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

Here's one I came up with a few years ago that I'm quite proud of.

Q: What do you get when you cross a chicken with an elephant?
A: The trivial elephant bundle on a chicken.

Answer 2

Mike's last joke reminded me of this one: a comathematician is a device for turning cotheorems into ffee.

Answer 3

Your momma's so fat she's not embeddable in R^3. Oh yeah? Your momma's so fat she contradicts Whitney's theorem.

A topologist is someone who doesn't know the difference between his ass and a hole in the ground but does know the difference between his ass and two holes in the ground.

I went to visit him while he was lying ill at the hospital. I had come in taxi cab number 14 and remarked that it was a rather dull number. "No" he replied, "it is a very interesting number. It's the smallest number expressible as the product of 7 and 2 in two different ways."

Answer 4

My favourite, from Eilenberg's obituary:

When someone once asked Professor Eilenberg if he could eat Chinese food with three chopsticks, he answered, "Of course," according to Professor Morgan. The questioner asked, "How are you going to do it?" and Professor Eilenberg replied, "I'll take the three chopsticks, I'll put one of them aside on the table, and I'll use the other two."

Answer 5

Here are a few of my own inventions:

Old Macdonald had a form; e_i /\ e_i = 0

Save the environment: use continuation passing style!

What shape of pasta takes the least time to eat? Brachistochroni!

You might be a mathematician if you think fog is a composition.

The Yoda embedding, contravariant it is.

How are Goethe's Faust novels like isomorphisms of sets? Dey're de monic epics.

I'm kind of in two minds about this whole Schroedinger's cat thing...

qwhine, n. self-recrimination

recursive: (λ damn. damn (damn)) (λ damn. damn (damn))

Coeschatology: the study of the beginning of times. The coend is ming!

Answer 6

A British mathematician was giving a talk in Grothendieck's seminar in Paris. He started "Let X be a variety...". This caused some talking among the students sitting in the back, who were asking each other "What's a variety?". Serre, sitting in the front row, turns around a bit annoyed and says "Integral scheme of finite type over a field".

Answer 7

I like this one:

A mathematican walks into a bar accompanied by a dog and a cow.
The bartender says, “Hey, no animals are allowed in here!”
The mathematician replies, “These are very special animals.”
“How so?”
“They’re knot theorists.”
The bartender raises his eyebrows and says, “I’ve met a number of knot theorists who I thought were animals, but never an animal that was a knot theorist.”
“Well, I’ll prove it to you. Ask them them anything you like.”
So the bartender asks the dog, “Name a knot invariant.”
“Arf! Arf!” barks the dog.
The bartender scowls and turns to the cow asking, “Name a topological invariant.”
“Mu! Mu!” says the cow.
At this point the bartender turns to the mathematican and says, “Very funny.” With that, he throws the three out of the bar.
Outside, sitting on the curb, the dog turns to the mathematican and asks, “Do you think I should have said the Jones polynomial instead?”

Answer 8

I've always thought that "What's the value of a contour integral around Western Europe?" "Zero. All the Poles are in Eastern Europe." was pretty good, although not laugh-out-loud funny by any means.

Another one I personally like is "What's an anagram of Banach-Tarski?" "Banach-Tarski Banach-Tarski."

It's not really a "joke," (and whether it's "mathematical" is, I suppose, debatable), but Knuth's article on the complexity of songs is pretty great.

Answer 9

An engineer, a physicist and a mathematician are driving through the high country in Scotland. Atop a hill, they see a black sheep.

The engineer says: "All sheep are black!" The physicist says: "No, no, some sheep are black." The mathematician: "At least one sheep is black on at least one side."

Answer 10

an anecdote about David Hilbert from the wonderful book (for us laymen ;-) Prime Obsession:

Hilbert had a student who one day presented him with a paper purporting to prove the Riemann Hypothesis. Hilbert studied the paper carefully and was really impressed by depth of the argument; but unfortunately he found an error in it which even he could not eliminate. The following year the student died. Hilbert asked the grieving parents if he might be permitted to make a funeral oration. While the student's relatives and friends were weeping beside the grave in the rain, Hilbert came forward. He began by saying what a tragedy it was that such a gifted young man had died before he had had an opportunity to show what he could accomplish. But, he continued, in spite of the fact that this young man's proof of the Riemann Hypothesis contained an error, it was still possible that some day a proof of the famous problem would be obtained along the lines which the deceased had indicated. "In fact," he continued with enthusiasm, standing there in the rain by the dead student's grave, "let us consider a function of a complex variable...."

Answer 11

Based on the answers above, no.

Answer 12

Here is the one I heard recently.

Professor: What is a root of $f(z)$ of multiplicity $k$?

Student: It is a number $a$ such that if you plug it into $f$, you get $0$; if you plug it in again, you again get $0$, and so $k$ times. But if you plug it into $f$ for the $k+1$-st time, you do not get $0$.

Answer 13

The spectral sequence is like the mini-skirt; it shows what is interesting while hiding the essential.

This saying is attributed to someone from Bourbaki in Bourbaki's Art of Memory.

Answer 14

Here's a legend we have at our institute:

Prof: "Give an example of a vector space."

Student: "V"

Answer 15

"Why did the chicken cross the Mobius band?"

The question isn't whether good math jokes exist, but whether they can be classified. The example above works because it plays on ones expectation of the "chicken crossing the road" jokes. Another one in the same vein, known as the shortest math joke:

"Let epsilon<0."

Another one, which I actually heard in class:

"Take a positive integer N. No wait, N is too big; take a positive integer k."

Here is a non-exhaustive classification of math jokes:

• Puns on mathematical terminology
• Mathematical reasoning in non-mathematical setting
• Twists on expectations
• Meta-jokes approached in a mathematical mode of enquiry

A joke can belong to more than one classification. For example, the "Dog and cow knot theorists" has both puns and a twist on expectations.

By the way, I would exclude jokes which are purely made on stereotypes, like the above joke on extrovert mathematician, because I don't find it funny.

I leave with one of my favorite meta-jokes:

"How many members of a certain demographic group does it take to perform a specified task? A finite number: one to perform the task and the remainder to act in a manner stereotypical of the group in question."

Answer 16

Here are some of my favorites that were invented by friends of mine:

Q: What kind of maps should you take with you on car trips?

A: Automorphisms.

Q: What do you call it when you're trying to prove that a map is injective, but you just can't do it?

A: Monic fail.

Answer 17

There's a Notices article on this.

Answer 18

Q: How do you tell an extroverted mathematican from an introverted one?

A: An extroverted mathematician stares at your shoes when talking to you.

Answer 19

Q: How many mathematicians does it take to change a light bulb?

A: One: she gives it to three physicists, thus reducing it to a problem that has already been solved.

Answer 20

There's a mathematician whose non-mathematician friends are constantly ribbing him because his field is just so abstract and seems to have no relevance to the real world. One day, it gets to him, and he resolves to arm himself with some practical applications of research mathematics for the next encounter. He realizes that his own specialty (mathematical logic) is probably too far beyond them to be of any use there, so he goes to the department bulletin board to find an upcoming talk about something practical. Luckily, a talk is scheduled that afternoon on "the theory of gears." "Perfect!" he says. Nothing could be more practical, more down-to-earth. Finally, he'll be able to prove to his friends that mathematics is relevant to the real world. That afternoon, he's so excited that he goes to the talk five minutes early and sits in the first row of seats. Then, at the scheduled time, the speaker stands up and begins: "While the theory of gears with real numbers of teeth is well understood...."

Answer 21

My favorite one-liner:

Why did the mathematician name his dog "Cauchy"? Because he left a residue at every pole.

My favorite anecdote:

An engineer, a physicist, and a mathematician find themselves in an anecdote, indeed an anecdote quite similar to many that you have no doubt already heard. After some observations and rough calculations the engineer realizes the situation and starts laughing. A few minutes later the physicist understands too and chuckles to himself happily, as he now has enough experimental evidence to publish a paper. This leaves the mathematician somewhat perplexed, as he had observed right away that he was the subject of an anecdote and deduced quite rapidly the presence of humor from similar anecdotes, but considers this anecdote to be too trivial a corollary to be significant, let alone funny.

Answer 22

"Finite Simple Group (of Order Two)" by the Klein Four a cappella group at Northwestern University (lyrics by Matt Salomone):

The path of love is never smooth
But mine's continuous for you
You're the upper bound in the chains of my heart
You're my Axiom of Choice, you know it's true

But lately our relation's not so well-defined
And I just can't function without you
I'll prove my proposition and I'm sure you'll find
We're a finite simple group of order two

I'm losing my identity
I'm getting tensor every day
And without loss of generality
I will assume that you feel the same way

Since every time I see you, you just quotient out
The faithful image that I map into
But when we're one-to-one you'll see what I'm about
'Cause we're a finite simple group of order two

Our equivalence was stable,
A principal love bundle sitting deep inside
But then you drove a wedge between our two-forms
Now everything is so complexified

When we first met, we simply connected
My heart was open but too dense
Our system was already directed
To have a finite limit, in some sense

I'm living in the kernel of a rank-one map
From my domain, its image looks so blue,
'Cause all I see are zeroes, it's a cruel trap
But we're a finite simple group of order two

I'm not the smoothest operator in my class,
But we're a mirror pair, me and you,
So let's apply forgetful functors to the past
And be a finite simple group, a finite simple group,
Let's be a finite simple group of order two
(Oughter: "Why not three?")

I've proved my proposition now, as you can see,
So let's both be associative and free
And by corollary, this shows you and I to be
Purely inseparable. Q. E. D.

Answer 23

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 24

Q: What is non-orientable and lives in the ocean?
A: Möbius Dick...

---

A mathematician organizes a raffle in which the prize is an infinite amount of money paid over an infinite amount of time. Of course, with the promise of such a prize, his tickets sell like hot cake.

When the winning ticket is drawn, and the jubilant winner comes to claim his prize, the mathematician explains the mode of payment: "1 dollar now, 1/2 dollar next week, 1/3 dollar the week after that..."

---

"The number you have dialed is imaginary. Please, rotate your phone by 90 degrees and try again..."

---

From a former prof. - http://www.math.ualberta.ca/~runde/jokes.html

Answer 25

I have a few that I've heard and liked.

(1) The Mobius strippers always show their backside.

(2) Apparently, a quote of Paul Erdos, but it's funny nonetheless : Another roof, another proof.

(3) An experimental physicist meets a mathematician in a bar and they start talking. The physicict asks, "What kind of math do you do?" to which the mathematician replies, "Knot theory." The physicist says, "Me neither!"

(4) The primary reason Bourbaki stopped writing books was the realization that Lang was one single person.

Answer 26

A biologist, a physicist and a mathematician were all drinking coffee and tea and observing a house across the street from them. They notice that two people walk into the house and then an hour later, three people walk out.

Physicist: An experimental error. Our first measurement was incorrect.

Biologist: No, they've obviously reproduced.

Mathematician: No, now when a one person enters the house, it'll be empty again.

http://www.physicsforums.com/archive/index.php/t-4409.html

Answer 27

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 28

Don't remember where I saw this, but as a woman in mathematics, it tickles me no end:

A poet, a priest, and a lawyer are discussing whether it's better to have a wife or a mistress.

The poet argues that it's better to have a mistress because love should be free and spontaneous.

The priest argues that it's better to have a wife because love should be sanctified by God.

The mathematician says, "I think it's better to have both. That way, when each of them thinks you're with the other, you can do some mathematics."

Answer 29

What did the forgetful dealer do for his stoner friend?

He left adjoint as a free object.

Answer 30

Theorem: There are infinitely many composite numbers.

Proof: Suppose there are only finitely many, and multiply them together.