Augustus De Morgan

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Augustus De Morgan

Augustus De Morgan (born June 27, 1806 in Madurai , India , † March 18, 1871 in London ) was an English mathematician . He was a co-founder and first president of the London Mathematical Society .

Live and act

Augustus De Morgan was born the son of a soldier stationed in India, but his family soon returned to England. He was hardly noticed in school, but has always been interested in strange number games. In 1823 he attended Trinity College in Cambridge , where he was taught by George Peacock , among others , and graduated with a BA . He returned to London in 1826 and received a chair there in 1828 at the newly founded University College .

De Morgan was a friend of Charles Babbage . At his suggestion, he taught Ada Lovelace mathematics so that she could better understand Babbag's drafts of the Analytical Engine . De Morgan wrote numerous mathematical articles such as Elements of Arithmetic (1830), Trigonometry and Double Algebra (1849), a geometric interpretation of complex numbers, and Formal Logic (1847), one of his most important works. In 1838 he was the first to use the term "mathematical induction " in his publication Induction (Mathematics) in Penny Cyclopedia , for which he wrote a total of 712 articles. His famous work The Differential and Integral Calculus was also printed in it. He became best known for two rules named after him, the De Morgan Laws :

These state that every conjunction can be expressed by a disjunction and vice versa. They have since been widely used in mathematical proofs and also in programming. De Morgan is now considered to be the founder of formal logic together with George Boole .

George Boole published a small volume called Mathematical Analysis of Logic in 1847 . The reason to work it out and publish it was the fierce dispute over priorities between William Rowan Hamilton and de Morgan over the quantification of predicates . In 1854, Boole's second major work on algebra appeared: Laws of Thought. De Morgan said: "Nobody would have believed that the symbolic processes of algebra, originally invented for the purpose of numerical calculations, should be able to express every act of thought and provide the grammar and dictionary of an all-encompassing system of logic, this would not have been believed before in" Laws of Thought "has been proven."

De Morgan was the first President of the London Mathematical Society from 1865 to 1866 . At the same time he was the only president of this society who was not also a member (Fellow) in the Royal Society of London , as he refused this membership.

The moon crater De Morgan is named after him.

De Morgan and Quantitative Linguistics / Quantitative Stylistics

De Morgan also plays a role in quantitative linguistics and quantitative stylistics , insofar as he developed the idea that the problem of identifying anonymous authors could be solved by statistical means. He suggested that the problem of the authorship of Paul's letters be addressed with the help of word length analyzes, and suggested that the average word length could be instructive.

Fonts

  • The Elements of Arithmetic . London 1830
  • Elements of Spherical Trigonometry . London 1834
  • The Elements of Algebra Preliminary to the Differential Calculus . London 1835
  • The Connexion of Number and Magnitude: An Attempt to Explain the Fifth Book of Euclid . London 1836
  • Elements of Trigonometry and Trigonometrical Analysis, Preliminary to the Differential Calculus . London 1837
  • An Essay on Probabilities, and on Their Application to Life Contingencies and Insurance Offices . London 1838
  • First Notions of Logic, Preparatory to the Study of Geometry . London 1839
  • Arithmetical Books From the Invention of Printing to the Present Time. Being Brief Notices of a Large Number of Works Drawn up From Actual Inspection . London 1847, reprint London 1967 (with biography of AR Hall)
  • The Differential and Integral Calculus . London 1842
  • Formal Logic: or The Calculus of Inference, Necessary and Probable . London 1847
  • Trigonometry and Double Algebra . London 1849
  • The Book of Almanacs With an Index of Reference, by Which the Almanac May Be Found for Every Year… up to AD 2000. With Means of Finding the Day of Any New or Full Moon From BC 2000 to AD 2000 . London 1851
  • Syllabus of a Proposed System of Logic . London 1860
  • A Budget of Paradoxes . London 1872

See also

literature

  • John M. Dubbey: De Morgan, Augustus . In: Charles Coulston Gillispie (Ed.): Dictionary of Scientific Biography . tape 4 : Richard Dedekind - Firmicus Maternus . Charles Scribner's Sons, New York 1971, p. 35-37 .
  • Sophia De Morgan: Memoir of Augustus de Morgan, with selections of his letters . London 1882
  • Ronald Anderson: Augustus de Morgan's inaugural lecture of 1882 . In: Mathematical Intelligencer , 2006, No. 3 (with reprint of the lecture)
  • Adrian Rice: Augustus de Morgan . In: Mathematical Intelligencer , Volume 18, 1996, pp. 40-43
  • De Morgan, Augustus . In: Encyclopædia Britannica . 11th edition. tape 8 : Demijohn - Edward . London 1910, p. 8 (English, full text [ Wikisource ]).

Web links

Commons : Augustus De Morgan  - Album with pictures, videos and audio files

Individual evidence

  1. ^ List of Presidents of the London Mathematical Society. mcs.st-andrews.ac.uk
  2. ^ Peter Grzybek: History and Methodology of Word Length Studies. The State of the Art. In: Peter Grzybek (Ed.): Contributions to the Science of Text and Language. Word Length Studies and Related Issues . Springer, Dordrecht NL, 2006, pp. 15-90; on De Morgan: p. 15. ISBN 1-4020-4067-9 (HB)
  3. ^ RD Lord: Studies in the history of probability and statistics. VIII: De Morgan and the statistical study of literary style. In: Biometrika , 45, 1958, p. 282.
personal data
SURNAME De Morgan, Augustus
BRIEF DESCRIPTION English mathematician
DATE OF BIRTH June 27, 1806
PLACE OF BIRTH Madurai , India
DATE OF DEATH March 18, 1871
Place of death London