Bad Math Jokes

[benorin]

So here it is: prove that \lim_{n\rightarrow\infty}\frac{\sin x}{n}=6

Hint: algebra I students may not get the joke, but to them the proof comes easy.

Okay, so let them flow... post 'em if you got 'em [jokes, that is] .

[dx]

I dont get the joke.. Im a calculus student.

[amcavoy]

You divide the sin(x) by n to get six = 6. Wow, that is a new low for math jokes lol.

[jtbell]

Q: Why do computer scientists always confuse Halloween and Christmas?

A: Because 31 OCT(al) = 25 DEC(imal).

[shmoe]

One of my favorites, find:

\int\frac{1}{cabin}d(cabin)


This next one isn't a joke so much as it is a cute poem. What does it say?

\frac{12+144+20+3\sqrt{4}}{7}+5\times 11=9^2+0

[jtbell]

One of my favorites, find:

\int\frac{1}{cabin}d(cabin)


Houseboat! :rofl:

[amcavoy]

One of my favorites, find:

\int\frac{1}{cabin}d(cabin)


This next one isn't a joke so much as it is a cute poem. What does it say?

\frac{12+144+20+3\sqrt{4}}{7}+5\times 11=9^2+0
Help me out here shmoe. :smile:

\int\frac{d\left(\text{cabin}\right)}{\text{cabin} }=\ln{\left(\text{cabin}\right)}

[shmoe]

Well done. Out of a typical first year calculus class, usually one or two students will shout out "log cabin", causing much groaning in the classroom. I then get to proclaim "Close, it's actually a houseboat" and get confused stares. "You forgot the C!" prompts even louder groans, a double whammy.

[amcavoy]

Well done. Out of a typical first year calculus class, usually one or two students will shout out "log cabin", causing much groaning in the classroom. I then get to proclaim "Close, it's actually a houseboat" and get confused stares. "You forgot the C!" prompts even louder groans, a double whammy.
Nice, I like that one.

[shmoe]

I'll put the poem in white below, highlight to see clearly:


A dozen, a gross, and a score,
Plues three times the square root of four,
Divided by seven,
Plues five times eleven,
Is nine squared, and not a bit more

[amcavoy]

I'll put the poem in white below, highlight to see clearly:

A dozen, a gross, and a score,
Plues three times the square root of four,
Divided by seven,
Plues five times eleven,
Is nine squared, and not a bit more
Keep 'em coming :rofl:

[pi-r8]

Here's one I made up
Q: How do you tell that a sailor used to be a mathematician?
A: Instead of saying "aye aye, captain!", he says "negative one, captain!"

[bomba923]

**Warning: this may sound inappropriate, and uses suggestive language !!

Professor to aspiring female math student:
*"HEY!! :eek: How would YOU like to integrate my natural log??"

Female math student-->says: ":yuck:!"

(:rofl: High school humor :rolleyes:)

[fourier jr]

ummmm not sure how that integral makes a houseboat. i get the log cabin part though.

here's my favourite math joke:

\lim_{8\rightarrow9} \sqrt{8} = 3

[kreil]

Q: What is the difference between a mathematician and a computer scientist?

A: A mathematician and a computer scientist work side by side in the basement of a building. Every day, they go up to the second floor at 10am for coffee. One day at 10am, they are both on the first floor and leave to get their coffee. The computer scientist hops in the elevator and goes to the second floor for his coffee. The mathematician, however, gets in the elevator, goes to the basement to reduce the problem to a problem with a known solution, and then goes to the second floor for his coffee.

josh

[kreil]

simplify the expression:

(\frac{1}{m^{-1}})(e^1)(r^2)(\sqrt{y^2})(\frac{d}{dx}\frac{x^2}{ 2})(\frac{force}{acceleration})

[shmoe]

ummmm not sure how that integral makes a houseboat. i get the log cabin part though.

A log cabin + sea (C) = a houseboat

It is indeed a terrible joke.


This is supposedly elementary school humour but I only heard it recently (I'm not in elementary school anymore, but my sense of humour is):

Q: Why was six afraid of seven?
A: Because seven ate nine.

[amcavoy]

simplify the expression:
(\frac{1}{m^{-1}})(e^1)(r^2)(\sqrt{y^2})(\frac{d}{dx}\frac{x^2}{ 2})(\frac{force}{acceleration})
Merry Christmas!

[quasar987]

Wow, nice apmcavoy!

[benorin]

Much like the ski lodge full of girls hunting for husbands and husbands hunting for girls, things aren't always quite as symmetric as they seem. --[I don't remember]

Now when Heisenberg noticed that, he was really scared. --Paul Dirac, Quoted in D MacHale, Comic Sections (Dublin 1993)

...it would be better for the true physics if there were no mathematicians on earth. -- Daniel Bernoulli, Quoted in The Mathematical Intelligencer 13 (1991).

[Upon losing the use of his right eye:] Now I will have less distraction. --Leonhard Euler, Quoted in H Eves In Mathematical Circles (Boston 1969).

I recall once saying that when I had given the same lecture several times I couldn't help feeling that they really ought to know it by now. --John E Littlewood, A Mathematician's Miscellany, 1953.

[tmc]

let epsilon be < 0...

[Hurkyl]

What's an anagram of Banach-Tarski?

Banach-Tarski Banach-Tarski

[quasar987]

I recall once saying that when I had given the same lecture several times I couldn't help feeling that they really ought to know it by now. --John E Littlewood, A Mathematician's Miscellany, 1953.

That is my fav, provided "they" means "his students".

I've seen Dirac's quote on several occasions but I don't understand what's funny with it. :grumpy:

Here's one that's pretty funnny nowdays:

"To divide a cube into two other cubes, a fourth power or in general any power whatever into two powers of the same denomination above the second is impossible, and I have assuredly found an admirable proof of this, but the margin is too narrow to contain it. -- Fermat, in the margin of his copy of Diophantus' Arithmetica"

Another:

"Napier's logarithms, by shortening the labours, doubled the life of the astronomer." --Laplace

and another...

"In science one tries to tell people, in such a way as to be understood by everyone, something that no one ever knew before. But in poetry, it's the exact opposite." --Dirac

[benorin]

Love and Tensor Algebra

Come, let us hasten to a higher plane
Where dyads tread the fairy fields of Venn,
Their indices bedecked from one to n
Commingled in an endless Markov chain!

Come, every frustrum longs to be a cone
And every vector dreams of matrices.
Hark to the gentle gradient of the breeze:
It whispers of a more ergodic zone.

In Riemann, Hilbert or in Banach space
Let superscripts and subscripts go their ways.
Our asymptotes no longer out of phase,
We shall encounter, counting, face to face.

I'll grant thee random access to my heart,
Thou'lt tell me all the constants of thy love;
And so we two shall all love's lemmas prove,
And in our bound partition never part.

For what did Cauchy know, or Christoffel,
Or Fourier, or any Bools or Euler,
Wielding their compasses, their pens and rulers,
Of thy supernal sinusoidal spell?

Cancel me not - for what then shall remain?
Abscissas some mantissas, modules, modes,
A root or two, a torus and a node:
The inverse of my verse, a null domain.

Ellipse of bliss, converge, O lips divine!
the product o four scalars is defines!
Cyberiad draws nigh, and the skew mind
Cuts capers like a happy haversine.

I see the eigenvalue in thine eye,
I hear the tender tensor in thy sigh.
Bernoulli would have been content to die,
Had he but known such a^2 cos 2 phi!


--from "The Cyberiad" by Stanislaw Lem

[devious_]

Complex variables are always fun until someone loses an i.

[Hurkyl]

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


What do you get when you cross a tse-tse fly and a mountan climber?

Nothing! You can't cross a vector with a scalar!

[Hurkyl]

Oh, here's a limerick:


\int_1^{\sqrt[3]{3}} z^2 \, dz \cdot \cos \frac{3 \pi}{9} = \ln \sqrt[3]{e}

[devious_]

Oh, here's a limerick:

\int_1^{\sqrt[3]{3}} z^2 \, dz \cdot \cos \frac{3 \pi}{9} = \ln \sqrt[3]{e}

Wow... :rofl:

[AKG]

Oh, here's a limerick:


\int_1^{\sqrt[3]{3}} z^2 \, dz \cdot \cos \frac{3 \pi}{9} = \ln \sqrt[3]{e}

I don't get it.

[fourier jr]

ya me neither. & that cabin joke is actually pretty bad now that i get it. :rolleyes:

[AKG]

I thought this was funny:

In his lecture, ** (some professor) formulated a theorem and said: "The proof is obvious". Then he thought for a minute, left the lecture room, returned after 15 minutes and happily concluded: "Indeed, it is obvious!"

From here (http://www.math.utah.edu/~cherk/mathjokes.html)

[devious_]

I don't get it.
I think it says:

The integral from 1 to the cube root of three
Of zee squared dee zee
Times the cosine of 3pi by nine
Equals the log of the cube root of e

[spongebob_79]

I like this one...

"Did you hear about the constipated mathmatician?"

"He had to work it out with a pencil!!"


Or along similar lines...

"Did you hear about the constipated accountant?"

"He couldnt budget, so he had to use a pencil!!"

tee hee:rofl:

[Hurkyl]

The integral from 1 to the cube root of three
Of zee squared dee zee
Times the cosine of 3pi by nine
Equals the log of the cube root of e
That works -- when I originally heard it, it was pronounced:

The integral of the square of 'z',
From one to the cube root of three,
Multiplied by cosine,
Of three pi over nine,
Is the log of the cube root of 'e'.

I think it's a little more poetic this way, but yours is good too! Actually, I fiddled with it a bit to see if I could get it a bit more rhythmic (since it seems a bit clumsy to me), but without success.

[mathwonk]

these are sad.

[mattmns]

Well done. Out of a typical first year calculus class, usually one or two students will shout out "log cabin", causing much groaning in the classroom. I then get to proclaim "Close, it's actually a houseboat" and get confused stares. "You forgot the C!" prompts even louder groans, a double whammy.
ROFL!!! Were you my high school math teacher? :rofl: :smile:

[Quadratic]

One time, I was just standing around in the school hallway, and I overheard three people debating over something. They eventually found that one of them was right, and the others complimented each other's efforts. I interrupted their conversation and told them that they were just like the angles in a right triangle, and everyone looked at me like I was crazy or something. (One is right, and the others compliment each other)

Regarding that Sin(x)/n=6 thing, it made me think about the secant of x devided by c...

That works -- when I originally heard it, it was pronounced:
The integral of the square of 'z',
From one to the cube root of three,
Multiplied by cosine,
Of three pi over nine,
Is the log of the cube root of 'e'.
I think it's a little more poetic this way, but yours is good too! Actually, I fiddled with it a bit to see if I could get it a bit more rhythmic (since it seems a bit clumsy to me), but without success.
That's awesome! My only issue is that it wouldn't really work where I live, since "z" isn't pronounced with an "eee" sound here.

[Paulanddiw]

Great limit joke!

I suppose when a log cabin goes to sea (C) it's a house boat.

[fourier jr]

That's awesome! My only issue is that it wouldn't really work where I live, since "z" isn't pronounced with an "eee" sound here.

yeah that was my problem, we say zed here

[quasar987]

French fourier_jr?

[fourier jr]

no, canadian

[Quadratic]

French fourier_jr?
I'm pretty sure the US is the only english-speaking country that pronounces it as "zee". It's just like the spelling of colour, flavour, etc., and the way the word "schedule" is pronounced. When I first saw a "Lay-Z-Boy" store, I was like "... huh?". Anyway, just change the z into something like T or B, and the poem works just fine all around. :smile:

[benorin]

Q: Why do computer scientists always confuse Halloween and Christmas?
A: Because 31 OCT(al) = 25 DEC(imal).

C really is a great programming language. I mean, without it, we would be coding in BASI, OBOL, and PASAL.

[benorin]

Excuse me professor, but I think I've found a counter-example.
That's ok, I've got two proofs.

[Jimmy Snyder]

When the math lecture has you drowning in a sea of abstraction, ask the professor to toss you a concrete life preserver.

[quasar987]

no, canadian
Which university?

[fourier jr]

Which university?
uvic, aka university of victoria (i hope that's more than 10 characters)

[quasar987]

Oh! What are you doing so far from Quebec and speaking French? Are you lost? :biggrin:

[Quadratic]

People are right about my sense of humour: it has 180 degree symmetry about the origin. :rofl:

[neutrino]

This is |BS|!

[Galileo]

My grades are always complex. They have a real and an imaginary part.

[Bob3141592]

"Have solved the Riemann Hypothesis" - G.H. Hardy

For anyone here who doesn't know the story, Hardy wrote this on a postcard to a colleague just before embarking on a stormy sea voyage. Hardy (an atheist) felt God wouldn't allow him to perish with such a claim to fame.

[Pseudo Statistic]

So, e^x the exponential function was walking down the street one day.. when he sees a running constant...
"AAHHH!!! THE DIFFERENTIAL OPERATOR IS COMING!!!" screamed the constant
"Hah, I'm not afraid of him, unlike you he can't change me!"
e^x looks into the far distance only to notice the differential operator on his way....
Once he gets close to e^x...
"Hey there!"
The differential operator lets out his hand..
"Hello, I'm d/dt!"

Got it off some site... but it was explained differently.

[fourier jr]

"Have solved the Riemann Hypothesis" - G.H. Hardy
For anyone here who doesn't know the story, Hardy wrote this on a postcard to a colleague just before embarking on a stormy sea voyage. Hardy (an atheist) felt God wouldn't allow him to perish with such a claim to fame.
yeah i think that's kind of a reference to fermat who left his note in the margin of a book saying... well everyone knows that. hilbert said if he were to wake up after sleeping for 1000yrs the 1st thing he'd do is ask whether the riemann hypothesis has been proven or not. i think i'd do what austin powers did, take a huge pee. :cool:

[JesseM]

Got it off some site... but it was explained differently. Here's a more elaborate version (the longer setup makes it funnier, IMO) I found here (http://homepage.mac.com/ehgoins/iblog/B335600579/C307790143/E20050730135430/index.html): The cocky exponential function e^x is strolling along the road insulting the functions he sees walking by. He scoffs at a wandering polynomial for the shortness of its Taylor series. He snickers at a passing smooth function of compact support and its glaring lack of a convergent power series about many of its points. He positively laughs as he passes |x| for being nondifferentiable at the origin. He smiles, thinking to himself, "Damn, it's great to be e^x. I'm real analytic everywhere. I'm my own derivative. I blow up faster than anybody and shrink faster too. All the other functions suck."

Lost in his own egomania, he collides with the constant function 3, who is running in terror in the opposite direction.

"What's wrong with you? Why don't you look where you're going?" demands e^x. He then sees the fear in 3's eyes and says "You look terrified!"

"I am!" says the panicky 3. "There's a differential operator just around the corner. If he differentiates me, I'll be reduced to nothing! I've got to get away!" With that, 3 continues to dash off.

"Stupid constant," thinks e^x. "I've got nothing to fear from a differential operator. He can keep differentiating me as long as he wants, and I'll still be there."

So he scouts off to find the operator and gloat in his smooth glory. He rounds the corner and defiantly introduces himself to the operator. "Hi. I'm e^x."

"Hi. I'm d / dy."

[abelian]

...and impure mathematics =D

http://bash.org/?450693/

[fourier jr]

that was published first in http://www.maledicta.org vol III #1 which came out in 1979. it's very old. (but funny)

[MajikWaffle]

These are funny too me o_O

Not really math, but amusing non the less

Q: Why couldnt the anarchist draw a straight line?

A: Because he didnt have a ruler

[spongebob_79]

ok, not really math, but funny nonetheless

2 atoms were walking down the street. One says to the other "oh no, i think i have lost a electron"

The other says "are yout sure?"

To which the first replies "Yes, im positive!"

[uart]

Three Statisticians went on a hunting trip. They came over a rise and saw a rabbit sitting on the next hill.

The first one aimed his rifle and said "Just watch, I'll get him", but he shot way too low with the bullet landing well short of the rabbit.

The second one said "Ok he's mine now, I'll get him", but he aimed way too high with the bullet passing well over the rabbits head.

The third statistician immediately leapt in the air with excitement and cried out "We got him!".

[Galileo]

Not so much a joke as a brainteaser.

Three prisoners, strangers to each other, were suspects of a murder case. One day they came to hear that a sentence has been drawn. Two of them have been found guilty and will be executed, but they don't know which of the two . One guy, a statistician, figures his chances for survival are 1/3, so he goes to the bars of his cell and hails the guard: "Hey psst, do you know which of us has been sentenced?".
"Eh, yes.", says the guard, "But I'm not allowed to tell you.".
"Tell you what", says the guy, "I already know that 2 of us will executed, that means at least one of the other guys will be. I don't know them or anything, surely you can point to one which is guilty?". The guard sees no harm in that and points one of the prisoners, "He is guilty".
"Thanks!", proclaims the statistician, "my chances have just increased to 1/2".

[Reshma]

OK, here is another bad math joke:

What do you get when you cross a Pig and a Rat?

Answer: \mbox{Pig Rat}\sin \theta \hat n
:rofl:

[Joffe]

Thats an interesting puzzle Galileo, had me confused for a moment.

[Galileo]

A 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 ..."

Sad, but true:
The Evolution of Math Teaching

1960s: A peasant sells a bag of potatoes for $10. His costs amount to 4/5 of his selling price. What is his profit?
1970s: A farmer sells a bag of potatoes for $10. His costs amount to 4/5 of his selling price, that is, $8. What is his profit?
1970s (new math): A farmer exchanges a set P of potatoes with set M of money. The cardinality of the set M is equal to 10, and each element of M is worth $1. Draw ten big dots representing the elements of M. The set C of production costs is composed of two big dots less than the set M. Represent C as a subset of M and give the answer to the question: What is the cardinality of the set of profits?
1980s: A farmer sells a bag of potatoes for $10. His production costs are $8, and his profit is $2. Underline the word "potatoes" and discuss with your classmates.
1990s: A farmer sells a bag of potatoes for $10. His or her production costs are 0.80 of his or her revenue. On your calculator, graph revenue vs. costs. Run the POTATO program to determine the profit. Discuss the result with students in your group. Write a brief essay that analyzes this example in the real world of economics.

Math problems? Call 1-800-[(10x)(13i)2]-[sin(xy)/2.362x].

Let the lameness commence! :devil:

Q: What's yellow, linear, normed and complete?
A: A Bananach space.

Q: What's yellow and equivalent to the Axiom of Choice.
A: Zorn's Lemon.

[Palindrom]

You people are sad...:rofl:

Allow me to join you.:biggrin:


A mathematician, a physicist and a chemist are watching an empty house.
About ten minutes to their watch, they see two people go inside the house. All three of them write it down, and continue watching, when at their surprise, ten more minutes later, three people are seen leaving the house.
The biologist then says, "Well, there was probably someone inside and we didn't know about it".
The physicist replies, "No, no, it is a common mistake of measurement".
The mathematician looks at them both and states, "If one man were to enter the house now, it would be empty!".

[NateTG]

"Thanks!", proclaims the statistician, "my chances have just increased to 1/2".

Must be a Baysian.

[Physics Monkey]

At a party:

What do you do?
I'm interested in topology.
Oh, so you study maps?
Only continuous ones.

[LeonhardEuler]

Not so much a joke as a brainteaser.
Three prisoners, strangers to each other, were suspects of a murder case. One day they came to hear that a sentence has been drawn. Two of them have been found guilty and will be executed, but they don't know which of the two . One guy, a statistician, figures his chances for survival are 1/3, so he goes to the bars of his cell and hails the guard: "Hey psst, do you know which of us has been sentenced?".
"Eh, yes.", says the guard, "But I'm not allowed to tell you.".
"Tell you what", says the guy, "I already know that 2 of us will executed, that means at least one of the other guys will be. I don't know them or anything, surely you can point to one which is guilty?". The guard sees no harm in that and points one of the prisoners, "He is guilty".
"Thanks!", proclaims the statistician, "my chances have just increased to 1/2".
Alright, this is killing me! Can someone please explain it!

[ranger]

Sad, but true:
The Evolution of Math Teaching
1960s: A peasant sells a bag of potatoes for $10. His costs amount to 4/5 of his selling price. What is his profit?
1970s: A farmer sells a bag of potatoes for $10. His costs amount to 4/5 of his selling price, that is, $8. What is his profit?
1970s (new math): A farmer exchanges a set P of potatoes with set M of money. The cardinality of the set M is equal to 10, and each element of M is worth $1. Draw ten big dots representing the elements of M. The set C of production costs is composed of two big dots less than the set M. Represent C as a subset of M and give the answer to the question: What is the cardinality of the set of profits?
1980s: A farmer sells a bag of potatoes for $10. His production costs are $8, and his profit is $2. Underline the word "potatoes" and discuss with your classmates.
1990s: A farmer sells a bag of potatoes for $10. His or her production costs are 0.80 of his or her revenue. On your calculator, graph revenue vs. costs. Run the POTATO program to determine the profit. Discuss the result with students in your group. Write a brief essay that analyzes this example in the real world of economics.


I got a kick from that one :rofl: :rofl:

[jim mcnamara]

Back to pathetic:

Pi r squared.
No.
Pi r circles.

[uart]

Originally Posted by Galileo
Not so much a joke as a brainteaser.
Three prisoners, strangers to each other, were suspects of a murder case. One day they came to hear that a sentence has been drawn. Two of them have been found guilty and will be executed, but they don't know which of the two . One guy, a statistician, figures his chances for survival are 1/3, so he goes to the bars of his cell and hails the guard: "Hey psst, do you know which of us has been sentenced?".
"Eh, yes.", says the guard, "But I'm not allowed to tell you.".
"Tell you what", says the guy, "I already know that 2 of us will executed, that means at least one of the other guys will be. I don't know them or anything, surely you can point to one which is guilty?". The guard sees no harm in that and points one of the prisoners, "He is guilty".
"Thanks!", proclaims the statistician, "my chances have just increased to 1/2".


Alright, this is killing me! Can someone please explain it!

His chances have not changed as no new information (that would change the statics) was really added by the guards revelation.

One thing I do find weird about this problem is how two people whom have never meet can both be found guilty of the same murder. That's some pretty whacky justice system.

[GregA]

I don't really have much knowledge of stats and so I apologise if this seems like a stupid reply but I just have to chip in...

the three prisoners each have a 1/3 chance of survival...the guard however has just informed one prisoner that a different prisoner's chance of survival just dropped from 1/3 to 0/3...already the system has been changed no?
Also from the perspective of the statistician, before he found out who was doomed, the dice was weighted equally for all of them but now he can look at one prisoner and be absolubtely sure that his presence can have no effect on the outcome. (if we call the three prisoners A,B and C.., from C's perspective before speaking to the guard there are three people in the game. 'A' might die, but then again there is a chance that his luck is in and it will be B and C that die...knowing that 'A' is dead though, means there are only two people left in the game) thus his chances should be 1/2 no? (unless the guard is lying)
As I said earlier...my apologies If I am talking garbage

edit: had this discussion with a wiser person than myself and now know why I am wrong :)

[Denryoku]

Alright, this is killing me! Can someone please explain it!

Hi, this is my first post :biggrin:

I'm not really sure about this, but I agree with uart that no new significant information was given by the guard. I think the problem is in the way the prisoner simply eliminated the guy pointed by the guard from his reasoning.

Since we have no information about who commited the crime (or how the justice system works), we assume each one to have an equal chance of survival. At the beginning its clear that any given prisoner has a 1/3 chance of being declared innocent.

Later, one prisoner (say, prisoner A) asks the guard to point one of the other guys who is guilty. So he points one of the two suspects that will executed (lets say, prisoner B). Now A can figure his chances of survival using Bayes' theorem as follows:

P(A is innocent | B was pointed) = P(B was pointed | A is innocent) * P(A is innocent) / [ P(B was pointed | A is innocent) * P(A is innocent) + P(B was pointed | A is guilty) * P(A is guilty) ]

-The probability of B being pointed by the guard given that A is innocent is 1/2 (if A is innocent then the other two are guilty, but the guard had to point only one of them)
-The chances of A being innocent are still 1/3
-The probability of B being pointed by the guard given that A is guilty is, again 1/2 (since A is guilty, only one of the other two prisoners is guilty and thus was signaled by the guard; but we have no information to determine which one)
-The probability of A being guilty is 1 - 1/3 = 2/3

So the chances of A being innocent given that B was signaled by the guard are: (1/2 * 1/3) / (1/2 * 1/3 + 1/2 * 2/3) = 1/3 (not 1/2)


Well, back to the main topic... taken from http://www.xs4all.nl/~jcdverha/scijokes/1_6.html:

A bunch of Polish scientists decided to flee their repressive
government by hijacking an airliner and forcing the pilot to fly them
to a western country. They drove to the airport, forced their way on
board a large passenger jet, and found there was no pilot on board.
Terrified, they listened as the sirens got louder. Finally, one of
the scientists suggested that since he was an experimentalist, he
would try to fly the aircraft.

He sat down at the controls and tried to figure them out. The sirens
got louder and louder. Armed men surrounded the jet. The would be
pilot's friends cried out, "Please, please take off now!!! Hurry!!!!!"

The experimentalist calmly replied, "Have patience. I'm just a simple
pole in a complex plane."

[murshid_islam]

don't know whether this one's posted already:

a mathematician is one who cannot tell a teapot from a doughnut.

[fourier jr]

don't know whether this one's posted already:
a mathematician is one who cannot tell a teapot from a doughnut.
i think you mean coffee cup and a doughnut, since a teapot has 2 handles while a doughnut has only 1 :wink: :tongue2:

[murshid_islam]

i think you mean coffee cup and a doughnut, since a teapot has 2 handles while a doughnut has only 1 :wink: :tongue2:

well, the teapots i have seen have only one handle. anyway, the point is that both a doughnut and a teapot with one handle (or a coffee cup) has one hole in it. in the doughnut, the hole is in the middle, whereas in the coffee cup, it is in the handle.

[benorin]

don't know whether this one's posted already:
a mathematician is one who cannot tell a teapot from a doughnut.

That sounds more like a topologist.

[NateTG]

well, the teapots i have seen have only one handle. anyway, the point is that both a doughnut and a teapot with one handle (or a coffee cup) has one hole in it. in the doughnut, the hole is in the middle, whereas in the coffee cup, it is in the handle.

I think we have a new candidate -- "A topologist is someone who thinks that most teapots have two handles."

Most teapots I am familiar with have two holes (or handles) in them. One that your fingers go through, and the other that tea goes through.

[hypermorphism]

The spout for the tea is not equivalent to a handle (a torus with a disc removed). If anything, the teapot (without the lid) would be equivalent to a (circular) cylinder with a handle attached. The equivalence of the coffee cup and the donut has less ambiguity. :)

[shmoe]

The spout for the tea is not equivalent to a handle (a torus with a disc removed). If anything, the teapot (without the lid) would be equivalent to a (circular) cylinder with a handle attached. The equivalence of the coffee cup and the donut has less ambiguity. :)

A teapot is a two handled coffee cup. If your cylinder+handle hopes to be a teapot then the cylinder part has thickness, i.e. a 3 dimensional volume (like a coffee cup with a hole in the bottom). This can be deformed into a two handled coffee cup for safety purposes or into a two holed donut for delicousness.

Think of the classification theorem of compact connected orientable 2-manifolds without boundary (did I get everything?). The surface of the teapot is one of these, hence it's either a sphere or torus with some number of handles.

[podboy6]

Worst math joke ever:

"Okay, when you rotate a conic section, you slap on -iod to the end of its name, i.e, paraboloid, hyperboloid, ellipsiod, ect...

Okay, what do you get when you rotate a human?

A humaniod."

[uart]

Hi, this is my first post :biggrin:
Since we have no information about who commited the crime (or how the justice system works), we assume each one to have an equal chance of survival. At the beginning its clear that any given prisoner has a 1/3 chance of being declared innocent.
Later, one prisoner (say, prisoner A) asks the guard to point one of the other guys who is guilty. So he points one of the two suspects that will executed (lets say, prisoner B). Now A can figure his chances of survival using Bayes' theorem as follows:
P(A is innocent | B was pointed) = P(B was pointed | A is innocent) * P(A is innocent) / [ P(B was pointed | A is innocent) * P(A is innocent) + P(B was pointed | A is guilty) * P(A is guilty) ]
-The probability of B being pointed by the guard given that A is innocent is 1/2 (if A is innocent then the other two are guilty, but the guard had to point only one of them)
-The chances of A being innocent are still 1/3
-The probability of B being pointed by the guard given that A is guilty is, again 1/2 (since A is guilty, only one of the other two prisoners is guilty and thus was signaled by the guard; but we have no information to determine which one)
-The probability of A being guilty is 1 - 1/3 = 2/3
So the chances of A being innocent given that B was signaled by the guard are: (1/2 * 1/3) / (1/2 * 1/3 + 1/2 * 2/3) = 1/3 (not 1/2)
:

Ouch Denryoko, I really think it can be put a lot more simply than that :). You're right to use Bayes thm with this type of problem however I'd prefer to tackle it as follows,

Define the events as follows,
Event A : Person asking guard is innocent.
Event B : Person picked out by guard is guilty.

The reason why this one is so simple is that P(B)=1 because it is given as data!!!!

Now since P(B)=1, it is trivial that P(A and B) = P(A) hence Bayes theorem gives,

P(A | B) = P(A and B) / P(B) = P(A)

That is, the probability of event A given that event B has occurred is identical with the original probability of event A, so it remains at 1/3. This is really a trivial application of Bayes in this case.

---------------------------------

It's interesting to note that if you change the problem so that the guard does not have to pick guilty but instead selects one of the other two at random to reveal that persons fate (say by withdrawing a name from a hat or whatever) then you do end up with a non-trivial application of Bayes thm. In this case then the probability of the original guy's innocence does indeed rise from 1/3 up to 1/2 if the guard reveals one of the other two to be guilty. Using the same event definitions as above you now get the following,

P(A and B) = P(A), because if the original person is innocent then both the other two are guilty so the name withdrawn from the hat (or whatever) must be guilty.

This time however P(B) is not equal to unity but is instead P(B)=2/3.

So Bayes thm results in,

P(A | B) = P(A and B) / P(B) = 1/3 divide 2/3 = 1/2

I hope that helps anyone who was still unsure about that one.

[biggins]

:smile: alcohol and calculus don't mix, don't drink and derive.:rofl:

[Lisa!]

A real mathematician is someone who writes 'A', then read it 'B', but actually he means 'c'.:tongue2:

[benorin]

I'm supposed to prove the freshman’s dream identity,

\left( a + b\right) ^p \equiv a^p + b^p \left( \mbox{mod }p\right)

for p prime.

Can't I just use the binomial theorem? j/k

[benorin]

How they 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.

Professor: 3 is prime, 5 is prime, 7 is prime, and the rest are left as an exercise for the student.

Physicist: 3 is a prime, 5 is a prime, 7 is a prime, 9 is an experimental error, 11 is a prime,...

Engineer: 3 is a prime, 5 is a prime, 7 is a prime, 9 is a prime, 11 is a prime,...

Programmer: 3 is a prime, 5 is a prime, 7 is a prime, 7 is a prime, 7 is a prime,...

Salesperson: 3 is a prime, 5 is a prime, 7 is a prime, 9 -- we'll do for you the best we can,...

Computer Software Salesperson: 3 is prime, 5 is prime, 7 is prime, 9 will be prime in the next release,...

Biologist: 3 is a prime, 5 is a prime, 7 is a prime, 9 -- results have not arrived yet,...

Advertiser: 3 is a prime, 5 is a prime, 7 is a prime, 11 is a prime,...

Lawyer: 3 is a prime, 5 is a prime, 7 is a prime, 9 -- there is not enough evidence to prove that it is not a prime,...

Accountant: 3 is prime, 5 is prime, 7 is prime, 9 is prime, deducing 10% tax and 5% other obligations.

Statistician: Let's try several randomly chosen numbers: 17 is a prime, 23 is a prime, 11 is a prime...

Computational linguist: 3 is an odd prime, 5 is an odd prime, 7 is an odd prime, 9 is a very odd prime,...

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

I coppied this from here (http://www.workjoke.com/projoke22.htm).

[Galileo]

A real mathematician is someone who writes 'A', then read it 'B', but actually he means 'c'.:tongue2:
Sounds like my professor. He writes A, says B, means C, while the answer is D.

[hypermorphism]

...
Think of the classification theorem of compact connected orientable 2-manifolds without boundary (did I get everything?). The surface of the teapot is one of these,...
Ah, then you're including the fact that the teapot contains a non-zero 3-dimensional volume, or the surface of a 3-dimensional manifold analogous to a teapot. I was thinking of a 2-dimensional manifold analogous to a teapot, in that the handle was attached to a sphere with two discs removed. In that case, my teapot does have a boundary, but yours doesn't. :smile:

[uart]

prove the identity,
\left( a + b\right) ^p \equiv a^p + b^p \left( \mbox{mod }p\right)
for p prime.
Can't I just use the binomial theorem? j/k

What's wrong with using the binomal theorem there ?

[Lisa!]

Here's my favorite! (http://www.physicsforums.com/showpost.php?p=805754&postcount=268):cool:
Sounds like my professor. He writes A, says B, means C, while the answer is D.
But he must be a bad mathematician since he doesn't get the answer!:tongue:

[AlphaNumeric]

My first post here :)

Q : Why didn't didn't Cauchy like taking his dog for a walk?

A : It kept leaving residues at all the poles.

This (http://movies.collegehumor.com/items/2005/05/collegehumor.149448.wmv) song cracks me up. I expected it to be cheesy as hell, but the amount of puns they fit in is very impressive.

[Cexy]

What's purple and commutes?

An abelian grape.




What's purple, and worshipped by only a limited number of people?

A finitely venerated abelian grape.

[Alkatran]

For this statistical problem, why are we going all the way into Bayes theorem? We can just distinguish between the three available cases, being:

A goes free
B goes free
C goes free

Each is just as likely until the guard points out that B isn't going free, so then you have:

A goes free
C goes free

being equally likely.

But lets assume the probability is still a third. Given that we know that B is not going free and that the sum of all the probabilities should equal to 1...

P(A) + P(B) + P(C) = 1
1/3 + 1/3 + 0 = 1
2/3 = 1
contradiction

This sounds a lot like that case with the chance of the 'other child being a boy' is really non-intuitive.

[alfredblase]

Not so much a joke as a brainteaser.
Three prisoners, strangers to each other, were suspects of a murder case. One day they came to hear that a sentence has been drawn. Two of them have been found guilty and will be executed, but they don't know which of the two . One guy, a statistician, figures his chances for survival are 1/3, so he goes to the bars of his cell and hails the guard: "Hey psst, do you know which of us has been sentenced?".
"Eh, yes.", says the guard, "But I'm not allowed to tell you.".
"Tell you what", says the guy, "I already know that 2 of us will executed, that means at least one of the other guys will be. I don't know them or anything, surely you can point to one which is guilty?". The guard sees no harm in that and points one of the prisoners, "He is guilty".
"Thanks!", proclaims the statistician, "my chances have just increased to 1/2".

No no no. Think of it like a bag of balls, hahaha :P. What I mean is there are three balls in his bag...odd..., the stats guy is cupping one ball in his hand... Since balls are indistinguishable he removes one of the others, ouch, and then he has two balls so hes happy! see?... oh lets face it I only put this post up for the crummy balls gag...

But seriously I'm still confused by this, emm its a 0.5 probability all along isn't it? He knows one of the others is guilty without asking the guard. The probability that either he or one of the other two prisoners is going to be executed is equal to one. Since this system has only two balls, about and both are equally likely to be innocent then the chances of innocence are 0.5 for each. He wrongly calculated his chances of survival in the first place, and asking the guard further compunded his stupidity.

[amcavoy]

My first post here :)
Q : Why didn't didn't Cauchy like taking his dog for a walk?
A : It kept leaving residues at all the poles.
This (http://movies.collegehumor.com/items/2005/05/collegehumor.149448.wmv) song cracks me up. I expected it to be cheesy as hell, but the amount of puns they fit in is very impressive.
Nice video lol.

[Joffe]

No no no. Think of it like a bag of balls, hahaha :P. What I mean is there are three balls in his bag...odd..., the stats guy is cupping one ball in his hand... Since balls are indistinguishable he removes one of the others, ouch, and then he has two balls so hes happy! see?... oh lets face it I only put this post up for the crummy balls gag...
But seriously I'm still confused by this, emm its a 0.5 probability all along isn't it? He knows one of the others is guilty without asking the guard. The probability that either he or one of the other two prisoners is going to be executed is equal to one. Since this system has only two balls, about and both are equally likely to be innocent then the chances of innocence are 0.5 for each. He wrongly calculated his chances of survival in the first place, and asking the guard further compunded his stupidity.

Actually posting that just compounds your stupidity (joking). For anybody who cannot see, the main man still has a 1/3 chance of survival, the known guilty guy has a 0 chance and the other a 2/3 chance. It has already been explained so I won't bother.

[Alkatran]

Actually posting that just compounds your stupidity (joking). For anybody who cannot see, the main man still has a 1/3 chance of survival, the known guilty guy has a 0 chance and the other a 2/3 chance. It has already been explained so I won't bother.

Hold on, how is the other guy any different than the current one? In the context of the problem the only difference is who asked the question!

[alfredblase]

exactly (all I wanted to say was exactly)

[Joffe]

Hold on, how is the other guy any different than the current one? In the context of the problem the only difference is who asked the question!

The guy who asked the question differs from the other because he was not involved in the selection. Imagine it this way, there are a thousand people and all but one are guilty, I could ask the guard which 998 of the others are guilty and it would narrow it down to me and one other guy, obviously the other guy has a much greater chance of running free.

[alfredblase]

no, your argument is lame

[Cexy]

no, your argument is lame
Only if you 'lame' you mean 'correct'

This is a version of the Monty Hall problem, explained here:

http://www.comedia.com/hot/monty.html

[alfredblase]

bah not convinced, I trust my argument and the judgment of Alkatran over yours, Joffe's and that random webpage. I sahll repeat my argument for the readers benefit.

Before he asks the guard he knows one of the other prisoners is guilty. He can discard that prisoner from the system. He is left with himself and one of the other prisoners; 1 prisoner + 1 prisoner = 2 prisoners. Since the chances of survival are equal for both, and since one of them is going to be executed, then the probability of survival = 1/2.

He could have calculated all of this BEFORE asking the guard. Now when he asks the guard all he is doing is discarding one of the prisoners, something he could have done before asking him. So the calculation of his chances of survival remains the same, i.e he has a fifty percent chance of survival. His chances of survival were 0.5 all throughout the story. Nuff said.

[Alkatran]

The guy who asked the question differs from the other because he was not involved in the selection.

I understand now. A has more information, but it doesn't help his odds, it helps the other inmate's odds. To make sure of this, I wrote a simple little program:


int main() {
int a, b, n;
int data[3];
int asum = 0, osum = 0;
#define size 1000
for (b = 0; b < size; b++) {
for (a = 0; a < 3; a++)
data[a] = 0;
for (a = 0; a < 2; a++)
do {
n = (int)(rand() * 2);
} while (data[n] = 1)

osum += (data[2] == 1) ? data[1] : data[2];
aSum += data[0]
}
printf("Asker chance: %f, other chance: %f\n", asum, osum)
return 0;
}


The output makes it pretty clear: the asker dies 2/3 of the time and the one who isn't pointed to dies 1/3 of the time.

[Martin Rattigan]

When I first read the explanation I thought it meant C+log cabin i.e. a place where Dutchmen live.

[alfredblase]

OMG this is a great "brain teaser" and I think it contains something very deep about statistics. Like a good little physicist after my ally alkatran left me all alone I decided to experiment. The results are conclusive. I describe the experiment in the following paragraph. Please repeat the experiment yourself.

I made three squares and labelled two with a G for guilty, and one with an I for innocent, then folded them, then put them in a hat. There were three very little squares in the hat. So if I were to pick one of the squares and assign that to the main man, and I repeated the experiment 100 times, roughly 1/3 times the main man would be innocent.

Now I take one of the squares out and assign it to the main man. I dont look at the paper. Now I play the part of the guard. So I look at both papers remaining and remove one with G on it from the hat. Now I put the main mans paper back in the hat along with the other paper the guard didnt remove. What am I left with? One paper with I and one paper with G. This would be the outcome every time no matter how many times I repeat the excersise. If I were to then remove one paper and assign it to the main man, and repeated the experiment 100 times, roughly half the time the main would be guilty and roughly half the time innocent. There's no argument against this experiment is there??

So wow, statistics is odd.

[benorin]

Kronecker Delta Function Song (http://www.haverford.edu/physics-astro/songs/kronecker_master.htm)

[rachmaninoff]

Just to clarify, a 2-teapot is homeomorphic to the surface of a torus. If you remove the lid, it's the surface of a double torus*.

*which has very interesting homotopy groups, I'm trying to calculate them right now...

[Your.Master]

Actually, you can argue with your experiment, because you did it wrong.

To explain your problem: IF the main man is guilty (1/3 of the time), then only one of the other guys is guilty, and the guard HAS to point to him. He will point at him 100% of the time. So 1/3 of the time this situation occurs, and the not-pointed-to guy gets off free. Your experiment, however, does not account for the fact that the guilty man must always be chosen: your experiment has the guard choosing among the other two ~50/50 ALL the time.

Let us analyse that. This case, which obviously occurs 1/3 of all times (and as is borne out by your experiment with no removals), leads to the not-pointed-to, not-main guy being innocent. The main guy is, by assumption, guilty.

IF the main man is not guilty (2/3 of the time), then the other guys are BOTH guilty. The guard can point at either of the other men. Now the odds are 50/50 which of these two will be selected.

Let us analyse this. This case, which occurs the other 2/3 of all times, leads to the not-pointed-to, not-main-guy as being guilty. The main guy is, by assumption, not guilty.

THEREFORE, the not-pointed-to guy is guilty 1/3 of the time, the pointed-to guy is guilty ALL the time, and the main man is guilty 2/3 of the time.

Or think of it like this, in a much less-rigorous way: all three have a 2/3 chance of being guilty to start with. When the guy is pointed-to, he gets an additional 1/3 chance of being guilty. Somebody has to donate that 1/3 chance, and that has the other guy, since the guard was NEVER going to point at you so you weren't involved in that selection.

Or simply: If main guy is guilty, then the guy not pointed to is always innocent. Therefore, if you are NOT the main guy AND the guard doesn't point at you, you've increased the chances that YOU are innocent -- if you were guilty, he'd point at you half the time, if you were not guilty, he'd NEVER point at you, and combine half with never and you get something LESS than half.

A more analogous experiment that you could try is to pick the innocent guy out of the hat FIRST, then remove one of the guilty, non-main guys, then see how often the main guy was innocent and how often the not-pointed-to not-main guy was innocent. After all, in the example, the guard knew which one was innocent even before the main guy asked.

Even better, if you know anything about computer programming, you can make a simple program to convince you. The program randomly determines who is guilty, and you play the role of the main guy. You hit enter, the computer tells you (choosing at random if necessary) one of the other guys who is guilty, then you hit enter again and see who is actually guilty. There's one already made here:

http://chrisc.freeshell.org/random/pages/montyhall.html

ALTHOUGH given your bias against random webpages it could just be a conspiracy to give you the wrong answer and not ACTUALLY an instantiation of the code shown on that page.

-----

Before ignoring a website as "random" you might want to read what it says -- it does not matter how credible that site is, if the reasoning is sound.

But maybe you trust wikipedia more? http://en.wikipedia.org/wiki/Monty_Hall_problem

Or a math site?
http://mathforum.org/dr.math/faq/faq.monty.hall.html
http://mathworld.wolfram.com/MontyHallProblem.html

Or the site whose very URL refers to the problem in question?
http://www.montyhallproblem.com/

Honestly, I'm not sure what kind of website you were expecting. The CIA?

In general, don't believe everything you see on the Internet, but also don't disbelieve everything just because it's on the Internet, at least not without a second look when a majority of people are telling you you are wrong.

[BobG]

bah not convinced, I trust my argument and the judgment of Alkatran over yours, Joffe's and that random webpage. I sahll repeat my argument for the readers benefit.

But, surely you have to trust Marilyn Mach vos Savant! She holds the record for the highest IQ score, ever. :biggrin:

See the discussion under Marilyn is tricked by a game show host (http://www.wiskit.com/marilyn.html) or check the link titled "Behind Monty Hall's Doors" towards the bottom of the page.

Edit: Oops, my bad. I inadvertantly directed you to the "Marilyn is Wrong!" website with link above. I meant to direct you to the "Marilyn is Right!" (http://www25.brinkster.com/ranmath/marlright/) website - check out "The Monty Hall Problem".

[alfredblase]

Ok I read a few of those sites, I can see the argument but I disagree with it. And you can't argue that someone wrote a program "proving" anything. The program is based on your understanding of the problem. If you have a preconcieved way of setting up the problem in programing language, then of course the program will give you the answer you imagined it would. I think one of the links from the wikipedia article you gave me, although arguing against my opinion, illustrates how a reasonable argument could be set up arguing for my point of view.

http://www.angelfire.com/trek/nfold/monty.html

This is my version of his over easy proof. The player chooses A at first.

..............A.....B....C
case 1.....0....(0....1)
case 2.....0....(1....0)
case 3.....1....(0....0)
case 4.....1....(0....0)

case 1: Monty opens B, switch succeeds
case 2: Monty opens C, switch succeeds
case 3: Monty opens B, switch fails
case 4: Monty opens C, switch fails

In two out of the four cases the switch succeeds, and in 2/4 cases the switch fails. So there.

Anyway, the ONLY way to really know for sure is to carry out an EXPERIMENT like physicists do. Not using a computer program but setting up the scenario physically say 1000 times and seeing the results. I still cant see how my experiment wasn't ok; I think you misunderstood what I wrote or something... it seems perfectly simple to me.

I mean FGS!!! if someone offers you a choice between two doors (that is what is done when you are offered the chance to switch), one of which hides a goat and the other a car what are the chances you will make the right decision??!! COME ON people!!!

[Galileo]

You shouldn't take into account the action of the gameshow host. Which door he opens doesn't matter, but which door YOU choose does, since those 3 choices have equal probabilities.

This has been debated to death, the chances of winning are 2/3 when you switch and the argument is very very simple:
Suppose you decide to switch.
Picking the right door means you will lose, since you then switch to a wrong door.
Picking a wrong door means you win, since you will switch to the correct door.
Because you have 2/3 chance your initial guess is wrong, you have a 2/3 chance of winning if you switch.

[LeonhardEuler]

Ok I read a few of those sites, I can see the argument but I disagree with it. And you can't argue that someone wrote a program "proving" anything. The program is based on your understanding of the problem. If you have a preconcieved way of setting up the problem in programing language, then of course the program will give you the answer you imagined it would. I think one of the links from the wikipedia article you gave me, although arguing against my opinion, illustrates how a reasonable argument could be set up arguing for my point of view.
http://www.angelfire.com/trek/nfold/monty.html
This is my version of his over easy proof. The player chooses A at first.
..............A.....B....C
case 1.....0....(0....1)
case 2.....0....(1....0)
case 3.....1....(0....0)
case 4.....1....(0....0)
case 1: Monty opens B, switch succeeds
case 2: Monty opens C, switch succeeds
case 3: Monty opens B, switch fails
case 4: Monty opens C, switch fails
In two out of the four cases the switch succeeds, and in 2/4 cases the switch fails. So there.
I don't really understand what those 1's and 0's are supposed to represent and I don't know what exactly you mean by 'succeed' and 'fail', but in any event I believe you are mistaken. Monty will never open a door that contains the prize, and he can't change where it is. Surely you agree that the odds of the player chosing the prize on the first try are 1/3. Clearly whatever anybody does after that can not affect the fact that there was a 1/3 chance that the prize was behind that door.

Now what happens when the host opens a door? Suppose he chooses one of the other doors at random. Then if there is no prize behind the door he opens, you have gained information about the probability of there being a prize behind your door: If the prize wasn't behing your door it would be less likely for the host to choose a door without the prize behind it than if it was. This changes the probability that a prize is behind your door.

But suppose we know beforehand that the host will pick a door that does not have the prize behind it. Obviously the chances of picking the door with the prize on the first try are 1/3. Obviusly this does not change when another door is revealed not to have the prize, since we knew that was going to happen in the first place. Now the chances that your door has the prize are still 1/3 while the chances that the prize is in the open door have dropped to zero. Since there are no other possibilities, the probability that the other door has the prize must be 2/3.

Anyway, the ONLY way to really know for sure is to carry out an EXPERIMENT like physicists do. Not using a computer program but setting up the scenario physically say 1000 times and seeing the results. I still cant see how my experiment wasn't ok; I think you misunderstood what I wrote or something... it seems perfectly simple to me.
Actually, that is not true. The only way to know for sure is to come up with a mathematical proof. There is always a finite probability that that statistical data are misleading you when you carry out a process a finite number of times. The probability may get very small that you are being mislead, but you will never know for certain.

[Your.Master]

Ok I read a few of those sites, I can see the argument but I disagree with it. And you can't argue that someone wrote a program "proving" anything. The program is based on your understanding of the problem. If you have a preconcieved way of setting up the problem in programing language, then of course the program will give you the answer you imagined it would.

...

Anyway, the ONLY way to really know for sure is to carry out an EXPERIMENT like physicists do. Not using a computer program but setting up the scenario physically say 1000 times and seeing the results. I still cant see how my experiment wasn't ok; I think you misunderstood what I wrote or something... it seems perfectly simple to me.


This is frustrating -- these are world-class mathematicians and professionals who have laid this out point by point.

First of all, you can't disagree with mathematical proof, and if you do, you aren't reading it right. And yes, you can argue that somebody wrote a program proving stuff. It's identical to carrying out a physical experiment. What's the difference? Anyway, the experiment should carry no preconceptions if done properly and exactly as outlined in the problem. But this is solvable by pure math, anyway.

Your experiment wasn't okay because you didn't account for the fact that the guard will NEVER choose the guy who is innocent, even if it isn't the main guy. You just chose at random.

Your wikipedia example fails; here's why:


..............A.....B....C
case 1.....0....(0....1)
case 2.....0....(1....0)
case 3.....1....(0....0)
case 4.....1....(0....0)
case 1: Monty opens B, switch succeeds
case 2: Monty opens C, switch succeeds
case 3: Monty opens B, switch fails
case 4: Monty opens C, switch fails
In two out of the four cases the switch succeeds, and in 2/4 cases the switch fails. So there.

Hello? Look at cases 3 and 4...they are the *same*. it should read:

case 1.....0....(0....1)
case 2.....0....(1....0)
case 3.....1....(0....0)
case 1: Monty opens B, switch succeeds
case 2: Monty opens C, switch succeeds
case 3: Monty opens either B or C (at random), switch fails

What you seem to be missing is that Monty chooses which door to open AFTER the door that the car is behind is determined -- AFTER the cases. The fact that he has a choice after the chooser chose the car door does not magically make it more likely that the chooser chose the car door in the first place.

I mean FGS!!! if someone offers you a choice between two doors (that is what is done when you are offered the chance to switch), one of which hides a goat and the other a car what are the chances you will make the right decision??!! COME ON people!!!

If somebody offered me a choice of TWO doors, then it's 50/50. I was not offered a choice of two doors. I was offered a choice of THREE doors.

I already knew that at least one of the other doors had a goat behind it. The guy revealed it, but that did not tell me anything new -- I already knew that one of those doors had a goat behind it, and those doors are basically indistinguishable. Essentially, when I'm switching at the end, I'm saying "I think there's a car behind one of the two doors I *didn't* pick in the first place".

Imagine this. Say there are a billion doors. You choose one, Monty Hall opens nine hundred ninety nine million, nine hundred ninety nine thousand, nine hundred ninety eight doors with goats behind it. You now have your door, and another door. Do you *really* believe that this proves that your door is right 50% of the time? Because what that means is that ANY guess you make at the billion doors, any at all, is right 50% of the time (because no matter what you guess, the requisite number of other doors can ALWAYS be opened...it does not even matter if they ARE opened or not). Does that make sense? Do you win the lottery 50% of the time?

Or put it this way. A billion doors. You choose one. Monty Hall ALWAYS says, you are either absolutely right and you chose the correct door, OR, it is this other door that he points out. You can then choose the other door that he points out.

Is it really 50/50? Remember, 100% of the time, when you make the initial choice, Monty Hall reduces it to two. Do you really guess the right door the first time, out of a billion, half the time?

If you do, can I have your lottery numbers?

[alfredblase]

:blushing: ok guys and gals, I am going to bow down. I like Galileo's explanation and it sounds very reasonable and simple to me. Since his reasoning, as far as I can percieve, is at least as valid as mine, and since I have trustworthy accounts from trustworthy sources that there is overwhelming experimental evidence in the form of computer program code and readouts, I will accept the very high probabilty that my experiment was faulty, and that the orthodox arguments are correct. This also means that I have realised that an unbiased program can reproduce the real thing (in terms of statistics).

I apologise if I have caused any of you tear your hair out in frustration :shy:

I appreciate your patience and repeated, good natured efforts to make me see the light. hehe :tongue2:

Here's a crummy maths joke to compensate

I will prove that girls are evil:

Girls mean money*time
time equals money
money is the root of all evil
therefore girls are evil

[Your.Master]

No harm done. I was also sort of impatient with you...it's exam time, you see.

In the spirit of your joke:

Stupid people will always make more money.

Proof:

By definition,

Power = Work / Time

Rearranging:

Time = Work / Power

Time IS Money, and Knowledge IS Power, so substituting:

Money = Work / Knowledge

Therefore, as knowledge goes to 0, money goes to infinity, regardless of the work being done (if Work > 0 and it is impossible to have negative knowledge).

[Cybersteve]

Monty Hall problem. Non-mathematical(ish) explanation.

The key to the answer to this problem is that Monty knows the answer.

When you make your choice of 3 doors you are in effect dividing the doors into two groups - yours and Monty's.

He has more twice as many doors, so it is twice as likely that he has the correct door.

He will always show the goat, so by switching you get to choose the best of his group - which is twice as likely to have contained the goat as your original selection.

[Number Lover]

I remember hearing a story on another forum at one point where a high school math club of some sort made t-shirts which imitated the anti-drug commercials. Here's the design: http://img236.imageshack.us/img236/6195/integrals9tr6uo.jpg

I found it extremely funny the first time I saw it. :)

[alfredblase]

Your experiment wasn't okay because you didn't account for the fact that the guard will NEVER choose the guy who is innocent, even if it isn't the main guy. You just chose at random.

Your.Master

Although I still admit the orthodox explanation is the correct one due to overwhelming experimental evidence, the statement concerning where you think my experiment went wrong is incorrect. As the guard I did not just choose one of the papers at random, (after removal of the randomly chosen main man paper). As the guard I looked at both of the other prisoner's papers and removed one that was guilty. So we have still to ascertain where my experiment went wrong.

[Martin Rattigan]

How many people got executed while you were collecting your overwhelming experimental evidence?

[Martin Rattigan]

Actually the easiest way to convince people the argument is wrong is to increase the number of people. Would so many people take it seriously if it read it read:

"A thousand prisoners, strangers to each other, were suspects of a murder case. One day they came to hear that a sentence has been drawn. Nine hundred and ninety nine of them have been found guilty and will be executed, but they don't know which nine hundred and ninety nine. One guy, a statistician, figures his chances for survival are 1/1000, so he goes to the bars of his cell and hails the guard: "Hey psst, do you know which of us has been sentenced?".
"Eh, yes.", says the guard, "But I'm not allowed to tell you.".
"Tell you what", says the guy, "I already know that 999 of us will executed, that means at least 998 of the other guys will be. I don't know them or anything, surely you can point to 998 which are guilty?". The guard sees no harm in that and points 998 of the prisoners, "They are guilty".
"Thanks!", proclaims the statistician, "my chances have just increased to 1/2".

[JasonRox]

I remember hearing a story on another forum at one point where a high school math club of some sort made t-shirts which imitated the anti-drug commercials. Here's the design: http://img236.imageshack.us/img236/6195/integrals9tr6uo.jpg

I found it extremely funny the first time I saw it. :)

That's a nice one.

For everyone else, keep the jokes coming. :rolleyes:

[alfredblase]

The experimental evidence I keep banging on about is in the form of computer programs apparently written by many in this forum. One of the major advances that Newton made in science, in my opinion, is that he was a pioneer of the system of looking at experimental results, and THEN making arguments, laws, equations, to fit the thoery, not the other way round. You guys seem to think your argument would hold true if experiments told you otherwise. However it seems that experiment bears out your argument, and so it is the correct argument. That is the only reason I accept it over my old argument, which to me seems as logical and reasonable as the argument I now believe in.

[Joffe]

http://img207.imageshack.us/img207/4050/unfindxlol12fb.png

[Reshma]

Not exactly a joke...but happened often when I was in grade 3 when we were introduced to a bit "advanced" geometry like points, segments, angles etc.

A common typo made by students is instead of writing "Angle ABC" they write "Angel ABC".

[benorin]

Another limerick:

Pi goes on and on and on ...
And e is just as cursed.
I wonder: Which is larger
When their digits are reversed?

[Rach3]

That's not a limerick.

[BSMSMSTMSPHD]

Descartes walks into a bar.

The waitress says, "can I get you something?"

Descartes says, "I think not," and promptly disappears.

[BSMSMSTMSPHD]

Here's one that we actually saw in a pre-calculus class.

Upon learning that
\lim_{x\rightarrow 8}
\frac{1}{(x-8)^2}
= \infty


the class was asked to consider
\lim_{x\rightarrow 3}
\frac{1}{(x-3)^2}
.

One student raised his hand and said, "m".

Of course, I guess the answer could also be "\omega"

[rhj23]

Here's one that we actually saw in a pre-calculus class.

Upon learning that
\lim_{x\rightarrow 8}
\frac{1}{(x-8)^2}
= \infty


the class was asked to consider
\lim_{x\rightarrow 3}
\frac{1}{(x-3)^2}
.

One student raised his hand and said, "m".

Of course, I guess the answer could also be "\omega"

if it was intended to be an omega that's pretty clever..

[BSMSMSTMSPHD]

Originally Posted by rhj23
if it was intended to be an omega that's pretty clever..

Yeah - I never thought of that. The actual joke requires a sideways 5, but I didn't have enough imagination to create that symbol.

[benorin]

Math humor-A list of some common proof techniques (http://www.maths.uwa.edu.au/~berwin/humour/invalid.proofs.html#TopPageAnchor)

[benorin]

Q: How do you make one burn?
A: Differentiate a log fire!

[Nimz]

These integrals are sweet!
\int dy
\int_{-C}^y dt

Q: What is a proof that is based on two prior results called?
A: A dilemma.


"Once I thought I was capable of making mistakes, but then I found out I was wrong."

[Edgardo]

Why are mathematicians convergent?
Because they are monotonic and bounded!

[BSMSMSTMSPHD]

Funny, I've always seen myself as just being Cauchy...

[ajsingh]

I really like the following one which I got from SimonSingh.net. Not sure if its a "bad math joke" :)

Two mathematicians are in a bar. The first one
says to the second that the average person
knows very little about basic mathematics.
The second one disagrees, and claims that most
people can cope with a reasonable amount
of mathematics.

The first mathematician goes off to the washroom,
and in his absence the second calls over the waitress.
He tells her that in a few minutes, after his friend has
returned, he will call her over and ask her a question.
All she has to do is answer "one third x cubed."

She repeats "one thir -- dex cue"?

He repeats, "one third x cubed".

She asks, "one thir dex cubed?"

"Yes, that's right," he says.

So she agrees, and goes off mumbling to herself,
"one thir dex cubed...".

The first guy returns and the second proposes a bet
to prove his point, that most people do know something
about basic mathematics. He says he will ask the blonde waitress
an integral, and the first laughingly agrees. The second man
calls over the waitress and asks "what is the integral of x squared?".

The waitress says "one third x cubed" and whilst walking away,
turns back and says over her shoulder "plus a constant!"

[tony873004]

What's the square root of 69?

8-something.

[Curious3141]

What's the square root of 69?

8-something.

That's so wrong!! :rofl:

[Nimz]

That's terrible.

Conversation Starter #176
One theme that comes up in many of my lectures is "The Fourth Dimension: It's not just 'time' anymore." To illustrate, I tell the story of the herb distributor who wanted to use a vector space to keep track of orders. There would be one coordinate for parsley, one for sage, one for rosemary, and one for oregano--because the fourth dimenstion isn't just thyme anymore. The reaction of the class? Well, let's just say their groans give my story yet another dimension.
-Tom Banchoff, Brown University
(From 777 Mathematical Conversation Starters)

Keep 'em coming :biggrin:

[eljose]

-What,s purple and Commutative?----> An Abelian Grape

-What,s the contour integral over all Western Europe?---> 0 because all the "Poles" live in Eastern Europe.

[cliowa]

Now here's one I really LOVE (especially the first few lines):
"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 three 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 concluded, "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."

[cliowa]

This one's good, too:
Halfway through a recent airplane flight from Warsaw to New York, there was nearly a major disaster when the flight crew got sick from eating the fish. After they had passed out, one of the flight attendants asked over the intercom if there were any pilots in the cabin.

An elderly gentleman, who had flown a bit in the war, raised his hand and was rushed into the cockpit of the 747. When he got there, took the seat, and saw all the displays and controls, he realized he was in over his head. He told the flight attendant that he didn't think he could fly this plane. When asked why not, he replied,

"I am just a simple Pole in a complex plane"

So, they just had to rely on the method of steepest descents.

[rajasardar]

Hi
I am a new ANSYS user and trying to work with Concrete65
Can anybody help me giving some guidelines how to deal this element...
thanks in advance.....

[murshid_islam]

What's the square root of 69?

8-something.
i didn't get it.

[SigmaTheAtheist]

When my physics professor makes a simple math error he likes to comment, "There are three kinds of physicists, those that can count and those that can't."

[momentum_waves]

What's the square root of 69?


1 + 1 + offspring

[Data]

When my physics professor makes a simple math error he likes to comment, "There are three kinds of physicists, those that can count and those that can't."

Reminiscent of the ever-popular "There are 10 types of people: Those who understand binary, and everyone else."

[Office_Shredder]

There are 10 types of people: Those who know trinary, those who don't, and those who think I just screwed up a binary joke

[murshid_islam]

There are 10 types of people: Those who know trinary, those who don't, and those who think I just screwed up a binary joke
lol. great joke.
but, is the term "trinary"? or "ternary"?

[uart]

A bunch of Systems Engineers from Warsaw were flying out to attend a conference on “Automatic Control System’s” in Geneva. The weather conditions were perfect, no wind and blue sky with just a few light fluffy clouds. So once the plane reached cruising altitude the flight crew switched over to auto-pilot and settled in for a nice easy flight.

After some time one of the Engineers noticed a really strange cloud formation (resembling part of a women’s anatomy) off to the right hand side of the plane. He immediately alerted the others of this amazing curiosity and soon all the Engineers from both rows of seats had rushed over the take a look.

The sudden shift in weight caused the plane to pitch alarmingly to the right. The auto-pilot tried to correct but unfortunately it over-responded causing the plane to pitch ever more violently to the left. After several more failed over corrections the plane eventually spiralled out of control and crashed killing all on board.

Air-crash investigators examining the black box flight recorder eventually determined that the crash resulted from: “an instability in the auto-pilot system caused by” ...….punch line ….... “ too many Poles in the right half plane”.

[Data]

There are 10 types of people: Those who know trinary, those who don't, and those who think I just screwed up a binary joke

ahahah, that one's good :rofl:

[fopc]

Here's a story (perhaps more than just a joke) told by Stan Ulam many years ago.

"Chen Ning Yang, Nobel Prize in Physics (1957), tells a joke which illustrates an aspect of the intellectual relationship between physicists and mathematicians at present. One afternoon, a group of friends came to a city. They had to wash their clothes, so they searched the streets looking for a laundry. They found a place with the shop-sign on the window: WE WASH CLOTHES. One of them went in and asked: 'Can we leave our clothes here for a wash?' The owner answered: 'We don't wash clothes here.' - 'How's that?' asked the newcomer, 'there is a sign on the window that says you do.' - 'We make shop-signs', was the answer. Something similar happens here. We mathematicians make shop-signs for any trade. Physicists use them."

[Feldoh]

A 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 ..."

Sad, but true:
The Evolution of Math Teaching

1960s: A peasant sells a bag of potatoes for $10. His costs amount to 4/5 of his selling price. What is his profit?
1970s: A farmer sells a bag of potatoes for $10. His costs amount to 4/5 of his selling price, that is, $8. What is his profit?
1970s (new math): A farmer exchanges a set P of potatoes with set M of money. The cardinality of the set M is equal to 10, and each element of M is worth $1. Draw ten big dots representing the elements of M. The set C of production costs is composed of two big dots less than the set M. Represent C as a subset of M and give the answer to the question: What is the cardinality of the set of profits?
1980s: A farmer sells a bag of potatoes for $10. His production costs are $8, and his profit is $2. Underline the word "potatoes" and discuss with your classmates.
1990s: A farmer sells a bag of potatoes for $10. His or her production costs are 0.80 of his or her revenue. On your calculator, graph revenue vs. costs. Run the POTATO program to determine the profit. Discuss the result with students in your group. Write a brief essay that analyzes this example in the real world of economics.

I've got one similar to that, but it's a bit darker:
1. Teaching Math In 1950
A logger sells a truckload of lumber for $100.. His cost of production is 4/5 of the price. What is his profit?

2. Teaching Math In 1960
A logger sells a truckload of lumber for $100. His cost of production is 4/5 of the price, or $80. What is his profit?

3. Teaching Math In 1970
A logger sells a truckload of lumber for $100. His cost of production is $80. Did he make a profit?

4. Teaching Math In 1980
A logger sells a truckload of lumber for $100. His cost of production is $80 and his profit is $20. Your assignment: Underline the number 20.

5. Teaching Math In 1990
A logger cuts down a beautiful forest because he is selfish and inconsiderate and cares nothing for the habitat of animals or the preservation of our woodlands.. He does this so he can make a profit of $20.
What do you think of this way of making a living? Topic for class participation after answering the question: How did the birds and squirrels feel as the logger cut down their homes? (There are no wrong answers.)

6. Teaching Math In 2006
Un hachero vende una carretada de maderapara $100. El costo de la producciones es $80.

[tpm]

- What's purple and commutative?--> An Abelian Grape

- What's Yellow normed and complete --> A Bananach space..

[andybham]

what do you get if you cross a pig and a rat?

[tpm]

what do you get if you cross a pig and a rat?

A journal referee?.. i suppose they're right all the paper are PIG-reviewed.

[andybham]

A journal referee?.. i suppose they're right all the paper are PIG-reviewed.

No, lol!

|pig||rat|*sin(x)

Hah, sorry, that is terrible!

[LukeD]

but that's just its size

sorry, I'm killing it even worse

[radou]

Didn't bother checking if this one has already been posted, but anyway:

Let \epsilon < 0.

[Dathascome]

I didn't read through all 11 pages so I hope no one said these.

There are 3 types of mathematicians in the world...those who can count, and those who can't.


My quantum mechanics professor a few years ago said this one.

Q:Why doesn't Heisenberg live in the suburbs???

A: Because he doesn't like to commute.

[radou]

Confusing one single letter can turn a homomorphism into a dog.

[bit188]

Oh my God. I found this on another forum:

A mathematician and an engineer agreed to take part in a psychological test. They sat on one side of a room and waited not knowing what to expect. A door opened on the other side and a naked woman came in the room and stood on the far side. They were then instructed that every time they heard a beep they could move half the remaining distance to the woman. They heard a beep and the engineer jumped up and moved halfway across the room while the mathematician continued to sit, looking disgusted and bored. When the mathematician didn't move after the second beep he was asked why. "Because I know I will never reach the woman." The engineer was asked why he chose to move and replied, "Because I know that very soon I will be close enough for all practical purposes!"

[Thrice]

Wow this thread is bad... :D

[DeadWolfe]

Confusing one single letter can turn a homomorphism into a dog.

...I don't get it.

[Reshma]

Oh my God. I found this on another forum:

A mathematician and an engineer agreed to take part in a psychological test. They sat on one side of a room and waited not knowing what to expect. A door opened on the other side and a naked woman came in the room and stood on the far side. They were then instructed that every time they heard a beep they could move half the remaining distance to the woman. They heard a beep and the engineer jumped up and moved halfway across the room while the mathematician continued to sit, looking disgusted and bored. When the mathematician didn't move after the second beep he was asked why. "Because I know I will never reach the woman." The engineer was asked why he chose to move and replied, "Because I know that very soon I will be close enough for all practical purposes!"

Oh, he means Zeno's paradox! :rofl:

[Reshma]

Confusing one single letter can turn a homomorphism into a dog.
Does it mean DoG (Domain of G) ?? :confused:

[radou]

Does it mean DoG (Domain of G) ?? :confused:

Nah, I meant kernels vs. kennels. :tongue2:

[CompuChip]

No harm done. I was also sort of impatient with you...it's exam time, you see.

In the spirit of your joke:

Stupid people will always make more money.

Proof:

By definition,

Power = Work / Time

Rearranging:

Time = Work / Power

Time IS Money, and Knowledge IS Power, so substituting:

Money = Work / Knowledge

Therefore, as knowledge goes to 0, money goes to infinity, regardless of the work being done (if Work > 0 and it is impossible to have negative knowledge).

You said indeed, if Work > 0. But if Work is identically zero (which is not uncommon for stupid people) then Money is the limit of 0 / Knowledge and hence zero.
That sucks (for me, at least).

[Thrice]

One of my favorites, find:

\int\frac{1}{cabin}d(cabin)

Houseboat!Would "beach house" work better?

[Office_Shredder]

Freezers are ice-o-morphic to water

[radou]

Freezers are ice-o-morphic to water

People are homomorphic to humans.

[Gib Z]

I dont get post 169 >.< In cabin?...

[AKG]

log cabin. Mathematicians use "log" to mean what non-mathematicians refer to as "ln". Because base 10 is mathematically less interesting than the natural base.

[Feldoh]

I dont get post 169 >.< In cabin?...

log(cabin)+C -- Think about it...

[Reshma]

log(cabin)+C -- Think about it...
This one's a repeat! :biggrin:
Cruise boat! :tongue2::tongue2::wink:

[mongoose]

someone probably already posted this, but:

Two mathematicians are in a bar. The first one says to the second that the average person knows very little about basic math. The second one disagrees, and claims that most people can cope with a reasonable amount of math. The first mathematician goes off to the washroom, and in his absence the second calls over the waitress. He tells her that in a few minutes, after his friend has returned, he will call her over and ask her a question; all she has to do is answer, "One third x cubed." She agrees, and goes off mumbling to herself. The first guy returns and the second proposes a bet to prove his point. He says he will ask the blonde waitress an integral, and the first laughingly agrees. The second man calls over the waitress and asks, "What is the integral of x squared?" The waitress says, "One third x cubed." Then, while walking away, she turns back and says, "Plus a constant!"

from wikipedia...funyy stuff

[mongoose]

Wow, nice apmcavoy!

hey man...that's a killer quote

hahaha

[strings235]

Warning: The may contain suggestive info, just a bit though XD

A slutty girl walks up to a mathematician and says (suggestively) "Do you know what 69 is?" He says "Well duh, any idiot would its product 3 and 13"
The girl reacts, "..." and he says, "Oh I'm sorry, how strange of me--I forgot to mention they're primes with spacing of 10...haha." You figure what goes on from there.


ahaha.....not that funny, but i was getting at the "bad" in the bad jokes.

[mongoose]

Warning: The may contain suggestive info, just a bit though XD

A slutty girl walks up to a mathematician and says (suggestively) "Do you know what 69 is?" He says "Well duh, any idiot would its product 3 and 13"
The girl reacts, "..." and he says, "Oh I'm sorry, how strange of me--I forgot to mention they're primes with spacing of 10...haha." You figure what goes on from there.


ahaha.....not that funny, but i was getting at the "bad" in the bad jokes.

i don't get it

!

[ZioX]

http://mathworld.wolfram.com/FrivolousTheoremofArithmetic.html

[ZioX]

2+2=5 for very large 2's.

[sam1]

A mathematician, a physicist, and an engineer are at a conference, and are asked to determine the volume of a red ball.

The mathematician carefully measures the ball's diamater and calculates the volume from there.

The physicist fulls a beaker with water, and submerges the ball and records the difference in water level.

The engineer records the ball model type and serial number and looks it up in his red ball handbook.

[itsjustme]

Mathematical proof that women are evil

First we know that women are the product of time and money

Women = Time * Money

Then we know that time is money

Women = Money * Money

And that money is the root of all evil

Women = Sqrt(Evil) * Sqrt(Evil)

Women = Evil

[CompuChip]

2+2=5 for very large 2's.

As in, for any \epsilon > 0 there exists \delta > 0 such that for \left| 2 - \frac12 \right| < \delta,
2 + 2 = 5

I like the ball gag

[CoCoA]

"Did you hear about the constipated mathmatician?"

"He had to work it out with a pencil!!"
tee hee:rofl:

That's supposed to be - he worked it out with a slide rule.

That joke just doesn't have the same effect since slide rules are gone. You need the word "slide" in there.

[olliemath]

An engineer a physicist and a mathematician are being tested on their approaches to problem solving by some psychologists. Each is left alone in a room with cans of food and no tin opener..

Several days later the psychologists return. The engineer has managed to open some of the cans by bashing them with a rock, he sits eating hapily. The physicist has obtained large amounts of funding and set up a complex system of high powered tin-opening lasers, but has now become too distracted to eat any of the food. When the psychologists visit the mathematician (geometer/topologist) there are pages and pages of calculations and diagrams, but he has disapeared and there are banging noises and groans coming from inside one of the tins. Concerned they prise it open and the mathematician pops out - "Sorry about that, I got a sign wrong!" he exclaims.

[Runner43]

His chances have not changed as no new information (that would change the statics) was really added by the guards revelation.

One thing I do find weird about this problem is how two people whom have never meet can both be found guilty of the same murder. That's some pretty whacky justice system.

No.
The chance of survival of the statistician is 0/3.

The fact that the guard points out to one of the OTHER two prisoners means that only one of them guilty. This implies that the statistician is the other to die. Poor guy...

c'mon...let's think outside of 'physics and mathematics', look at it from a psychological perspective ;)
-Liberal arts student

[M Grandin]

What's the square root of 69?

8-something.

I also didn't get that joke - but thought it perhaps was meant "square root of 79" instead.

The answer "8-something" then had been fun in an other sense (if you calculate that root...) :smile:

[Reshma]

I also didn't get that joke - but thought it perhaps was meant "square root of 79" instead.

The answer "8-something" then had been fun in an other sense (if you calculate that root...) :smile:
That's funny! :rofl:

[Mensanator]

I didn't read through all 11 pages so I hope no one said these.

There are 3 types of mathematicians in the world...those who can count, and those who can't.


My quantum mechanics professor a few years ago said this one.

Q:Why doesn't Heisenberg live in the suburbs???

A: Because he doesn't like to commute.

One day Heisenberg got pulled over for speeding.

Cop: Do you know how fast you were going?

Heisenberg: No, but I know where I am.

[tauon]

3 friends: a chemist, an engineer and a mathematician are at the seaside in the mathematician's mountain log cabin. after much drinking and partying the mathematician decides to go to bed upstairs in his room. 2 minutes later, disturbed by the smell of fire the chemist and engineer hurriedly go upstairs as well and notice a fire in the hallway. the chemist immediately starts thinking of how to make a concoction that can extinguish the fire while the engineer after looking around notices a bucket of water and uses it to kill the fire. in the morning they ask the mathematician why he didn't do anything about the fire, to which he replied:

"I noticed fire, and a bucket of water nearby: a solution obviously existed."

[Borek]

As my math professor used to say back in eighties, you can always draw a straight line through three points. It just have to be sufficiently thick.

[Borek]

Why does

\frac {16} {64} = \frac 1 4

?

Because six cancels out.

[Hurkyl]

You've obviously never seen

\frac{\sin x}{n} = 6

[LebLlama]

A mathematician, a physicist, and a llama microbiologist are in a room together with a hot girl. The scientists all say that they'll be the one who gets the girl.

The mathematician walks up to her and does a complex math problem to impress her.

The physicist smirks and says he can top that. He walks to her, sets up a conductor AND does a complex math problem to impress her.

The microbiologist walks up to her, smacks her *** and says "Lets go dancing baby girl" and the girl leaves with the microbiologist.

[Mensanator]

Not exactly a Math joke, but still good.

A physicist, chemist, electrcian and Bill Gates were riding along in a car when it suddenly stopped.

The phystcist says: "Engine must have thrown a rod."

The chemist says: "We would have felt that. Probably not getting gas."

The electrician says: "But we would have noticed it sputtering to a halt. The electrical systen probably failed."

Bill Gates says: "Why don't we get out of the car and get back in again."

[HallsofIvy]

Not exactly a Math joke, but still good.

A physicist, chemist, electrcian and Bill Gates were riding along in a car when it suddenly stopped.

The phystcist says: "Engine must have thrown a rod."

The chemist says: "We would have felt that. Probably not getting gas."

The electrician says: "But we would have noticed it sputtering to a halt. The electrical systen probably failed."

Bill Gates says: "Why don't we get out of the car and get back in again."

No, no, no! Bill gates says "Why don't we try closing all the windows, then opening them again"!

[l'Hôpital]

Not really a math joke, but a true funny story:

At the question period after a Dirac lecture at the University of Toronto, somebody in the audience remarked: "Professor Dirac, I do not understand how you derived the formula on the top left side of the blackboard."
"This is not a question," snapped Dirac, "it is a statement! Next question, please."

[Borek]

Our physics lecturer used to say "...according to what I have already erased..."

[HallsofIvy]

I have always loved "obvious to the most casual observer" to mean "I have no idea how to derive this"!

There is the old story of the professor who said "No, it is obvious that", hesitated, said "Now why is that obvious?", sat down at his desk, scribbled furiously for 20 minutes, then jumped up and said "Yes, it is obvious!"

[Dragonfall]

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 then spends the rest of his life generalizing results for tables with N legs, where N is not necessarily a natural number.

This thread is 4 years old now, by the way.

[Dragonfall]

METHODS FOR PUTTING AN ELEPHANT INTO A REFRIGERATOR:

Algebra: Show that parts of the elephant can be put into the fridge, then show that the fridge is closed under addition.

Number Theory: Use induction, you can always squeeze a bit more in.

Analysis: Differentiate the elephant, put it inside the fridge, then integrate.

Topology: The elephant is compact, so it can be put into a finite collection of refrigerators. That's usually good enough.

Algebraic topology: Replace the interior of the refrigerator by its universal cover, R^3.

Set theory: refrigerator = { elephant }

Numerical analysis: Put its trunk in and refer the rest to the error term.

[Mark44]

I have always loved "obvious to the most casual observer" to mean "I have no idea how to derive this"!

There is the old story of the professor who said "No, it is obvious that", hesitated, said "Now why is that obvious?", sat down at his desk, scribbled furiously for 20 minutes, then jumped up and said "Yes, it is obvious!"

"Obvious to the most casual observer" was always a favorite of mine as well. An instructor I had at a small community college used that one frequently. Another he used a lot was "Even my own mother could integrate that!" When he was about to do something tricky, he would say "Watch closely! At no time will the chalk leave my hand or will my hand leave my arm."

[jasonRF]

"Obvious to the most casual observer" was always a favorite of mine as well. An instructor I had at a small community college used that one frequently. Another he used a lot was "Even my own mother could integrate that!" When he was about to do something tricky, he would say "Watch closely! At no time will the chalk leave my hand or will my hand leave my arm."

I think we all had profs that did these things! For 2nd semester intro physics (EM+special relativity), the professor would always say things like, "from grade-school calculus we know ...". I recall the TA asking the prof in lecture "how did you go from the top equation to the second equation?" Answer: "I just integrated by parts 3 times in my head", as if it should have been obvious.

For the final, one of the problems began, "if photons have a mass, the wave equation becomes ..." followed by an equation with a bunch of dels floating around. I remember it well because I walked out of the exam stunned, just shaking my head.

I think profs get a kick out of this sort of thing.

jason

[molinaro]

A mathematician, a physicist and an astronomer are riding a train across the Scotish countryside.

The astronomer looks out the window and sees a sheep in the field. He points and says, "Look in Scotland sheep are black!"

The physicist sighs and says, "Now, now. In Scotland, at least one sheep is black."

The mathematician loses it! "Will you two ever learn? In Scotland there exists a field. In that field there exists a sheep. One side of which is black!"


That's actually my all time favorite joke out of all jokes.

[fourier jr]

hermann weyl used to say that a compact city can be guarded by a finite number of arbitrarily-nearsighted policemen

[Mark44]

I saw this one in a different section, and thought it deserved to be here as well. Credit goes to Cronxeh (http://www.physicsforums.com/member.php?u=9787).

Six engineers and six mathematicians are attending a conference and are traveling by train. One by one, each of the engineers goes up to the ticket counter and buys a ticket to the conference. But only one of the mathematicians does. The engineers look puzzled and one of the mathematicians says, "Optimization."

The twelve get on the same car and one mathematician stands at each end of the car. Now the engineers are really puzzled. After a while, the mathematician at one end, yells, "Conductor!" On that cue, all the mathematicians pile into the rest room and lock the door.

The conductor enters the car and announces, "Tickets, please. Tickets!" He passes the engineers and punches each of their tickets. At the end of the car, he notices the restroom is occupied and knocks on the door, "Ticket, please."

The ticket slides out from under the door, he punches it and slides it back, then leaves the car and continues to the next car.

The engineers look at each other and decide how clever the mathematicians have been, and then wink at each other.

They all attend the conference and have a good time. Upon arriving at the train station, one engineer buys a ticket and they giggle at each other. The mathematicians do not buy any. This time again, the engineers look puzzled, and the same mathematician says, "Optimization."

This time all the mathematicians sit down and the engineers have the lookouts. One engineer, peers down a couple of cars and shouts, "Conductor!" Immediately all the engineers pile into the rest room, while the mathematicians just sit there. Once the engineers are in the rest room, one of the mathematicians knocks on the door and says, "Ticket, please." The ticket slides out under the door, the mathematician grabs it and along with the other mathematicians, runs to the other rest room and they lock themselves in.

[Relay]

This one is from my High School Days. π is pie

QTπ RU/18

[Martin Rattigan]

Our physics lecturer used to say "...according to what I have already erased..."
We had a lecturer who was reputed to be able to make a term disappear by writing it fainter each line.

[Max™]

A bunch of Polish scientists decided to flee their repressive
government by hijacking an airliner and forcing the pilot to fly them
to a western country. They drove to the airport, forced their way on
board a large passenger jet, and found there was no pilot on board.
Terrified, they listened as the sirens got louder. Finally, one of
the scientists suggested that since he was an experimentalist, he
would try to fly the aircraft.

He sat down at the controls and tried to figure them out. The sirens
got louder and louder. Armed men surrounded the jet. The would be
pilot's friends cried out, "Please, please take off now!!! Hurry!!!!!"

The experimentalist calmly replied, "Have patience. I'm just a simple
pole in a complex plane."

Perhaps it's just from too much time learning about the Riemann Hypothesis recently, but this one killed me.

Already saw my favorites posted: What's purple and commutes? An abelian grape.
I'm sorry, the number you have dialed is imaginary, please multiply by i and try again.

[mathPsych]

153 and 641 were dating, and 153 said to 641, "I love you 641. I love how you're a sum of fourth powers. I love how you're a divisor of a Fermat number."

641 replied, "I, uh, I love you too, 153."

"Why do you love me, 641?" asked 153.

"Well, I uh, I love how you're the sum of the cubes of your digits."

"You don't love me!" cried 153. "You just like my base ten representation!"

[Dodo]

Old but good:

http://www.youtube.com/watch?v=6HkLsfa67mA

[snipez90]

A mathematician walks into \overline{A} and says "I'm sorry, I didn't realize you were closed".

[micromass]

METHODS FOR PUTTING AN ELEPHANT INTO A REFRIGERATOR:

Algebra: Show that parts of the elephant can be put into the fridge, then show that the fridge is closed under addition.

Number Theory: Use induction, you can always squeeze a bit more in.

Analysis: Differentiate the elephant, put it inside the fridge, then integrate.

Topology: The elephant is compact, so it can be put into a finite collection of refrigerators. That's usually good enough.

Algebraic topology: Replace the interior of the refrigerator by its universal cover, R^3.

Set theory: refrigerator = { elephant }

Numerical analysis: Put its trunk in and refer the rest to the error term.

Analysis:
1) Differentiate it and put into the refrig. Then integrate it in the refrig.
2) Redefine the measure on the referigerator (or the elephant).
3) Apply the Banach-Tarski theorem.


Number theory:
1) First factorize, second multiply.
2) Use induction. You can always squeeze a bit more in.

Algebra:
1) Step 1. Show that the parts of it can be put into the refrig.
Step 2. Show that the refrig. is closed under the addition.
2) Take the appropriate universal refrigerator and get a surjection from refrigerator to elephant.

Topology:
1) Have it swallow the refrig. and turn inside out.
2) Make a refrig. with the Klein bottle.
3) The elephant is homeomorphic to a smaller elephant.
4) The elephant is compact, so it can be put into a finite collection of refrigerators. That's usually good enough.
5) The property of being inside the referigerator is hereditary. So, take the elephant's mother, cremate it, and show that the ashes fit inside the refrigerator.
6) For those who object to method 3 because it's cruel to animals. Put the elephant's BABY in the refrigerator.

Algebraic topology:
Replace the interior of the refrigerator by its universal cover, R^3.

Linear algebra:
1) Put just its basis and span it in the refrig.
2) Show that 1% of the elephant will fit inside the refrigerator. By linearity, x% will fit for any x.

Affine geometry:
There is an affine transformation putting the elephant into the refrigerator.

Set theory:
1) It's very easy!
refrigerator = { elephant }
2) The elephant and the interior of the refrigerator both have cardinality c.

Geometry:
Declare the following:
Axiom 1. An elephant can be put into a refrigerator.

Complex analysis:
Put the refrig. at the origin and the elephant outside the unit circle. Then get the image under the inversion.

Numerical analysis:
1) Put just its trunk and refer the rest to the error term.
2) Work it out using the Pentium.

Statistics:
1) bright statistician.
Put its tail as a sample and say "Done."

2) dull statistician.
Repeat the experiment pushing the elephant to the refrig.

3) Our NEW study shows that you CAN'T put the elephant in the refrigerator.

[camilus]

^lol

\int e^x = e^x + C

i know its missing the dx, its supposed to read sex = extc

sorry, i know its lame..

[Borek]

We have separate thread for lame jokes.

[mathPsych]

These are supposedly questions actually asked of applicants for a programming job:




How do you put a giraffe into the refrigerator?








Correct answer: Open the refrigerator door, put the giraffe in, and close the door. This question tests whether or not the candidate is doing simple things in a complicated way.




How do you put an elephant in the refrigerator?








Incorrect answer: Open the refrigerator door, put in the elephant, and close the door. Correct answer: Open the refrigerator door, take out the giraffe, put in the elephant, and close the door. This question tests your foresight.





The Lion King is hosting an animal conference. All the animals in the world attend except one. Which animal does not attend?









Correct answer: The elephant. The elephant is in the refrigerator, remember? This tests if you are capable of comprehensive thinking.








There is a river notoriously known for it’s large crocodile population. With ease, how do you safely cross it?










Correct answer: Simply swim across. All of the crocodiles are attending the Lion King’s animal conference. This questions your reasoning ability.

[Mark44]

^lol

\int e^x = e^x + C

i know its missing the dx, its supposed to read sex = extc

sorry, i know its lame..
I learned it as

\int e^x = f(u^n)

[camilus]

I like my version because it's an actual formula.

[Borek]

Without dx it is not.

[camilus]

ok smart guy it can still be read like a real integral: integral of e to the x equals e to the x + c.

[camilus]

or Sex=ex t C