(with a small
of jokes, facts and interesting stores:
An Indian chief had three wives, each of whom was pregnant. The first gave birth to a boy. The chief was so elated he built her a teepee made of deer hide. A few days later, the second gave birth, also to a boy. The chief was very happy. He built her a teepee made of antelope hide. The third wife gave birth a few days later, but the chief kept the details a secret. He built this one a two story teepee, made out of a hippopotamus hide. He challenged the tribe to guess what had occurred. Many tried, unsuccessfully.
Finally, one young brave declared that the third wife had given birth to twin boys. "Correct," said the chief. "How did you figure it out?"
The warrior answered, "It's elementary. The value of the squaw of the hippopotamus is equal to the sons of the squaws of the other two hides."
At 12:00 noon Grewnwich Mean Time (GMT) an astronaut on Moon drops a wrench on
his toe and shouts ``Damn!'' into his helmet microphone (event A), carried by
a radio signal toward Earth. At one second after 12:00 noon GMT a short circuit
(event D) temporarily disables the receiving amplifier at Mission Control on
Earth. Take Earth and Moon to be 3.84 x 10^8 meters apart in the Earth frame
and assume zero relative motion.
a. Does Mission Control on Earth hear the astronaut's expletive?
b. Could the astronaut's strong language have caused the short circuit on
Source: My physics book, Sample Problem 6-2:
Taylor, Edwin F and John Archibald Wheeler.
Spacetime Physics. NY: W. H. Freeman, 1992.
Shearing a Sheep
Question: How do you shear a sheep horizontally?
Answer: Left-multiply the sheep by a matrix of the form
[ 1 k ]
[ 0 1 ].
Note: This is a
linear transformation using a
to perform a
Once upon a time, Yoyo was a big thing amongst the younger kids.
A mathematician's son was sad because he did not have enough money to buy a Yoyo.
His dad wrote on a paper
r(u,v) = < ( 4 u2 - u4 ) cos v, u, ( 4 u2 - u4 ) sin v >
and gave it to the son.
The young kid was so fascinated by the equation of a Yoyo that he lived happily ever after.
Note: I got the inspiration by a homework problem on identifying
Setting: University Physics by Young and Freedman. On Electric Flux
Consider a closed box that may or may not contain electric charge.
We'll imagine that the box is made of a material that has no effect
on any electric fields; it's of the same breed as the massless rope,
the frictionless incline, and the free college education.
Conversation in the Number Kingdom
Once upon a time, in a land called the Number Kingdom, 0 was walking on the street. He saw 8 and said, ``Nice belt!''
Setting: The, sadly, highest level math class at my local community college: Intermediate Analysis (UW equivalent 324).
Htam: I think we should describe things in mathematical language. (Commenting on fellow classmates' use of sophisticated vocabulary words.)
Teacher: The problem is, Jed, that you would lose the ability to communicate with
Classmate: Not in Jed's world.
Note: If someone is
to me, our
is zero and communication is not required since the
of our respective sets of interests is the
Conversation of Hydrogen Atoms
Once upon a time, two hydrogen atoms were walking on the street.
Atom A said, ``I lost my electron.''
Atom B asked, ``Are you sure?''
Atom A replied, ``Yup, I'm positive.''
Setting: Geometry lecture in MOP some time t in the past.
Zuming Feng (US IMO coach): You have to be careful when drawing additional lines. It's like financial aid. It's need-based.
Question: Once upon a time there were two trains heading directly towards one another. One train at 30mph and the other 50mph. When they are 240 miles apart from collision, a superfly started on one train and flew to the other at 100mph. The superfly changed direction and head straight back the instant it touched its target. The fly simply flew at constant speed to and fro the moving trains--Until it was crushed in the train head-on collision. How far did the superfly fly before it was crushed?
Answer: It is possible to calculate the location of the second train when the superfly reaches it, and calculate the next location when the first train was landed upon. You could get an
and find its sum. Another way, which common people usually use, is to simply calculate the time elapsed before the train collide and calculate the superfly's flight length.
Note: The above question is neither clever nor funny, but the funny part is this. Once one asked John von Neumann this question. Von Neumann stated the answer immediately. His friend said, "Oh, you saw the trick." Von Neumann replied, "Yes, it was an easy