• Transfinite NIM (the game, not the programming language) https://jdh.hamkins.org/transfinite-nim/ 26 comments 6/2/2025
• How the continuum hypothesis could have been a fundamental axiom https://jdh.hamkins.org/how-ch-could-have-been-fundamental/ 48 comments 3/7/2024
• The propagation of error in classical geometry constructions (2018) https://jdh.hamkins.org/propagation-of-error-in-classical-geometry-constructions/ 27 comments 6/3/2024
• Transfinite game values in infinite chess (2013) http://jdh.hamkins.org/game-values-in-infinite-chess/ 7 comments 28/10/2022
• Coming to Agreement, a logic puzzle for Oxford admissions interviews http://jdh.hamkins.org/coming-to-agreement-logic-puzzle/ 92 comments 27/12/2021
• A program that accepts exactly any desired finite set, in the right universe http://jdh.hamkins.org/a-program-that-accepts-any-desired-finite-set-in-the-right-universe/ 18 comments 7/5/2017
• Transfinite epistemic logic puzzle challenge: Cheryl's birthday on steroids http://jdh.hamkins.org/transfinite-epistemic-logic-puzzle-challenge/ 3 comments 19/4/2015
• Math for eight-year-olds: graph theory for kids http://jdh.hamkins.org/math-for-eight-year-olds 45 comments 10/4/2015
• The rule-making game http://jdh.hamkins.org/the-rule-making-game/ 2 comments 2/9/2014
• Math for seven-year-olds http://jdh.hamkins.org/math-for-seven-year-olds-graph-coloring-chromatic-numbers-eulerian-paths/ 66 comments 13/6/2014

• A program that accepts exactly any desired finite set, in the right universe http://jdh.hamkins.org/a-program-that-accepts-any-desired-finite-set-in-the-right-universe/ 2 comments 8/5/2017 compsci , math

• [Joel David Hamkins' blog] A model of set theory with a definable copy of the complex field in which the two roots of -1 are set-theoretically indiscernible http://jdh.hamkins.org/a-model-of-set-theory-with-a-definable-copy-of-the-complex-field-in-which-the-two-roots-of-1-are-set-theoretically-indiscernible/ 16 comments 7/11/2022 math
• Coming to Agreement, a logic puzzle for Oxford admissions interviews http://jdh.hamkins.org/coming-to-agreement-logic-puzzle/ 29 comments 27/12/2021 philosophy
• An algebra of orders http://jdh.hamkins.org/an-algebra-of-orders/ 25 comments 21/9/2021 math
• The lattice of sets of natural numbers is rich http://jdh.hamkins.org/the-lattice-of-sets-of-natural-numbers-is-rich/ 16 comments 18/9/2021 math
• Counting to Infinity and Beyond. A poster by Joel David Hamkins (Oxford) http://jdh.hamkins.org/counting-to-infinity-poster/ 17 comments 13/9/2021 math
• On Joel David Hamkins' blog: "Different set theories extending ZF are never bi-interpretable! For example, ZF and ZFC are not bi-interpretable, and neither are ZFC and ZFC+CH, nor ZFC and ZFC+ CH, despite the fact that all these theories are equiconsistent." http://jdh.hamkins.org/different-set-theories-are-never-bi-interpretable/ 9 comments 14/5/2020 math
• The real numbers are not interpretable in the complex field http://jdh.hamkins.org/the-real-numbers-are-not-interpretable-in-the-complex-field/ 13 comments 29/2/2020 math
• Transfinite recursion as a fundamental principle in set theory http://jdh.hamkins.org/transfinite-recursion-as-a-fundamental-principle-in-set-theory/ 3 comments 11/4/2019 math
• Different set theories extending ZF are never bi-interpretable! http://jdh.hamkins.org/different-set-theories-are-never-bi-interpretable/ 15 comments 14/5/2018 math
• Buckets of fish! A mathematical game---can you find the winning strategy? http://jdh.hamkins.org/buckets-of-fish/ 9 comments 5/3/2017 math
• A proof that every triangle is isosceles -- can you spot the error? http://jdh.hamkins.org/all-triangles-are-isosceles/ 15 comments 12/2/2017 math
• Every function can be computable, if you run this program in the right universe http://jdh.hamkins.org/every-function-can-be-computable/ 55 comments 27/3/2016 math
• Can you translate these famous quotations from first-order logic? http://jdh.hamkins.org/famous-quotations-in-their-original-language/ 15 comments 17/3/2016 math
• A position in infinite chess with game value omega^4 -- the bishop cannon gun battery fires bishops http://jdh.hamkins.org/a-position-in-infinite-chess-with-game-value-omega-to-the-4/ 44 comments 29/10/2015 math
• Win at Nim! The secret mathematical strategy for kids (with challange problems in transfinite Nim for the rest of us) http://jdh.hamkins.org/win-at-nim-the-secret-mathematical-strategy/ 3 comments 22/5/2015 math
• A transfinite epistemic logic puzzle challenge: Cheryl's birthday on steroids http://jdh.hamkins.org/transfinite-epistemic-logic-puzzle-challenge/ 5 comments 19/4/2015 philosophy
• A transfinite epistemic logic puzzle challenge: Cheryl's birthday on steriods http://jdh.hamkins.org/transfinite-epistemic-logic-puzzle-challenge/ 20 comments 19/4/2015 math
• Math for eight-year-olds: graph theory for kids! http://jdh.hamkins.org/math-for-eight-year-olds/ 7 comments 17/4/2015 programming
• Graph Theory for Third Graders http://jdh.hamkins.org/math-for-eight-year-olds/ 26 comments 10/4/2015 compsci
• Math for eight-year-olds: graph theory for kids http://jdh.hamkins.org/math-for-eight-year-olds/ 24 comments 10/4/2015 math
• MathOverflow, the eternal fountain of mathematics: reflections on a hundred kiloreps http://jdh.hamkins.org/mathoverflow-the-eternal-fountain-of-mathematics-reflections-on-a-hundred-kiloreps/ 5 comments 19/9/2014 math
• Math for seven-year-olds: graph coloring, chromatic numbers, and Eulerian paths and circuits http://jdh.hamkins.org/math-for-seven-year-olds-graph-coloring-chromatic-numbers-eulerian-paths/ 26 comments 13/6/2014 math
• Kelley-Morse set theory implies Con(ZFC) http://jdh.hamkins.org/km-implies-conzfc/ 3 comments 27/2/2014 math
• How to win at Nim: an excellent explanation that first-graders can understand http://jdh.hamkins.org/files/2013/05/win-at-nim.jpg 20 comments 23/5/2013 math