Monday, January 26, 2015

Turing, Veblen, Bicycles, Movies and Theater

I'm posting with permission this email from Steve Kruse, who among many other interests is a strong advocate for better bicycle routes in Princeton. He offers all sorts of interesting links and connections related to Alan Turing and the movie about him that's showing in town. Other recent events related to Turing in the Princeton area were a talk by author Andrew Hodges ("Alan Turing: The Enigma") this past December at the public library, and a Passage Theatre performance I happened to catch by the extraordinary actor June Ballinger of a solo piece she is developing about her mother, who worked for Turing at the Bletchley Park codebreaking center.

Various themes associated with Veblen House can be found in Kruse's email. First of course is Veblen's role in building the Princeton math department that attracted Turing to town for two years. There's also the reference to prefab housing, which the Veblen House is a unique example of, the house-in-the-woods theme of Snow White, and the bicycles we hope will one day have good routes out to Herrontown Woods from town.

Steve Kruse's email:

I recently watched "The Imitation Game" at the Garden Theater,
and can recommend it. As a computer engineer, and having 
seen "Breaking the Code" on Broadway many years ago, I already
knew quite a bit about Alan Turing's triumphal/tragic story. Plus
my parents both grew up during WW2 in coastal towns where
convoys, escort warships, and long-range patrol planes were part
of the everyday scenery; our cottage had been a prefab naval hut.

Turing spent 1936-38 in Princeton, obtaining his doctorate in
mathematics. He resided at 183 Graduate College and likely
spent a substantial amount of time in Fine Hall, which has
since been renamed Jones Hall. His supervisor was Alonzo
Church, who was recruited by Oswald Veblen (no relation),
lived at 30 Jefferson Rd and is buried in Princeton Cemetery.

Turing defended his Ph.D. thesis in May 1938, at a time when 
his favorite movie, Snow White and the Seven Dwarfs, had
already been playing in the cinema for several months. Since
the Garden Theater opened in September 1920, there's a
chance I watched the Alan Turing biopic in the same space
where Turing watched and was inspired by the Disney movie.
However, since Turing actually wrote most of his thesis while
back in Cambridge, this coincidence seems almost as unlikely
as the odds that a machine-assisted human would crack Enigma.
 
There are several anecdotes with regard to Alan Turing and
the bicycle. One concerns cryptography, as it relates to the
links of a bicycle chain, as told in Understanding the Enigma:

   "Cryptonomicon by Neal Stephenson is an interesting and 
    informative novel tying together different generations of 
    cryptography. A passage I found most interesting was in 
    the chapter ‘Cycles’. In this chapter, Stephenson expands  
    on the fundamental mathematics behind the Enigma machine: 
    modular arithmetic. Stephenson compares modular arithmetic
    to Turing’s bike. For some reason, Turing’s bike has a rear wheel
    with one bent spoke and a weak chain link. When the spoke comes
    into contact with the chain at a certain position the chain will fall apart.

Additional details are given in That Strange Bicyclist, Alan Turing:

   While working at Bletchley Park, Alan would use the bicycle to 
   commute to work as well as to get around Cambridge. The bike, 
   however, was an old and defective machine. It also had an interesting 
   problem. As you pedaled it, every so often, the chain would pop off 
   and disengage from the chain ring. Every time this happened, he had 
   to hop off the bike and put the chain back on. [...] He loved his dying 
   bike and would not give it up for something better. In fact, he enjoyed 
   riding such a poorly functioning machine that no one else could. So how 
  did he ride it? Well, legend (from reading an article by Ian Stewart in 
  Nature) has it that he chose the most tortuous path to devising a 
  solution for the problem.     
 
  [...] That's not all. Turing had a bad case of hay fever allergy from an early 
  age. He rationalized that to filter pollen away from irritating and exacerbating
  town, even in the rain. He was indifferent to what others thought about this practice.

In cycling lingo, you eventually decide it's more cool to say "I shipped the chain"
than "my chain has fallen off". So whenever this happens, remember Alan Turing
and all those ships he kept from going to the bottom of the North Atlantic ocean.