Around my leg, I have a few hundred of the digits of φ tattooed in a spiral.

Phi (the letter φ and pronounced like “fly” without an l) is a Greek letter that stands for approximately 1.61803398874989484820… and so on. As an irrational number, it never repeats and never ends.

So if you opened up a web page with a big list of the first 10,000 digits, you’d probably find your birthday in it somewhere.

As a math teacher, I have a lot of things to say about Phi and its mathematical implications, which is why I got a tattoo on φ-day, 1/6/18 at 3:39. If this all sounds foreign and weird, this page should give a primer for math-enthusiasts and regular people, too.

Ugh. I don’t want to read all this.

If you’d like some more easy-to-swallow descriptions, here’s what I showed my 10th graders:

Why φ as a tattoo?

The math-teacher-in-a-classroom part of my career is pretty much over. For seven years of my past, teaching students about math was the most important thing while I was on the clock, and I want to pay some homage to that part of my life with a number-themed tattoo. This tattoo goes well with some text on my other leg, which also has writing from a sister.

For irrational numbers, I have some options; π is the most popular. The connection of math to nature and creation has fascinated me since I first heard about it, and it’s soothing to know that there’s order in the universe and that [prior to humans] nature has found a sort of equilibrium that scientists can mostly describe. That’s why I chose φ instead of π.

And, I’m on the early end of the generation called Millenials who typically value uniqueness, and this is probably a tattoo that, like, nobody else has, man.

Where does φ come from?

First, the Fibonacci Sequence:

Then, the Golden Spiral

Five hundred years after Fibonacci (and a few thousand after Pythagoras), another famous mathematician named Johannes Kepler noticed that dividing [a Fibonacci number by the one previous to it] resulted in an approximation of Golden Ratio, a comparison between two things that is pleasing to the eye.

Here are some notable examples:

As a math teacher, I had my students measure their bones and divide them (to find their own Golden Ratio). Then I awarded a Burger King crown to the students who were “the ideal Renaissance beauty! All hail Lupe of the Golden Arms!” or whatever.

I should note, as far as the Weirdest Lessons I’ve Done, this one doesn’t even crack the top ten.

And I used this dope setup from TTT Press as an Appetizer at least once a week that whole year.

How did you make that font?

Okay, maybe you weren’t curious about that part, but I’m hella proud, so here it is:

  1. Ask my two sisters to send me a handwriting sample of  φ ≈ 0123456789
  2. Copy-paste their values (half from each sister) onto the template from Calligraphr.
  3. Upload the PDF with pasted-sisters’ handwritings onto Calligraphr
  4. Using the Wi-Fi on a Southwest flight, which is the most effective it’s ever been
  5. Download the font file,
  6. Upload the font into Microsoft Word,
  7. And apply that font to the big list of φ digits from this site, which I’d grabbed when wi-fi was good.
  8. Print in a few varying font sizes, because I want options when I arrive at the tattoo studio.
  9. Forget the prints on the printer at home and be late for your tattoo appointment to go back and get them.

I’ve got lots of tattoos, ask me to see them.

~Matt “It’s ouchy but worth it” Vaudrey