Question

Have a good joke? Share.

I know this is subjective, but the principle "should be of interest to mathematicians" trumps. (I hope.)

Answer 1

What did the forgetful functor do for his stoner friend?

He left adjoint as a free object.

Answer 2

An engineer hears that a famous mathematician will be giving a public lecture, and always having a soft spot for math, he attends. The mathematician then talks at length about all sorts of amazing phenomena that happen in 17 dimensional space. The engineer, amazed at this mathematician's intuition for 17 dimensional space, goes up to him afterwards and asks 'How do you picture 17 dimensions?", to which the mathematician answers 'Oh, its easy. Just imagine n-dimensional space, and set n equal to 17.'

My dad (an engineer) loves that joke.

Answer 3

Mathematician1: So why did you become a mathematician?

Mathematician2: I don't like working with numbers.

Answer 4

Q: What's purple and commutes? A: A dead baby in a suitcase.

Q: What's purple and commutes and has a certain number of followers? A: A dead baby Jesus in a suitcase.

Answer 5

Here is a joke I invented (based on a famous one) and had mixed reaction.

A young mathematician comes to present to a famous mathematician his conjecture and ideas. "You are absolutely wrong," the famous mathematician dismissed the young one. Next enters another young mathematician and presents precisely the opposite conjecture. "You are absolutely wrong" replies the famous mathematician. The famous mathematician's wife interferes. "How could you tell both of them that they are wrong," she sais. "They have made completely opposite claims, one of them must be right!" "You are also wrong," replied the famous mathematician.

Answer 6

There's a Notices article on this.

Answer 7

One of my favorites. It's about a statistician - close enough for me. (I found this version of the joke here)

A physicist, an engineer, and a statistician were out game hunting. The engineer spied a bear in the distance, so they got a little closer. "Let me take the first shot!" said the engineer, who missed the bear by three metres to the left. "You're incompetent! Let me try" insisted the physicist, who then proceeded to miss by three metres to the right. "Ooh, we got him!!" said the statistician.

Answer 8

After introducing general topological spaces, the professor began to introduce the notion of convergence without a metric. He turned around and said,

"I have no balls."

A hit for months.

Answer 9

Perhaps the question should be, not "Do good math jokes exist", but "are they unique"?

Answer 10

I find the observation that the grade school carry operation from addition-with-carry forms a non-trivial degree 1 cocycle in the group cohomology of Z/10 a pretty good joke embedded in mathematics.

Answer 11

There are 10 types of people in the world: those who understand binary, and 9 others.

Answer 12

My favourite is supposedly a joke made by a mathematician who was interviewing a not very good graduate student who was taking generals. The interview was going badly, so to make the student feel better the mathematician asked him for an example of a non-compact topological space. "The reals?" suggested the student, to which the mathematician replied, "Which topology were you taking?"

Answer 13

Do good math jokes exist? Under the axiom of choice, sure. But it's not possible to find an explicit example.

Answer 14

The water receded and the Ark came to rest upon the land. Noah opened the doors and commanded the animals, “Go forth and multiply.” The animals slowly departed the Ark except for two snakes that remained in the back. Again Noah proclaimed ,“Go forth and multiply” yet the two snakes did not move. Noah walked to the back of the Arc and asked, “Why have you not followed my command”.? The snakes answered, “Noah, we can’t because we are Adders.”

Noah then went out upon the land and felled several large trees; from these trees he made a four legged platform. He then went inside the Arc and carried the snakes outside and upon placing them on the platform, his words became true.

As everyone knows … Adders can multiply using log tables.

Answer 15

The continuous functions are having a ball. At the dance floor, cosine and sine are jumping up and down, and the polynomials are forming a ring. But the exponential function is standing separately the whole evening. Due to sympathy for it, the identity joins it and suggest: "Come one, just integrate yourself!" – "I've tried that already", answers the exponential function, "but it didn't change a bit!"

another one

Why the mathematician named his dog "Cauchy"? Because he leaves a residue at every pole

Answer 16

Less of a joke than an observation, but...

I've always found it appropriate that online identity thieves are in the business of stealing ones and zeroes.

Answer 17

A swiftie. Most of you are probably too young to remember them...

“ ” said Tom at length.

Answer 18

It was proven by Cantor that a good math joke exists. Unfortunately, his proof was entirely non-constructive.

Answer 19

I enjoy this page of Milne's Tips for Authors.

I also find the book Mathematics Made Difficult by Linderholm to be hilarious. I'm not going to search for favorites, but I find the first 2 exercises amusing:

"1. Show that a finite subset of an arbitrary set E in a ring suffices to generate the ideal generated by E if, and only if, the ring is Noetherian.

*2. Show that 17 x 17 = 289. Generalize this result."

Answer 20

A friend made this up recently (I prefer the first half on its own):

"No meal is complete without soup. But you have to order it first."

Also I like this meta-joke, also by a friend (who didn't understand the original):

"What's purple and commutes? An abelian eggplant."

EDIT: one more, by Elizabeth: "Does this Hausdorff measure make me look fat?"

Answer 21

Tom Lehrer was a Mathematician and this comes through in several of his famous skits. Not precisely a "math joke", but still mathy and pretty darn funny.

Answer 22

An excerpt from H. Petard, "A contribution to the mathematical theory of big game hunting," The American Mathematical Monthly, vol. 45, no. 7, pp. 446-447, 1938:

The Hilbert, or axiomatic, method. We place a locked cage at a given point of the desert. We then introduce the following logical system.

• Axiom I. The class of lions in the Sahara Desert is non-void.
• Axiom II. If there is a lion in the Sahara Desert, there is a lion in the cage.
• Rule of Procedure. If p is a theorem, and "p implies q" is a theorem, then q is a theorem.
• Theorem I. There is a lion in the cage.

The method of inversive geometry. We place a spherical cage in the desert, enter it, and lock it. We perform an inversion with respect to the cage. The lion is then in the interior of the cage, and we are outside.

The method of projective geometry. Without loss of generality, we may regard the Sahara Desert as a plane. Project the plane into a line, and then project the line into an interior point of the cage. The lion is projected into the same point.

The Bolzano-Weierstrass method. Bisect the desert by a line running N-S. The lion is either in the E portion or in the W portion; let us suppose him to be in the W portion. Bisect this portion by a line running E-W. The lion is either in the N portion or in the S portion; let us suppose him to be in the N portion. We continue this process indefinitely, constructing a sufficiently strong fence about the chosen portion at each step. The diameter of the chosen portions approaches zero, so that the lion is ultimately surrounded by a fence of arbitrarily small perimeter.

Answer 23

I once ad-libbed this one. (Alas, it is a late entrant.)

Q: Why is it important to study Verma modules of Lie algebras?

A: The most widely used modules of Lie algebras and Lie groups are finite-dimensional irreducible representations, the Weyl modules. Of course, you should learn them first when you study representation theory. But they are only the tip of the iceberg.

Answer 24

If somebody likes mathematical logic, category theory, lambda calculus, combinatory logic, then the following article can provide him/her jokes that are at the same time correct mathematical theorems:

Ruehr, Fritz (2001). The Evolution of a Haskell Programmer. Willamette University.

The article provides approaches to implement a mere Fibonacci function with such "over-calibrated" methods like harnessing deep metamathematical theorems (combinatory logic, category theory).

Haskell is a programming language (named after the logician Haskell B. Curry). It has been developed by academia (not by industry or market), and most motivations behind its creation was cleanness and purity. And it is based directly on lambda calculus, type theory, combinatory logic. Many of the programmer practice in it is based on category theory and algebra.

Answer 25

What did the zero say to the eight? "Nice belt."

Answer 26

Have you head the one about the constipated mathematician?

He had to work it with a pencil.

Answer 27

I excuse my english if you spot some flaws...., since this is my first post here I thought it would be nice to share some neat jokes.

1) A mathematician, a physicist and an engineer were out in the countryside when they met a farmer trying to build a fence. They introduced themselves and the farmer asked them if they could help him shape the fence so he would get as much space as possible within it. The engineer stepped forward and said, that it would be best for the farmer to make the fence square, that would be easiest. The physicist then said that it would be better to make it as a circle, because then he would get as much space as possible. The mathematician laughed and said that you can get a lot more space then that! He took some pieces of fence and rolled it around himself, then he defined himself outside the fence!

2) Infinitely many mathematicians walked into a bar, the first one asked for one beer, the next one asked for half a beer, the third one asked for a quarter of a beer and the fourth one asked for one eight of a beer, then the bartender said :"screw this" and filled two glasses of beer!

3) An engineer was working on a problem when suddenly his trash bin caught fire. He immediately grabbed the fire extinguisher and put out the fire. In the next room a physicist was also working on a problem when his trash caught fire, he thought, fire extinguisher block oxygen from the fire, ergo fire is put out. So he grabs the fire extinguisher and puts out the fire. In the third room there was a mathematician working on a problem, his trash bin also caught fire so he looked at and thought, problem has a solution, and continued working!

Answer 28

A millionaire is trying to scientifically develop the best racing horse. He asked a biologist, veterinary, trainer, and a mathematician. The biologist gives him an advice about which type of horse to cross with which other type, the veterinary advices on how to feed the horse, and how to keep him healthy, the trainer explains how to physically train the horse. The mathematician does not reply. After a few weeks the millionaire meets the mathematician and it looks that the mathematician did not sleep much in recent days. Do you have a solution for me, ask the millionaire? It is a difficult problem, answers the mathematician, but I think I have a satisfactory solution to the case of spherical horses.

Answer 29

Kurd Lasswitz, mathematician, writer, inventor of science fiction in Germany, wrote this "nth part of Faust" for the Breslau Mathematical Society 1882:

"Personen:
Prost, Stud. math. in höheren Semestern, steht vor dem Staats-Examen,
Mephisto, Dx (sprich De-ix), Differentialgeisterkönig, ein Fuchs.
Ort Breslau. Zeit: Nach dem Abendessen. (Rechts ein Sofa, auf dem Tische zwischen allerlei Büchern ein Bierseidel und Bierflaschen, links eine Tafel auf einem Gestell, Kreide und Schwamm. Auf der Tafel ist eine die gesamt Fläche einnehmende ungeheuerliche Differentialgleichung aufgeschrieben).

Prost am Tische, mit den Büchern beschäftigt. Er stärkt sich.

Prost

Habe nun, ach, Geometrie, Analysis und Algebra
und leider auch Zahlentheorie studiert,
und wie, das weiß man ja!
Da steh' ich nun als Kandidat
und finde zur Arbeit keinen Rat.
Ließe mich gern Herr Doktor lästern;
zieh' ich doch schon seit zwölf Semestern
herauf, herab und quer und krumm
meine Zeichen auf dem Papiere herum,
und seh', daß wir nichts integrieren können.
Es ist wahrhaftig zum Kopfeinrennen.

Zwar bin ich nicht so hirnverbrannt,
daß ich mich quälte als Pedant,
wenn ich 'ne Reihe potenziere,
zu seh'n, ob sie auch konvergiere,
... "

Answer 30

A creation of my own:

Q:What did the simplicial set say to the fibrant replacement functor?

A:"Oh, I'm so horny..."