Sam henry | Particle Physics Gadgeteering 

One of the most memorable lectures I have attended was a talk by 93-year-old Joseph Rotblat, entitled “Preservation of Life in a Nuclear Age”. Professor Rotblat was a Polish-born British physicist who had worked on nuclear fission and the Manhattan Project. He was the only scientist to quit the project on moral grounds, once it was clear that Nazi Germany was not a nuclear threat. He had subsequently campaigned for nuclear disarmament and was awarded the Nobel Peace Prize in 1995 together with the Pugwash Conferences.

The event was the International Conference of Physics Students (ICPS) 2001 in Dublin, attended by undergraduate and postgraduate physicists from all around the world. He was an old man. He spoke slowly and carefully. He had some difficulty standing for long periods and hearing questions. But he had the young audience’s absolute attention throughout and got a standing ovation at the end—the only time I remember that happening in a physics lecture.

ICPS was an appropriate event for such a talk. The student conference had been started in Hungary in 1986 with an idea of promoting interactions being east and west. At that time it was rare for students from Warsaw Pact countries to meet with those from Western Europe, but borders were starting to open. In 1989 the Berlin Wall fell and a decade later the Iron Curtain was no more. Unusually for a student-run event, the event has been held every year since then, allowing hundreds of students to meet up for a mix of physics talks and social events. It continues today.

When we all arrived in the Irish capital that summer, we weren’t thinking about grand visions to advance international friendship. We just saw it as a chance to meet up for a fun-filled week of physics and parties. Which was, in effect, the same thing. Rotblat was one guest speaker, alongside other talks exploring subjects such as the physics of Guinness. Our biggest worry that week was preparing for the traditional ‘national party’ where participants were expected to perform a short song or dance from their home country.

Rotblat told how, upon learning of the principle of the nuclear chain reaction, he found the idea of such a weapon so abhorrent that he put it out of mind. Yet he then reluctantly decided it was necessary to develop it as there was a real fear of Nazi scientists getting there first. He said his decision to leave Los Alamos came after learning from a conversation with an American general that by that point they saw the primary reason for developing the bomb was the Soviet Union. In his mind the point of building the bomb was never to use it, but to deter the other side from doing so. In a 1985 article he wrote the same argument he gave to us:

“With the wisdom of hindsight, I can see the folly of the deterrent thesis, quite apart from a few other flaws in my rationalization. For one thing, it would not have worked with a psychopath like Hitler. If he had had the bomb, it is very likely that his last order from the bunker in Berlin would have been to destroy London, even if this were to bring terrible retribution to Germany.”

His talk had none of the apocalyptic visions that you might expect from an anti-nuclear campaigner. It was a straightforward analysis of the logic of a nuclear deterrent. He explained that the flaw in the concept was the assumption that you were dealing with a sane adversary. In 1962, when the world held its breath during the Cuban missile crisis, we were fortunate that Kennedy and Khruschchev were both sane.

The logic of his argument was sound, but at the time it did strike me as hypothetical. It was surely extremely unlikely for a political leader at the top to fall victim to insanity. I had the worldview of a young student. 1945 was distant history to me, but not for Rotblat. This week, over sixteen years after that summer, his argument came back to me as I read Donald Trump’s boasting of the size of his Nuclear Button, followed by this analysis of the president’s state of mind, and potential consequences, in The Atlantic:

“A president could be actively hallucinating, threatening to launch a nuclear attack based on intelligence he had just obtained from David Bowie, and the medical community could be relegated to speculation from afar.”

Particle physicists invented the bomb. The Cold War was the main reason why politicians in the 1950s were happy to put large amounts of money into our field. Not many physicists express any enthusiasm for nuclear weapons. Indeed we often do all we can to distance our research from anything military. We would rather enthuse about all the amazing medical applications and other things that we are responsible for. There are famous physicists who have actively campaigned for nuclear disarmament, such as Rotblat and Andrei Sakharov, but it seems the most common attitude is just to ignore the issue and work on other projects.

One reason why, at his advanced age, Joseph Rotblat was willing to travel to Dublin to talk to an audience of physics students, was his desire to educate the scientific community about the issues surrounding weapons research. At the time he promoted the idea of a ‘Scientist’s Oath’,  a promise to not knowingly carry out research to the detriment of humanity, and (in the event that it is used to the detriment of humanity) to actively combat its development.

The idea of a formal oath never really took off. Activism of any sort requires dedication and time, and to students with exams to prepare for and theses to write, this is not easy to sustain. Like the rest of the audience I applauded Rotblat’s talk, but never joined any campaigns.

Sixteen years later we watch the posturing of Kim Jong-un and Donald Trump, and hope that both men are sane.