Sunday, April 1, 2018

Deep Creek Hot Springs Hike and the History of Mathematics (Review of “How Not to Be Wrong”)




In my high school calculus class, many students find it difficult to remain perfectly attentive throughout each 45 minute lecture, taking notes on each problem while also engaging in class to answer questions or perhaps question the teacher. I am, of course, no exception to this rule.

In what I’ve learned from my 13 years in the American public education system (I did not, by the way, take any common core classes), the math education goes something like this: teacher lectures and does a few example problems, you the student independently do homework, review answers, take a test with slightly different questions, and then proceed to forget the majority of whatever you’ve just learned.

A few days ago, my class began delving deeper into the realm of limits and sequences. At one point in the lecture, my teacher interrupted to say something like this: all your life, you’ve been taught to do math, empirically. You may not have understood why to proceed a certain way when solving a test or understood which formula to use, but you begin learning some of these reasonings as you graduate from class to class.

Which I guess, makes sense.

But a while ago, someone had recommended to me a book entitled How Not to Be Wrong: the Power of Mathematical Thinking by Jordan Ellenberg. I had read the introduction (only, yeah I know, I know) and wrote a review of the novel’s beginning anecdote, which can be found here.

Several months later, I decide to take a hike outside of San Bernardino, to a hot spring site in a place called Deep Creek Canyon.

The hike and subsequent adventure were actually wonderful: it felt so good to enjoy the absolute, irrevocable silence of the canyon -- no noise, traffic, or pollution -- so quiet you could only hear the blood rushing in your ears.

The springs themselves were a delight as well! After about an hour hike down into a canyon, we waded across a freezing stream to have lunch on some sun-drenched rocks overlooking the cold river. Afterwards, we alternated between the just-on-this-side-of-uncomfortable hot springs and the freezing creek, not unlike Japanese onsen. Someone had set up a slackline across the freezing river, which we took turns attempting to cross as well.


Where does the math come in? you might ask. Well, we used Newton’s Law of Cooling to calculate the rate at which our body temperature dropped after plunging into the mountaintop snow-cold water. Just kidding.

Hardly any math was used that day: we relished in the torpor of a hidden getaway in the middle of the desert, sprawling in the drowsy hot springs before feeling the adrenaline paramount to a freediver’s thrill at submerging in our icy creek.

But -- there was a lull in the middle of the day wherein my companion pulled out a new copy of a Cicero book, and I my iPhone, finally beginning to read Ellenberg again.

It didn’t feel like math.

Ellenberg explains one of the basic ideas in calculus: limits. He begins with explaining how early mathematicians found the number pi -- anecdotal style.

It’s not a strange concept to me -- irrational numbers. Pi, Euler’s number, and the like. But discovering irrational numbers? Basic human intuition understands the concept of whole numbers relatively easily. One toga, two goats, three laurel wreaths, four stuffed grape leaves. Half of a stuffed grape leaf may be easy to imagine. But 3.1415 grape leaves?

When graphing curves and parabolas in math, if you zoom in close enough to any curve, it resembles a line. In statistics, this method of representing data, known as linear regression, often simplifies trends when viewing data with a microscope -- that is, looking at only small chunks of data.

The legend Archimedes decided to find the area of a circle by inscribing other shapes, like squares, pentagons, and octagons, inside of a circle. The area of the polygon contained with the circle represents the area of a circle the more sides that polygon has.

For example, the area of an octagon within a circle better resembles the circle’s area than a square within a that same circle. Archimedes theorized that a circle was simply a polygon, and its area could be calculated by calculating the area of a polygon whose numbers of sides approaches infinity. Here’s a catchy slogan Ellenberg presents: “straight locally, curved globally.”

Math has this wonderful, complex, and quirky history seemingly irreconcilable with what I’ve learned in class, at least up until this year.

This year, I’ve had the pleasure of encountering several elegant equations, such as this one:


Euler’s equation uses two of the most irrational numbers, e and pi, as well as the imaginary i and 1 and 0.

It seems counterintuitive to read about math, but I think the introduction of mathematical ideas through anecdotes -- such as how Cauchy, a professor who both infuriated and inspired coworkers and students alike when he taught his freshmen students his own cutting edge take on calculus when the curriculum nearly the opposite -- makes math more approachable, less of a tool you use out of necessity and more of a concept you develop and harness as your own. It’s a living thing with its own history and archaic notions, an art form if you look at it a certain way as well. I’m sure many more complicated equations relating to earth and space are equally as deserving of awe. But for now, I’ll continue reading on.

Until then!