**A mathematician, a physicist, and an engineer…**

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.

A mathematician belives nothing until it is proven.

A physicist believes everything until it is proven wrong.

A chemist doesn’t care, and a biologist doesn’t understand the question.

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.^{1}

The graduate with a Mathematics degree asks, “Why does it work?”

The graduate with a Science degree asks, “How does it work?”

The graduate with an Engineering degree asks, “How does one build it?”

The graduate with an Accounting degree asks, “How much will it cost?”

The graduate with a Liberal Arts degree asks, “Do you want fries with that?”

A mathematician is a person who says that, when 3 people are supposed to be in a room but 5 came out, 2 have to go in so the room gets empty.

A statistician is a person who, if his head was in an oven and his feet were ice, would say that on the average he feels fine.^{2}

An economist is a person who is good with numbers but lacks the personality to be an accountant.

Chemistry is physics without thought.

Mathematics is physics without purpose.

Philosophy is a game with objectives and no rules.

Mathematics is a game with rules and no objectives.

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

When a pure mathematician is asked, say, to calculate the stability of an ordinary four-legged table, he rapidly enough arrives at preliminary results which pertain to a one-legged table or a table with an infinite number of legs. He will spend the rest of his life unsuccessfully solving the ordinary problem of the table with an arbitrary, finite, number of legs.

Relations between pure and applied mathematicians are based on trust and understanding. Namely, pure mathematicians do not trust applied mathematicians, and applied mathematicians do not understand pure mathematicians.

To mathematicians, solutions mean finding the answers.

To chemists, solutions are things that are still all mixed up.

When considering the behavior of a howitzer, a mathematician will be able to calculate where the shell will land, a physicist will be able to explain how the shell gets there, and an engineer will stand there and try to catch it.

Notes

1. The last line is based on Plato, who said “God geometrizes.”

2. Anyone who has taken a statistics class has probably heard this gag at least once, but few have ever bothered to look at very unusual physical conditions assumed by the joke. If the said statistician burns only paper in the oven (so the temperature of the oven is 451 degrees F, as a famous science fiction story reminds us), and if he is comfortable at 98 degrees F (the normal body temperature), then calling the ice temperature X and doing the simplest method of averaging, we find:

(451 + X)/2 = 98

451 + X = 196

X = -255

This is some *cold *ice!

**… are incarcerated**

A mad scientist who kidnapped three colleagues, an engineer, a physicist, and a mathematician, and locked each of them in seperate cells with plenty of canned food and water but no can opener.

A month later, returning, the mad scientist went to the engineer’s cell and found it long empty. The engineer had constructed a can opener from pocket trash, used aluminum shavings and dried sugar to make an explosive, and escaped.

The physicist had worked out the angle necessary to knock the lids off the tin cans by throwing them against the wall. She was developing a good pitching arm and a new quantum theory.

The mathematician had stacked the unopened cans into a surprising solution to the kissing problem; his desiccated corpse was propped calmly against a wall, and this was inscribed on the floor in blood:

Theorem:

If I can open these cans, the I shall not die.Proof.

Assume the opposite…

**… are executed
**

By guillotine:

A physicist, a mathematician, and an engineer vacationing abroad, when (for reasons never made clear to them), they are arrested and sentenced to death by guillotine. The day of the execution come, and the three unlucky men are lead up to the top of the platform.

The mathematician is put on the block, and the executioner pulls the rope. Nothing happens: the blade does not move. Quickly, the mathematician exclaims “the events are equally likely, so *P*(*E*)=1/2 and all is well.” He declares that he cannot be executed for the same crime twice. The executioner mulls over this slowly, and decides the law is on the side of the mathematician. He is set free.

Next on the block is the physicist. The executioner pulls the rope, and again nothing happens. Remembering what the mathematician did, the physicist declares, “*KE* = *mv*^{2}/2 and *v*=0 so all is well.” He reminds the executioner that he cannot be executed for the same crime twice. He is set free.

Finally, the engineer, who has been watching the goings-on intently, is up. As his head is shoved into the guillotine, he looks up at the release mechanism and replies “Wait a minute! I see the your problem…”

By electric chair:

A priest, a lawyer, and an engineer vacationing in Texas, when (for reasons never made clear to them), they are arrested and sentenced to death by electric chair. The day of the execution come, and the three unlucky men are lead up into the execution chamber.

The priest is strapped in first, and for his last words declares “I believe God will intervene on my behalf!” The guards throw the switch and nothing happens, so they assume God has intervened and let the priest go free.

The lawyer is strapped in next, and for his last words declares “I believe in the power of justice to protect the innocent!” The guards throw the switch and nothing happens, so they assume justice has been served and let the lawyer go free.

Finally, the engineer is strapped in, and for his last words declares “Well shoot! You ain’t gonna electrocute nobody if you don’t plug this dang thing in!”

**… are stranded on an island
**

A mathematician and an physicist are on desert island. They find two palm trees with one coconut each.

The physicist shins up one tree, gets the coconut, eats.

The mathematician shins 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.”

**… bet on the horses
**

An engineer, a physicist, and a mathematician went to the races one Saturday 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, between puffs on the pipe, “first I assumed all the horses were identical and spherical…”

**… build a better cow**

The USDA once wanted to make cows produce milk faster, to improve the dairy industry.

First, they decided to consult the foremost biologists and recombinant DNA technicians to build them a better cow. They assembled this team of great scientists, and gave them unlimited funding. They requested rare chemicals, weird bacteria, tons of quarantine equipment, there was a horrible typhus epidemic they started by accident, and, 2 years later, they came back with the “new, improved cow.” It had a milk production improvement of 2% over the original.

They then tried with the greatest Nobel Prize winning chemists around. They worked for six months, and, after requisitioning tons of chemical equipment, and poisoning half the small town in Colorado where they were working with a toxic cloud from one of their experiments, they got a 5% improvement in milk output.

Finally, in desperation, they turned to the mathematicians. The foremost mathematician of his time offered to help them with the problem. Upon hearing the problem, he told the delegation that they could come back in the morning and he would have solved the problem. In the morning, they came back, and he handed them a piece of paper with the computations for the new, 300% improved milk cow.

The plans began:

A Proof of the Attainability of Increased Milk Output from Bovines:

Consider a spherical cow…

**… build a small fence (I)
**

A physicist, an engineer and a mathematician were all challenged to build the shortest possible fence around a small herd of resting cattle.

The physicist went first. He took out a piece of graph paper and plotted the position of each cow, giving each cow a pair of x-y coordinates. Then he determined the lines connecting all the points. Finally he constructed a fence based on his diagram. When he finished he turned to the others and said “I’m done. And since the interior region bounded by line segments connecting the cattle-points is convex, it follows that the boundary is minimal. Q.E.D.”

Then it was the engineer’s turn. First he secured a strong fence-pole near the cattle. Next he attached one end of a six-foot-high roll of wire fence to the pole and walked around the cows slowly letting out the roll of wire fence until he came back to the post. Then he gave the roll to the physicist and told him to start pulling. As he the physicist pulled, the engineer ran around the outside of the fence kicking the cows, flailing his arms, and screaming at them to make them get up and move into the middle; meanwhile while he was yelling “Pull the fence tighter! Pull the fence tighter!” Finally the cows were shoved so close together that they couldn’t move and the fence was wrapped around them so tightly that it was leaving marks on their hides. The engineer nailed the other end of the fence to the post, cut away the roll and said “There, that is the shortest fence.”

Finally it was the mathematician’s turn. He walked over to the roll of wire fence, cut off a small piece, wrapped it around himself and declared: “I’m on the outside.”

**… build a small fence (II)**

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 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.”

**… compare notes**

An experimental physicist had completed an important experiment on the determination of the relationship between two physical quantities A and B. He rushed across the campus to the office of a theoretical mathematician who was occupied with the same problem.

“Volodya! I have finished the experiment. *A* has turned out to be larger than *B*!”

The mathematician thought about this for a moment before replying.

“This is completely understandable. You didn’t even have to make your experiment, as *A* must be larger than *B* for the following reasons…”

“Oh dear,” interrupted the physicist. “Did I really say that *A* was larger than *B*? I slipped up — it is *B* that is larger than *A*!”

The mathematician thought about this for a moment more before replying.

“Then this is even more understandable, and here is why…”

— (c) V. Berezinsky

“How a theoretical physicist works,”

*Paths into the Unknown* No 2, 1968.

*In fact, according to Berezinsky, it is based off an actual true story involving Ia I Frankel, which is charming in an of itself. According to Berezinsky:*

During the 30s, a certain experimenter caught up with him in a corridor and showed him a curve obtained from an experiment. After a minute’s thought Frankel gave an explanation for the form of this curve. However, it was explained that the curve had accidentally been turned upside down. The curve was put into place and having thought it over he explained this behavior too.

**… count people**

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.

“The original measurement wasn’t accurate,” the physicist sighed.

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

**… count sheep**

A mathematician, a physicist, and an engineer were travelling 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!”

*This joke is famously attributed to Ian Stewart.*

**… discuss God**

A bunch of engineers are sitting around at a party, discussing the wonder of the human body and its implications about the nature of God.

The mechanical engineer states that God must also be a mechanical engineer because “if you look at all the pulleys and levers that drive the body, how the tendons and muscles and bones all work together, well, it’s just amazing.”

“No, no, no,” disagrees the chemical engineer. “God has to be a chemical engineer because if you look at all the chemical processes that drive the body, how the hormones and the brain and the glands and everything else all interact, well, it’s just astounding.”

“Wrong!” snaps the electrical engineer. “God has to be an electrical engineer because if you look at the circuitry of the body, how the thousands upon millions of nerve cells transmit signals from one part to another, well, it boggles the mind.”

At this point, a mathematician, who has been listening to the conversation with some interest, speaks up. “No, no, you’ve all three got it wrong,” he says. “God is definitely a civil engineer.”

“How do you figure?” the engineers demand.

The mathematician shrugs. “Only a civil engineer would run a sewer right through the middle of a playground.”

**… discuss multidimensional space**

A mathematician and an engineer attend a lecture by a Physicist. The topic concerns Kulza-Klein theories involving physical processes that occur in spaces with dimensions of 11, 12 and even higher. The mathematician is sitting, clearly enjoying the lecture, while the engineer is frowning and looking generally confused and puzzled. By the end the engineer has a terrible headache. At the end, the mathematician comments about the wonderful lecture. The engineer says “How do you understand this stuff?”

“I just visualize the process,” replies the mathematician.

“How can you possibly visualize something that occurs in 11-dimensional space?” asks the engineer.

The mathematician shrugs his shoulders. “Easy, first visualize it in *n*-dimensional space, then let *n* go to 11.”

**… discuss primality
**

Several people are asked to prove that all odd integers greater than 2 are prime.

*Tenured mathematician*: 3 is prime, 5 is prime, 7 is prime, 9 is not prime. Ha! A counterexample.*Untenured mathematician*: 3 is prime, 5 is prime, 7 is prime… so by induction, all subsequent odd integers are prime.*Math professor*: 3 is prime, 5 is prime, 7 is prime, and the rest are left as an exercise for the student.*Statistician*: Let’s verify this on several randomly selected odd numbers, say, 23, 47, and 83.*Computer scientist*: 3 is prime, 5 is prime, 7 is prime, segmentation fault?*Computer programmer*: 3 is prime, 3 is prime, 3 is prime, 3 is prime…*Physicist*: 3 is prime, 5 is prime, 7 is prime, 9 is an experiemntal error, 11 is prime…*Mechanical engineer*: 3 is prime, 5 is prime, 7 is prime, 9 is approximately prime, 11 is prime…*Civil engineer*: 3 is prime, 5 is prime, 7 is prime, 9 is prime…*Biologist*: 3 is prime, 5 is prime, 7 is prime, 9 is… still awaiting results…*Psychologist*: 3 is prime, 5 is prime, 7 is prime, 9 is prime but suppresses it, 11 is prime…*Accountant*: 3 is prime, 5 is prime, 7 is prime, 9 is prime, deducing 10% tax and 5% other obligations.*Economist*: 2 is prime, 4 is prime, 6 is prime…*Computational linguist*: 3 is an odd prime, 5 is an odd prime, 7 is an odd prime, 9 is a very odd prime,…*Casino Card Counters*: 3 is a prime, 5 is a prime, 7 is a prime, but I’ll take a 21 over any of them.*Democrat*: Shouldn’t the goal really be to create a greater society where all numbers are prime?*Republican*: What’s a prime?

**… discuss women**

A doctor, a lawyer and a mathematician were discussing the relative merits of having a wife or a mistress.

“For sure a mistress is better,” says the lawyer. “If you have a wife and want a divorce, it causes all sorts of legal problems.”

“No, no, it’s better to have a wife,” says the doctor, “because the sense of security lowers your stress and is good for your health.

“No, no, you’re both wrong,” replies the mathematician. “It’s best to have both so that when the wife thinks you’re with the mistress and the mistress thinks you’re with your wife, you can slip away and do some mathematics.”

**… get a flat tire**

An engineer, a mathematician, and a computer programmer are driving down the road when the car they are in gets a flat tire.

The engineer says that they should buy a new car.

The mathematician says they should sell the old tire and buy a new one.

The computer programmer says they should drive the car around the block and see if the tire fixes itself.

**… go hunting**

A mathematician, an engineer, and a physicist are out hunting together. They spy a deer in the woods.

The physicist calculates the velocity of the deer and the effect of gravity on the bullet, aims his rifle and fires. Alas, he misses; the bullet passes three feet behind the deer. The deer bolts some yards, but comes to a halt, still within sight of the trio.

“Shame you missed,” comments the engineer, “but of course with an ordinary gun, one would expect that.” He then levels his special deer-hunting gun, which he rigged together from an ordinary rifle, a sextant, a compass, a barometer, and a bunch of flashing lights which don’t do anything but impress onlookers, and fires. Alas, his bullet passes three feet in front of the deer, who by this time wises up and vanishes for good.

“Well,” says the physicist, “your contraption didn’t get it either.”

“What do you mean?” pipes up the mathematician. “Between the two of you, that was a perfect shot!”

Follow up — how did they know it was a deer?

The physicist observed that it behaved in a deer-like manner, so it must be a deer.

The mathematician asked the physicist what it was, thereby reducing it to a previously solved problem.

The engineer was in the woods to hunt deer, therefore it was a deer.

**… go on safari**

A biologist, a statistician, a mathematician and a computer scientist are on a photo-safari in Africa. They drive out on the savannah in their jeep, stop and scout the horizon with their binoculars.

The biologist: “Look! There’s a herd of zebras! And there, in the middle : A white zebra! It’s fantastic! There are white zebra’s! We’ll be famous!”

The statistician: “It’s not significant. We only know there’s one white zebra.”

The mathematician: “Actually, we only know there exists a zebra, which is white on one side.”

The computer scientist: “Oh, no! A special case!”

**… gotta lotta balls**

Little balls:

A mathematician, a physicist and an engineer were undergoing a thought-process experiment. As part of the experiment, they were given 2 brass ball bearings and left alone for a while. After an hour or so, the experimenter returned to each of the three professionals and asked what they had done with the 2 ball bearings.

The physicist replied: “I’ve tried to balance one on the other, and have some ideas about friction.”

The mathematician, rather sheepishly, admitted “I haven’t done anything with them.” But then he excitedly added, “but I’ve some theories about two-ness.”

The engineer shrugged. “They broke.”

Midsize balls:

A mathematician, a physicist and an engineer were undergoing a thought-process experiment. As part of the experiment, they were seated at a table, given 3 metal spheres, and left alone for a while. After an hour or so, the experimenter returned to each of the three professionals.

He checks in on the mathematician first, and finds the balls neatly arranged in a triangle at the center of the table.

He checks in on the physicist next, and finds the balls stacked precariously, one on top of the other, in the center of the table.

He then checks in on the engineer, and finds one of the balls is broken, one is missing, and the third being carried out in the engineer’s lunchbox.

Big balls:

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 large bucket of water, places 3 gallons of water in the bucket, drops in the ball, and measures the displacement to six significant figures.

The engineer writes down the serial number of the ball, and looks it up.

**… have a beer**

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 chemical solution 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.”

**… look for keys**

A mathematician, physicist, and engineer are walking through a parking lot at night when they meet an old woman standing by a Volkswagen in tears. They ask her what’s wrong, and she replies: “I was trying to get into my car to drive home, but I dropped my keys. My eyes are too old to see them in the dark… my legs are to old to bend down and search for them. What am I to do?”

The three professionals offer to help. Immediately, the engineer drops to all fours, crawling around the car in the dark, reaching and feeling for the keys. But he does not find them.

The physicist reaches into his pocket and pulls out a small magnet and cigarette lighter. He uses the lighter to dimly illuminate the area around the car; he uses the magnet to try and attract the keys to him. But he does not find the keys.

Finally, the mathematician surveys the problem. He then goes to the other end of the parking lot, where the light is better, and looks for the keys over there.

**… measure a flagpole**

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. They’d get it a bit up the pole, but then the tape would buckle and it would fal down.

A mathematician comes along and listens to their problem. After inspecting both the tape measure and the flag pole, he proceeds to remove the pole from its base in the ground. He lays it down flat, measures it easily with the tape measure, and then resets the pole in the ground.

When he leaves, one engineer says to the other and sighs. “Just like a mathematician! We need to know the height, and he gives us the length!”

**… play golf**

A preacher, a doctor and a mathematician were waiting one morning for a particularly slow group of golfers. Irate, they complain about the extensive wait and the ineptitude of the group ahead of them until a groundskeeper passes by.

“Say George,” asks the preacher, “What’s with that group ahead of us? They’re rather slow, aren’t they?”

“Oh, yes,” replies the groundskeeper. “That’s a group of blind firefighters. They lost their sight saving our clubhouse from a fire last year, so we always let them play for free anytime.”

The group is silent for a moment.

“That’s so sad,” remarks the preacher. “I think I will say a special prayer for them tonight.”

“That’s a good idea,” agrees the doctor. “And I’m going to contact my ophthalmologist buddy and see if there’s anything he can do for them.”

The mathematician considers this further, and then asks, “Why can’t these guys play at night?”

**… see a fire (I)**

A mathematician and a physicist were walking along during their lunch break when at a two-day convention when they realized they are going to be late for the afternoon session. “We’re going to be late,” says the physicist.

So the two begin to scramble back to their seats. However, no sooner do they start then they spy the engineering building on fire. Immediately, the physicist springs into action. He finds a nearby length of hose, jerry-rigs it to a nearby fire hydrant, and quickly puts the fire out. He then rushes into the building to make sure everyone is okay (they are). He then grabs the mathematician’s arm and rushes back to their seats. Amazingly, they make it on time.

The next day, the pair are again out walking about on their lunch break when they realize they are going to be late for the afternoon session.

Immediately the mathematician springs into action. He sets the nearby engineering building on fire, thus reducing the problem to one previously solved.

**… see a fire (II)**

A physicist and a mathematician setting in a faculty lounge. Suddenly, the coffee machine catches on fire. The physicist grabs a bucket and leaps towards the sink, fills the bucket with water and puts out the fire.

The second day, the same two sit in the same lounge. Again, the coffee machine catches on fire. This time, the mathematician stands up, gets a bucket, hands the bucket to the physicist, thus reducing the problem to a previously solved one.

**… see a fire (III)**

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 the 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, and so forth, 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

**… see a fire (IV)**

There are a mathematician and a physicist are out walking when they spy a burning building with people inside. There is a fire hydrant and a hose on the sidewalk.

The physicist has to put the fire out…so, he attaches the hose to the hydrant, puts the fire out, and saves the house and the family.

They continue walking, and come across a second burning building with people inside. The mathematician has to put the fire out… so, he takes the hose off the hydrant and lays it on the sidewalk. “Now I’ve reduced it to a previously solved problem,” and walks away.

**… see a fire (V)**

An engineer, physicist, and a mathematician were playing cards in a parlor. A fire breaks out. The engineer starts to calculate how much water it takes to put out the fire. The physicist figures out the best theory on how to put out the fire. The mathematician tries to prove the fire doesn’t exist.

**… travel by train**

A math convention and an engineering convention were being held in the same city. Consequently, a bunch of mathematicians and a bunch of engineers were on the same train headed for the city. Each of the engineers had his/her train ticket. The group of mathematicians had only ONE ticket for all of them. The engineers started laughing and snickering.

Then, one of the mathematicians said “here comes the conductor” and then all of the math majors went into the bathroom. The engineers were puzzled. The conductor came aboard and said “tickets please” and got tickets from all the engineers. He then went to the bathroom and knocked on the door and said “ticket please” and the mathematicians stuck the ticket under the door. The conductor took it and then the mathematicians came out of the bathroom a few minutes later. The engineers were dumbfounded.

So, on the way back from the convention, the group of engineers had one ticket for the group. They started snickering at the mathematicians, for the whole group had no tickets amongst them. Then, the mathematicians’ lookout said “Conductor coming!”. All the mathematicians went to the bathroom. All the engineers went to another bathroom. Then, before the conductor came on board, one of the mathematicians left the bathroom, knocked on the other bathroom, and said “ticket please.”

**… undergo a psychology experiment (I)**

A group of scientists were doing an investigation into problem-solving techniques, and constructed an experiment involving a physicist, an engineer, and a mathematician. The experimental apparatus consisted of a water spigot and two identical pails, one of which was fastened to the ground ten feet from the spigot.

Each of the subjects was given the second pail, empty, and told to fill the pail on the ground.

The engineer was the first subject: he carried his pail to the spigot, filled it there, carried it full of water to the pail on the ground, and poured the water into it. Standing back, he declared, “There: I have solved the problem.”

The physicist and the mathematician each approached the problem similarly. Upon finishing, the physicist noted that the solution was exact, since the volumes of the pails were equal. The mathematician merely noted that he had proven that a solution exists.

Now, the experimenters altered the parameters of the task a bit: the pail on the ground was still empty, but the subjects were presented with a pail that was already half-filled with water.

The engineer immediately carried his pail over to the one on the ground, emptied the water into it, went back to the spigot, filled the pail, and finally emptied the entire contents into the pail on the ground, overflowing it and spilling some of the water. Upon finishing, he commented that the problem should have been better stated.

The physicist, in turn, thought for some time before going into action. He then took his half-filled pail to the spigot, filled it to the brim, and filled the pail on the ground from it. He noted that the problem had an exact solution, which he had found.

The mathematician thought for a long time before stirring. At last he stood up, emptied his pail onto the ground, and declared, “I have reduced it to the previous problem.”

**… undergo a psychology experiment (II)**

Psychologists subject an engineer, a physicist, and a topologist to an experiment: Each of them is locked in a room for a week — hungry, with a single can of tuna fish but without an opener; all they have is pencil and paper.

At the end of the day, the psychologists open the engineer’s room first. Pencil and paper are unused, but the walls of the room are covered with dents. The engineer is sitting on the floor and eating from the open can: He threw it against the walls until it cracked open.

The physicist is next. The paper is covered with formulas, there is one dent in the wall, and the physicist is eating, too. He calculated how exactly to throw the can against the wall, so that it would crack open.

When the psychologists open the topologists’s room, the paper is also full of formulas, the can is still closed, and the mathematician has disappeared. But there are strange noises coming from inside the can…

Someone gets an opener and opens the can. The topologist, covered in tuna fish, crawls out. “Dammit! I got a sign wrong again…”

**… undergo a psychology experiment (III)
**

A mathematician and a engineer agree to a psychological experiment. The mathematician is put in a chair in a large empty room and a beautiful naked woman is placed on a bed at the other end of the room. The psychologist explains, “You are to remain in your chair. Every ten seconds, I will move your chair to a position halfway between its current location and the woman on the bed.”

The mathematician looks at the psychologist in dismay. “What? I’m not going to go through this. I know I’ll never reach the bed!” And with that, he gets up and storms out. The psychologist makes a note on his clipboard and ushers the engineer in.

He explains the situation, and the engineer’s eyes light up and he starts drooling. The psychologist is a bit confused. “Don’t you realize that you’ll never reach her?”

The engineer smiles and replied, “Oh yeah… but in about two minutes, I’ll be close enough for all practical purposes!”

**… were asked “What is 2×2?”**

- A trained mathematician: “4.”
- A poorly trained mathematician:“I don’t what the answer is, but I can tell you, an answer exists.”
- A physicist, after consulting technical references, and setting up the problem on his computer: “It lies between 3.98 and 4.02.”
- An engineer, after consulting his slide rule: “3.99.”
- A philosopher: “But what do you
*mean*by 2 x 2 ?” - An accountant, after closing all the doors and windows, in a whisper: “What do you
*want*the answer to be?” - A computer hacker, after 2 hours of breaking into the NSA super-computer: “4.”

**… were asked “What is π?”**

- A math major: “3.14”
- A good math major: “3.14159”
- A physicist: ” 3.14159, plus or minus 0.000005.”
- A computer scientist: “3.141592653589 in double precision.”
- An engineer: “3.”
- A nutritionist: “A delicious and healthy dessert.”

** … never metajoke they didn’t like**

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.