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Hans Christian Ørsted
Danish physicist & chemist
Born	August 14, 1777 Rudkøbing, Denmark
Died	March 9, 1851 Copenhagen, Denmark

Ørsted redirects here. This article is about the Danish physicist. For the unit see Oersted and other uses Oersted (disambiguation)

Hans Christian Ørsted (August 14, 1777 – March 9, 1851) was a Danish physicist and chemist, influenced by the thinking of Immanuel Kant. He is best known for discovering the relationship between electricity and magnetism known as electromagnetism. Especially in older sources, his surname will sometimes be found spelled in the German manner as Oersted, or less often as Orsted.

From 1806, Ørsted was a professor at the University of Copenhagen. He was instrumental in the founding of the university's Faculty of Science shortly before his death. In the 1960's the main building complex of the university's new science campus was named in his honor.

Ørsted was the driving force behind the founding of the Technical University of Denmark in 1829 and served as its first director. The present-day department of applied electronics is named Ørsted·DTU in his honor.

Contents 1 Early days 2 Discovery of electromagnetism 3 Society 4 References 5 See also 6 External links

Early days

Hans Christian Ørsted was the son of Søren Christian Ørsted and Karen Hermandsen. His father was a pharmacist of Rudkøbing on the island of Langeland. Hans with his brother, Anders Sandøe Ørsted (1778-1860), later professor of jurisprudence and politician, received privately and by self-study an education which enabled them to travel in 1793 to Copenhagen and there, the next year, pass the university entrance examination, to which they had submitted themselves.

Both brothers early showed signs of exceptional gifts and set themselves great aims for their future. Hans's interest in natural science was early aroused by working in his father's pharmacy, and so it was natural that he should train for pharmacy, as there were no possibilities of studying physics and chemistry at Copenhagen University then; it was he who afterwards provided them. As early as 1797, he passed the pharmaceutical examination with distinction, and already in 1796 and 1797 succeeded in doing the prize papers (about treatise on amniotic fluid) in both aesthetics and medicine, in each case winning the prize. Two years later he was awarded a doctorate for a dissertation on Kant's philosophy.

In 1801, he received a travel scholarship and public grant that enabled him to spend three years traveling in Europe. While in Germany, he met Johann Wilhelm Ritter, a physicist who believed there was a connection between electricity and magnetism. The connection made sense to Ørsted since he believed in the unity of nature and that a relationship therefore must exist between most natural phenomena.

Returning home, in 1806, Ørsted became a professor at the University of Copenhagen, where his first physical researches dealt with electric currents and acoustics. He was the actual founder of physical studies at Copenhagen University. Considerable university activity was developed from his work, leading finally to thorough and systematic teaching of physics and chemistry, together with the establishment of relatively good laboratory conditions.

In the years 1812 and 1813 Ørsted went on his second major foreign journey to Germany, Belgium and France. Although still under the influence of the speculative philosophy of nature, he admitted that he had meanwhile moved away from its views and that it was not possible for him to achieve a profitable exchange of ideas between himself and Fichte and Schleiermacher.

Back home, he married Birgitte Ballum, with whom he lived a harmonious and very happy married life, having five daughters and three sons.

From 1815 to his death he was Secretary to the Royal Danish Academy of Sciences and Letters.

Discovery of electromagnetism

While preparing for an evening lecture in April 1820, Ørsted developed an experiment which provided evidence that surprised him. As he was setting up his materials, he noticed a compass needle deflected from magnetic north when the electric current from the battery he was using was switched on and off. This deflection convinced him that magnetic fields radiate from all sides of a live wire just as light and heat do, and it confirmed a direct relationship between electricity and magnetism.

At the time of discovery, Ørsted did not suggest any satisfactory explanation of the phenomenon, nor did he try to represent the phenomenon in a mathematical framework. However, three months later he began more intensive investigations. Soon thereafter he published his findings, proving that an electric current produces a magnetic field as it flows through a wire.

His findings resulted in intensive research throughout the scientific community in electrodynamics. They influenced French physicist André-Marie Ampère's developments of a single mathematical form to represent the magnetic forces between current-carrying conductors. Ørsted's discovery also represented a major step toward a unified concept of energy.

Ørsted may not have been the first person to discover that electricity and magnetism are related. He was perhaps preceded in this discovery by 18 years by Gian Domenico Romagnosi, an Italian legal scholar. An account of Romagnosi's work was published in 1802 in an Italian newspaper, but it was overlooked by the scientific community. Whether Romagnosi's experiment was in fact capable of producing this result is a matter of debate^[1].

In 1825, Ørsted made a significant contribution to chemistry by producing metallic aluminium for the first time.

The CGS unit of magnetic induction (oersted) is named in honor of his contributions to the field of electromagnetism.

Society

He appreciated the need to spread knowledge of scientific advance, and in 1824 created the still extremely active "Society for the Dissemination of Natural Science" - a society devoted to the spread of scientific knowledge among the general public. Since 1908 this society has awarded the H.C. Ørsted Medal for outstanding contributions by Danish physical scientists. It was on his initiative in 1829 that the Polytechnical Institute in Copenhagen, now the Technical University of Denmark, was established, where engineering received a scientific foundation. He became the first director of this Institute.

Apart from these accomplishments, Ørsted wrote poetry and prose. Influenced by the German Naturphilosophie, shortly before his death, he published a series of collected articles under the title "The Soul in Nature", a masterpiece expressing the essence of his philosophy of life. Finally, there remains to be mentioned Ørsted's great interest in the Danish language, to which he contributed a number of innovations, such as the words "brint" and "ilt", for hydrogen and oxygen. He was an influential mentor of Ludwig A. Colding and collaborated with him on the work that led to Colding's articulation of the principle of conservation of energy in 1843.

Hans Christian Ørsted is one of the most luminous figures in the intellectual life of Denmark. He had lasting influence on many aspects of Danish culture and society. Thus he was one of the first to appreciate and encourage Hans Christian Andersen when this great Danish writer found the fairy tale as his proper genre. By nature he was a kind and exceedingly helpful man, who was a great inspiration to his associates; but although his dealings were always marked by a high degree of consideration he could in crucial situations display great firmness and resolution, never hesitating to advance radical views and opinions. He is one of those figures in Danish history who appear in so noble a cast that the picture of him and his work comes to seem almost too undifferentiated.

On his passing in 1851, Hans Christian Ørsted was interred in the Assistens Kirkegård in the Nørrebro section of Copenhagen.

References

Notes

See also

• James Clerk Maxwell
• physics

External links

• Hans Christian Oersted on a former 100 Danish Kroner banknote.
• Oersted's Philosophy, Soul In Nature book: [[1]]