The need to combine theorists with engineers was particularly true in a field that was becoming increasingly important at Bell Labs: solid-state physics, which studied how electrons flow through solid materials. In the 1930s, Bell Labs engineers were tinkering with materials such as silicon—after oxygen the most common element in the earth’s crust and a key component of sand—in order to juice them into performing electronic tricks. At the same time in the same building, Bell theorists were wrestling with the mind-bending discoveries of quantum mechanics.
Quantum mechanics is based on theories developed by the Danish physicist Niels Bohr and others about what goes on inside an atom. In 1913 Bohr had come up with a model of atomic structure in which electrons orbited around a nucleus at specific levels. They could make a quantum leap from one level to the next, but never be in between. The number of electrons in the outer orbital level helped to determine the chemical and electronic properties of the element, including how well it conducted electricity.
Some elements, such as copper, are good conductors of electricity. Others, such as sulfur, are horrible conductors, and are thus good insulators. And then there are those in between, such as silicon and germanium, which are known as semiconductors. What makes them useful is that they are easy to manipulate into becoming better conductors. For example, if you contaminate silicon with a tiny amount of arsenic or boron, its electrons become more free to move.
The advances in quantum theory came at the same time that metallurgists at Bell Labs were finding ways to create new materials using novel purification techniques, chemical tricks, and recipes for combining rare and ordinary minerals. In seeking to solve some everyday problems, like vacuum-tube filaments that burned out too quickly or telephone-speaker diaphragms that sounded too tinny, they were mixing new alloys and developing methods to heat or cool concoctions until they performed better. By trial and error, like cooks in a kitchen, they were creating a revolution in materials science that would go hand in hand with the theoretical revolution that was occurring in quantum mechanics.
As they experimented with their samples of silicon and germanium, the chemical engineers at Bell Labs stumbled across evidence for much of what the theorists were conjecturing.I It became clear that there was a lot that the theorists, engineers, and metallurgists could learn from one another. So in 1936 a solid-state study group was formed at Bell Labs that included a potent mix of practical and theoretical stars. It met once a week in the late afternoon to share findings, engage in a bit of academic-style trash talk, and then adjourn for informal discussions that lasted late into the night. There was value to getting together in person rather than just reading each other’s papers: the intense interactions allowed ideas to be kicked into higher orbits and, like electrons, occasionally break loose to spark chain reactions.
Of all the people in the group, one stood out. William Shockley, a theorist who had arrived at Bell Labs right when the study group was being formed, impressed the others, and sometimes frightened them, with both his intellect and his intensity.
WILLIAM SHOCKLEY
William Shockley grew up with a love of both art and science. His father studied mine engineering at MIT, took music courses in New York, and learned seven languages as he wandered through Europe and Asia as an adventurer and mineral speculator. His mother majored in both math and art at Stanford and was one of the first known climbers to succeed in a solo ascent of Mt. Whitney. They met in a tiny Nevada mining village, Tonopah, where he was staking claims and she had gone to do surveying work. After they were married, they moved to London, where their son was born in 1910.
William would be their only child, and for that they were thankful. Even as a baby he had a ferocious temper, with fits of rage so loud and long that his parents kept losing babysitters and apartments. In a journal his father described the boy “screaming at the top of his voice and bending and throwing himself back” and recorded that he “has bitten his mother severely many times.”5 His tenacity was ferocious. In any situation, he simply had to have his way. His parents eventually adopted a policy of surrender. They abandoned any attempt to discipline him, and until he was eight they home-schooled him. By then they had moved to Palo Alto, where his mother’s parents lived.
Convinced that their son was a genius, William’s parents had him evaluated by Lewis Terman,II who had devised the Stanford–Binet IQ test and was planning a study of gifted children. Young Shockley scored in the high 120s, which was respectable but not enough for Terman to label him a genius. Shockley would become obsessed by IQ tests and use them to assess job applicants and even colleagues, and he developed increasingly virulent theories about race and inherited intelligence that would poison the later years of his life.6 Perhaps he should have learned from his own life the shortcomings of IQ tests. Despite being certified as a nongenius, he was smart enough to skip middle school and get a degree from Caltech and then a doctorate in solid-state physics from MIT. He was incisive, creative, and ambitious. Even though he loved performing magic tricks and playing practical jokes, he never learned to be easygoing or friendly. He had an intellectual and personal intensity, resonating from his childhood, that made him difficult to deal with, all the more so as he became successful.
When Shockley graduated from MIT in 1936, Mervin Kelly came up from Bell Labs to interview him and offered him a job on the spot. He also gave Shockley a mission: find a way to replace vacuum tubes with a device that was more stable, solid, and cheap. After three years, Shockley became convinced he could find a solution using solid material such as silicon rather than glowing filaments in a bulb. “It has today occurred to me that an amplifier using semiconductors rather than vacuum is in principle possible,” he wrote in his lab notebook on December 29, 1939.7
Shockley had the ability to visualize quantum theory, how it explained the movement of electrons, the way a choreographer can visualize a dance. His colleagues said that he could look at semiconducting material and see the electrons. However, in order to transform his artist’s intuitions into a real invention, Shockley needed a partner who was an adroit experimenter, just as Mauchly needed Eckert. This being Bell Labs, there were many in the building, most notably the merrily cantankerous westerner Walter Brattain, who enjoyed making ingenious devices with semiconducting compounds such as copper oxide. For example, he built electric rectifiers, which turn alternating current into direct current, based on the fact that current flows in only one direction through an interface where a piece of copper meets a layer of copper oxide.
Brattain grew up on an isolated ranch in eastern Washington State, where as a boy he herded cattle. With his raspy voice and homespun demeanor, he affected the self-deprecating style of a confident cowboy. He was a natural-born tinkerer with deft fingers, and he loved devising experiments. “He could put things together out of sealing wax and paper clips,” recalled an engineer he worked with at Bell Labs.8 But he also had a laid-back cleverness that led him to seek shortcuts rather than plod through repetitious trials.
Shockley had an idea for finding a solid-state replacement for a vacuum tube by putting a grid into a layer of copper oxide. Brattain was skeptical. He laughed and told Shockley that he had tried that approach before, and it never ended up producing an amplifier. But Shockley kept pushing. “It’s so damned important,” Brattain finally said, “that if you’ll tell me how you want it made, we’ll try it.”9 But as Brattain predicted, it didn’t work.