*We are concerned that publication of sacral lecture jokes may endanger the respect to math. teachers in freshmen classes. Our excuse for this risky ethnographic research is that the majority of the jokes already exists on the Internet.*

*Sometimes, people tend to attribute the jokes either to their beloved teachers (Peter Lax is so far the champion) or to legendary figures as Norbert Wiener or Paul Erdos; similarly, physical jokes are attributed to Albert Einstein or Niels Bohr and geometrical theorems — to Euclid. A number of collected jokes we learned from our professors in Saint-Petersburg. Generally, attributing the jokes is hopeless. Indeed, the phrasing of the narrator is as important as the essence of the humor (if this essence does exist at all). To our mind, a joke goes to «public domain» immediately after being created or modified and there should be no authorship in it. Most of the collected sayings and jokes are repeated in a number of webpages, which makes it difficult to credit a particular Internet source. Instead, we thank all Internet collectors of math. jokes.*

Mathematics is made of 50 percent formulas, 50 percent proofs, and 50 percent imagination.

«A mathematician is a device for turning coffee into theorems» (P. Erdos)

Addendum: American coffee is good for lemmas.

An engineer thinks that his equations are an approximation to reality. A physicist thinks reality is an approximation to his equations. A mathematician doesn’t care.

Old mathematicians never die; they just lose some of their functions.

Mathematicians are like Frenchmen: whatever you say to them, they translate it into their own language, and forthwith it means something entirely different. — Goethe

Mathematics is the art of giving the same name to different things. — J. H. Poincare

What is a rigorous definition of rigor?

There is no logical foundation of mathematics, and G�del has proved it!

I do not think — therefore I am not.

*Here is the illustration of this principle:*

One evening Rene Descartes went to relax at a local tavern. The tender approached and said, «Ah, good evening Monsieur Descartes! Shall I serve you the usual drink?». Descartes replied, «I think not.», and promptly vanished.

A topologist is a person who doesn’t know the difference between a coffee cup and a doughnut.

A mathematician is a blind man in a dark room looking for a black cat which isn’t there. (Charles R Darwin)

A statistician is someone who is good with numbers but lacks the personality to be an accountant.

Classification of mathematical problems as linear and nonlinear is like classification of the Universe as bananas and non-bananas.

A law of conservation of difficulties: there is no easy way to prove a deep result.

A tragedy of mathematics is a beautiful conjecture ruined by an ugly fact.

Algebraic symbols are used when you do not know what you are talking about.

Philosophy is a game with objectives and no rules.

Mathematics is a game with rules and no objectives.

Math is like love; a simple idea, but it can get complicated.

*The actual quote from the Webster dictionary:*

trillion n

syn SCAD, gob(s), heap, jillion, load(s), million, oodles, quantities, thousand, wad(s)

Mathematics is like checkers in being suitable for the young, not too difficult, amusing, and without peril to the state. (Plato)

The difference between an introvert and extrovert mathematicians is: An introvert mathematician looks at his shoes while talking to you. An extrovert mathematician looks at your shoes.

*A bit of theology. *

Math is the language God used to write the universe.

Asked if he believes in one God, a mathematician answered:

» Yes, up to isomorphism.»

God is real, unless proclaimed integer.

Medicine makes people ill, mathematics make them sad and theology makes them sinful. (Martin Luther)

The good Christian should beware of mathematicians and all those who make empty prophecies. The danger already exists that mathematicians have made a covenant with the devil to darken the spirit and confine man in the bonds of Hell. (St. Augustine)

He who can properly define and divide is to be considered a god. (Plato)

«God geometrizes» says Plato.

*and here is the analytical continuation of this saying:*

- Biologists think they are biochemists,

Biochemists think they are Physical Chemists,

Physical Chemists think they are Physicists,

Physicists think they are Gods,

And God thinks he is a Mathematician.

Physicists defer only to mathematicians, mathematicians defer only to God.

**2. A mathematician and …** *The following sketches show our dedication to abstract thinking in the most unusual situations and strong belief in the universality of mathematical methods. Mathematicians are always impatient and intelligent.*

A mathematician and a Wall street broker went to races. The broker suggested to bet $10,000 on a horse. The mathematician was sceptical, saying that he wanted first to understand the rules, to look on horses, etc. The broker whispered that he knew a secret algorithm for the success, but he could not convince the mathematician.

«You are too theoretical,» he said and bet on a horse. Surely, that horse came first bringing him a lot of money. Triumphantly, he exclaimed:

«I told you, I knew the secret!»

«What is your secret?» the mathematician asked.

«It is rather easy. I have two kids, three and five year old. I sum up their ages and I bet on number nine.»

«But, three and five is eight,» the mathematician protested.

«I told you, you are too theoretical!» the broker replied, «Haven’t I just shown experimentally, that my calculation is correct! 3+5=9!»

A mathematician, a physicist, an engineer went again to the races and laid their money down. Commiserating in the bar after the race, the engineer says, «I don’t understand why I lost all my money. I measured all the horses and calculated their strength and mechanical advantage and figured out how fast they could run…»

The physicist interrupted him: «…but you didn’t take individual variations into account. I did a statistical analysis of their previous performances and bet on the horses with the highest probability of winning…»

«…so if you’re so hot why are you broke?» asked the engineer. But before the argument can grow, the mathematician takes out his pipe and they get a glimpse of his well-fattened wallet. Obviously here was a man who knows something about horses. They both demanded to know his secret.

«Well,» he says, «first I assumed all the horses were identical and spherical…»

An engineer, a physicist and a mathematician are staying in a hotel.

The engineer wakes up and smells smoke. He goes out into the hallway and sees a fire, so he fills a trash can from his room with water and douses the fire. He goes back to bed.

Later, the physicist wakes up and smells smoke. He opens his door and sees a fire in the hallway. He walks down the hall to a fire hose and after calculating the flame velocity, distance, water pressure, trajectory, etc. extinguishes the fire with the minimum amount of water and energy needed.

Later, the mathematician wakes up and smells smoke. He goes to the hall, sees the fire and then the fire hose. He thinks for a moment and then exclaims, «Ah, a solution exists!» and then goes back to bed.

A physicist and a mathematician are sitting in a faculty lounge. Suddenly, the coffee machine catches on fire. The physicist grabs a bucket and leap towards the sink, filled the bucket with water and puts out the fire. Second day, the same two sit in the same lounge. Again, the coffee machine catches on fire. This time, the mathematician stands up, got a bucket, hands the bucket to the physicist, thus reducing the problem to a previously solved one.

A mathematician and an engineer are on desert island. They find two palm trees with one coconut each. The engineer climbs up one tree, gets the coconut, eats. The mathematician climbs up the other tree, gets the coconut, climbs the other tree and puts it there. «Now we’ve reduced it to a problem we know how to solve.»

A biologist, a physicist and a mathematician were sitting in a street cafe watching the crowd. Across the street they saw a man and a woman entering a building. Ten minutes they reappeared together with a third person.

— They have multiplied, said the biologist.

— Oh no, an error in measurement, the physicist sighed.

— If exactly one person enters the building now, it will be empty again, the mathematician concluded.

Several scientists were all posed the following question: «What is 2 * 2 ?»

The engineer whips out his slide rule (so it’s old) and shuffles it back and forth, and finally announces «3.99».

The physicist consults his technical references, sets up the problem on his computer, and announces «it lies between 3.98 and 4.02».

The mathematician cogitates for a while, then announces: «I don’t know what the answer is, but I can tell you, an answer exists!».

Philosopher smiles: «But what do you mean by 2 * 2 ?»

Logician replies: «Please define 2 * 2 more precisely.»

The sociologist: «I don’t know, but is was nice talking about it».

Behavioral Ecologist: «A polygamous mating system».

Medical Student : «4» All others looking astonished : «How did you know ??» Medical Student : :I memorized it.»

A physicist, a mathematician, and a mystic were asked to name the greatest invention of all time. The physicist chose the fire, which gave humanity the power over matter. The mathematician chose the alphabet, which gave humanity power over symbols. The mystic chose the thermos bottle.

«Why a thermos bottle?» the others asked.

«Because the thermos keeps hot liquids hot in winter and cold liquids cold in summer.»

«Yes — so what?»

«Think about it.» said the mystic reverently. That little bottle — how does it *know*?»

*At least this time we are together with the physicist! :*

An chemist, a physicist, and a mathematician are stranded on an island when a can of food rolls ashore. The chemist and the physicist comes up with many ingenious ways to open the can. Then suddenly the mathematician gets a bright idea: «Assume we have a can opener …»

A mathematician is asked to design a table. He first designs a table with no legs. Then he designs a table with infinitely many legs. He spend the rest of his life generalizing the results for the table with **N** legs (where **N** is not necessarily a natural number).

Several scientists were all posed the following question: «What is pi ?»

The engineer said: «It is approximately 3 and 1/7»

The physicist said: «It is 3.14159»

The mathematician thought a bit, and replied «It is equal to pi».

(A nutritionist: «Pie is a healthy and delicious dessert!» )

An engineer, a physicist and a mathematician were asked to hammer a nail into a wall.

The engineer went to build a Universal Automatic Nailer — a device able to hammer every possible nail into every possible wall.

The physicist conducted series of experiments on strength of hammers, nails, and walls and developed a revolutionary technology of ultra-sonic nail hammering at super-low temperature.

The mathematician generalized the problem to a N dimensional problem of penetration of a knotted one dimensional nail into a N-1 dimensional hyper-wall. Several fundamental theorems are proved. Of course, the problem is too rich to suggest a possibility of a simple solution, even the existence of a solution is far from obvious.

A mathematician, a physicist, and an engineer were traveling through Scotland when they saw a black sheep through the window of the train.

«Aha,» says the engineer, «I see that Scottish sheep are black.»

«Hmm,» says the physicist, «You mean that some Scottish sheep are black.»

«No,» says the mathematician, «All we know is that there is at least one sheep in Scotland, and that at least one side of that one sheep is black!»

A mathematician, scientist, and engineer are each asked: «Suppose we define a horse’s tail to be a leg. How many legs does a horse have?» The mathematician answers «5»; the scientist «1»; and the engineer says «But you can’t do that!

A mathematician, a physicist, and an engineer are all given identical rubber balls and told to find the volume. They are given anything they want to measure it, and have all the time they need. The mathematician pulls out a measuring tape and records the circumference. He then divides by two times pi to get the radius, cubes that, multiplies by pi again, and then multiplies by four-thirds and thereby calculates the volume. The physicist gets a bucket of water, places 1.00000 gallons of water in the bucket, drops in the ball, and measures the displacement to six significant figures. And the engineer? He writes down the serial number of the ball, and looks it up.

A Mathematician (M) and an Engineer (E) attend a lecture by a Physicist. The topic concerns Kulza-Klein theories involving physical processes that occur in spaces with dimensions of 9, 12 and even higher. The M is sitting, clearly enjoying the lecture, while the E is frowning and looking generally confused and puzzled. By the end the E has a terrible headache. At the end, the M comments about the wonderful lecture.

E: «How do you understand this stuff?»

M: «I just visualize the process»

E: «How can you POSSIBLY visualize something that occurs in 9-dimensional space?»

M: «Easy, first visualize it in N-dimensional space, then let N go to 9»

A team of engineers were required to measure the height of a flag pole. They only had a measuring tape, and were getting quite frustrated trying to keep the tape along the pole. It kept falling down, etc. A mathematician comes along, finds out their problem, and proceeds to remove the pole from the ground and measure it easily. When he leaves, one engineer says to the other: «Just like a mathematician! We need to know the height, and he gives us the length!»

A mathematician and a physicist agree to a psychological experiment. The (hungry) mathematician is put in a chair in a large empty room and his favorite meal, perfectly prepared, is placed at the other end of the room. The psychologist explains, «You are to remain in your chair. Every minute, I will move your chair to a position halfway between its current location and the meal.» The mathematician looks at the psychologist in disgust. «What? I’m not going to go through this. You know I’ll never reach the food!» And he gets up and storms out.

The psychologist ushers the physicist in. He explains the situation, and the physicist’s eyes light up and he starts drooling. The psychologist is a bit confused. «Don’t you realize that you’ll never reach the food?» T he physicist smiles and replies: «Of course! But I’ll get close enough for all practical purposes!»

One day a farmer called up an engineer, a physicist, and a mathematician and asked them to fence of the largest possible area with the least amount of fence.

The engineer made the fence in a circle and proclaimed that he had the most efficient design.

The physicist made a long, straight line and proclaimed «We can assume the length is infinite…» and pointed out that fencing off half of the Earth was certainly a more efficient way to do it.

The Mathematician just laughed at them. He built a tiny fence around himself and said «I declare myself to be on the outside.»

The physicist and the engineer are in a hot-air balloon. Soon, they find themselves lost in a canyon somewhere. They yell out for help: «Helllloooooo! Where are we?»

15 minutes later, they hear an echoing voice: «Helllloooooo! You’re in a hot-air balloon!!»

The physicist says, «That must have been a mathematician.»

The engineer asks, «Why do you say that?»

The physicist replied: «The answer was absolutely correct, and it was utterly useless.»

Several scientists were asked to prove that all odd integers higher than 2 are prime.

Mathematician: 3 is a prime, 5 is a prime, 7 is a prime, and by induction — every odd integer higher than 2 is a prime.

Physicist: 3 is a prime, 5 is a prime, 7 is a prime, 9 is an experimental error, 11 is a prime. Just to be sure, try several randomly chosen numbers: 17 is a prime, 23 is a prime…

Engineer: 3 is a prime, 5 is a prime, 7 is a prime, 9 is an approximation to a prime, 11 is a prime,…

Programmer (reading the output on the screen): 3 is a prime, 3 is a prime, 3 a is prime, 3 is a prime….

Biologist: 3 is a prime, 5 is a prime, 7 is a prime, 9 — results have not arrived yet,…

Psychologist: 3 is a prime, 5 is a prime, 7 is a prime, 9 is a prime but tries to suppress it,…

Chemist (or Dan Quayle): What’s a prime?

Politician: «Some numbers are prime.. but the goal is to create a kinder, gentler society where all numbers are prime… »

Programmer: «Wait a minute, I think I have an algorithm from Knuth on finding prime numbers… just a little bit longer, I’ve found the last bug… no, that’s not it… ya know, I think there may be a compiler bug here — oh, did you want IEEE-998.0334 rounding or not? — was that in the spec? — hold on, I’ve almost got it — I was up all night working on this program, ya know… now if management would just get me that new workstation that just came out, I’d be done by now… etc., etc. …»

(Two is the oddest prime of all, because it’s the only one that’s even!)

Dean, to the physics department. «Why do I always have to give you guys so much money, for laboratories and expensive equipment and stuff. Why couldn’t you be like the math. department — all they need is money for pencils, paper and waste-paper baskets. Or even better, like the philosophy department. All they need are pencils and paper.»

A mathematician, an engineer, and a chemist were walking down the road when they saw a pile of cans of beer. Unfortunately, they were the old-fashioned cans that do not have the tab at the top. One of them proposed that they split up and find can openers. The chemist went to his lab and concocted a magical chemical that dissolves the can top in an instant and evaporates the next instant so that the beer inside is not affected. The engineer went to his workshop and created a new HyperOpener that can open 25 cans per second.

They went back to the pile with their inventions and found the mathematician finishing the last can of beer. «How did you manage that?» they asked in astonishment. The mathematician answered, «Oh, well, I assumed they were open and went from there.»

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.

A mathematician organizes a lottery in which the prize is an infinite amount of money. 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…»

A Mathematician was put in a room. The room contains a table and three metal spheres about the size of a softball. He was told to do whatever he wants with the balls and the table in one hour. After an hour, the balls are arranges in a triangle at the center of the table. The same test is given to a Physicist. After an hour, the balls are stacked one on top of the other in the center of the table. Finally, an Engineer was tested. After an hour, one of the balls is broken, one is missing, and he’s carrying the third out in his lunchbox.

A mathematician decides he wants to learn more about practical problems. He sees a seminar with a nice title: «The Theory of Gears.» So he goes. The speaker stands up and begins, «The theory of gears with a real number of teeth is well known …»

When a statistician passes the airport security check, they discover a bomb in his bag. He explains. «Statistics shows that the probability of a bomb being on an airplane is 1/1000. However, the chance that there are two bombs at one plane is 1/1000000. So, I am much safer…»

What is the difference between a Psychotic, a Neurotic and a mathematician? A Psychotic believes that 2+2=5. A Neurotic knows that 2+2=4, but it kills him. A mathematician simply changes the base.

Q: What will a logician choose: a half of an egg or eternal bliss in the afterlife? A: A half of an egg! Because nothing is better than eternal bliss in the afterlife, and a half of an egg is better than nothing.

A physicist has been conducting experiments and has worked out a set of equations which seem to explain his data. He asks a mathematician to check them. A week later, the mathematician calls «I’m sorry, but your equations are complete nonsense.» «But these equations accurately predict results of experiments. Are you sure they are completely wrong? «To be precise, they are not always a complete nonsense. But the only case in which they are true is the trivial one where the field is Archimedean…»

A mathematician belives nothing until it is proven

A physicist believes everything until it is proven wrong

A chemist doesn’t care

biologist doesn’t understand the question.

An engineer and a topologist were locked in the rooms for a day with a can of food but without an opener. At the end of the day, the engineer is sitting on the floor of his room and eating from the open can: He threw it against the walls until it cracked open. In the mathematician’s room, the can is still closed but the mathematician has disappeared. There are strange noises coming from inside the can… When it is opened and the mathematician crawls out. «Damn! I got a sign wrong…»

A mathematician has spent ten years trying to prove the Riemann hypothesis. Finally, he decides to sell his soul to the devil in exchange for a proof. The devil promises to deliver a proof in the four weeks. Half a year later, the devil shows up again — in a rather gloomy mood. «I’m sorry», he says. «I couldn’t prove the hypothesis either. But» — and his face lightens up — «I think I found a really interesting lemma…»

To mathematicians, solutions mean finding the answers. But to chemists, solutions are things that are still all mixed up.

**The Evolution of Math Teaching**

(Anon: adapted from The American Mathematical Monthly, Vol. 101, No. 5, May 1994 (Reprinted by STan Kelly-Bootle in Unix Review, Oct 94)

**Top ten excuses for not doing homework:**

*Warning! It is against the rule to use these excuses in my classes! A. Ch.*

A professor’s enthusiasm for teaching precalculus varies inversely with the likelihood of his having to do it.

A student comes to the department with a shiny new cup, the sort of which you get when having won something. He explained:

I won it in the MD Math Contest. They asked what 7 + 7 is. I said 12 and got 3rd place!

A mathematician, native Texan, once was asked in his class: «What is mathematics good for?» He replied: «This question makes me sick. Like when you show somebody the Grand Canyon for the first time, and he asks you `What’s is good for?’ What would you do? Why, you would kick the guy off the cliff».

A somewhat advanced society has figured how to package basic knowledge in pill form.

A student, needing some learning, goes to the pharmacy and asks what kind of knowledge pills are available. The pharmacist says «Here’s a pill for English literature.» The student takes the pill and swallows it and has new knowledge about English literature!

«What else do you have?» asks the student.

«Well, I have pills for art history, biology, and world history,» replies the pharmacist.

The student asks for these, and swallows them and has new knowledge about those subjects.

Then the student asks, «Do you have a pill for math?»

The pharmacist says «Wait just a moment», and goes back into the storeroom and brings back a whopper of a pill and plunks it on the counter.

«I have to take that huge pill for math?» inquires the student.

The pharmacist replied «Well, you know math always was a little hard to swallow.»

Golden rule for math teachers: You must tell the truth, and nothing but the truth, but not the whole truth.

A math professor is one who talks in someone else’s sleep.

Q:What do you get when you add 2 apples to 3 apples?

A:Answer: A senior high school math problem.

Teacher: Now suppose the number of sheep is **x**…

Student: Yes sir, but what happens if the number of sheep is not **x**?

Mathematician U. was a great friend of his five-year old grandson. They discussed everything including math and U. was very proud of the boys math talents. The child went to kindergarten; In two weeks the he ask U.to help with the difficult math problem: «There are four airplanes flying, then two more airplanes join them. How many airplanes are flying now? U. was very disappointed by the simplicity of the problem. «What confuses you?» he asked. The child says: » I know, of course, that 4 + 2 =6, but I cannot figure out what the airplanes have do with this!»

A lecturer tells some students to learn the phone-book by heart.

The mathematicians are baffled: `By heart? You kidding?’

The mathematicians are baffled: `By heart? You kidding?’

The physics-students ask: `Why?’

The engineers sigh: `Do we have to?’

The chemistry-students ask: `Till next Monday?’

The accounting-students (scribbling): `Till tomorrow?’

The laws-students answer: `We already have.’

The medicine-students ask: `Should we start on the Yellow Pages?’

**Quotes from math students and lecturers **

- «This is a one line proof…if we start sufficiently far to the left.»

«The problems for the exam will be similar to the discussed in the class. Of course, the numbers will be different. But not all of them. Pi will still be 3.14159… »

«Roses are red,

Violets are blue,

Greens’ functions are boring

And so are Fourier transforms.»

«Sex and drugs? They’re nothing compared with a good proof!»

Yeah, I used to think it was just recreational… then I started doin’ it during the week… you know, simple stuff: differentiation, kinematics. Then I got into integration by parts… I started doin’ it every night: path integrals, holomorphic functions. Now I’m on diophantine equations and sinking deeper into transfinite analysis. Don’t let them tell you it’s just recreational.

Fortunately, I can quit any time I want.

«He was restless during the days and couldn’t sleep at night — always trying to solve his problem. When he had finally done it, he wasn’t happy: he calls himself a complete idiot and throws all his notes into the garbage. Then he said, he really enjoyed it.»

«Do you love your math more than me?»

«Of course not, dear — I love you much more.»

«Then prove it!»

«OK… Let * R * be the set of all lovable objects…»

**4. Seminar semantics, etc.** *Next passages contain little professional secrets. They reflect the conflict between the dreams of classical clear presentations, the complexity of modern math problems, and the survival tactics of the authors. *