What is Georg Cantor?
[[File:Georg Cantor3.jpg|thumb|250px|Georg Cantor, about 1870]] '''Georg Cantor''' (3 March 1845 - 6 January 1918<ref>{{Cite web |url=http://www-history.mcs.st-andrews.ac.uk/Biographies/Cantor.html |title=Georg Ferdinand Ludwig Philipp Cantor |work=MacTutor History of Mathematics archive }}</ref>) was an important German [[mathematician]]. He founded [[set theory]] and worked on [[transfinite]] numbers. ==Life== Cantor was born in [[St Petersburg]], [[Russia]]. His father had a Jewish-Danish, his mother an Austrian background. His father was a [[Protestant]]. He was a rich [[merchant]]. His mother was a [[Roman Catholic]]. She was very artistic. When his father became ill in [[1856]] the family moved to [[Frankfurt]]. Georg went to private schools and then to [[gymnasium (school)|gymnasien]] in [[Darmstadt]] and [[Wiesbaden]]. He soon showed that he was brilliant at maths. His father wanted him to be an [[engineer]] but Georg persuaded him to let him study mathematics. He spent a short time studying at the University of [[Zürich]], but soon went to [[Berlin]] where he studied [[physics]], [[philosophy]] and [[mathematics]]. He was very influenced by the teaching of [[Weierstrass]], [[Kummer]] and [[Kronecker]], who were later to become his enemies. He wrote a doctoral [[thesis]] in which he said that asking questions was more important than finding the answers. He was talking about a problem that [[Carl Friedrich Gauss]] had left unanswered. Cantor taught for a time at a girls’ school in Berlin, then he became a [[lecturer]] in [[Halle, Saxony-Anhalt|Halle]] where he remained for the rest of his life. He became full [[professor]] there in [[1879]]. Cantor worked on the [[number theory|theory of numbers]], [[continuum hypothesis]] and then on [[trigonometric function|trigonometric series]], starting with ideas that had been developed by [[Bernhard Riemann]] on [[complex variable]]s. He sent a paper on [[algebra]]ic numbers to be published in [[Crelle's Journal]], but Kronecker was against it. Howeve