Mathematics

A experimental physicist, a theoretical physicist and a mathematician are each locked up in a cell for the purpose of an experiment. There, one can find a piece of chalk and a can of beans. On the next day, the scientist look after them to see what has happend.

In the cell of the experimental physicist, there are thousands of dents all over the wall, and the experimental physicist has survived.

In the cell of the theoretical physicist, all walls are covered with chaotic formulas, and exactly one dent on one wall – and the theoretical physicist has survived, too.

And in the cell of the mathematician? There, all walls are likewise covered with chaotic formulas, but the can is still closed, and the mathematician has starved to death. The formulas are recalculated, but no error can be found, and the scientists begin to wonder why the mathematician has died – until they read the last line of the proof: "By this, we have proved that there is a way to open the can!"

Alternative punch-line: In the cell of the mathematician, all walls are again covered with chaotic formulas, the can is found in the middle of the room, but the mathematician cannot be seen. Then there is a knock. One scientist takes a tin-opener and opens the can. The mathematicians crawls out of it while he mutters: "Damned, I must have made an error concerning the sign!"

One more alternative: The physicists help themselves in the way described above, and the mathematician is rescued just in time. Then he is led to the cells of the other "guinea pigs": To the experimental physicists he says: "A quite rude method." In the cell of the theoretical physicist he looks at the can and at the formulas, points to a wall and states: "Well, those limits are not commutable, and that integral over there does not exist."

A mathematician, a physicist and a priest stand on the roof of a burning building. The only possibility to escape is to jump into the pool in front of the house. The priest thinks: "God will help me." He jumps down and hits the ground several meters away of the pool. The physicist takes out a pocket calculator and a pad, calcutes a few minutes, takes a run-up, and lands right in the middle of the pool. The mathematician calcutes a few minutes with the help of a pocket calculator and a pad, too. When he has finished, he takes a run-up and – "falls" towards the sky. What has happend? He has made an error concerning the sign!

A mathematician and a physicist were asked the following question: "Suppose you walked by a burning house and saw a hydrant and a hose not conneced to the hydrant. What would you do?"

• Physicist: "I would attach the hose to the hydrant, turn on the water, and put out the fire."
• Mathematician: "I would attach the hose to the hydrant, turn on the water, and put out the fire."

Then, they were asked this question: "Suppose you walked by a house and saw a hose connected to a hydrant. What would you do?"

• Physicist: "I would keep walking, as there is no problem to solve."
• Mathematician: "I would disconnect the hose from they hydrant and set the house on fire, reducing the problem to a previously solved form."

An experimental physicist, a theoretical physicist and a mathematician are discussing what is better: a wife or a girlfriend.

• The experimental physicist: "A girlfriend, because you still have freedom to experiment."
• The theoretical physicist: "A wife, because of security."
• The mathematician: "Both. When I'm not with my wife, she thinks I'm with my girlfriend. With my girlfriend it's vice versa. And I can be at the library without anyone disturbing me."

An engineer is convinced that his equations are an approximation of reality.
A physicist thinks that reality is an approximation of his equations.
A mathematician does not worry about that.

What is the fundamental principle of engineering mathematics?
Every function has a Taylor series which converges to the function and breaks off after the linear term.

There is one benefit from the advances in mathematics: One can err more exactly.

The typical mathematics-professor: He says A, writes B, means C, adds D, but E would be right.

A conversation in a bar:

• "Logician? What's that?"
• "Okay, I will explain it to you: Do you have an aquarium?" – "Yes ..."
• "Then you certainly have some fish in it!" – "Yes ..."
• "And as you have an aquarium with fish in it, you certainly like animals." – "Yes ..."
• "And as you like animals, you certainly like children." – "Yep ..."
• "And as you like children, you certainly have some." – "Yep ..."
• "And as you have children, you certainly have a wife." – "Yes ..."
• "And as you have a wife, you certainly love women." – "Yeah ..."
• "And as you love women, you do not love men!" – "Of course!"
• "And as you do not love men, you are not gay!" – "Right!"

The mathematician leaves, and a friend of his "erudite student" turns up:

• "Imagine that: I've just met a logician!" – "A what?"
• "A logician. I will explain it to you: Do you have an aquarium?" – "No ..."
• "Queer!"

A physics professor is walking across campus, runs into a math professor. The Physicist has been doing an experiment, and has worked out an emphirical equation that seems to explain his data, and asks the math professor to look at it.

A week later, they meet again, and the Math professor says the equation is invalid. By then, the physics professor has used his equation to predict the results of further experiments, and he is getting excellent results, so he askes the math professor to look again.

Another week goes by, and they meet once more. The Math professor tells the physics professor the equation does work, "But only in the trivial case where the numbers are real and positive."

A math professor is talking to her little brother who just started his first year of graduate school in mathematics.
"What's your favorite thing about mathematics?" the brother wants to know.
"Knot theory."
"Yeah, me neither."

Two people are getting into an elevator. A little bit, later three get off.

• The physicist: "The third one tunneled in."
• The biologist: "They have reproduced."
• The mathematician: "If one person gets in, the elevator is empty again."

At a bus stop, ten passengers are getting onto the bus. At the nect stop, eleven get off.

• The theologian: "A miracle! A miracle!"
• The biologist: "They must have proliferated."
• The physicist: "Never mind, ten percent measuring tolerance has to be accepted."
• The mathematician: "If one person gets in, the bus is empty again."

Satz: Mathematiker sind konvergent.
Beweis: Mathematiker sind monoton und beschränkt.       q.e.d.

Mensch zu Mathematiker: "Ich finde Ihre Arbeit ziemlich monoton"
Mathematiker: "Mag sein! Dafür ist sie aber stetig und unbeschränkt."

Mathematicians never die – they only loose some of their functions.

"What happened to your girlfriend, that really cute math student?"
"She no longer is my girlfriend – I have left her. A couple of nights ago I called her on the phone, and she told me that she was in bed wrestling with three unknowns!"

A mathematician gives his wife (likewise a mathematician) a bouquet of red roses as a present and says to her "I love you!" Thereupon, his wife beats him with the bouquet and throws him out. Why?
He should have said: "I love you and only you!"

When the math professor's wife returns home from work, she finds an envelope on the living room table. She opens it and finds a letter from her husband:

My dearest wife,
We have been married for nearly thirty years, and I still love you as much as on the day I proposed. You must realize, however, that you are now 54 years old and no longer able to satisfy certain needs I still have. I very much hope that you are not hurt to learn that, while you're reading this, I'm in a hotel room with an 18-year-old freshman girl from my calculus class. I'll be home before midnight.
Your husband, who will never stop loving you.

When the professor returns from the hotel shortly before midnight, he also finds an envelope in the living room. He opens it and reads:

My beloved husband,
You may recall that you, too, are 54 years old and no longer able to satisfy certain needs I still have. I thus hope that you are not hurt to learn that, while your're reading this, I am in a hotel room with the 18-year-old pool boy.
Your loving wife.
P.S. As a mathematician, you are certainly aware of the fact that 18 goes into 54 many more times than 54 goes into 18. Therefore, don't stay up and wait for me.

O.B.d.A. heißt eigentlich ohne Beschränkung der Allgemeinheit. Hier einige alternative Interpretationen:

• Ohne Bedeutung für die Allgemeinheit
• Ohne Bedenken des Autors
• Ohne Begründung der Annahme
• Ohne Berücksichtigung der Ausnahmen
• Ohne Beachtung der Angabe
• Ohne Berücksichtigung der Anfängerstudenten
• Offensichtlich bedingt durch Alkohol

Several people are asked the following question: "What is ?"

• The engineer takes out his pocket calculator, and after some minutes of calculation, he says: "3,999999999"
• The physicist: "In the order of ."
• The mathematician retires to his house, and one day later he reappears again happily holding a thick bundel of paper and states: "This problem is solvable!"
• The psychiatrist: "I don't know, but I'm glad that we talked about it ..."
• The accountant closes all doors and windows first, looks around carefully and whispers: "What would you like to hear?"
• The solicitor: "Four, but I do not know whether we will get through with this at court."
• The politician: "I do not understand your question ..."

A physicist, a mathematician and a medic were asked to compute :

• Physicist (with the help of a pocket calculator): "3.99999"
• Mathematician (fifteen auxiliary calculations, etc.): "There is a solution – a unique solution –, it is an element of , in the order of , between and !"
• Medic: "Four."
• The two others: "Pshaw! You have learned that by heart!"

Several people were asked the following problem: Prove that all odd integers higher than 2 are prime!

• Mathematician: "3 is prime, 5 is prime, 7 is prime, and by induction, we have that all the odd integers are prime."
  
• Statistician: "100% of the sample 5, 13, 37, 41 and 53 is prime, so all odd numbers must be prime."
  
• Physicist: "3 is prime, 5 is prime, 7 is prime, 9 is ... uh, 9 is an experimental error, 11 is prime, 13 is prime ... Well, it seems that you're right."
  
• Quantum Physicist: "All numbers are equally prime and non-prime until observed."
  
• Chemist: "3 is prime, 5 is prime, 7 is prime ... that's enough."
  
• Cosmologist: "3 is prime, yes it is true ..."
  
• Engineer: "3 is prime, 5 is prime, 7 is prime, 9 is ..., 9 is ..., well if you approximate, 9 is prime, 11 is prime, 13 is prime ... Well, it does seem right."
  
• Technician: "3 is prime, 5 is prime, 7 is prime, 9 is prime, 11 is prime ..."
  
• The computer programmer method is: "3 is prime, 5 is prime, 7 is prime, 9 is prime, 9 is prime, 9 is prime, 9 is ..."
  Opps, let's try that again: "3 is prime, 5 is prime, 7 is prime, 9 is ... 3 is prime, 5 is prime, 7 is prime, 9 is ... 3 is ..."
  Um, right. Okay, how about this: "3 is not prime, 5 is not prime, 7 is not prime, 9 is not prime ..."
  So much for the beta releases. Ship this: "3 is prime, 5 is prime, 7 is prime, 9 is a feature, 11 is prime ..." and put on the cover "More prime numbers than anyone else in the industry!"
  Coming soon: "3 is a prime, 4 is a feature, 5 is a prime, 6 is a feature, 7 is a prime, 8 is not yet implemented, 9 is our backwards compatibility module, ..."
  
• Logician:
  Hypothesis: All odd numbers are prime.
  Proof:
  1. If a proof exists, then the hypothesis must be true.
  2. The proof exists; you're reading it now.
  From 1 and 2 follows that all odd numbers are prime.
• Pope: "9 is prime. If you think otherwise, prepare to be damned."
• The Psychiatrist: "3 is prime, 5 is prime, 7 is prime, 9 is prime but trying to supress it, 11 is prime ..."
• Attorney: "According to Maths vs. Logic, 9 was judicially declared prime"
• Lawyer: "Hmm, let's have a look ... 3 is prime – there it is, our precedent! "

equals three, for sufficiently small and large 3 ...

Was schenkt ein Mathematiker seiner Frau zum Geburtstag?
Einen Polynomring in einer Intervallschachtelung!

Dazu war folgender Dialog in einer Newsgroup zu lesen:

• "Was schenkt ein Mathematiker seiner Frau zum Hochzeitstag? – Einen Polynomring in einer Intervallschachtelung verpackt."
• "... und dazu natürlich eine Markov-Kette mit Stein!"
• "Oh Gauss, das ist ja nun wirklich der letzte Euler."
• "Wieso? Er war ein Mann von Fermat; ein wahrer Mordelmathematiker. Und das ist nicht Thales. Er fand in jedem Halbkreisverkehr stets den rechten Winkel um abzubiegen. (Als Pythagoras dies erfuhr, titschte er im Dreieck.)"
• "Hilbert mal nicht so rum hier! Ich krieg' alles Schmidt!"

Two matrices meet. The first one suggests: "Let us go into the woods and do ." The other one answers: "Gee! You are really inverse!"

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 seperately the whole evening. Due to sympathy for it, the identity joins it und suggest: "Come one, just integrate yourself!" – "I've tried that already", answers the exponential function, "but it didn't change a bit!"

Every natural number is interesting. Let us assume, that there is an uninteresting natural number. Then there would be a smallest unteresting number – but this number would be very interesting indeed. Therefore it is an interesting number. This contradiction proves: All natural numbers are interesting.

To every problem, there is a one line proof ... if we start sufficiently far to the left.

The best moments in the life of a mathematician are the first few moments after one has proved the result, but before one finds the mistake.

There were three medieval kingdoms on the shores of a lake. There was an island in the middle of the lake, which the kingdoms had been fighting over for years. Finally, the three kings decided that they would send their knights out to do battle, and the winner would take the island. The night before the battle, the knights and their squires pitched camp and readied themselves for the fight.

The first kingdom had 12 knights, and each knight had five squires, all of whom were busily polishing armor, brushing horses, and cooking food. The second kingdom had 20 knights, and each knight had 10 squires. Everyone at that camp was also busy preparing for battle. At the camp of the third kingdom, there was only one knight, with his squire. This squire took a large pot and hung it from a looped rope in a tall tree. He busied himself preparing the meal, while the knight polished his own armor.

When the hour of the battle came, the three kingdoms sent their squires out to fight (this was too trivial a matter for the knights to join in). The battle raged, and when the dust cleared, the only person left was the lone squire from the third kingdom, having defeated the squires from the other two kingdoms, thus proving that the squire of the high pot and noose is equal to the sum of the squires of the other two sides.

Asked if he believes in one God, a mathematician answered: "Yes, up to isomorphism."

A topologist is a person who does not know the difference between a coffee cup and a doughnut.

"The world is everywhere dense with idiots."

At a press conference held at the White House, president George W. Bush accused mathematicians and computer scientists in the U.S. of misusing classroom authority to promote a Democratic agenda. "Every math or CS department offers an introduction to AlGore-ithms", the president complained. "But not a single one teaches GeorgeBush-ithms ..."

George W. Bush visits Algeria. As part of his program, he delivers a speech to the Algerian people: "You know, I regret that I have to give this speech in English. I would very much prefer to talk to you in your own language. But unfortunately, I was never good at algebra ..."

In a speech to a gathering of mathematics professors from throughout the United States, George W. Bush warned the academics not to misuse their position to force their often extremist political views on young Americans. "It is my understanding", the president said, "that you are frequently teaching algebra classes in which your students learn how to solve equations with the help of radicals. I can't say that I approve of that ..."

At New York's Kennedy airport today, an individual later discovered to be a public school teacher was arrested trying to board a flight while in possession of a ruler, a protractor, a setsquare, a slide rule, and a calculator.

At a morning press conference, Attorney general John Ashcroft said he believes the man is a member of the notorious al-gebra movement. He is being charged by the FBI with carrying weapons of math instruction.

"Al-gebra is a fearsome cult," Ashcroft said. "They desire average solutions by means and extremes, and sometimes go off on tangents in a search of absolute value. They use secret code names like 'x' and 'y' and refer to themselves as 'unknowns', but we have determined they belong to a common denominator of the axis of medieval with coordinates in every country. As the Greek philanderer Isosceles used to say, there are 3 sides to every triangle," Ashcroft declared.

When asked to comment on the arrest, President Bush said, "If God had wanted us to have better weapons of math instruction, He would have given us more fingers and toes.

"I am gratified that our government has given us a sine that it is intent on protracting us from these math-dogs who are willing to disintegrate us with calculus disregard. Murky statisticians love to inflict plane on every sphere of influence," the President said, adding: "Under the circumferences, we must differentiate their root, make our point, and draw the line."

President Bush warned, "These weapons of math instruction have the potential to decimal everything in their math on a scalene never before seen unless we become exponents of a Higher Power and begin to factor-in random facts of vertex."

Attorney General Ashcroft said, "As our Great Leader would say, read my ellipse. Here is one principle he is uncertainty of: though they continue to multiply,their days are numbered as the hypotenuse tightens around their necks."

2 is the oddest prime.

"Divide fourteen sugar cubes into three cups of coffee so that each cup has an odd number of sugar cubes in it."
"That's easy: one, one, and twelve."
"But twelve isn't odd!"
"It's an odd number of cubes to put in a cup of coffee ..."

As everyone knows, Noah built an arc. Here is some additional information about what happened when the animals were getting off ...
Now, the world was pretty well empty of land creatures, so Noah gave all of the animals instructions as they departed.
To the Aardvarks, he commanded, "Go forth and multiply!"
A couple snakes came slithering out, and he commanded, "Go forth and multiply!"
"We can't, we're adders." replied the snakes.
Well, Noah kept giving commands, until at last he told the zebras, "Go forth and multiply!"
A while later he was walking around and stepped over a fallen tree. There were those snakes, well, er ... multiplying.
"I thought you said you couldn't multiply?" asked Noah.
"By logs we can!" replied the adders.

Alternative: When Noah's ark had finally come to a rest on top of mount Ararat, and when the waters had receded, Noah and his family - along with all the animals - left the ark, and God told them to be fruitful and multiply upon the earth. But after all those months under deck on an overcrowded ark, none of the animals was in the mood for sex anymore. Noah, who knew all too well what God could do in his wrath if his creatures were disobedient, got desparate. So, he tore down one of the ark's masts, cut it into pieces, and built a table out of the logs. Then he told one of the snakes to perform a lascivious dance on top of the table and made all the other animals gather around it. After a while the snake's seductive moves showed an effect: One animal after the other started rocking in the rhythm of the snake's dance, and one after the other sneaked off with its mate to more private places ... Finally, the dancing snake and her mate were all alone, and they too disappeared. And Noah was pleased that God's will would be heeded.

So, what does this story from the book of Genesis teach us about math?

When you have to multiply, all you need are a log table and an adder!

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