Robert Oppenheimer, Hans Bethe and the value of balance and compromise

Should you be involved in political causes and activism as a scientist? This was a question that squarely confronted many of the twentieth century's scientists, and it heralded a meld of politics and science that continues to challenge and haunt us today. No other scientific development of the 20th century pushed the problem to the fore as much as the advent of atomic energy, and in some sense, no two individuals showcased the dilemmas and promises inherent in the participation of scientists in political affairs more than Robert Oppenheimer and Hans Bethe. This difference in their perception seems to have played a very significant role in the divergent paths their lives took, and it is one that is well-explored for instance in Sam Schweber’s outstanding contrasting study of Oppenheimer and Bethe, “In the Shadow of the Bomb”.

Both Oppenheimer and Bethe were precocious and were educated at the best universities in the world – Bethe at Munich and Oppenheimer at Göttingen. They met when Bethe fled the Nazis for the United States. Both of them became world-renowned for their accomplishments in research and teaching and for establishing world-class centers of physics; Oppenheimer at the University of California, Berkeley and Bethe at Cornell University. Early on Oppenheimer recognized Bethe as a truly outstanding theoretician and picked him to lead the important theoretical division of the Manhattan Project at Los Alamos. In turn Bethe enormously respected Oppenheimer's intellect, astonishingly quick mind and vast knowledge of diverse fields. After the war both Bethe and Oppenheimer served as top consultants to the government on atomic energy and defense. While Bethe spearheaded the development of physics in the country from Cornell, Oppenheimer served as director of the famed Institute for Advanced Study in Princeton, where he worked with individuals like Einstein, Dyson, Gödel and von Neumann. Both Bethe and Oppenheimer acted as wise men who others consulted for advice on important matters of science and policy. Both men remained very good friends till Oppenheimer's death in 1967; Bethe was one of three speakers at Oppenheimer’s memorial service.

On the other hand there were vast differences which partly owed their provenance to each man's personality and which were responsible for shaping their lives. Oppenheimer harbored a conflict of personality and self-doubt throughout his life. He was insecure in his Jewish identity whereas Bethe was largely indifferent to his Christian identity. While both men were prodigiously talented, Oppenheimer often searched for the center of his identity whereas Bethe was largely secure in his identity. Oppenheimer could be conceited, had a sharp tongue and made enemies, enemies who finally brought about his downfall in the government. Bethe on the other hand was one of the most balanced and strong-willed scientists of the century. He displayed remarkable equanimity and had rock solid self-confidence without a hint of arrogance. He could be calm under the most trying of circumstances and served as a sounding board on whom others could depend for sound advice. One of the reasons Oppenheimer picked Bethe rather than his volatile friend Edward Teller to lead the theoretical division of the project was because he knew that Bethe was far more likely to persevere, soothe egos and carry projects through to their end.

The differences in personality also led to each man's politics being quite different. While Bethe was avowedly liberal, his more balanced frame of mind and dedication to science kept him from actively pursuing radical political causes. Oppenheimer's soul-searching in the 30s led him to being associated with a variety of left-wing organizations on the West Coast. His brother, sister-in-law, wife, girlfriend and several students were active members of the Communist Party. While membership in the party was considered much more innocuous in the 30s than what it was later, I cannot imagine Bethe in a similar position. Such left-wing associations of course meant little of substance in Oppenheimer’s case and were common among intellectuals of that depressing decade; they mostly indicated nothing more than naive idealism, but nonetheless came to haunt Oppenheimer after the war. There is another interesting and unseemly difference between the two men’s personal relationships: Bethe was generally known to be very loyal to those he admired, whereas Oppenheimer was more political and attuned to what direction the wind was blowing in; this led to him denouncing a few of his left-wing colleagues as communists after the war.

A reading of Schweber’s book and other sources demonstrates that these great differences in personal traits were partly responsible for the path that each man's life took. With his plodding approach and enormous stamina, Bethe made contributions of astonishing breadth and depth to modern physics, won a Nobel Prize and continued to work until his death at the ripe age of 99. Oppenheimer's contributions were also outstanding but more limited. Perhaps his greatest contribution was the founding of modern theoretical physics in the United States, a school whose descendants continues to place the United States at the forefront of physics research. Scientifically his greatest feat was the discovery of black holes. Nonetheless, many people thought his contributions were not commensurate with his brilliance, partly because of his less focused approach and his being interested in several fields of study (among other things, he was as interested in French poetry and Sanskrit as he was in physics). Unlike Oppenheimer who in his friend Isidor Rabi’s words often saw the frontiers of physics as “surrounded by a fog”, Bethe was a practical man who stressed that he was not a philosopher, was self-assured in his science and always drove for hard agreement with experiment. He may not have been as quick as Oppenheimer, but he was more thorough in his approach to both physics and life.

Bethe served as a consultant to the government on important matters almost all his life because he could be more gentle and diplomatic than Oppenheimer, who with his sharp tongue and candid opinions quickly made powerful enemies. This led to him being hauled in front of a tribunal which revoked his security clearance. Wounded and depressed by this ungrateful action, Oppenheimer continued to write, teach and speak on science and society but could not influence government policy. On the other hand, Bethe continued to be more valuable as a government advisor throughout his life partly because he knew how to compromise and could be more diplomatic and modest than Oppenheimer. He could take courageous stands, but these stands often came in the form of well-argued and well-researched articles in magazines like Scientific American and the Bulletin of the Atomic Scientists. He was a key voice advising the government on the peaceful exploitation of atomic energy, and during the 80s he clashed with his old friend Edward Teller on the feasibility of Ronald Reagan’s Strategic Defense Initiative (‘Star Wars’). Even Republican administrations sought his advice.

The moral dilemmas generated by physics in the form of Oppenheimer and Bethe in the twentieth century have been picked up by other fields, most notably biology and climatology, in the twenty-first. As science grapples with more and more politically inflammatory topics – climate change, the teaching of evolution, stem cell research, recombinant DNA technology – scientists would do well to heed the lessons offered by Oppenheimer and Bethe. The question before many of them would be the following: should they take a more radical stance like Oppenheimer and try to change policy in the short-term, or should they be more plodding like Bethe and make modest but more solid contributions to policy in the long-term?