The first time I heard Alan Turing’s name was in a computer science class where we studied different kinds of basic machines and how they work. One of them was called a Turing machine. Alan invented it.
In modern academia, the focus lies on the theoretical model behind the machine, but this is what his implementation looked like:
It looks big and clunky and mysterious, but on the inside, you can imagine it a bit like this:
A Turing machine really only does a few things:
- It moves a tape back and forward. The tape has symbols on it, each written down in a single cell.
- The machine reads these symbols, one at a time.
- Then, it decides what outputs to generate based on the inputs it receives.
- Finally, it writes the output on the tape and moves on to the next cell.
Despite its seeming simplicity, the Turing machine changed the course of history unlike any other invention ever made. The moment Alan Turing got his theoretical model to work inside a real-world machine is one of the greatest moments in the history of mankind.
Here’s why.
The Device Behind the Glass
In the summer of 2016, I visited a spies and secret agents exhibition with my Dad. There were a ton of cool things to see, like tranquilizer pens, rigged phones, and agent files. But when I saw this one, little machine, sitting behind a window, I stopped dead in my tracks.
Photos weren’t allowed, but this is what it looked like:
The machine is called Enigma. The word is Greek and means ‘mysterious.’ It’s a coding device which was invented by a German engineer, Arthur Scherbius, at the end of WWI. Over time, others refined and improved the machine. In WWII, it was used to encrypt all German military communication.
By that point, its code was considered uncrackable. Since it used different rotors, letters and numbers to transform the letters in messages, Enigma could create up to 158,962,555,217,826,360,000 (nearly 159 quintillion) different settings — which the Germans changed every 24 hours. As I said: uncrackable.
Captain Ridley’s Shooting Party
After graduating from Cambridge and getting his PhD in mathematics from Princeton, Turing worked part-time for the Government Code and Cypher School, helping to decipher encrypted messages.
On 4 September 1939, the day after the UK declared war on Germany, Alan Turing reported to Bletchley Park, where he and a team of the best British scientists would work on breaking Enigma.
After almost two years of endless decoding, modeling, calculating, moving to a restricted area even within the already super secret government facility and spending thousands of pounds and hours on building his machine…Alan Turing got it to work.
On July 9th, 1941, the Turing machine broke the Enigma key.
An Unfair Advantage
From that moment on, the allied forces could decode all German intelligence, unbeknownst to them. This is what those decrypts looked like in progress:
Until the end of the war, for another four years, the allies had an incredible advantage, which, ultimately, won the war. Historians estimate that breaking enigma shortened the war by two years, saving over 14 million lives.
But here’s the kicker: After the war ended, the concept of the Turing machine was analyzed, improved, and built upon. As a result of generations of research about Turing machines, we now have a different name for them.
They’re called computers.
Out of the War and Into Prosperity
I couldn’t write this without Alan’s work. And you wouldn’t be able to read it.
One man almost single-handedly took us out of one of the worst periods in history and into one of the most prosperous. Alan Turing helped end WWII and invent the computer. The moment the gears of his machine clicked into place in the right position for the first time is the origin of both.
In one instant, he changed what history books would say looking back and what technology would allow humanity to do going forward.
That’s what I remembered when I saw that little machine, resting behind the glass in that museum. And I think it’s fascinating that one man was able to change history twice in a single moment.