Augustus De Morgan

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

Life and work

Augustus De Morgan was born the son of a soldier stationed in India, but his family soon returned to England. He fell to the school's hardly, however, interested always in strange numbers game. In 1823 he attended Trinity College, Cambridge, was taught there, among others, George Peacock and graduated as BA from. He returned in 1826 returned to London, where he received in 1828 at the newly founded University College a chair.

De Morgan was a friend of Charles Babbage. At whose suggestion he taught Ada Lovelace in mathematics so that these Babbage designs the Analytical Engine could better understand. De Morgan wrote numerous mathematical articles like 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 manufacturer to the term " mathematical induction " in its publication Induction (Mathematics ) in the Penny Cyclopedia, for which he wrote a total of 712 articles. It is also his famous work The differential and integral calculus was printed. Best known he was named after him by two rules that De Morgan's laws:

They state that each conjunct can be expressed by a disjunction, and vice versa. These laws have since been frequently used in mathematical proofs and also in programming. De Morgan is now in common with George Boole as the founder of formal logic.

George Boole published in 1847 a small volume called Mathematical Analysis of Logic. Occasion to work it out and publish, formed the fierce priority dispute between William Rowan Hamilton and De Morgan on the quantification of predicates. 1854 appeared Boole's second major work on algebra: Laws of Thought. For this purpose, said De Morgan: " That the symbolic processes of algebra, originally invented for the purpose of numerical calculations, should be able to express every act of thinking and to provide grammar and dictionary of an all-encompassing system of logic, this one would have believed before it in » Laws of Thought "has been proven. "

De Morgan was the first president of the London Mathematical Society from 1865 to 1866. Simultaneously, he was the only president of this society, who was not also a member ( Fellow ) of the Royal Society of London as he rejected this membership.

De Morgan and the Quantitative Linguistics / Quantitative Stylistics

De Morgan also plays for the Quantitative Linguistics and the Quantitative Stylistics a role, inasmuch as he developed the idea that one could solve the problem of identifying anonymous authors using statistical methods. So he suggested to tackle the problem of the authorship of the Pauline letters with the help of word-length analysis, and suspected that the average word length could be to revealing.