Operations Research 2025
Abstract Submission

96. Lothar Collatz: Mathematician, Scientist, V2-Ballistician, Professor

Invited abstract in session WB-7: Methods in Technical OR, stream Technical Operations Research.

Wednesday, 10:45-12:15
Room: U2-205

Authors (first author is the speaker)

1. Ingo Althöfer
Emeritus, Jena University

Abstract

Lothar Collatz (1910-1990) was the youngest of three siblings. His family thought that he was sort of a mathematical Wunderkind. Shortly after his promotion to Dr.rer.nat. (1935 in Berlin, advised originally by Richard von Mises) Collatz in 1937 invented the now famous 3n+1-Problem as a mathematical puzzle.

With the 3n+1-rule a sequence of natural numbers is formed. If the current number n is even, it is divided by 2. However, if n is odd, 3n+1 is built. If the sequence reaches number 1, it enters the cycle 1-4-2-1. Collatz conjured that each starting value reaches 1 after finitely many steps.

Also in 1937, Collatz got his Habilitation degree in Applied Mathematics at TH Karlsruhe. In December 1939 he joined the large German rocket project (A4, later called V2 by the Nazis) und became its chief ballistician. After the end of World War II Collatz cleverly and with much energy covered his tracks in this project.

At the International Congress of Mathematics in Harvard (1950) he told many participants about the 3n+1 problem, partly to make sure that they would not ask him about the rocket project.

Being a successful Professor (first in Hannover, from 1952 on in Hamburg), Collatz had many academic students. In the "Mathematics Genealogy Project" 52 doctoral students and 1711 academic descendants are listed for him (as of 22 April, 2025).

In the talk important stations of his life are discussed. We also present new partial results for the 3n+1 problem.

Reference: I. Althoefer. Lothar Collatz zwischen 1933 und 1950 - Eine Teilbiographie. 3-Hirn-Verlag, 2019.
Pages 1 - 46 of the book are digitally freely available at
http://www.3-hirn-verlag.de/collatz-bis-seite-46.pdf

Keywords

Status: accepted

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