## Archive for March 30, 2011

### MJ4MF Review

I was delighted to open the April issue of the *Mathematics Teacher* journal and discover a review of *Math Jokes 4 Mathy Folks*. Reviewer Leah Evans had some nice things to say:

Math Jokes 4 Mathy Folksis a delightful read. The author has compiled a vast array of puns, quips, and jokes meant for people of varied ages and mathematical expertise.[…]

I highly recommend this book as a diversion from the rigor of mathematics. It allows us to have a good laugh (or a long groan) at a joke that only “math nerds” would get, and it points out that humor can be found in all mathematical applications, even a telescoping series.

I love the cliffhanger at the end! The reference to a “telescoping series” is — I think — in regards to this joke (p. 89):

If you’re interested, here’s a copy of the entire review. (Click on the image to view a full-size version.)

### Lead by Counterexample

A wonderful, handwritten sign hangs on the door to my friend’s office:

There is no way of falsifying, “Unicorns exist.”

This is a good example of the nature of mathematics. Although providing just one counterexample is proof that something is not true, the inability to provide a counterexample is not proof that something is true. Understanding this concept is fundamental to understanding mathematics. Perhaps this guy could use a refresher…

At a conference, a mathematician proves a theorem. A young woman in the audience interrupts him. “Excuse me, sir, but I believe that your proof must be wrong. I have found a counterexample to your theorem.”

“Not a problem,” the speaker replies. “I have another proof.”