Hans Christian Ørsted
Danish physicist & chemist
Born	14 August 1777(1777-08-14) Rudkøbing, Denmark
Died	9 March 1851 (aged 73) Copenhagen, Denmark
Nationality	Danish
Fields	physics, chemistry
Known for	electromagnetism

Hans Christian Ørsted (often rendered Oersted in English; 14 August 1777 - 9 March 1851) was a Danish physicist and chemist who is most widely known for observing that electric currents induce magnetic fields, an important aspect of electromagnetism. He shaped post-Kantian philosophy and advances in science throughout the late 19th century.^[1]

In 1824, Ørsted founded Selskabet for Naturlærens Udbredelse (SNU), a society to disseminate knowledge of the natural sciences. He was also the founder of predecessor organizations which eventually became the Danish Meteorological Institute and the Danish Patent and Trademark Office. Ørsted was the first modern thinker to explicitly describe and name the thought experiment.

A leader of the so-called Danish Golden Age, Ørsted was a close friend of Hans Christian Andersen and the brother of politician and jurist Anders Sandøe Ørsted, who eventually served as Danish prime minister (1853–54).

The Oersted (Oe), the cgs unit of magnetic H-field strength, is named after him.

Contents 1 Early life and studies 2 Electromagnetism 3 Later years 4 Legacy 5 Writings 6 See also 7 References 8 Further reading 9 External links

[edit] Early life and studies

Ørsted was born in Rudkøbing. As a young boy Ørsted developed his interest in science while working for his father, who owned a pharmacy.^[2] 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 Architectonicks of Natural Metaphysics".

In 1801 Ørsted received a travel scholarship and public grant which enabled him to spend three years travelling across Europe. In Germany he met Johann Wilhelm Ritter, a physicist who believed there was a connection between electricity and magnetism. This made sense to Ørsted since he believed in Kantian ideas about the unity of nature and that deep relationships existed between natural phenomena.^[2]

Their conversations drew Ørsted into the study of physics. He became a professor at the University of Copenhagen in 1806 and continued his research with electric currents and acoustics. Under his guidance the University developed a comprehensive physics and chemistry program and established new laboratories.

[edit] Electromagnetism

In 1802 Gian Domenico Romagnosi had described electric current from a voltaic pile (an early type of battery) deflecting a magnetic needle. Although published in an Italian newspaper, this was largely overlooked by the scientific community.^[3]

On 21 April 1820, while preparing for an evening lecture, Ørsted noticed a compass needle deflected from magnetic north when electric current from a battery was switched on and off. This deflection convinced him that magnetic fields radiate from all sides of a wire carrying an electric current, as do light and heat, confirming a direct relationship between electricity and magnetism. Three months later he began more intensive investigations and soon thereafter published his findings, showing that an electric current produces a magnetic field as it flows through a wire.

His 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.

In 1822, he was elected a foreign member of the Royal Swedish Academy of Sciences.

[edit] Later years

In 1825, Ørsted made a significant contribution to chemistry by producing aluminium for the first time. While an aluminium-iron alloy had previously been developed by British scientist and inventor Humphry Davy, Ørsted was the first to isolate the element via a reduction of aluminium chloride.

In 1829, Ørsted founded Den Polytekniske Læreanstalt ('College of Advanced Technology') which was later renamed the Technical University of Denmark (DTU).^[4]

Ørsted died at Copenaghen in 1851 and was buried in the Assistens Cemetery in the same city.

[edit] Legacy

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

The 100 danske kroner note issued from 1950 to 1970 carried an engraving of Ørsted. The buildings which are home to the Department of Chemistry and the Institute for Mathematical Sciences at the University of Copenhagen are named The H.C. Ørsted Institute, after him. The first Danish satellite, launched 1999, was named after Ørsted. Two medals are awarded in Ørsted's name: the Oersted Medal for notable contributions in the teaching of physics in America, awarded by American Association of Physics Teachers, along with the H. C. Ørsted Medal for Danish scientists, awarded by the Danish Selskabet for Naturlærens Udbredelse (Society for the Dissemination of Natural Science), which Ørsted founded.

[edit] Writings

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.^[5] Shortly before his death, he submitted a collection of articles for publication under the title "The Soul of Nature". The book presents Ørsted's life philosophy and views on a wide variety of issues.^[6]

[edit] See also

• James Clerk Maxwell
• Thought experiment

[edit] References

[edit] Further reading

• Dibner, Bern, Oersted and the discovery of electromagnetism, New York, Blaisdell (1962).
• Ole Immanuel Franksen, H. C. Ørsted – a man of the two cultures, Strandbergs Forlag, Birkerød, Denmark (1981). (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.)

[edit] External links

Wikimedia Commons has media related to: Hans Christian Ørsted

• Interactive Java Tutorial on Oersted's Compass Experiment National High Magnetic Field Laboratory
• Hans Christian Ørsted at Find a Grave

Awards
Preceded by Robert Seppings	Copley Medal 1820	Succeeded by Edward Sabine and John Herschel

Persondata
NAME	Ørsted, Hans Christian
ALTERNATIVE NAMES
SHORT DESCRIPTION	Danish physicist and chemist
DATE OF BIRTH	14 August 1777
PLACE OF BIRTH	Rudkøbing, Denmark
DATE OF DEATH	9 March 1851
PLACE OF DEATH	Copenhagen, Denmark