Carl Ludwig Siegel

Carl Ludwig Siegel (31 December 1896 – 4 April 1981) was a German mathematician who won the Wolf Prize in Mathematics in 1978.

Quotes

• I am afraid that mathematics will perish by the end of this century if the present trend for senseless abstractin — as I call it: theory of the empty set — cannot be blocked up.
  • in a 1964 letter to L. J. Mordell as quoted by C. S. Yogananda (June 2015). "The Life and Times of Bourbaki". Resonance: 556–559. (quote from p. 558)

• Ours, according to Leibnitz, is the best of all possible worlds, and the laws of nature can therefore be described in terms of extremal principles. Thus, arising from corresponding variational problems, the differential equations of mechanics have invariance properties relative to certain groups of coordinate transformations.
  • Lectures on Celestial Mechanics.  (p. 1)

• One of the many importants ideas introduced by Minkowski into the study of convex bodies was that of gauge function. Roughly, the gauge function is the equation of a convex body. Minkowski showed that the gauge function could be defined in a purely geometric way and that it must have certain properties analogous to those possessed by the distance of a point from the origin. He also showed that conversely given any function possessing these properties, there exists a convex body with the given function as its gauge function.
  • Lectures on the Geometry of Numbers.  (p. 6)

Quotes about Siegel

• In 1966 Siegel oversaw the publication of his collected works in three volumes. He spent the rest of his life editing (and writing) a fourth volume. As the story goes, he burned everything else, fearing that a historian—as he himself had done with Riemann—would get into his papers.
  • Benjamin Yandell: The Honors Class: Hilbert's Problems and Their Solvers. 2001. p. 191.