Chapter 1 Chapter 1
In the first decade of the twentieth century, science initiated a second American revolution. A nation on horseback was soon transformed by the internal combustion engine, manned flight and a multitude of other inventions. These technological innovations quickly changed the lives of ordinary men and women. But simultaneously an esoteric band of scientists was creating an even more fundamental revolution. Theoretical physicists across the globe were beginning to alter the way we understand space and time. Radioactivity was discovered on March 1, 1896, by the French physicist Henri Becquerel. Max Planck, Marie Curie and Pierre Curie and others provided further insights into the nature of the atom. And then, in 1905, Albert Einstein published his special theory of relativity. Suddenly, the universe appeared to have changed.

Around the globe, scientists were soon to be celebrated as a new kind of hero, promising to usher in a renaissance of rationality, prosperity and social meritocracy. In America, reform movements were challenging the old order. Theodore Roosevelt was using the bully pulpit of the White House to argue that good government in alliance with science and applied technology could forge an enlightened new Progressive Era.

Into this world of promise was born J. Robert Oppenheimer, on April 22, 1904. He came from a family of first- and second-generation German immigrants striving to be American. Ethnically and culturally Jewish, the Oppenheimers of New York belonged to no synagogue. Without rejecting their Jewishness they chose to shape their identity within a uniquely American offshoot of Judaism—the Ethical Culture Society—that celebrated rationalism and a progressive brand of secular humanism. This was at the same time an innovative approach to the quandaries any immigrant to America faced—and yet for Robert Oppenheimer it reinforced a lifelong ambivalence about his Jewish identity.

As its name suggests, Ethical Culture was not a religion but a way of life that promoted social justice over self-aggrandizement. It was no accident that the young boy who would become known as the father of the atomic era was reared in a culture that valued independent inquiry, empirical exploration and the free-thinking mind—in short, the values of science. And yet, it was the irony of Robert Oppenheimer’s odyssey that a life devoted to social justice, rationality and science would become a metaphor for mass death beneath a mushroom cloud.

Robert’s father, Julius Oppenheimer, was born on May 12, 1871, in the German town of Hanau, just east of Frankfurt. Julius’ father, Benjamin Pinhas Oppenheimer, was an untutored peasant and grain trader who had been raised in a hovel in “an almost medieval German village,” Robert later reported. Julius had two brothers and three sisters. In 1870, two of Benjamin’s cousins by marriage emigrated to New York. Within a few years these two young men—named Sigmund and Solomon Rothfeld—joined another relative, J. H. Stern, to start a small company to import men’s suit linings. The company did extremely well serving the city’s flourishing new trade in ready-made clothing. In the late 1880s, the Rothfelds sent word to Benjamin Oppenheimer that there was room in the business for his sons.

Julius arrived in New York in the spring of 1888, several years after his older brother Emil. A tall, thin-limbed, awkward young man, he was put to work in the company warehouse, sorting bolts of cloth. Although he brought no monetary assets to the firm and spoke not a word of English, he was...