1843 in science

The year 1843 in science and technology involved some significant events, listed below.

File:Ada Lovelace portrait.jpg

Ada Lovelace, computing pioneer

File:William Rowan Hamilton Plaque - geograph.org.uk - 347941.jpg

Plaque on Broom Bridge, Cabra, Dublin commemorating where William Rowan Hamilton inscribed his formula for quaternions

File:Anna Atkins algae cyanotype.jpg

Cyanotype photogram by Anna Atkins

Astronomy

• March 11–14 – Eta Carinae flares to become the second brightest star.
• February 5–April 19 – "Great March Comet" observed.
• December 21 – The first total solar eclipse of Saros 139 occurs over southern Asia.
• Heinrich Schwabe reports a periodic change in the number of sunspots: they wax and wane in number according to a ten-year cycle.

Chemistry

• Jean-Baptiste Dumas names lactose.<ref>Dumas (1843). Traité de Chimie, Appliquée aux Arts. 6 Paris: Bechet Jeune. p. 293.</ref>
• Carl Mosander discovers the chemical elements Terbium and Erbium.<ref>{{#invoke:citation/CS1|citation

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• John J. Waterston produces an account of the kinetic theory of gases.<ref>Template:Cite book</ref>
• Alfred Bird produces single-acting baking powder.<ref>Template:Cite news</ref>

Mathematics

• September – Ada Lovelace translates and expands Menabrea’s notes on Charles Babbage's analytical engine, including an algorithm for calculating a sequence of Bernoulli numbers, regarded as the world's first computer program.<ref>Template:Cite journal</ref><ref>{{#invoke:citation/CS1|citation

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• October 16 – William Rowan Hamilton discovers the calculus of quaternions and deduces that they are non-commutative.<ref>{{#invoke:citation/CS1|citation

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• Arthur Cayley and James Joseph Sylvester found the algebraic invariant theory.
• John T. Graves discovers the octonions.
• Pierre-Alphonse Laurent discovers and presents the Laurent expansion theorem.

Physics

• James Prescott Joule experimentally finds the mechanical equivalent of heat.<ref>Template:Cite journal</ref>
• Ohm's acoustic law is proposed by German physicist Georg Ohm.

Physiology and medicine

• April–May – English surgeon Benjamin Brodie extracts a coin lodged in the bronchus of engineer Isambard Kingdom Brunel using novel methods.<ref>Brodie, Benjamin. "An account of a case in which a foreign body was lodged in the right bronchus." Paper to Royal Medical & Chirurgical Society 27 June 1843.</ref>
• British surgeon James Braid publishes Neurypnology: or the Rationale of Nervous Sleep, a key text in the history of hypnotism.
• Oliver Wendell Holmes Sr., argues that puerperal fever is spread by lack of hygiene in physicians.<ref>"The Contagiousness of puerperal fever". New England Quarterly Journal of Medicine and Surgery.</ref>

Technology

• March 25 – Completion of the Thames Tunnel, the first bored underwater tunnel in the world (engineer: Marc Isambard Brunel).<ref>Template:Cite book</ref>
• July 19 – Launch of Template:SS, the first iron-hulled, propeller-driven ship to cross the Atlantic Ocean (designer: Isambard Kingdom Brunel).<ref>Template:Cite news</ref>
• November 21 – Thomas Hancock patents the vulcanisation of rubber using sulphur in the United Kingdom
• The steam powered rotary printing press is invented by Richard March Hoe in the United States.<ref>Template:Cite book It receives Template:US Patent in 1847 and is placed in commercial use the same year.</ref>
• Robert Stirling and his brother James convert a steam engine at a Dundee factory to operate as a Stirling engine.
• The first public telegraph line in the United Kingdom is laid between Paddington and Slough.
• Approximate date – Euphonium invented.

Publications

• October – Anna Atkins begins publication of Photographs of British Algae: Cyanotype Impressions, a collection of contact printed cyanotype photograms of algae which forms the first book illustrated with photographic images.<ref>Template:Cite book</ref><ref>Template:Cite book</ref><ref>{{#invoke:citation/CS1|citation

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Awards

• Copley Medal: Jean-Baptiste Dumas<ref>{{#invoke:citation/CS1|citation

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• Wollaston Medal for Geology: Jean-Baptiste Elie de Beaumont; Pierre Armand Dufrenoy

Births

• January 13 – David Ferrier (died 1928), Scottish neurologist.<ref>Template:Cite ODNB</ref>
• May 6 – G. K. Gilbert (died 1918), American geologist.
• June 12 – David Gill (died 1914), Scottish astronomer.
• June 23 – Paul Heinrich von Groth (died 1927), German mineralogist.
• July 24 – William de Wiveleslie Abney (died 1920), English astronomer.
• August 17 – Alexandre Lacassagne (died 1924), French forensic scientist.
• November 30 – Martha Ripley (died 1912), American physician.<ref>Template:Cite book</ref>
• December 11 – Robert Koch (died 1910), German physician, famous for the discovery of the tubercle bacillus (1882) and the cholera bacillus (1883) and for his development of Koch's postulates; awarded the Nobel Prize in Physiology or Medicine in 1905
• Adelaida Lukanina (died 1908), Russian chemist.

Deaths

• July 25 – Charles Macintosh (born 1766), Scottish inventor of a waterproof fabric.<ref>Template:Cite book</ref>
• August 10 – Robert Adrain (born 1775), Irish American mathematician.
• September 11 – Joseph Nicollet (born 1786), French geographer, explorer, mathematician and astronomer.
• September 19 – Gaspard-Gustave Coriolis (born 1792), French mathematician and discoverer of the Coriolis effect.
• September 30 – Richard Harlan (born 1796), American zoologist.
• November 16 – Abraham Colles (born 1773), Anglo-Irish surgeon.