## Archive for November 2, 2010

### Pun and Games

If you’ve read this blog for a while, you know that I love puns. In fact, many people think I’m a very punny guy.

The following joke is a math pun that I created:

One-Half was talking to the Square Root of 3. But the Square Root of 3 was speaking very quietly, and One-Half had trouble hearing him. “Speak up!” said One-Half.

The problem, of course, is that fractions speak louder than surds.

As you probably know, the punch line is a modified version of the idiom, “Actions speak louder than words.”

In a quick poll of my office mates, however, I learned that 75% did not know that *surd* is another term for an irrational number. It’s an archaic term, to be sure, but it was the predecessor of *radical*. Sir Francis Bacon used the term in his writing to simply mean “conveying no sense, or meaningless,” so it therefore makes sense that it would be used to describe irrational numbers.

Around 820 AD, Al-Khwarizmi (the Persian mathematician who gave us the words *algebra* and *algorithm*) described irrational numbers as “‘inaudible.” Later, this description was translated to the Latin *surdus*, which means “deaf” or “mute.” (In a linguistics context, *surd* refers to a consonant produced without sound from the vocal cords.)

Anyway, I recognized that if only 1 in 4 know what a surd is, then it probably doesn’t make sense to use the word in the punch line of a joke. So I modified:

One-Half was talking to a blue jay. But the blue jay was speaking very softly, and One-Half had trouble hearing him. “Speak up!” said One-Half.

The problem, of course, is that fractions speak louder than birds.

Well, phooey. It’s not as mathematical as the original (nor as funny, in my opinion), but at least more people will understand it.

The lone co-worker who knew the word *surd* said that my joke reminded him of a math joke that was popular many years ago.

Two mathematicians are in a bath tub, and one says to the other, “Please pass the slope.” And the other says, “No slope… ratio!”

I had never heard this joke, nor did I have any idea why it was funny. As it turns out, it is a spoof of the following joke, which I had also never heard, and which I also had no idea why it was funny:

Two elephants are in a bath tub, and one says to the other, “Please pass the soap.” And the other says, “No soap… radio!”

As it turns out, this joke was never meant to be funny. The punch line was meant to be a prank. In the 1950’s, the punch line was used in sociological experiments on mob mentality, showing that people are often willing to laugh at an unfunny joke simply because other people are laughing, and they don’t want to feel left out. Wikipedia has a nice description of the no soap radio punch line.

For your entertainment, here are some more math jokes involving an elephant:

Several mathematicians are asked, “How do you put an elephant in a refrigerator?”

Analyst:Differentiate it and put into the refrig. Then integrate it in the refrig.

Different Analyst:Apply the Banach-Tarsky theorem.

Number Theorist:Use induction. You can always squeeze a bit more in.

Algebraist:Show that parts of it can be put into the refrigerator. Then show that the refrigerator is closed under addition.

Topologist:Have the elphant swallow the refrigerator and then turn it inside out.

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

Linear Algebraist:Show that 1% of the elephant will fit inside the refrigerator. Then, by linearity,x% will fit for anyx.

Affine Geometer:There exists an affine transformation that will allow the elephant to be put into the refrigerator.

Set Theorist:It’s very easy — refrigerator = {elephant}

Geometer:Create an axiomatic system in which “An elephant can be placed in a refrigerator” is an axiom.

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

Numerical Analyst:Put its trunk inside the refrigerator and refer the rest to the error term.

Statistician:Put its tail in the refrigerator as a sample, and say, “Done.”