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1.5: C.5- Emmy Noether

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    121767
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    Emmy Noether (ner-ter) was born in Erlangen, Germany, on March 23, 1882, to an upper-middle class scholarly family. Hailed as the “mother of modern algebra,” Noether made groundbreaking contributions to both mathematics and physics, despite significant barriers to women’s education. In Germany at the time, young girls were meant to be educated in arts and were not allowed to attend college preparatory schools. However, after auditing classes at the Universities of Göttingen and Erlangen (where her father was professor of mathematics), Noether was eventually able to enroll as a student at Erlangen in 1904, when their policy was updated to allow female students. She received her doctorate in mathematics in 1907.

    Despite her qualifications, Noether experienced much resistance during her career. From 1908–1915, she taught at Erlangen without pay. During this time, she caught the attention of David Hilbert, one of the world’s foremost mathematicians of the time, who invited her to Göttingen. However, women were prohibited from obtaining professorships, and she was only able to lecture under Hilbert’s name, again without pay. During this time she proved what is now known as Noether’s theorem, which is still used in theoretical physics today. Noether was finally granted the right to teach in 1919. Hilbert’s response to continued resistance of his university colleagues reportedly was: “Gentlemen, the faculty senate is not a bathhouse.”

    In the later 1920s, she concentrated on work in abstract algebra, and her contributions revolutionized the field. In her proofs she often made use of the so-called ascending chain condition, which states that there is no infinite strictly increasing chain of certain sets. For instance, certain algebraic structures now known as Noetherian rings have the property that there are no infinite sequences of ideals \(I_1 \subsetneq I_2 \subsetneq \dots\). The condition can be generalized to any partial order (in algebra, it concerns the special case of ideals ordered by the subset relation), and we can also consider the dual descending chain condition, where every strictly decreasing sequence in a partial order eventually ends. If a partial order satisfies the descending chain condition, it is possible to use induction along this order in a similar way in which we can use induction along the \(<\) order on \(\Nat\). Such orders are called well-founded or Noetherian, and the corresponding proof principle Noetherian induction.

    Noether was Jewish, and when the Nazis came to power in 1933, she was dismissed from her position. Luckily, Noether was able to emigrate to the United States for a temporary position at Bryn Mawr, Pennsylvania. During her time there she also lectured at Princeton, although she found the university to be unwelcoming to women (Dick, 1981, 81). In 1935, Noether underwent an operation to remove a uterine tumour. She died from an infection as a result of the surgery, and was buried at Bryn Mawr.

    noether-emmy-small.png
    Figure \(\PageIndex{1}\): Emmy Noether. (Portrait of Emmy Noether, ca. 1922, courtesy of the Abteilung für Handschriften und Seltene Drucke, Niedersächsische Staats- und Universitätsbibliothek Göttingen, Cod. Ms. D. Hilbert 754, Bl. 14 Nr. 73. Restored from an original scan by Joel Fuller.)

    Further Reading

    For a biography of Noether, see Dick (1981). The Perimeter Institute for Theoretical Physics has their lectures on Noether’s life and influence available online (Institute, 2015). If you’re tired of reading, Stuff You Missed in History Class has a podcast on Noether’s life and influence (Frey and Wilson, 2015). The collected works of Noether are available in the original German (Jacobson, 1983).

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