He earned his doctorate in 1799 for a dissertation based on the works of Kant entitled The Architectonics of Natural Metaphysics.

In 1800, Alessandro Volta reported his invention of the voltaic pile, which inspired Ørsted to investigate the nature of electricity and to conduct his first electrical experiments. In 1801, Ørsted received a travel scholarship and public grant which enabled him to spend three years traveling across Europe. He toured science headquarters throughout the continent, including in Berlin and Paris.[4]

In Germany Ørsted met Johann Wilhelm Ritter, a physicist who believed there was a connection between electricity and magnetism. This idea made sense to Ørsted as he subscribed to Kantian thought regarding the unity of nature.[3][5] Ørsted's conversations with Ritter drew him into the study of physics. He became a professor at the University of Copenhagen in 1806 and continued research on electric currents and acoustics. Under his guidance the university developed a comprehensive physics and chemistry program and established new laboratories.

Ørsted welcomed William Christopher Zeise to his family home in autumn 1806. He granted Zeise a position as his lecturing assistant and took the young chemist under his tutelage. In 1812, Ørsted again visited Germany and France after publishing Videnskaben om Naturens Almindelige Love and Første Indledning til den Almindelige Naturlære (1811).

Ørsted was the first modern thinker to explicitly describe and name the thought experiment. He used the Latin-German term Gedankenexperiment circa 1812 and the German term Gedankenversuch in 1820.[6]

In 1820, Ørsted published his discovery that a compass needle was deflected from magnetic north by a nearby electric current, confirming a direct relationship between electricity and magnetism.[7] The often reported story that Ørsted made this discovery incidentally during a lecture is a myth. He had, in fact, been looking for a connection between electricity and magnetism since 1818, but was quite confused by the results he was obtaining.[8][9]

His initial interpretation was that magnetic effects radiate from all sides of a wire carrying an electric current, as do light and heat. Three months later, he began more intensive investigations and soon thereafter published his findings, showing that an electric current produces a circular magnetic field as it flows through a wire.[10][8] For his discovery, the Royal Society of London awarded Ørsted the Copley Medal in 1820 and the French Academy granted him 3,000 francs.

Ørsted's findings stirred much research into electrodynamics throughout the scientific community, influencing French physicist André-Marie Ampère's developments of a single mathematical formula to represent the magnetic forces between current-carrying conductors. Ørsted's work also represented a major step toward a unified concept of energy.

Gravestone

Ørsted was elected a foreign member of the Royal Swedish Academy of Sciences in 1822 and a Foreign Honorary Member of the American Academy of Arts and Sciences in 1849.[11]

He founded Selskabet for Naturlærens Udbredelse (SNU), a society to disseminate knowledge of the natural sciences, in 1824. He was also the founder of predecessor organizations which eventually became the Danish Meteorological Institute and the Danish Patent and Trademark Office. In 1829, Ørsted founded Den Polytekniske Læreanstalt ('College of Advanced Technology') which was later renamed the Technical University of Denmark (DTU).[12]

In 1825, Ørsted made a significant contribution to chemistry by producing aluminium in a near-pure form for the first time.[13] In 1808, Humphry Davy had predicted the existence of the metal which he gave the name of alumium. However his attempts to isolate it using electrolysis processes were unsuccessful. The closest he came was an aluminum-iron alloy.[14][15] Ørsted was the first to isolate the element via a reduction of aluminium chloride. Although the aluminium alloy he extracted still contained impurities, he is credited with discovery of the metal. His work was developed further by Friedrich Wöhler who obtained aluminium powder on October 22, 1827, and solidified balls of molten aluminium in 1845. Wöhler is credited with the first isolation of the metal in a pure form.[15][16]

Ørsted died in Copenhagen in 1851, aged 73, and was buried in the Assistens Cemetery.

The centimetre-gram-second system (CGS) unit of magnetic induction (oersted) is named for his contributions to the field of electromagnetism.

Monuments and memorials

Statue of Ørsted in Ørstedsparken, in Copenhagen.

A statue of Hans Christian Ørsted was installed in the Ørsted Park in 1880. A commemorative plaque is located above the gate on the building in Studiestræde where he lived and worked. The 100 danske kroner note issued from 1950 to 1970 carried an engraving of Ørsted.

Ørsted was a published writer and poet. His poetry series Luftskibet ("The Airship") was inspired by the balloon flights of fellow physicist and stage magician Étienne-Gaspard Robert.[19] Shortly before his death, he submitted a collection of articles for publication under the title Aanden i Naturen ("The Soul in Nature"). The book presents Ørsted's life philosophy and views on a wide variety of issues.[20]

• History of aluminium
• James Clerk Maxwell
• Michael Faraday
• Gian Domenico Romagnosi, who observed an electrostatic attraction of a compass needle

• Brain, R. M.; et al. (2007). Hans Christian Ørsted and the Romantic Legacy in Science. Ideas, Disciplines, Practices. Boston Studies in the Philosophy of Science, 241. Dordrecht. pp. 273–338.
• Christensen, D. C. (2013). Hans Christian Ørsted. Oxford: Oxford University Press. ISBN 978-0-19-966926-4.
• Bern Dibner (1962) Oersted and the discovery of electromagnetism, New York, Blaisdell.
• Ole Immanuel Franksen (1981) H. C. Ørsted – a man of the two cultures, Strandbergs Forlag, Birkerød, Denmark. (Note: Both the original Latin version and the English translation of his 1820 paper "Experiments on the effect of a current of electricity on the magnetic needle" can be found in this book.)
• Hans Christian Ørsted (1997). Karen Jelved, Andrew D. Jackson, and Ole Knudsen, translators from Danish to English. Selected Scientific Works of Hans Christian Ørsted, ISBN 0-691-04334-5.

• Media related to Hans Christian Ørsted at Wikimedia Commons
• Physics Tree: Hans Christian Ørsted Details
• Interactive Java Tutorial on Oersted's Compass Experiment National High Magnetic Field Laboratory
• The soul in nature : with supplementary contributions, London: H. G. Bohn, 1852.
• Hans Christian Ørsted at Find a Grave
• "Oersted, Hans Christian" . Encyclopedia Americana. 1920.