—Three employees of BARC (an engineer, a physicist and a mathematician) are staying in a hotel while attending a technical seminar. The engineer wakes up and smells smoke. He goes out into the hallway and sees a fire, so he fills a trashcan from his room with water and douses the fire. He goes back to bed. Later, the physicist wakes up and smells smoke. He opens his door and sees a fire in the hallway. He walks down the hall to a fire hose and after calculating the flame velocity, distance, water pressure, trajectory, etc. extinguishes the fire with the minimum amount of water and energy needed. Later, the mathematician wakes up and smells smoke. He goes to the hall, sees the fire and then the fire hose. He thinks for a moment and then exclaims, "Ah, a solution exists!" and then goes back to bed.

—What's the contour integral around Western Europe? Answer: Zero, because all the Poles are in Eastern Europe!

—What's purple and commutes? A: An abelian grape.

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

—"Algebraic symbols are used when you do not know what you are talking about." Philippe Schnoebelen

—Noah lets all the animals out. Says, "Go and multiply." Several months pass. Noah decides to check up on the animals. All are doing fine except a pair of snakes. "What's the problem?" says Noah. "Cut down some trees and let us live there", say the snakes. Noah follows their advice. Several more weeks pass. Noah checks on the snakes again. Lots of little snakes, everybody is happy. Noah asks, "Want to tell me how the trees helped?" "Certainly", say the snakes. "We're adders, and we need logs to multiply

—Lemma: All horses are the same color. Proof (by induction): Case n=1: In a set with only one horse, it is obvious that all horses in that set are the same color. Case n=k: Suppose you have a set of k+1 horses. Pull one of these horses out of the set, so that you have k horses. Suppose that all of these horses are the same color. Now put back the horse that you took out, and pull out a different one. Suppose that all of the k horses now in the set are the same color. Then the set of k+1 horses are all the same color. We have k true => k+1 true; therefore all horses are the same color. Theorem: All horses have an infinite number of legs. —Proof (by intimidation): Everyone would agree that all horses have an even number of legs. It is also well-known that horses have forelegs in front and two legs in back. 4 + 2 = 6 legs, which is certainly an odd number of legs for a horse to have! Now the only number that is both even and odd is infinity; therefore all horses have an infinite number of legs. However, suppose that there is a horse somewhere that does not have an infinite number of legs. Well, that would be a horse of a different color; and by the Lemma, it doesn't exist.

—A bunch of Polish scientists decided to flee their repressive government by hijacking an airliner They drove to the airport, forced their way on board a large passenger jet, and found there was no pilot on board. One of the scientists suggested that since he was an experimentalist, he would try to fly the aircraft. 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

—A biologist, a statistician, a mathematician and a computer scientist are on a photo-safari in africa. They drive out on the savannah in their jeep, stop and scout the horizon with their binoculars. The biologist : "Look! There's a herd of zebras! And there, in the middle : A white zebra! It's fantastic ! There are white zebra's ! We'll be famous !" The statistician : "It's not significant. We only know there's one white zebra." The mathematician : "Actually, we only know there exists a zebra, which is white on one side." The computer scientist : "Oh, no! A special case!"

—The usual techniques for proving things are often inadequate because they are merely concerned with truth. For more practical objectives, there are other powerful - but generally unacknowledged - methods. Here is an (undoubtedly incomplete) list of them:

Proof of Blatant Assertion: Use words and phrases like "clearly...,""obviously...,""it is easily shown that...," and "as any fool can plainly see..."

Proof by Seduction: "If you will just agree to believe this, you might get a better final grade."

Proof by Intimidation: "You better believe this if you want to pass the course."

Proof by Interruption: Keep interrupting until your opponent gives up.

Proof by Misconception: An example of this is the Freshman's Conception of the Limit Process: "2 equals 3 for large values of 2." Once introduced, any conclusion is reachable.

Proof by Obfuscation: A long list of lemmas is helpful in this case - the more, the better.

Proof by Confusion: This is a more refined form of proof by obfuscation. The long list of lemmas should be arranged into circular patterns of reasoning - and perhaps more baroque structures such as figure-eights and fleurs-de-lis.

A Party of Famous Physicists

One day, all of the world's famous physicists decided to get together for a tea luncheon. Fortunately, the doorman was a grad student, and able to observe some of the guests...