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Workshop season · 30 days

20th-Century Crisis & the Birth of the Computer — 1900 to 1963

At the 1900 Paris ICM Hilbert discussed ten problems; the published paper contained the full list of twenty-three. In the early 1920s he proposed a program to formalize classical mathematics and justify its consistency by finitary methods. Over 30 days we follow how Russell's paradox (1901–1902), Gödel's incompleteness results (1930–1931), and Cohen's independence proof (1963) redrew the scope of those aims, while work on computability grew into computer science.

Start anywhere. Every reading remains available after the season ends.

  1. Day 1

    David Hilbert

    Season opens — 1900 Paris ICM, ten problems discussed and all twenty-three published

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  2. Day 2

    Georg Cantor

    1874 hierarchy of infinity — the crisis seed grew from uncountable infinity

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  3. Day 3

    Infinity

    Infinity — philosophy before Cantor, foundation of mathematics after

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  4. Day 4

    Cantor's Infinity — What He Saw But Did Not Believe

    Infinity even its discoverer doubted — 50-second cinematic, the inner landscape of the crisis

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  5. Day 5

    Gottlob Frege

    Begriffsschrift 1879 — published by Louis Nebert in Halle while Frege taught at Jena, laying foundations for modern predicate logic

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  6. Day 6

    Bertrand Russell

    16 June 1902 — 30-year-old Russell wrote to Frege about the briefly stated paradox he had discovered in 1901

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  7. Day 7

    Continuum Hypothesis — Proven Independent of ZFC

    Cantor's lifelong question — is there an infinity between ℵ₀ and ℵ₁? (resolved on Day 28)

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  8. Day 8

    David Hilbert

    Hilbert's early-1920s program — formalize classical mathematics and justify its consistency by finitary methods

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  9. Day 9

    Infinite Series

    Infinite series — soil of Hilbert's 6th problem (axiomatising physics), the bridge to quantum mechanics

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  10. Day 10

    Emmy Noether

    1915-1933 Göttingen — symmetry, conservation, and structural abstract algebra

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  11. Day 11

    Alfred Tarski

    1933 Warsaw — recursive truth definitions for specified formal languages and the adequacy requirement of Convention T

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  12. Day 12

    Andrey Kolmogorov

    1933 Moscow — axiomatising probability, proving axiomatisation still works in the crisis era

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  13. Day 13

    Probability

    Probability — after Kolmogorov's axioms, even uncertainty becomes mathematics. The next day asks what Gödel's theorems imply about the scope of axiomatisation

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  14. Day 14

    Kurt Gödel

    1930 Königsberg announcement → 1931 paper — two theorems exposing limits to the aims of Hilbert's program

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  15. Day 15

    Incompleteness Theorems

    Incompleteness — the 38 pages of Über formal unentscheidbare Sätze I (Monatshefte 38) changed mathematics' self-understanding of 2,000 years

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  16. Day 16

    von Neumann's Life — One Man, Five Fields

    A translator across fields — quantum mechanics, game theory, wartime research, EDVAC, cellular automata, and collaborators

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  17. Day 17

    John von Neumann

    1932 quantum mechanics + 1944 game theory + 1945 EDVAC: linking axioms, strategies, and programs without erasing collaborators

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  18. Day 18

    Measure and Lebesgue Integration

    Foundation of Hilbert space — the measure theory von Neumann's 1932 quantum mechanics rested on

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  19. Day 19

    Alan Turing

    Cambridge 1936, age 24 — using an idealized machine to define both the power and limits of algorithms

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  20. Day 20

    Alonzo Church

    1936 Princeton — lambda calculus gave a negative answer to Hilbert's decision problem 5 months before Turing, and Church supervised Turing's PhD

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  21. Day 21

    Turing's Life — Journey to the Apple

    1912-1954 — computation, codes, machine intelligence, morphogenesis, and the harm caused by state prosecution

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  22. Day 22

    Claude Shannon

    1948 Bell Labs — the crisis ended in bits: information became a measurable quantity

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  23. Day 23

    Information Entropy

    Information entropy — Shannon entropy = the unit of uncertainty, the crisis era's last great axiomatisation

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  24. Day 24

    Paul Erdős

    1913 Budapest — pure number theory exploded even during the crisis, the start of the wandering genius

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  25. Day 25

    Prime Number Theorem

    Prime Number Theorem — 1896 Hadamard & de la Vallée Poussin: the great number-theory theorem just before the crisis, flowing into the Erdős generation

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  26. Day 26

    L. E. J. Brouwer

    1907 Amsterdam — foundations of intuitionism plus the 1911 fixed-point theorem from his early classical topology. The 1928–29 Mathematische Annalen editorial conflict marked the climax of the Grundlagenstreit

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  27. Day 27

    Paul Cohen

    Spring 1963, Stanford — invented forcing to establish the ¬CH relative-consistency direction, complementing Gödel's 1940 result for CH

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  28. Day 28

    Continuum Hypothesis — Proven Independent of ZFC

    Gödel 1940 + Cohen 1963 — resolving Day 7: ZFC decides neither CH nor ¬CH

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  29. Day 29

    Transfinite Numbers

    Transfinite ℵ — a 90-year mirror from Cantor 1874 to Cohen 1963: the crisis became new mathematics

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  30. Day 30

    Alan Turing

    From limits to a new field — the Day 19 model meets contemporary and later engineering on the way to computer science

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