Alan Turing and the Day of Silence
One of the things I wish I did more in my physics classes is to introduce students to more of the history and social implications of science. I personally find the history of science to be fascinating, and books like Age of Wonder (which I’m still dying to read) really make wish I could find a way to share this with students, particularly the idea that science isn’t just the pursuit of stodgy old white men.
Since I teach modeling physics, which puts students in the role of having to discover most of the laws of physics for themselves, I somehow hope this message will just sort of be absorbed by osmosis as they see themselves reflected in their own work, but, in reality, I know this isn’t true.
Typically, I’ve had one day each year where I do digress into a a lecture and give my students a presentation on one aspect of the history of science I find to be particularly important. One of the best history of science shows I’ve ever seen is the show Connections, by James Burke, who is this wonderful charismatic historian, who starts every show off with a modern vignette, like the NYC blackout of 1965, and describes how it all started with the invention of the plow in ancient Egypt. You can watch almost all of these episodes online, if you’re looking something to watch.
So I tell my students about Connections, and how I’m going to try to weave my own little story together, describing how cracking the Enigma, winning a world war, inventing the ipod and Alan Turing are related. You can see the slide deck at the end of this post.
I start with the story Alan Turing, a person who none of my students have ever heard of. I describe how he was a boy deeply fascinated by science, who went on to study math and logic at Cambridge. I tell them about how there was some focus in philosophical circles to prove all of mathematics from the most fundamental principles, and mention Bertrand Russel’s and Afred North Whitehead’s humongous proof of 1+1=2 in Principia Mathematica. We then talk about how this world was thrown upside down by Godel, who showed that even in the most formal system of mathematics, there are some questions that lie outside the reach of logical proof—so called undecidable questions (eg. There is no proof of P). (Every year, I read up more and more on this stuff, and find myself able to explain it to students only with the wildest of hand-waving).
But this is the world Alan Turing found himself in at college, and he was instantly fascinated by the idea of what makes a question decidable. This eventually led turing to imagine a machine (computer) that could perform any question (calculation) using an algorithm (program), and ultimately to theorize that any decidable question should be computable (The church Turing Thesis). This became the big idea of computer science—given enough space and time, any decidable question can be answered by a computer. This imaginary machine predates electronic computers by more than 10 years.
From there, we divert into a brief history of codes and ciphers, and I discuss how breaking encryption really is nothing more than a decidable question that a computer should be able to solve given enough time and storage space. I discuss the german encryption machine, Enigma, used extensively in WWII, and how Alan Turing’s work was critical to breaking its cipher, which gave the Allies a decisive advantage in the war, shortening it by years, and saving many lives.
From there, I take a leap to the ipod, which again, is an example of a turing machine in action.
- Write music down digitally on a hard disk
- Build a machine to read and write to that disk
- Write an algorithm (program) to manipulate that data on the disk and send it to the speaker
But the computer is a universal machine, so it’s easy to change the algorithm to make it record your voice, edit your songs, or even auto-tune to correct your pitch. By adding a camera you can do similar things with photos, and it’s no wonder that thanks to 10 years of Moores Law working on the ipod, you can now use your iphone to translate speech in near real time. But of course, the power of computing also has a down side, as every bad use of your data is just as possible as good uses.
And so, this is where things wind down, and I tell my students that Alan Turing wasn’t just one of the greatest mathematicians of the 20th century, or the key figure in the Allied Victory in WWII, or even just the father of the iPod/iPhone/iPad…
He was also a homosexual. And he was silenced. (I give this talk on the day of Silence—April 15, a day when when students nationwide take a vow of silence to bring attention to anti-LGBT name-calling, bullying and harassment in schools”).
Turing admitted a homosexual relationship in 1952, and was charged, tried and convicted of “Gross Indecency” in the british courts. He was forced to consult a psychiatrist, undergo hormone treatment, and lost his security clearance.
In 1954, he became depressed, and committed suicide, dying at age 42, in the prime of his life.
If he had lived, he would be 98 today—what contributions might he have continued to make to society with the rest of his life?
Usually, this is a powerful talk, my students are truly stunned when they learn of the suffering Turing had to endure. Few of my students have heard of the day of silence, and like many schools, many of my students treat homophobic language and harassment far more casually than they should.
And while I to think this talk has an effect on my students, I really wonder if I could transform it to be even more effective by making it more engaging, but I’m not quite sure how.
So I’m throwing it out on the internets for your thoughts, criticisms and ideas. How have I mangled Godel’s theorem or the Church Turing thesis? What would be a good follow up to get my students thinking more about the contributions marginalized people have made to science? How can you extend conversations like this throughout the year?
Many of the ideas in this talk were inspired by and borrowed from Simon Singh, whose book The Code Book gives a fantastic accounting of the race to crack Enigma and a presentation on the power of computers I once saw by Princeton Computer Science Professor Ed Felten.
update: I just found out that a documentary about Alan Turning seems to be in the works, and the trailer looks fantastic. I will definitely add this to my presentation.