Like Paracelsus, Lawrence promised to turn lead into gold—but in infinitesimal amounts, and at prodigious cost. Mindful of the recent discovery of fission, Ernest chose to emphasize to Sproul another long-held hope of humanity that most scientists, he among them, had until now dismissed as illusory: “we may be able to tap the unlimited store of energy in the atom.”
* * *
Lawrence’s moment of discovery had come a decade earlier, in early 1929. Then an unmarried twenty-eight-year-old associate professor of physics newly arrived from Yale, he was living at Berkeley’s Faculty Club and working late nights at the university library. It was on one such lonely evening, while struggling through a recent article by a Norwegian engineer, Rolf Wideröe, in a German journal, the Archiv für Elektrotechnik, that Ernest had his epiphany.
Wideröe’s article was about a new way of speeding particles to high energies by repeated applications of a lower voltage. Resonance acceleration was an electromagnetic phenomenon without obvious practical application, in which positively charged particles are accelerated sequentially by electrical impulses as they pass through a succession of vacuum tubes. The acceleration ceased only when the experimenter ran out of tubes, or the particles fell out of step with the electrical impulses and spread out, shotgun-like, hitting the tube walls. A diagram in the article showed the vacuum tubes arranged in a straight line, end to end. Since his German was weak, Lawrence was drawn to the diagram rather than the text.
With the intuitive understanding that was always his greatest strength, Lawrence instantly recognized that if the particles could be confined to a circle rather than a straight line, and kept focused by a magnet while electrical impulses accelerated them—alternately pulling and pushing—there might be no limit to the energies obtained. The following day, Ernest excitedly described his idea for a “proton merry-go-round” to Berkeley colleagues.2
For $25, Ernest built a tabletop model of his machine, debuting it a few months later before the American Physical Society. Lawrence reported on its promise to a September 1930 meeting of the National Academy of Sciences.3 Attached to a kitchen chair by a clothes hanger, it was a sensation among the scientists assembled. The first lilliputian device never achieved the energies that Lawrence promised the National Academy, but proved the principle sound. A twenty-five-year-old graduate student from Dartmouth, Stanley Livingston, helped Lawrence fashion his next machine of durable brass.
Progress thereafter was rapid, for both Lawrence and his machines. In 1930, at the age of twenty-nine, Ernest became the youngest full professor in the history of the University of California. Magnetic resonance accelerator—Livingston’s term for the proton merry-go-round—gradually gave way to cyclotron, a word inspired by the particles’ path and the Radiotron vacuum-tube oscillators that propelled them. Cyclotron had the additional bonus of sounding futuristic to prospective funders.4
An enthusiast by nature, Lawrence began planning larger cyclotrons even before the capabilities of the existing one had been explored. A little more than a year after his first success, Lawrence and Livingston had built a machine capable in theory of accelerating protons to energies of 1 million electron volts. Measured by the diameter of the magnet’s pole face, the 11–inch cyclotron was nearly three times the size of their first effort and cost disproportionately more to build: $800. Lawrence installed it, without fanfare, next to his office on the second floor of Berkeley’s physics building, LeConte Hall.
That summer, Lawrence and Livingston discovered the principle of magnetic focusing, using soft iron shims between the poles and the vacuum tank to compensate for variations in the magnetic field. Voltages obtained by the 11-inch were doubled, and then doubled again—approaching the energy believed necessary to penetrate the invisible barrier that surrounds the atomic nucleus. Moving gradually up the slope, Lawrence and Livingston crossed the milestone million volts in August 1931. On a visit to New Haven to see his fiancée, Molly Blumer, Lawrence received the good news in a telegram from his secretary: “Dr. Livingston has asked me to advise you that he has obtained 1,100,000 volt protons. He also suggested that I add ‘Whoopee!’”5
Ernest wed his longtime sweetheart in May 1932. Molly was a tall, statuesque Vassar honors graduate whose father was dean of Yale’s medical school. Enrolled in bacteriology courses at Radcliffe, Molly gave up her own promising scientific career to marry Lawrence. While still on their honeymoon, the newlyweds had just returned from a sail on Long Island Sound when Ernest learned in a radio broadcast that British scientists had been first to disintegrate an atom, using a simple voltage multiplier and a few hundred thousand volts. In a properly designed experiment, the 11-inch could have accomplished the same feat a year earlier. Quickly returning to California, Ernest made sure that he and his colleagues got credit for achieving the first atomic disintegration outside Europe. He promised Molly a longer honeymoon later.
The British discovery highlighted the fact that Lawrence’s enthusiasm sometimes overcame the discipline necessary to do science. Since he was often more interested in building grand new machines than in doing the hard work necessary to interpret experimental results, Ernest had paid less attention to having sensitive detection instruments.
To remedy that weakness, Ernest imported a friend from his Yale days, Donald Cooksey, a journeyman physicist who specialized in designing detectors. The son of a Yale professor and scion of an old California family, Cooksey had never bothered to finish the language requirement for his graduate degree. Nine years older than Lawrence, Cooksey was more cosmopolitan by far. Ernest’s first view of the New York City skyline had come from the roof of the Yale Club, where he was staying as Cooksey’s guest.6 “DC,” as he was known, soon became Ernest’s factotum, troubleshooter, and confidant at the lab.7
Following his embarrassment at the hands of the British, Lawrence proposed an order-of-magnitude
