#BookOfInfinity
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joeldavidhamkins.bsky.social
Just submitted the completed manuscript of The Book of Infinity to MIT Press. Hoping for the best! #BookOfInfinity
December 31, 2024 at 7:35 PM
joeldavidhamkins.bsky.social
I am very pleased to announce that
The Book of Infinity
is available for pre-order!
All my favorite paradoxes and conundrums.
#BookOfInfinity #InfinitelyMore
March 28, 2026 at 6:02 PM
joeldavidhamkins.bsky.social
Introducing the Lectures on Infinity, containing all my favorite paradoxes and conundrums.
www.infinitelymore.xyz/p/lectures-o... #InfinitelyMore #BookOfInfinity
Lectures on Infinity
A series of lectures on infinity, with all my favorite paradoxes and conundrums.
www.infinitelymore.xyz
July 9, 2026 at 2:58 AM
joeldavidhamkins.bsky.social
The Book of Infinity has been released!
If you are enjoying it, may I ask you kindly to post a brief review on the site where you bought it? Even just a sentence or two is very helpful. #BookOfInfinity
August 30, 2026 at 1:40 AM
joeldavidhamkins.bsky.social
One of the publication reviewers of The Book of Infinity had objected that some chapters seem to be about the very large finite numbers, rather than infinity itself. Is that a problem? Let me know...
#BookOfInfinity
April 6, 2026 at 11:29 PM
joeldavidhamkins.bsky.social
Today's lecture for my infinity class is on
The Largest Tweetable Number
Follow along on Infinitely More.
www.infinitelymore.xyz/p/the-larges... #InfinitelyMore #BookOfInfinity
The largest tweetable number
What is the largest tweetable number?
www.infinitelymore.xyz
February 5, 2026 at 4:34 PM
joeldavidhamkins.bsky.social
Today in my Infinity class we shall discuss the paradox of the infinite liars.
www.infinitelymore.xyz/p/infinite-l... #InfinitelyMore #BookOfInfinity
Infinite liars
Regrettably, this chapter consists entirely of lies—every sentence in it, including this one, is false.
www.infinitelymore.xyz
December 5, 2024 at 2:06 PM
joeldavidhamkins.bsky.social
Today's lecture for my Infinity class is on the infinite coastline paradox.
www.infinitelymore.xyz/p/the-infini... #InfinitelyMore #BookOfInfinity
The infinite coastline paradox
How unexpected difficulties in a practical measurement problem challenged fundamental conceptions of length and led to a new theory of dimension, while revealing monsters lurking at small scales.
www.infinitelymore.xyz
January 29, 2026 at 5:04 PM
joeldavidhamkins.bsky.social
Todays's topic in my Infinity class. Why not join us and follow along?
www.infinitelymore.xyz/p/the-book-o... #InfinitelyMore #BookOfInfinity
The Book of Numbers
All the numbers, placed in a curious order
www.infinitelymore.xyz
January 15, 2026 at 10:37 PM
joeldavidhamkins.bsky.social
Tomorrow's lecture for my Infinity class will be on the distinction between actual and potential infinity.
open.substack.com/pub/joeldavi... #InfinitelyMore #BookOfInfinity
Potential versus actual infinity
Potentialism and actualism offer radically different conceptions of the infinite—the dispute between them will lead us to ultrafinitism and the diverse modal conceptions of potentialism
open.substack.com
February 16, 2026 at 5:37 PM
joeldavidhamkins.bsky.social
Just informed that everything is in place for a Chinese translation of The Book of Infinity, via China Renmin University Press. Available November 2027. #BookOfInfinity
July 18, 2026 at 12:34 AM
joeldavidhamkins.bsky.social
The paradox of Gabriel's horn.
youtu.be/8f-k3tpKVHc
An excerpt from the Lectures on Infinity
#BookOfInfinity
Lectures on Infinity with Joel David Hamkins
YouTube video by Ergo
youtu.be
July 20, 2026 at 2:58 AM
joeldavidhamkins.bsky.social
Today's topic in my Infinity class: The axiom of choice.
www.infinitelymore.xyz/p/axiom-of-c... #BookOfInfinity #InfinitelyMore
The Axiom of Choice
Can we choose an element from each set in a family of nonempty sets? Does every set have a well order? Is the axiom of choice arrogant overreach or does it rather express an enduring logical truth?
www.infinitelymore.xyz
April 9, 2026 at 10:19 PM
joeldavidhamkins.bsky.social
Join us in my class on Infinity and follow along this semester. This week we'll get into Zeno's paradox, and then the "most-contested equation of middle school," eventually reaching the Riemann rearrangement theorem.
open.substack.com/pub/joeldavi... #InfinitelyMore #BookOfInfinity
Zeno's paradox
An ancient puzzle leads ultimately to a remarkable observation on the malleable nature of infinite sums
open.substack.com
January 17, 2026 at 12:42 PM
joeldavidhamkins.bsky.social
The paradox of the largest tweetable number.
Lectures on Infinity—lecture 4.
www.infinitelymore.xyz/p/largest-tw... #InfinitelyMore #BookOfInfinity
The Largest Tweetable Number—Lectures on Infinity (lecture 4)
The paradox of the largest tweetable number. What is the largest number you can tweet?
www.infinitelymore.xyz
August 12, 2026 at 1:29 PM
joeldavidhamkins.bsky.social
The Lectures on Infinity—lecture 2
Supertasks: Doing Infinitely Many Things
Let's explore my favorite supertasks, tasks with infinitely many steps. Deal with the Devil, balls in a sack, the Chocolatier's game, and more!
www.infinitelymore.xyz/p/supertasks... #InfinitelyMore #BookOfInfinity
Supertasks: Doing Infinitely Many Things — Lectures on Infinity (Lecture 2)
Let us explore several paradoxical supertasks—the deal with the Devil, balls in a sack, the Chocolatier's game, and more.
www.infinitelymore.xyz
July 16, 2026 at 10:42 AM
joeldavidhamkins.bsky.social
Today's lecture for my Infinity class is on equinumerosity and the notion of size. You are welcome to follow along with the readings for our class.
www.infinitelymore.xyz/p/equinumero... #InfinitelyMore #BookOfInfinity
Equinumerosity and comparison of size
What does it mean for two sets to have the same size? Galileo's paradox identifies tension between notions of equinumerosity and Euclid's principle that the whole is greater than any proper part.
www.infinitelymore.xyz
February 10, 2026 at 4:14 PM
joeldavidhamkins.bsky.social
Why Human Giants Defy the Laws of Physics, my article in the MIT Press Reader, adapted from The Book of Infinity.
thereader.mitpress.mit.edu/why-human-gi... #BookOfInfinity
Why Human Giants Defy the Laws of Physics
Without different anatomical proportions, a scaled-up body would collapse under its own weight.
thereader.mitpress.mit.edu
August 13, 2026 at 1:42 PM
joeldavidhamkins.bsky.social
Today's topic for my infinity class: Infinite Liars!
www.infinitelymore.xyz/p/infinite-l... #InfinitelyMore #BookOfInfinity
Infinite liars
Regrettably, this chapter consists entirely of lies—every sentence in it, including this one, is false.
www.infinitelymore.xyz
April 21, 2026 at 4:51 PM
joeldavidhamkins.bsky.social
Here is the reading the quiz is based on.
www.infinitelymore.xyz/p/supertasks #InfinitelyMore #BookOfInfinity
Supertasks
Is it perfectly sensible or fundamentally incoherent to speak of completing a task with infinitely many steps?
www.infinitelymore.xyz
February 4, 2026 at 2:21 AM
joeldavidhamkins.bsky.social
The Book of Infinity is released this coming week! Tuesday 25 August. Get your order in now for free Amazon shipping on Release Day.
www.amazon.com/dp/0262054019 #BookOfInfinity
Amazon.com: The Book of Infinity: 9780262054010: Hamkins, Joel David: Books
Amazon.com: The Book of Infinity: 9780262054010: Hamkins, Joel David: Books
www.amazon.com
August 21, 2026 at 7:52 PM
joeldavidhamkins.bsky.social
The Paradox of Giants—Strange Consequences in High Dimension
The Lectures on Infinity, lecture 3.
The paradox of giants, Gabriel's horn, the painter's paradox, and other paradoxes of dimension.
www.infinitelymore.xyz/p/paradox-of... #InfinitelyMore #BookOfInfinity
The Paradox of Giants: Strange Consequences in High Dimension—Lectures on Infinity (lecture 3)
The paradox of giants, the paradox of Gabriel's horn, the painter's paradox, and further paradoxes of dimension.
www.infinitelymore.xyz
July 23, 2026 at 12:32 PM
joeldavidhamkins.bsky.social
The most contested equation of middle school. Have you ever argued about it?
youtu.be/4Y9p0yp8Mow?... #BookOfInfinity
Zeno's Paradox and Infinite Sums — Lectures on Infinity (Lecture 1)
YouTube video by Ergo
youtu.be
July 12, 2026 at 2:50 AM
joeldavidhamkins.bsky.social
The lectures on Infinity, lecture 1:
Zeno's paradox and Infinite sums.
infinitelymore.xyz/p/zenos-para... #InfinitelyMore #BookOfInfinity
Zeno's Paradox and Infinite Sums—Lectures on Infinity (lecture 1)
An ancient puzzle leads ultimately to a remarkable observation on the malleable nature of infinite sums.
infinitelymore.xyz
July 10, 2026 at 2:22 AM
joeldavidhamkins.bsky.social
Today's lecture for my Infinity class is on
The paradox of giants.
You are kindly welcome to follow along with us in the reading—post your comments, and try the exercise questions!
www.infinitelymore.xyz/p/the-parado... #InfinitelyMore #BookOfInfinity
www.infinitelymore.xyz
February 3, 2026 at 2:58 PM