Hans Christian Ørsted

Hans Christian Ørsted FRSE (/ˈɜːrstɛd/,[5] Danish: [ˈhænˀs ˈkʰʁestjæn ˈɶɐ̯steð] ; often rendered Oersted in English[note 1]; 14 August 1777 – 9 March 1851) was a Danish physicist and chemist who discovered that electric currents create magnetic fields, which was the first connection found between electricity and magnetism. Oersted's law and the oersted unit (Oe) are named after him.

Hans Christian Ørsted
Born(1777-08-14)14 August 1777
Rudkøbing, Denmark-Norway
Died9 March 1851(1851-03-09) (aged 73)
Copenhagen, Denmark
Alma materUniversity of Copenhagen (PhD, 1799)[4]
Known for
SpouseInger Birgitte Ballum
ChildrenKaren Ørsted; Sophie Wilhelmine Bertha Ørsted; Mathilde Elisabeth Ørsted; Anders Sandøe Ørsted; Albert Nicolay Ørsted; Anna Dorthea Maria Ørsted and Niels Christian Ørsted
Scientific career
FieldsPhysics, chemistry, aesthetics
InstitutionsUniversity of Copenhagen, Technical University of Denmark (Founder and Principal)

A leader of the Danish Golden Age, Ørsted was a close friend of Hans Christian Andersen and the brother of politician and jurist Anders Sandøe Ørsted, who served as Prime Minister of Denmark from 1853 to 1854.

Early life and studies

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 was a pharmacist in the town's pharmacy.[6] 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.[7]

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.[6][8][page needed] 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. [citation needed]

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.[9]

In 1819 Ørsted was the first to extract piperine and subsequently name it. He extracted it from Piper nigrum, the plant from which both white and black pepper comes from.[10]

Ørsted designed a new type of piezometer to measure the compressibility of liquids in 1822.[11]


A compass needle with a wire, showing the effect Ørsted discovered.

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.[12]: 274  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[how?] by the results he was obtaining.[13][12]: 273 

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.[1][13] 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.

The Ørsted effect brought about a communications revolution due to its application to the electric telegraph. The possibility of such a telegraph was suggested almost immediately by mathematician Pierre-Simon Laplace and Ampère presented a paper based on Laplace's idea the same year as Ørsted's discovery.[12]: 302–303  However, it was almost two decades before it became a commercial reality.

Later years

Statue of Ørsted at Oxford

Ørsted was elected a Fellow of the Royal Society of Edinburgh in March 1821,[14] a Foreign Member of the Royal Society of London in April 1821,[2] a foreign member of the Royal Swedish Academy of Sciences in 1822, a member of the American Philosophical Society in 1829,[15] and a Foreign Honorary Member of the American Academy of Arts and Sciences in 1849.[16]

He founded the Selskabet for Naturlærens Udbredelse [da] (Society for the Dissemination of Natural Science, SNU) 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).[17]

In 1824, Ørsted made a significant contribution to chemistry by being the first person to successfully produce aluminium in its metallic state, albeit in a less-than-pure form.[18][19] 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 aluminium-iron alloy.[20] Ørsted succeeded in isolating the metallic form by reacting aluminium chloride with potassium amalgam (an alloy of potassium and mercury) and then boiling away the mercury, which left small "chunks" of metal that he described as appearing similar to tin.[18][note 2] He presented his results and a sample of the metal at meetings of the Danish Academy of Sciences in early 1825, but otherwise appears to have considered his discovery to be of limited importance.[21] This ambivalence, coupled with the limited audience for the Danish Academy's journal in which the results had been published, meant that the discovery went mostly unnoticed by the wider scientific community at the time.[21][22] Busy with other work, in 1827 Ørsted gave his friend, the German chemist Friedrich Wöhler, permission to take over the research.[21] Wöhler was able to produce approximately 30 grams (1.1 oz) of aluminium powder soon thereafter, using a process of his own design, before finally, in 1845, isolating a quantity of solid metal sufficient for him to describe some of its physical properties.[19]

Portrait of Hans Christian Ørsted by Christian Albrecht Jensen (1842)

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.

The company Danish Oil and Natural Gas (DONG), was renamed Ørsted to signal its transition from fossil fuels to becoming one the world's leading developers and operators of offshore windfarms.

The first Danish satellite, launched in 1999, was named after Ørsted.



The Ørsted Park in Copenhagen was named after Ørsted and his brother in 1879. The streets H. C. Ørsteds Vej in Frederiksberg and H. C. Ørsteds Allé in Galten are also named after him.

The buildings that are home to the Department of Chemistry and the Institute for Mathematical Sciences at the University of Copenhagen's North Campus are named the H.C. Ørsted Institute, after him. A dormitory named H. C. Ørsted Kollegiet is located in Odense.

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.

In 1885, a statue of Ørsted was installed in the Oxford University Museum of Natural History.

Ørsted's likeness has appeared twice on Danish banknotes; for the first time on 500 kroner notes issued in 1875, and for the second time on 100 kroner notes issued between 1962 and 1974.[23]

Awards and lectures


Two medals are awarded in Ørsted's name: the H. C. Ørsted Medal for Danish scientists, awarded by the Danish Society for the Dissemination of Natural Science (SNU), as founded by Ørsted, and the Oersted Medal for notable contributions in the teaching of physics in America, awarded by American Association of Physics Teachers.

The Technical University of Denmark hosts the H. C. Ørsted Lecture series for prominent and engaging researchers from around the world.[24]



Ørsted was a published poet, as well as scientist. His poetry series Luftskibet ("The Airship") was inspired by the balloon flights of fellow physicist and stage magician Étienne-Gaspard Robert.[25]

  • Ørsted, H. C. (1836). Luftskibet, et Digt [The Airship, a Poem] (in Danish). København: Gyldendal. OCLC 28930872.

In 1850, shortly before his death, he submitted for publication a two-volume collection of philosophical articles in German under the title Der Geist in der Natur ("The Soul in Nature"). It was translated into English and published in one volume in 1852, the year after his death.

Other works:

A significant number of Ørsted's papers were made available in English for the first time in a compilation published in 1998:[26]

See also



  1. ^ Depending on orthography and editorial convention, it may also be rendered Orsted or Örsted.
  2. ^ This description, combined with others Ørsted gave subsequently, suggests that he had actually obtained an alloy of aluminium and potassium.[19]


  1. ^ a b Oersted, J. C. (1820). "Experiments on the Effect of a Current of Electricity on the Magnetic Needle". In Thomson, T. (ed.). Annals of Philosophy; or, Magazine of Chemistry, Mineralogy, Mechanics, Natural History, Agriculture, and the Arts. Vol. XVI. London: Baldwin, Cradock, and Joy. pp. 273–276. hdl:2027/osu.32435051156651. OCLC 9529852.
  2. ^ a b "Bibliographic Record: NA7482". The Royal Society of London. Retrieved 20 March 2023.
  3. ^ Orden Pour le Mérite für Wissenschaften und Künste (1975). Die Mitglieder des Ordens (PDF) (in German). Vol. 1. Berlin: Gebrüder Mann Verlag. p. 78. ISBN 978-3-78616-189-9. OCLC 2090453.
  4. ^ Daintith, J.; Mitchell, S.; Tootill, E., eds. (1981). "Oersted, Hans Christian". Biographical Encyclopedia of Scientists. Vol. 2. New York: Facts on File. p. 603. ISBN 978-0-87196-396-3. OCLC 6709010. OL 4108681M.
  5. ^ "Oersted". Random House Webster's Unabridged Dictionary.
  6. ^ a b Jacobsen, A. S.; Knudsen, O. (14 April 2021). "H.C. Ørsted". Den Store Danske (in Danish). Gyldendal. Retrieved 12 April 2023.
  7. ^ "Inspiration fra Europa – planer i København" [Inspiration from Europe – Plans in Copenhagen] (in Danish). Niels Bohr Institutet, Københavns Universitet. 27 February 2023. Retrieved 12 April 2023.
  8. ^ Brain, R. M.; Cohen, R. S.; Knudsen, O., eds. (2007). Hans Christian Ørsted and the Romantic Legacy in Science: Ideas, Disciplines, Practices. Boston Studies in the Philosophy and History of Science. Vol. 241. Dordrecht: Springer. doi:10.1007/978-1-4020-2987-5. ISBN 978-1-40202-979-0. OCLC 181067920.
  9. ^ Witt-Hansen, J. (1976). "H.C. Ørsted, Immanuel Kant, and the Thought Experiment". Danish Yearbook of Philosophy. 13 (1): 48–65. doi:10.1163/24689300-01301004. ISSN 0070-2749.
  10. ^ Ørsted, Hans Christian (1820). "Über das Piperin, ein neues Pflanzenalkaloid" [On piperine, a new plant alkaloid]. Schweiggers Journal für Chemie und Physik (in German). 29 (1): 80–82.
  11. ^ Aitken, F.; Foulc, J.-N. (2019). From Tait's Work on the Compressibility of Seawater to Equations-of-State for Liquids. From Deep Sea to Laboratory. Vol. 3. London: ISTE. doi:10.1002/9781119663362. ISBN 978-1-78630-376-9. S2CID 204258765.
  12. ^ a b c Fahie, J. J. (1884). A History of Electric Telegraphy to the Year 1837. London: E. & F. N. Spon. OCLC 1417165. OL 6993294M.
  13. ^ a b Martins, R. A. (2003). "Resistance to the Discovery of Electromagnetism: Ørsted and the Symmetry of the Magnetic Field" (PDF). In Bevilacqua, F.; Giannetto, E. (eds.). Volta and the History of Electricity. Milano: Editore Ulrico Hoepli. pp. 245–265. ISBN 978-8-82033-284-6. OCLC 1261807533. Archived from the original (PDF) on 23 July 2011.
  14. ^ Waterston, C. D.; Macmillan Shearer, A. (July 2006). Biographical Index of the Former Fellows of the Royal Society of Edinburgh, 1783–2002 (PDF). Vol. II. The Royal Society of Edinburgh. p. 703 (in work p. 215). ISBN 978-0-90219-884-5. Retrieved 20 March 2023.
  15. ^ "APS Member History". American Philosophical Society. Retrieved 7 April 2021.
  16. ^ "Chapter O" (PDF). Members of the American Academy of Arts & Sciences: 1780–2012. American Academy of Arts and Sciences. p. 401. Archived from the original (PDF) on 20 December 2016. Retrieved 8 September 2016.
  17. ^ "History of DTU". Kongens Lyngby: Danmarks Tekniske Universitet. Archived from the original on 2 September 2009. Retrieved 14 August 2009.
  18. ^ a b Ørsted, H. C., ed. (1825). "Physisk Classe". Oversigt over det Kongelige Danske Videnskabernes Selskabs Forhandlinger og dets Medlemmers Arbeider fra 31 Mai 1824 til 31 Mai 1825 (in Danish). København. pp. 15–16. hdl:2027/osu.32435054254693. ISSN 0369-7169. OCLC 32565767.
  19. ^ a b c Drozdov, A. (2007). Aluminium: The Thirteenth Element (PDF). Moscow: RUSAL Library. pp. 36–37. ISBN 978-5-91523-002-5. Archived from the original (PDF) on 16 April 2016. Retrieved 20 March 2023.
  20. ^ Kvande, H. (2008). "Two hundred years of aluminum... or is it aluminium?". JOM. 60 (8): 23–24. Bibcode:2008JOM....60h..23K. doi:10.1007/s11837-008-0102-3. S2CID 135517326.
  21. ^ a b c Christensen, D. C. (2013). "Aluminium: Priority and Nationalism". Hans Christian Ørsted: Reading Nature's Mind. Oxford University Press. pp. 424–430. doi:10.1093/acprof:oso/9780199669264.001.0001. ISBN 978-0-19966-926-4. OCLC 847943710.
  22. ^ Fontani, M.; Costa, M.; Orna, M. V. (2015). The Lost Elements: The Periodic Table's Shadow Side. Oxford University Press. p. 30. ISBN 978-0-19938-334-4. OCLC 873238266.
  23. ^ "Sedler og Mønter: Portræt- og Landskabsserien" [Notes and Coins: The Portrait and Landscape Series] (in Danish). København: Danmarks Nationalbank. 10 February 2014. Retrieved 20 March 2023.
  24. ^ "DTU Ørsted Lectures". Kongens Lyngby: Danmarks Tekniske Universitet. Retrieved 20 March 2023.
  25. ^ "1802: Balloon Expedition over Copenhagen". The Soul in Nature: The Danish Golden Age 1800–1850. København: Nationalmuseet. Archived from the original on 27 September 2007. Retrieved 30 July 2007.
  26. ^ Caneva, K. L. (1999). "Book Review: Hans Christian Ørsted, 'Selected Scientific Works of Hans Christian Ørsted', Edited and translated by Karen Jelved, Andrew D. Jackson, and Ole Knudsen ...". Isis. 90 (4): 819–820. doi:10.1086/384554.

Further reading