Four years after America dropped the atomic bombs on Japan, writer Lincoln Barnett went to Princeton to interview J. Robert Oppenheimer. Barnett found a noticeably relieved Oppenheimer, deep into new research—a “revival of physics”—after years spent building a weapon that to his mind was “merely a gadget, a technological artifact that exploited principles well known before the war.” This remarkable profile, available via Google Books in its original print format, includes ones of the earliest descriptions of Oppenheimer’s famous observation upon the detonation of the first atomic bomb test:

Los Alamos took its toll of his physical energies, for in the final phases of the work he slept but four hours a night. By the pre-dawn of July 16, 1945, when the first bomb was raised to the test tower at Alamogordo, his weight had fallen from its normal 145 to 115 pounds. Above and beyond the fatigue he felt as he peered across the darkened desert that morning, he was beset by two complementary anxieties: he feared first that the bomb would not work; second he feared what would happen to the world if it did. And then when the great ball of fire rolled upward to the blinded stars, fragments of the Bhagavad-Gita flashed into his mind: “If the radiance of a thousands suns were to burst at once into the sky, that would be like the splendor of the Mighty One…. I am become death, the shatterer of worlds.” And as the shock waves and sound waves hurled themselves furiously against the distant mountains, Oppenheimer knew that he and his co-workers had acquired a promethean burden they could never shed. “In some crude sense,” he observed later, “which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.” These sentiments were no sudden by-product of the explosion’s terror and fury. The moral problem adduced by their work had been debated by the Los Alamos scientists incessantly from the beginning. Oppenheimer once analyzed their ethical position in these words: “We thought that since atomic weapons could be realized they must be realized for the world to see, because they were the best argument that science would make for a new and more reasonable idea of relations between nations.” Although Oppenheimer represented the idealist wing, who thought development of the bomb might lead to some good end, many of the physicists justified their work on purely empirical grounds. This “operational” standpoint was expressed bluntly by Oppenheimer’s former teacher, Dr. Bridgman of Harvard, who pooh-poohed his famous student’s feelings of guilt, declaring, “Scientists aren’t responsible for the facts that are in nature. It’s their job to find the facts. There’s no sin connected with it—no morals. If anyone should have a sense of sin, it’s God. He put the facts there.”