Georg Alexander Pick

Georg Pick出生于一个犹太家庭。他的母亲是Josefa Schleisinger，父亲是Adolf Josef Pick，一家私立机构的负责人。Georg在家接受父亲的教育，直到十一岁进入Leopoldstaedter社区文理中学的第四班。他于1875年参加了学校毕业考试，获得了大学入学资格。

Pick于1875年进入维也纳大学。第二年，他发表了一篇数学论文，当时只有十七岁。他学习数学和物理，1879年毕业，获得了教授这两门科目的资格。1877年，莱奥·柯尼希斯贝格尔从德累斯顿技术高等学校转到维也纳大学担任讲席。他成为Pick的导师，并于1880年4月16日，Pick因其学位论文Über eine Klasse abelscher Integrale Ⓣ（论一类阿贝尔积分）获得博士学位。Emil Weyr被任命为该论文的第二考官。

获得博士学位后，Pick被任命为布拉格卡尔-费迪南德大学恩斯特·马赫的助手。马赫于1867年从格拉茨（他在那里任数学教授）迁至布拉格，接任那里的物理学讲席。他与Pick一样，曾在维也纳大学学习，到Pick成为他的助手时，他已被视为欧洲领先的科学家之一。Pick当时的目标是在布拉格成为讲师，而为了获得授课资格，他必须写一篇教授资格论文（Habilitation）论文。他很快完成了这项工作，并于1881年凭借其资格论文Über die Integration hyperelliptischer Differentiale durch Logarithmen Ⓣ（《用对数求超椭圆微分的积分》）获得了在布拉格授课的权利。

除了1884-85学年Pick在莱比锡大学师从菲利克斯·克莱因学习之外，他的其余职业生涯都在布拉格度过。他于1888年晋升为数学特聘教授，随后于1892年在布拉格的德意志大学被任命为正式教授（正教授）。他的数学工作极为广泛，其67篇论文涵盖线性代数、不变量理论、积分学、位势论、泛函分析和几何学等诸多主题。然而，他的论文中有超过一半是关于复变量函数、微分方程和微分几何的。诸如“Pick矩阵”、“Pick-罗尔夫·内万林纳插值”和“赫尔曼·阿曼杜斯·施瓦茨-Pick引理”等术语至今仍有时被使用。然而，他最令人铭记的是Pick定理，该定理出现在他1899年的八页论文Geometrisches zur Zahlenlehre Ⓣ（几何数论）中，该论文于Sitzungber. Lotos, Naturwissen Zeitschrift在布拉格出版。

Pick定理是关于网状几何的。在平面上建立两组等距平行直线系，平面就成为一个格。Pick将这些线称为“主网线”，其交点称为“网点”。连接任意两个网点的线称为“网线”。注意，主网线是网线，但还有许多其他网线。边为网线的多边形，Pick称之为网多边形。Pick定理指出，网多边形的面积是$L + \large\frac{1}{2}\normalsize B - 1$，其中$L$是多边形内部的网点数，$B$是多边形边上的网点数。该结果在Pick发表后并未引起太多关注，但1969年胡戈·施泰因豪斯将其收录于他的著名著作Mathematical Snapshots中。从那时起，Pick定理因其简洁和优雅而备受关注和赞赏。

在布拉格德意志大学，Pick于1900-01年成为哲学系主任。他指导了约20名学生的博士学位，其中最著名的是查尔斯·娄威纳，他在Pick的指导下工作，并于1917年因其关于几何函数论的学位论文而被授予博士学位。Pick的生活中还有另一个方面值得关注。1910年，他参加了布拉格德意志大学设立的一个委员会，考虑任命阿尔伯特·爱因斯坦到该大学。Pick是这一任命的推动力，阿尔伯特·爱因斯坦于1911年被任命为布拉格德意志大学的数学物理讲席。他担任此职至1913年，在这些年里，两人是亲密的朋友。他们不仅共享科学兴趣，还共享对音乐的浓厚兴趣。Pick在一个四重奏中演奏，他将阿尔伯特·爱因斯坦引入了布拉格的科学和音乐社团。事实上，Pick的四重奏由该大学的四位教授组成，包括机械工程教授卡米洛·克尔纳。

After Pick于1927年退休，被授予荣休教授称号，并回到了他的出生地维也纳。然而，在1938年3月12日德国军队进军奥地利（德奥合并）后，他于1938年返回布拉格。1938年9月底，布拉格政府被要求将波希米亚和摩拉维亚所有人口中德国人占50%或以上的地区交给德国。捷克斯洛伐克的领导人辞职而非同意，但接任者将这些地区交给了德国。希特勒的军队于1939年3月14日入侵，希特勒在布拉格安插了他的代表来管理这个国家。Pick曾被选为捷克科学院与艺术院的成员，但在纳粹接管布拉格后，Pick被逐出科学院。纳粹于1941年11月24日在北波希米亚的特莱西恩施塔特设立了一个营地，用于安置年老的、有特权的和著名的犹太人。在被送往特莱西恩施塔特的约144,000名犹太人中，约四分之一死在那里，约60%被送往奥斯维辛或其他死亡营。Pick于1942年7月13日被送往特莱西恩施塔特，两周后在那里去世，享年82岁。

他被描述如下：——

Pick是一位单身汉……在衣着和举止上异常得体。

Georg Pick was born into a Jewish family. His mother was Josefa Schleisinger and his father was Adolf Josef Pick, the head of a private institute. Georg was educated at home by his father up to the age of eleven when he entered the fourth class of the Leopoldstaedter Communal Gymnasium. He sat his school leaving examinations in 1875 which qualified him for university entrance.

Pick entered the University of Vienna in 1875. He published a mathematics paper in the following year when only seventeen years old. He studied mathematics and physics, graduating in 1879 with a qualification which would allow him to teach both of these subjects. In 1877 Leo Königsberger had moved from Technische Hochschule in Dresden to take up a chair at the University of Vienna. He became Pick's supervisor and, on 16 April 1880, Pick was awarded his doctorate for his dissertation Über eine Klasse abelscher Integrale Ⓣ. Emil Weyr had been appointed as second examiner of the thesis.

After the award of his doctorate, Pick was appointed as an assistant to Ernest Mach at the Karl-Ferdinand University in Prague. Mach had moved from Graz, where he was professor of mathematics, to Prague in 1867 to take up the chair of physics there. He, like Pick, had studied at the University of Vienna and, by the time Pick became his assistant, he was regarded as one of the leading scientists in Europe. Pick now aimed at becoming a lecturer in Prague and in order to obtain the right to lecture he had to write an habilitation thesis. This he did quite quickly and received the right to lecture in Prague in 1881 with his habilitation thesis Über die Integration hyperelliptischer Differentiale durch Logarithmen Ⓣ.

Except for the academic year 1884-85 which Pick spent studying under Klein at the University of Leipzig, he remained in Prague for the rest of his career. He was promoted to extraordinary professor of mathematics in 1888, then he was appointed as ordinary professor (full professor) in 1892 at the German University of Prague. His mathematical work was extremely broad and his 67 papers range across many topics such as linear algebra, invariant theory, integral calculus, potential theory, functional analysis, and geometry. However more than half of his papers were on functions of a complex variable, differential equations, and differential geometry. Terms such as 'Pick matrices', 'Pick-Nevanlinna interpolation', and the 'Schwarz-Pick lemma' are sometimes used today. He is best remembered, however, for Pick's theorem which appeared in his eight page paper of 1899 Geometrisches zur Zahlenlehre Ⓣ published in Prague in Sitzungber. Lotos, Naturwissen Zeitschrift.

Pick's theorem is on reticular geometry. The plane becomes a lattice on setting up two systems of parallel equally spaced straight lines in the plane. These Pick calls the 'main reticular lines' and their points of intersection are called 'reticular points'. A line joining any two reticular points is called a 'reticular line'. Notice that the main reticular lines are reticular lines but there are many other reticular lines. A polygon whose edges are reticular lines Pick calls a reticular polygon. Pick's theorem states that the area of a reticular polygon is $L + \large\frac{1}{2}\normalsize B - 1$ where $L$ is the number of reticular points inside the polygon and $B$ is the number of reticular points on the edges of the polygon. The result did not receive much attention after Pick published it, but in 1969 Steinhaus included it in his famous book Mathematical Snapshots. From that time on Pick's theorem has attracted much attention and admiration for its simplicity and elegance.

At the German University of Prague Pick became dean of the philosophy faculty in 1900-01. He supervised about 20 students for their doctorates, the most famous being Charles Loewner who worked under Pick's supervision and was awarded his doctorate for his thesis on geometric function theory in 1917. There is another aspect of Pick's life which merits attention. In 1910 he was on a committee set up by the German University of Prague to consider appointing Einstein to the university. Pick was the driving force behind the appointment and Einstein was appointed to a chair of mathematical physics at the German University of Prague in 1911. He held this post until 1913 and during these years the two were close friends. Not only did they share scientific interests, but they also shared a passionate interest in music. Pick, who played in a quartet, introduced Einstein into the scientific and musical societies of Prague. In fact Pick's quartet consisted of four professors from the university including Camillo Körner, the professor of mechanical engineering.

After Pick retired in 1927 he was named professor emeritus and returned to Vienna, the town of his birth. However, in 1938 he returned to Prague after the Anschluss on 12 March when German troops marched into Austria. At the end of September 1938 the Prague government was asked to give Germany all districts of Bohemia and Moravia with populations that were 50 percent or more German. The leaders of Czechoslovakia resigned rather than agree, but those who took over gave the regions to Germany. Hitler's armies invaded on 14 March 1939 and Hitler installed his representative in Prague to run the country. Pick had been elected as a member of the Czech Academy of Sciences and Arts, but after the Nazis took over Prague, Pick was excluded from the Academy. The Nazis set up a camp at Theresienstadt in Nordboehmen on 24 November 1941 to house elderly, privileged, and famous Jews. Of around 144,000 Jews sent to Theresienstadt about a quarter died there and around 60% were sent on to Auschwitz or other death camps. Pick was sent to Theresienstadt on 13 July 1942 and he died there two weeks later aged 82.

He was described as follows:-

Pick was a bachelor ... uncommonly correct in clothes and attitude.