Over the next years I came to realise how foolish I had been. The Plumbbob series, to which Smoky and Galileo belonged, were the biggest and longest series of tests ever done in the continental United States. There were 29 tests beginning on 28 May and ending on 7 October. The highest explosive yield was Hood, the test that took place on 5 July – the equivalent of 74 kilotons of TNT. The Nagasaki bomb was about 20 kilotons. Smoky was the second highest, with 44 kilotons equivalent. The series, during which the total yield was about 306 kilotons – something like a tenth of the yield of one hydrogen bomb – released about 58,300 kilocuries of radioiodine into the atmosphere. This fallout was distributed all over the United States and is estimated to have caused about 32,000 cases of thyroid cancer. Twelve hundred pigs were exposed to the explosions in blast-effect studies, and 18,000 servicemen also participated. Roughly 1200 watched the Smoky explosion from a distance of about 13 kilometres. A unit was flown to ground zero some 15 minutes later. They declared that it was safe to occupy so the rest were flown in twenty minutes after the explosion. The exercise was completed at 9.45 a.m., which was when I heard the helicopters. Some of these men later contracted leukaemia.

The plutonium pit I was given to hold was so light because it was hollow. The weapons being tested that summer were ‘boosted’: deuterium and tritium gas were injected into the cavity just before the explosion. I believe the vacuum pump I heard when we visited Galileo was connected to this. When the pit is imploded, and the density is increased enough to reach a supercritical mass, the fission chain reaction begins. When about 1 per cent of the plutonium has been fissioned, the temperature is raised to the point where the fusion reactions of the deuterium and tritium take place. These produce a blast of very high energy neutrons which boost the subsequent fission efficiency. That is what accounted for the large yields in some of the bombs tested that summer. There is no end to the ingenuity that was being applied to weapons design.

At Los Alamos by Jeremy Bernstein [London Review of Books]

I struggle with this all of the time, this being a simultaneous love, horror and respect for the conclusions and implications of certain scientific work. In one of my courses last semester I had a lot of debates with my classmates. I had to concede that despite sharing similar reservations about the scenarios in our readings, I was also enthralled by the ingenuity of some of the science that we were critiquing. I couldn’t help it. They would accuse me of being a part of the problem, and I would accuse them of flattery.

There are a wide range of opinions on the proper limits of science, I don’t know them all but I am grateful for all of them.

Reasonable men can dream monstrous dreams. It is the lesson of the 20th century: a lesson articulated from various perspectives since Adorno and Horkheimer wrote Dialectic of Enlightenment amid the wreckage of World War Two. Defenders of the Enlightenment can cogently argue (and many have) that Nazi science was a grotesque caricature, that the Holocaust was a betrayal of the Enlightenment rather than a fulfilment of its fatal dialectic. But it is harder to make that case with respect to the development of nuclear weapons. Indeed the subject seems designed to lay bare the contradictions at the core of Enlightenment culture by revealing them at work in the subculture of professional physicists bent to the needs of government power. Few social laboratories could more clearly reveal the tensions between chauvinist impulses and humanist aspirations, or between careerist plotting and disinterested service, or – perhaps most important – between the Enlightenment ideal of intellectual openness and the demands for secrecy made by the national security state.

The history of nuclear weapons began in an atmosphere of creative ferment and international trade in ideas. This was the world of Knaben3physik (‘boy physics’) in the 1920s and 1930s, when young men who had not been shaving for more than a few years were excitedly reading one another’s papers and poring over the results of experiments in Cambridge, Göttingen, Copenhagen and (eventually) Berkeley. This was how Niels Bohr, Werner Heisenberg and others created the foundations of quantum physics. Yet within less than a decade this moment had passed. Olympian conversations were drowned out by fascist chants. Jewish physicists, led by Einstein, fled to America; Heisenberg stayed in Germany; Bohr stayed out of sight in occupied Denmark. The concentration of research effort shifted westwards across the Atlantic. But it was research with a new, pragmatic mission: to build an atomic bomb before Hitler did. Theories conceived in open exchange were harnessed to secret purposes, and illuminating ideas were pressed into the service of mass death. No wonder some of the atomic scientists felt remorse, or at least ambivalence, about their achievement; no wonder some began to glimpse the darker dimensions of Enlightenment when the blinding flash of the first atomic explosion revealed their labours had not been in vain

Oh God, what have we done? by Jackson Lears [London Review of Books]

The campus I currently study at has a street named after J. Robert Oppenheimer,

Granted that alongside Ernest Orlando Lawrence he built the damn American school of physics on this campus, but I’ve always found it incredibly fascinating given the conflict presented in the text above.

I also love Hans Bethe’s quote that Oppenheimer ‘worked at physics mainly because he found physics the best way to do philosophy.’ And I think that many on this campus, and elsewhere, still believe this to be true of themselves because of figures like J. Robert Oppenheimer.

Although Philosophy of Physics is still pretty cool.