The Digital Big Bang

March 12, 2012

Recently, in a couple of posts about some recently declassified correspondence between the mathematician John Nash and the National Security Agency, I mentioned the confluence of very bright people in and around Princeton NJ shortly before, during, and after World War II.  Besides John Nash, the list includes Albert Einstein, John von Neumann, Kurt Gödel, and Alan Turing.  Another was the theoretical physicist Freeman Dyson, now Professor Emeritus at the Institute for Advanced Study (IAS).

I have just come across another discussion of that period, in the form of an interview at Wired with the science historian George Dyson, Freeman Dyson’s son.  concerning his new book on the origins of modern computing, Turing’s Cathedral.  George Dyson grew up in Princeton, while his father was at the IAS, and had some direct personal experience with some of the early computer development there.

The institute was a pretty boring place, full of theoreticians writing papers. But in a building far away from everyone else, some engineers were building a computer, one of the first to have a fully electronic random-access memory. For a kid in the 1950s, it was the most exciting thing around. I mean, they called it the MANIAC!

After the work of the Manhattan Project in developing the atomic bomb, von Neumann had persuaded the US government to fund the development of a digital computer, to be used for the development of the hydrogen bomb.  Although there were other early computers, including ENIAC and EDSAC, the development was significant, because it was the first computer to have a fully modern stored-program architecture (which is still called a von Neumann architecture).

George Dyson’s initial fascination with the project apparently developed into a more apprehensive feeling a little later, when he tried to distance himself from computers.

Computers were going to take over the world. So I left high school in the 1960s to live on the islands of British Columbia. I worked on boats and built a house 95 feet up in a Douglas fir tree. I wasn’t anti-technology; I loved chain saws and tools and diesel engines. But I wanted to keep my distance from computers.

He eventually returned to study digital development, because he was struck by the similarities between the biological and digital worlds.

When I looked at the digital universe, I saw the tracks of organisms coming to life. I eventually came out of the Canadian rain forest to study this stuff because it was as wild as anything in the woods.

In the balance of the interview, Dyson talks about some of the people most directly involved in the project, including Turing, von Neumann, and Julian Bigelow, the engineer who directed the actual construction — a difficult job just after the war, when many materials and facilities were hard to come by.   The biologist Nils Barricelli used the machine to simulate the evolution of digital “life forms” when it was not busy simulating thermonuclear explosions.  Dyson also makes an interesting observation about a side effect of the early hardware’s unreliability.

Vacuum tubes in the early machines had an extremely high failure rate, and von Neumann and Turing both spent a lot of time thinking about how to tolerate or even take advantage of that. If you had unreliable tubes, you couldn’t be sure you had the correct answer, so you had to run a problem at least twice to make sure you got the same result. Turing and von Neumann both believed the future belonged to nondeterministic computation and statistical, probabilistic codes.

As Dyson points out, the idea of probabilistic computations has produced some intriguing results recently, in areas like language translation, as well as in IBM’s Watson project.

Although I have not yet got my hands on a copy of Dyson’s book, it sounds most interesting  There is a review at The Economist, and another at The Wall Street Journal.

%d bloggers like this: