1843 in science

The year 1843 in science and technology included many events, some of which are listed here.

Astronomy

• John Couch Adams predicts the existence and location of Neptune from irregularities in the orbit of Uranus
• Heinrich Schwabe reports a periodic change in the number of sunspots: they wax and wan in number according to a ten-year cycle

Chemistry

• Carl Mosander discovers Terbium and Erbium

Mathematics

• Pierre-Alphonse Laurent discovers and presents the Laurent expansion theorem
• William Rowan Hamilton discovers the calculus of quaternions and deduces that they are non-commutative
• Arthur Cayley and James Joseph Sylvester found the algebraic invariant theory

Physics

• James Joule experimentally finds the mechanical equivalent of heat

Technology

• Launch of SS Great Britain, the first iron-hulled, propeller-driven ship to cross the Atlantic Ocean
• 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
• Completion of the Thames Tunnel, the first underwater tunnel in the world

Awards

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

Births

• June 12 – David Gill (d. 1914), astronomer.
• December 11 – Robert Koch (d. 1910), physician, famous for the discovery of the tubercle bacillus (1882) and the cholera bacillus (1883) and for his development of Koch's postulates. He was awarded the Nobel Prize in Physiology or Medicine in 1905

Deaths

• July 25 – Charles Macintosh (b. 1766), inventor of a waterproof fabric.
• September 19 – Gaspard-Gustave Coriolis (b. 1792), mathematician and discoverer of the Coriolis effect.