Monday, May 21, 2007

The curve of binding energy

I'm teaching about fission, fusion, nuclear power and bombs in class this week. I always search for the simplest way to organize and present complex material (students may disagree ;-). For this set of topics, I am struck by the elegance of the curve below.

It reminded me of The Curve of Binding Energy by New Yorker writer John McPhee, which I read many years ago. In it, he profiles Theodore Taylor, a leading bomb designer at Los Alamos who eventually became an anti-nuclear activist.

Theodore Brewster Taylor was born on July 11, 1925, in Mexico City. His grandparents had been missionaries, and his father was general secretary of the Y.M.C.A. in Mexico. A brilliant boy (he completed sixth grade the same year he started fourth), Ted was enthralled by his chemistry set, or, more precisely, its explosive possibilities.

"He enjoyed putting potassium chlorate and sulfur under Mexico City streetcars," Mr. McPhee wrote. "There was a flash, and a terrific bang."

Dr. Taylor received a bachelor's degree from the California Institute of Technology in 1945 and pursued a doctorate in physics at the University of California. But he failed his oral examinations - he lacked the capacity to focus on things that did not interest him - and he left the department in 1949. (He would eventually earn a Ph.D. from Cornell in 1954.)

He found a job at Los Alamos. "Within a week, I was deeply immersed in nuclear weaponry," Dr. Taylor wrote in a 1996 article in Bulletin of the Atomic Scientists. "I was fascinated by every bit of information I was given during those first few days."

Preternaturally inept at ordinary tasks (parking a car defeated him), he became an artist of the fission bomb, taking the massive nuclear weapons developed for the Manhattan Project and making them smaller and lighter without sacrificing explosive power. Over the next seven years, he designed a series of ever-smaller bombs, whose cunning names - Scorpion, Wasp, Bee, Hornet - captured both their size and their sting.

Dr. Taylor would develop the smallest fission bomb of its time, Davy Crockett, which weighed less than 50 pounds. (By contrast, Little Boy, dropped on Hiroshima, weighed almost 9,000 pounds.) At the other extreme, he designed Super Oralloy, which was at the time, Mr. McPhee wrote, "the largest-yield pure-fission bomb ever constructed in the world."

Viewed as a theoretical abstraction, Dr. Taylor's work had a cool, compelling elegance. Exploded in the Nevada desert, it made a satisfying flash and bang. The weapons, he often reminded himself, were meant to deter nuclear war, and if the United States did not develop them, the Soviets soon would.

In his 1996 article, he recalled how he spent Nov. 15, 1950, the day his daughter Katherine was born:

"Instead of being with my wife, Caro, I had spent the day at a military intelligence office, poring over aerial photographs of Moscow, placing the sharp point of a compass in Red Square and drawing circles corresponding to distances at which moderate and severe damage would result from the explosion at different heights of a 500-kiloton made-in-America bomb. I remember feeling disappointed because none of the circles included all of Moscow."

Nuclear Weapons Responsibility

Presentation by Theodore B. Taylor, PhD, 20 April 1998, at Mickleton Monthly Meeting, Religious Society of Friends (Quakers)

...It's a long and dreary story, those twenty years or so of working on nuclear weapons. How that happened to take place after my writing home and saying I'm never going to work on these things was, I think, the kind of rationalization that anybody goes through when they are facing an addiction of some kind. That is, you have to make excuses for why you're doing this.

After some student activism at the University of California at Berkeley, in which three of us got very intense about calling for a general strike of all nuclear physicists worldwide, until the bombs were gone, we presented that to [J. Robert] Oppenheimer, who said, "Take it, burn it, forget you ever had anything to do with it, because you're going to be labeled as Communists the rest of your lives if you don't do what I say." Well, we didn't burn it, we didn't forget it, but we didn't pursue it.

Not long after that, I found myself very interested in the work I was doing, which at that time wasn't on bombs, it was high-energy physics at the University of California laboratory. In that situation, I did very well at the laboratory, but I did very poorly preparing for my oral exams on various subjects. I wasn't interested in those subjects. To make a somewhat long story short, I flunked out of graduate school. Although I was reinstated later if I wanted to, my boss at the Radiation Laboratory in Berkeley, Robert Serber, calmed me down. He was very happy with some work I had been doing for him and with other theoretical physicists, and he said, "Don't worry; I'll get you a job at Los Alamos." And so, he called a person who, slightly later, became my boss, Carson Mark, and said, "There's this fellow, here, who's very good at what he's interested and very bad at what he's not interested in. Why don't you hire him? I'll bet he'll do something very helpful to the laboratory."

So Caro - my wife - and I and a four-month-old baby arrived at Los Alamos, November 1949. I suddenly just got so high within a week on what I was doing - finding out there were some real secrets about how these things work, things I had never imagined - but more important to me, as it turned out later, was there were a lot of things not yet followed through. My job was to look for extremes, things that people hadn't really tried before, to answer the question, can you make a bomb that can be fired out of a cannon, can you make a bomb that can be fired out of something more like a rifle, how big can you make a bomb, can you make a bomb that would destroy all of Moscow - which the bomb that destroyed Hiroshima would not do, by a long shot. So I got caught up in extremes. That went on for almost 20 years, not all of it at Los Alamos. I then changed jobs, because I wanted to try my hand at designing nuclear power systems, for peaceful purposes. ...

In reading about Taylor, I couldn't help but notice strange parallels with the life of another cold war Theodore -- Ted Kaczynski, the unabomber.

1 comment:

Orcas granddaughter said...

This was very interesting to find. Ted was my cousin (first cousin once removed, actually) and I knew he was a prominate physicist but I had no idea how remarkable he was. I met him just once (that I remember) when I was a teenager and his family visited for a few days at our home in Tacoma, Washington.

Blog Archive