Jon was born and raised in Minnesota, learned mathematics at Gustavus Adolphus College, in Budapest, and finally earned his PhD at the University of Oregon. After positions at the Universities of Toronto, Georgia, and Oklahoma, he's now on the faculty at Oregon State University. He thinks it a shame how badly math fares in the modern educational-industrial complex and occasionally tries to do something about it when not indulging his other interests. Email: jonkujawa@gmail.com
by Jonathan Kujawa Among our many flaws, humanity prefers to be shortsighted. We tend to set our priorities by what we see right in front of us. This makes some sense. After all, there is no point in worrying about storing food for the winter when facing down a saber toothed tiger. But eventually winter…
by Jonathan Kujawa Four years ago was peak COVID-19. I was thinking about moving furniture, which led to this essay here at 3QD. The topic was the problem of moving a sofa down a hallway with a 90° corner: The problem is to find the “couch” of largest possible area that could be smoothly pushed…
by Jonathan Kujawa Prime numbers are the atoms of arithmetic. Just as a water molecule can be broken into two hydrogen and one oxygen atoms, 12 can be broken into two 2s and a 3. Indeed, the defining feature of a prime number is that it cannot be factored into a nontrivial product of two…
by Jonathan Kujawa Nearly two years ago we talked at 3QD about the Busy Beaver problem [1]. Since then, the beavers have been busy. As discussed in that essay, the Busy Beaver problem measures how complicated a computation might be. It does so by measuring how long a Turing might run before stopping. A Turing machine…
by Jonathan Kujawa One of the great pleasures in life is learning about something today that you couldn’t have imagined yesterday. The infinite richness of mathematics means I get to have this experience regularly. However much I think I know, it is a drop in the ocean of things yet to be learned. And even…
by Jonathan Kujawa My nieces, Hannah and Sydney, came to visit for the weekend. Since they’re 8 and 9, the delightful Guardian Games in downtown Corvallis was a must-stop. Along with games galore, they have an amazing assortment of puzzles. They have puzzles with micro-sized pieces, puzzles with jumbo-sized pieces, puzzles with only a few…
by Jonathan Kujawa The State of Georgia has a lottery guaranteed to turn an enterprising 3QD reader into a millionaire [1]. Playing the lottery can be fun. It is a tradition for Anne and me to buy lottery tickets when stopping for gas on long road trips. Imagining what you’d do with our new wealth…
by Jonathan Kujawa In 2016, here and here at 3QD, we talked about some of the inherent paradoxes in democratic voting [1]. We discussed Arrow’s Impossibility Theorem, along with related results like the Gibbard-Satterthwaite Theorem. They tell us that there is no way to convert the individual preferences of the voters into a single group…
by Jonathan Kujawa Functions are machines that take in a number as an input, apply some rule to that input, and generate an output. The input might be cost, temperature, wind speed, a politician’s favorability rating, or whatever you like. The output could tell you the resulting profit, windchill, chance of a tornado forming, the…
by Jonathan Kujawa Mathematicians can be extraordinarily fussy about how they write. From having a near fetish on their choice of chalk to Donald Knuth taking 10 years in the middle of writing a multi-volume book series to develop an entirely new typesetting system [1], they spend an inordinate time thinking about how to write something.…
by Jonathan Kujawa In March David Smith, Joseph Samuel Myers, Craig S. Kaplan, and Chaim Goodman-Strauss announced that they discovered an “Ein Stein”. The choice of name can only be described as a tour-de-force of PR: Ein Stein translates as One Stone but also evokes a certain physicist. The Ein Stein got wide play in…
by Jonathan Kujawa In the movies the mathematician is always a lone genius, possibly mad, and uninterested in socializing with other people. Or they are Jeff Goldblum — a category of its own. While it is true that doing mathematics involves a certain amount of thinking alone, I’ve frequently argued here at 3QD that math…
by Jonathan Kujawa On “The Joy of Abstraction” by Eugenia Cheng. Category theory has variously been called “abstract nonsense,” “diagram chasing,” or the “mathematics of mathematics.” Some mathematicians find it a useful language, some a crucial tool for developing insights and obtaining new results, and more than a few have no use for it at…
by Jonathan Kujawa Recently some colleagues and I were out to lunch. It was our University’s “Dead Week.” This is the week before finals when students are in a last-minute rush to finish projects and study for exams, and faculty are planning how to wind up their courses and beginning to draft their final exams.…
by Jonathan Kujawa Some years ago we discussed Brobdingnagian numbers. You can find the 3QD essay here. These are numbers that are so mind-bogglingly large they defy human imagination. Perhaps the most famous is Graham’s number. It’s so large I can’t write it down for you. It’s not that I refuse to write it down; I can’t.…
by Jonathan Kujawa In May of 2020 we lost John Conway [0]. We discussed some of his mathematical accomplishments here at 3QD. He was a true original. At the time, I deliberately avoided discussing Conway’s most famous work: the Game of Life. Like a 60s rock band, Conway had mixed feelings about his most famous…
by Jonathan Kujawa At the end of April heartbreaking news spread through my area of mathematics. Georgia Benkart had unexpectedly passed away. I first met Georgia when I was a graduate student, we’d seen each other at numerous conferences and other events, shared a few dinners, and I considered her a friend. Still, I was a little…
by Jonathan Kujawa On Friday before sunrise, I walked across campus with our dog, Lola. Summers in Oklahoma are unpleasantly hot. If you can manage, it is best to be out early. Besides, Lola is an early riser. It is hard to stay in bed when you can hear the pacing of impatient paws. While…
by Jonathan Kujawa In 1969, the mathematician Hans Freudenthal proposed a seemingly unsolvable puzzle: Abbas says to Sally and Penelope: I have two whole numbers between 1 and 100 which are not equal and whose sum is not more than 100. Abbas tells the sum of these numbers to Sally only, and their product to…
by Jonathan Kujawa In a research project with Brian Boe and Dan Nakano at the University of Georgia some years ago we computed the following list of numbers [1]: 2, 3, 6. There is one of these numbers for each pair of numbers m and n. The 2 is from when m and n both…