American physicists watched most of the quantum physics revolution from the sidelines. The action was all taking place in Europe, among European physicists, since many of the senior physicists in the United States were unable or unwilling to grasp the seemingly counterintuitive principles that lay at the base of the new physics. For some, this led to intense frustration; for others, this led to a rejection of the importance of the new theoretical physics. For those American students who learned of the new physics and understood that it was the physics of the future, they had to accept being shut out of all the fun. It was difficult enough to find an American physics department that taught about the discoveries on this forefront of physics, much less one that allowed for the type of breakthrough research that was being done in Europe.

Oppenheimer arrived in the United States determined to change all that. He would bring the secrets of European physics home to the United States and use them to mold the minds of a new generation of American physicists. He would build a physics department from the ground up, creating a center of thought that would rival any in Europe.

It was a lofty goal, but Oppenheimer was used to aiming high. He was determined to turn the United States into a physics force with which to be reckoned. And he did just that.

In 1929, Oppenheimer became a professor at the University of California at Berkeley. It was an unexpected decision, bypassing as it did many of the schools on the East coast with more solid reputations, but Oppenheimer loved the West. Berkeley would give him the chance to make a fresh start, and perhaps something appealed to him about expanding the frontier of American physics at the physical edge of the American frontier.

Oppenheimer, or "Oppie," as he was now called by all who knew him well, got off to an inauspicious start. It was one thing to dream about inspiring a new generation of physicists, but it was quite another to face a roomful of students and come up with something to say. For his first few years as a professor, Oppenheimer couldn't come up with anything that did the job. He was, quite simply, a bad teacher. His lectures were so confusing that by the end of his first semester, only one student was still taking the course for credit. This didn't last for long.

Within a few years, "Oppie" had learned enough tricks of the trade to become not only a well-liked teacher at Berkeley, but one of the most popular theoretical physics professors in the country. Students flocked to California to hear his eloquent lectures, and his students–nicknamed "Oppie's boys"–formed a cult of adulation that followed him around everywhere and took to imitating his mannerisms and style of speaking.

Oppenheimer was a generous and engaged mentor to his flock of admirers. Discussions in class were often continued at his house, over dinner–often physics was left behind, as "Oppie" and his students drank, danced, and talked about art and literature late into the night. Many students even followed him to the California Institute of Technology, where he taught during the spring semester each year. Every April, these loyal Berkeley physics students would rent out their houses, pack up their cars, and drive up to Pasadena to listen to their beloved teacher lecture to his flock.

He was still the distant, arrogant man who had turned off fellow students in his New York high school, but he had a new charisma, a power of personality that led him to a level of success that he could never have attained with his physics skills alone.

Oppenheimer was still a practicing physicist, and he consistently published well-respected papers recording his gifted research in quantum physics. But while Oppenheimer was considered a good or even great physicist, it was clear that he did not rank among the world's top physicists. Despite expectations– those of his own and of his peers–Oppenheimer made no ground-breaking, cutting-edge discoveries, no lasting contributions to his discipline.

Although he never practiced world-class physics, Oppenheimer's years at Berkeley were far from fruitless. Working together with Ernest Lawrence, another Berkeley physicist who was also determined to elevate his department's reputation, Oppenheimer turned Berkeley into a world-class physics institution. Within two decades, American physics departments had taken their place among the world's top centers for theoretical physics, thanks, in large part, to Oppenheimer.