Robert Andrews Millikan

Physicist

• Born: March 22, 1868
• Birthplace: Morrison, Illinois
• Died: December 19, 1953
• Place of death: San Marino, California

American physicist

As a skilled and meticulous experimenter, Millikan made major contributions to twentieth-century physics. As a textbook author, university teacher, and supervisor of research, he greatly influenced the way that physics is studied in the United States.

Born: March 22, 1868; Morrison, Illinois

Died: December 19, 1953; San Marino, California

Primary field: Physics

Specialty: Atomic and molecular physics

Early Life

Robert Andrews Millikan was born to Silas Franklin Millikan, a Congregational preacher, and Mary Jane Andrews Millikan, a graduate of Oberlin College and former dean of a small college in Michigan. When he was five years old, his family moved westward to Iowa, where they settled permanently in Maquoketa.

Millikan began his education at home under his mother’s tutelage, continuing in the local public schools through high school. He entered Oberlin College in 1886 and initially embarked on a classical course of study, later shifting to physics, in which he was largely self-taught. After receiving an MA from Oberlin in 1893, he enrolled as the sole graduate student in physics at Columbia University, where he came under the strong influence of Michael Pupin, a self-made scientist who had arrived in the United States virtually penniless from Eastern Europe in 1874. Encouraged and financially aided by Pupin, Millikan set off for a year of study in Europe after completing his PhD in 1895. A year later, he was invited to the University of Chicago as an assistant in physics by Albert A. Michelson, America’s best-known experimental physicist at the time, under whom Millikan had taken a summer course in 1894.

In 1902, Millikan married Greta Blanchard. The couple produced three sons, and their marriage endured until their deaths in 1953.

Life’s Work

Millikan was given heavy teaching responsibilities at Chicago, the more so because Michelson did not enjoy working with students. Millikan took his duties seriously, throwing himself into classroom teaching and laboratory instruction as well as writing textbooks and laboratory manuals in physics. These ventures into writing, usually in collaboration with others, were highly successful. They were revised many times and widely used for decades. Interestingly, Millikan was among the first authors to incorporate historical material as background into physics texts. When the History of Science Society was formed in 1923, he was a founding member.

Working twelve hours a day, six days a week, at the University of Chicago, Millikan embarked on a research program, achieving notable success in two areas. Through his oil-drop method, he showed that electric charge always occurs in exact multiples of a fundamental unit quantity, whose numerical value he was able to calculate. Millikan’s second area of success was the photoelectric effect, an action that occurs when electrons are emitted from the surface of certain metals under illumination by light of suitable wavelength. The results he obtained in 1916 exactly confirmed the theoretical prediction made by Albert Einstein in 1905. Einstein had based his theory on a belief in “quanta,” units of energy first introduced by Max Planck in 1899. Interestingly, Millikan, despite his experimental confirmation of Einstein’s equation, could not bring himself to accept the existence of quanta until several years later, as these new entities were so much at odds with the ideas of classical physics.

In 1915, Millikan was elected to membership in the National Academy of Sciences, the prestigious body established during the American Civil War to provide scientific assistance to the federal government. A year after Millikan’s election, the organization moved to form the National Research Council to mobilize the nation’s scientific talent for defense. Millikan was a member of the organizing committee of the council and subsequently was named its executive officer and director of research. Among the areas of concern were submarine detection and chemical warfare. When the United States became actively involved in World War I, Millikan moved to Washington, DC, for the duration of the war, donning an army uniform and becoming a lieutenant colonel in the Signal Corps.

After the war, Millikan was instrumental in expanding the function of the National Research Council to establish and supervise a program of postdoctoral fellowships for young Americans entering scientific professions. Funding for the program was provided by the Rockefeller Foundation. The aim of the program was twofold: The individual National Research Council fellow could engage in research unencumbered by heavy teaching duties (as Millikan had been), and the institutions where they chose to take their fellowships would benefit from their presence. As a result of this program, American scientific competence was strengthened.

Following Millikan’s return to the University of Chicago in 1919, he was sought out by the Throop College of Technology in Pasadena, California, having come to its attention through contacts he had made while in Washington. Initially, Millikan served at Throop only in a visiting capacity, but by 1921, he had moved there permanently as professor of physics and chair of the executive council. Although he refused the title of president, he insisted that the name of the institution be changed to the California Institute of Technology. He convinced a group of wealthy and influential Californians that Caltech, as it became known, was a unique state asset, well worth the support of businessmen, philanthropists, and ordinary citizens alike.

In 1923, Millikan was awarded the Nobel Prize in Physics for his experiments on electric charge and the photoelectric effect. As he had moved to Caltech by that time, Millikan declined to make the journey to Stockholm for the ceremony, pleading the urgency of his research and teaching. In those days, such a trip would have required him to be away from California for more than a month.

From 1921 until his retirement in 1945, at the age of seventy-seven, Millikan worked tirelessly to enhance the prestige of Caltech, not only in the United States but also around the world. One way of achieving this was to have an eminent European physicist as guest lecturer nearly every year. Among such visitors were Niels Bohr, Max Born, Albert Einstein, Hendrik Antoon Lorentz, Erwin Schrödinger, and Arnold Sommerfeld. The generous funding from the trustees of Caltech made it possible for such visitors to lecture at other academic institutions as well, on their way to or from Pasadena, thereby benefiting the entire physics community. Furthermore, each year a group of National Research Council fellows found Caltech a stimulating environment.

In addition to his administrative duties, Millikan continued an active research program, usually in collaboration with his doctoral candidates or postdoctoral fellows. A new area of study that attracted him was cosmic rays, mysterious rays that caused electroscopes spontaneously to lose their charge. Millikan devoted great attention to this phenomenon during the 1920s and early 1930s. His research made it clear that these rays were of extraterrestrial origin, but he failed to recognize their true nature. For years, Millikan argued, often acrimoniously and publicly, that the rays were electromagnetic—that is, similar to light but at invisible wavelengths. Other investigators, notably Arthur Holly Compton, another American recipient of the Nobel Prize in Physics, had evidence that the rays consisted of charged particles, namely protons. Millikan was eventually proven wrong in this case.

Impact

Millikan was a leading figure in the American scientific community during the first half of the twentieth century, a period during which science in the United States rapidly rose to worldwide preeminence. Millikan traveled often to Europe, where he was well known and respected in scientific circles as early as 1912. His success as an experimenter was widely recognized, which could be said of many of his contemporaries. Yet what distinguished Millikan was his unswerving devotion to the promotion of science, not only in his personal laboratory but also in its institutional context and in the development of first-class educational opportunities for America’s young scientific talent. He viewed science as a positive, vital element in the growth of the United States as a nation. He never failed to respond to critics of science who argued that it was inimical to religion or was responsible for human unemployment when improved technology made some jobs unnecessary.

After his death in 1953, Millikan was eulogized by his colleague L. A. DuBridge as a contributor to knowledge, a creator of a scientific institution, and an inspiration to countless students as well as a contributor to the maturing of science in the United States.

Bibliography

Franklin, Allan. No Easy Answers: Science and the Pursuit of Knowledge. Pittsburgh: U of Pittsburgh P, 2005. Print. Offers nontechnical explanations of scientific experiments to analyze the role experimentation plays in scientific discovery. Includes information about Millikan’s experiments with electrons.

Millikan, Robert A. The Autobiography of Robert A. Millikan. 1950. New York: Arno, 1980. Print. Presents a firsthand account of how life and science had changed in the United States during Millikan’s lifetime. Narrates the details of his own career as he saw it. Includes photographs of Millikan, family members, and colleagues.

“The Nobel Prize in Physics 1923.” Nobelprize.org. Nobel Foundation, 2012. Web. 21 June 2012. Contains a biography and photographs of Millikan, along with a copy of his Nobel lecture.