Dogs teaching chemistry

Chemical bonds

The Atom

Lands’ End catalog

Under the category “Weird but True”: In today’s junk mail, I learned that Lands’ End has an entire line of clothing $f(x)$ , apparently targeted toward mathematicians.

Epsilon

Years ago, when I taught calculus, I’d usually include the following extra credit question on the first exam: “In the small box, write a good value for $\varepsilon$ . A valid answer gets 4 points; the smallest answer in the class will get 5 points.” It was basically free extra credit… any positive number would work, but it was a (hopefully) fun way for students to be a little competitive in coming up with small positive numbers, which is the intuitive meaning of $\varepsilon$ in mathematics. (I still remember when my high school math teacher was giving me directions to a restaurant, concluding “You’ll know you’re within $\varepsilon$ of the restaurant when you see the signs for Such-and-Such Mall.”)

Most students volunteered something like $0.0000001$ or $10^{-9999999999999999}$ . Except for one particularly gutsy student who wrote, “The probability that Dr. Q gets a date on Friday night.” For sheer nerve, he got the 5 points that year.

Also getting 5 points that year was the best answer of the class: “Let $x$ be the smallest answer that anyone else wrote. Then $\varepsilon = x/2$ .” That was especially clever from a calculus student, as that’s the essence of a fairly common technique when writing proofs in real analysis.

Typographical error (perhaps)

Here’s a great typo that I saw on a paper submitted by one of my former students who aspires to be a secondary math teacher. Instead of writing “engaging one’s students,” she accidentally wrote “encaging one’s students.”

Something we’ve lost

A quote from George Will, from the extended commentary of Ken Burns’ excellent series on the Civil War.

How the common men and women of [the Civil War era] used the English language at that time is worth pondering. I think the normally literate 19th century American had as his entertainment popular novels: Balzac, Dickens, George Eliot. They didn’t turn on the television; they weren’t in that passive receiving mode. They were in the active mode, which reading is, and popular entertainment then was popular novels. Dickens: not bad. Also, they didn’t pick up the phone when they wanted to communicate. They wrote letters. They had the discipline of expressing themselves in complete sentences and rounded paragraphs. And that’s something we’ve lost.

Binary magic trick

I found this magic trick in a set of Christmas crackers a couple years ago which is completely based on binary arithmetic. The link above does a good job of explaining why the trick works — and how a new trick can be generated using base-3 arithmetic.

Finite simple group of order 2

I like showing this to my students around Valentine’s Day. The singers were math grad students at Northwestern.

Design of scientific trials

For years, I’ve used the following clip in my Applied Statistics class when introducing randomized controlled experiments and observational studies. It was a big hit every single time.

STEM promotional video

A few years ago, the folks at Change the Equation asked various corporations to make 3-minute videos that could inspire children to take their studies of math and science more seriously. Here is one of the most impressive entries.

Pendulum waves

Courtesy of the physicists at Harvard: pendulum waves. Click here for more information.