Bioethics Forum Essay
Oppenheimer’s Nuclear Value Judgment Wasn’t the First
Christopher Nolan’s film, “Oppenheimer,” which opens in theaters on July 21, highlights a value judgment that the Manhattan Project scientists had to make before Trinity, the test of the first atomic bomb. They had to calculate the odds that the “gadget” wouldn’t initiate a catastrophic chain reaction that could ignite Earth’s atmosphere. In so doing they implicitly invoked two dimensions of risk, probability and magnitude, where in this case the probability of an error was low, but the magnitude of an error was immense. They also needed to factor in another dimension of risk: the suspicion that Nazi Germany’s formidable scientific establishment was on course for its own atomic device, which would have been a catastrophe for human civilization of a different sort.
But that fateful judgment in Los Alamos, New Mexico, in 1945 wasn’t the first such determination that Project scientists needed to make. That took place in 1942 as part of the work in the top-secret Metallurgical Laboratory on the University of Chicago campus, where other great physicists like Arthur Compton, Enrico Fermi, and Leo Szilard were working on the first nuclear reactor. Known as the Chicago Pile, the immediate purpose of the reactor was to generate sufficient plutonium to power a bomb. In the course of testing when the material would reach the point of criticality, they controlled the reactor by inserting and withdrawing cadmium control rods. If their calculations had been incorrect, a large part of Chicago would have ceased to exist.
We don’t know if the experience with the Pile figured into the judgment of Robert Oppenheimer and his team, but scientists make value determinations all the time. In a classic 1953 paper called “The Scientist Qua Scientist Makes Value Judgments,” the philosopher of science Richard Rudner (who was my dissertation director) used the Pile as an example of the way scientists inevitably make moral choices. He argued that the acceptance of any scientific hypothesis requires that the evidence in its favor must be strong enough for the risks to be morally acceptable. To the atomic scientists in charge of the Pile and the Trinity test the hypotheses were strong enough for them to accept the risks of an error. In other words, they made a value judgment.
Rudner argued that moral choices in science are so routine that we don’t notice them. Take an example from drug research. Imagine that of two potential medications one would be far more beneficial to future patients if it worked, but an experiment for that one would pose higher risk to human volunteers. The experimenters would have to find the risk-benefit balance to be favorable enough to offer the drug to human subjects. Though far less spectacular than the Manhattan Project experiments, the consequences of error would be significant in placing people in a study at risk. Unlike the Pile and Trinity, in which neither the people of Chicago nor the inhabitants of the whole planet were asked for their permission, the people who agree to be in a drug study must give their informed consent.
Human civilization is now in a different sort of experiment, one that Oppenheimer predicted. This poorly managed experiment is based on the theory that human control of these awful weapons can succeed indefinitely. Thus, we are sleepwalking into disaster. The consequences of being wrong are too great, and the probabilities are not in our favor.
Jonathan D. Moreno the David and Lyn Silfen Professor of Ethics at the University of Pennsylvania and a Hastings Center Fellow. (@pennprof)