Previous  (Chronologically)  Next  Biographies Index

Previous  (Alphabetically)  Next  Welcome page 
Georg Cantor founded set theory and introduced the concept of infinite numbers with his discovery of cardinal numbers. He also advanced the study of trigonometric series.Cantor attended the University of Zürich for a term in 1862 but then went to the University of Berlin where he attended lectures by Weierstrass, Kummer and Kronecker. He received his doctorate in 1867 from Berlin and accepted a position at the University of Halle in 1869, where he remained until he retired in 1913. In 1885 he built a house on Händelstrasse, a street named after the German composer Handel.
Cantor founded set theory and introduced the mathematically meaningful concept of infinite numbers with his discovery of transfinite numbers. He also advanced the study of trigonometric series and was the first to prove the nondenumerability of the real numbers.
His first papers (18701872) showed the influence of Weierstrass's teaching, dealing with trigonometric series. In 1872 he defined irrational numbers in terms of convergent sequences of rational numbers. In 1873 he proved the rational numbers countable, i.e. they may be placed in 11 correspondence with the natural numbers.
A transcendental number is an irrational number that is not a root of any polynomial equation with integer coefficients. Liouville established in 1851 that transcendental numbers exist. Twenty years later Cantor showed that in a certain sense 'almost all' numbers are transcendental.
Closely related to Cantor's work in transfinite set theory was his definition of the continuum.
Cantor's work was attacked by many mathematicians, the attack being led by Cantor's own teacher Kronecker. Cantor never doubted the absolute truth of his work despite the discovery of the paradoxes of set theory. He was supported by Dedekind, Weierstrass and Hilbert, Russell and Zermelo. Hilbert described Cantor's work as
the finest product of mathematical genius and one of the supreme achievements of purely intellectual human activity .
A major event planned in Halle to mark Cantor's 70 th birthday in 1915 had to be cancelled because of the war. Cantor died in a psychiatric clinic in Halle in 1918.
Cantor was given an honorary degree by the University of St Andrews in 1911.
References (13 books/articles)
References elsewhere in this archive:
Tell me about Cantor's work on set theory and on on topology
Tell me about his part in the history of mathematics
Georg Cantor was awarded the Sylvester Medal of the Royal Society in 1904. You can see a history of the Sylvester Medal and a list of the winners.
There is a Crater Cantor on the moon (named after this mathematician, as well as Moritz Cantor). You can see a list of lunar features named after mathematicians.
Other Web sites: