Charles H. Townes was awarded a share of the 1964 Nobel Prize in physics for his discovery in 1951 of the maser , a device that can amplify microwaves for practical applications. About six years later, Townes speculated on the possibility of building a maser-like instrument using solid crystals instead of gases. A device of this kind--the laser --was actually constructed two years afterwards by Theodore Maiman.
Charles Hard Townes was born in Greenville, South Carolina, on July 28, 1915. His father was Henry Keith Townes, an attorney, and his mother was the former Ellen Sumter Hard. Townes grew up in an intellectually stimulating environment in which both parents had an avid interest in natural history. He later told Shirley Thomas in a sketch for the book Men of Space that "there was always an inclination toward science" in his family. He was convinced that had the opportunity been available, his father "would have become a very excellent scientist."
Townes's genius was obvious early on. His parents allowed him to skip seventh grade, and by age 16 he was ready to enter Furman University in his hometown of Greenville. Although he planned to major in science, he also took a full schedule of language classes. As a result, he was able to graduate in 1935 with a B.S. in physics and a B.A. in modern languages. He continued his mastery of French, German, Italian, Russian, and Spanish throughout his life. In addition to his demanding class work at Furman, Townes was also curator of the college museum and a member of the band, glee club, swimming team, and newspaper staff.
Townes entered Duke University in the fall of 1935 to work on his master's degree. In addition to his thesis research on van der Graaf generators, he continued his study of French, Italian, and Russian. Having completed his work at Duke (various biographers credit him with either an M.A. or an M.S., awarded in either 1936 or 1937), Townes headed for the California Institute of Technology (Cal Tech) in Pasadena, California. There he completed his doctoral research on the spin of the carbon-13 nucleus in 1939 and was awarded his Ph.D.
War Research Leads to Interest in Microwaves
An offer from Bell Laboratories to pay Townes a salary of $3,016 a year "astonished" him, according to Mary Ann Harrell in Those Inventive Americans. He could scarcely believe that a career in physics would be "so highly paid," and he accepted the Bell offer quickly. Townes found an apartment in New York City and began to take full advantage of the city's cultural opportunities. He took evening classes at the Julliard School of Music and, according to Harrell, "changed apartments every three months to explore the city thoroughly."
For most of his time at Bell, Townes worked on projects related to national defense. In particular, he was involved in the development of radar systems. At one point he warned the army against using a 1.2-in (3-cm) band radar wave detection system because he knew that water molecules absorb in this range and that the system would, therefore, be ineffective. Having ignored this advice, the Army built three-centimeter radar devices anyway, only to find that they would not work.
As the pressures of war research receded, Townes turned his attention to a problem many scientists and engineers were thinking about: finding a way to amplify microwaves so that they could be used in practical applications, as were radio and radar waves. Albert Einstein had outlined a theoretical method for accomplishing this goal in 1917. He suggested using individual atoms as resonators rather than using macroscopic-sized objects. The problem was that, by 1950, no one had found a way to build a working device based on Einstein's principle.
Townes's breakthrough in this area came while he was sitting on a park bench in Washington D.C.'s Franklin Square in 1951, waiting for a restaurant to open so that he could have breakfast. As Harrell tells the story, "six years of work suddenly blossomed into insight: a way to make ammonia molecules amplify ... microwaves by the process Einstein had outlined." In classic storybook fashion, Townes outlined his ideas on the back of an old envelope he found in his pocket.
Producing a device that actually worked according to his theory, however, was no simple matter Townes worked with two colleagues, James P. Gordon and H. J. Zeiger, for more than two years before they had success. Finally, in late 1953, the three produced a successful model of Townes's Franklin Square idea, a device that amplified an incoming microwave beam while maintaining the signal wave's phase. They gave to their invention the name maser (for microwave amplification by stimulated emission of radiation). For his discovery of the maser, Townes was awarded a share of the 1964 Nobel Prize in Physics. He shared that prize with two Russian scientists, N. G. Basov and Aleksandr Prokhorov, who had independently and somewhat earlier come up with a similar method for using the Einstein principle to build a maser-like device, which they called a "molecular generator."
Outlines Laser Theory
By the time Townes announced the first working maser in 1954, he had already been at Columbia University for six years, having been appointed full professor there in 1954. He continued to teach and do research at Columbia until 1961, when he resigned to become professor of physics and provost at the Massachusetts Institute of Technology (MIT). While still at Columbia, he developed a theory with his brother-in-law Arthur L. Schawlow that described a method by which a maser-like device could be built that would operate with visible light instead of microwaves. Theodore Maiman's laser provided proof of Townes and Schawlow's theory some two years later.
In 1966 Townes left MIT to become University Professor of Physics at the University of California at Berkeley, where he remained until his retirement in 1986. Townes was married on May 4, 1941, to the former Francis H. Brown, and they raised four children. Townes has received many honors and awards in addition to his 1964 Nobel Prize in Physics. These include the Liebmann Memorial Prize of the Institute of Radio Engineers, the Sarnoff Award of the Institute of Electrical Engineers, the Comstock Medal of the National Academy of Sciences, the Ballantine Medal of the Franklin Institute, the Distinguished Public Service Medal of the National Aeronautics and Space Administration, and the National Medal of Science from the National Science Foundation.
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