Charles H. Townes Biography (1915-)



Nationality
American
Gender
Male
Occupation
physicist

Charles Townes is generally considered the American inventor of the maser (anacronym for microwave amplification by the stimulated emission of radiation), an honor he shares with two Russian scientists, Aleksandr Prokhorov and Nikolai Basov. The microwave theories he introduced and pursued throughout the 1960s paved the way for such advances as the modern laser.

The son of a South Carolina attorney, Townes studied modern languages and physics at Furman University in his home town of Greenville, S.C., graduating summa cum laude in 1935. He obtained his master's degree in one year at Duke University and his Ph.D. at the California Institute of Technology in 1939. After completing his education, Townes worked for Bell Telephone Laboratories onthe design of radar bombing systems, in support of the U.S. effort in WorldWar II. It was during these years at Bell that Townes' interest in microwavetechnology bloomed; in 1948, when he was asked to join the physics departmentat Columbia University, he gladly accepted.

Townes concentrated his research on microwave spectroscopy, the study of thebasic structure of matter. Though some advancement was made, it rapidly became clear that an oscillator was needed which could produce radiation of very short wavelengths. Unfortunately, Townes also knew that existing technology was incapable of constructing a device small enough to produce such radiation.In 1951, while sitting on a park bench in Washington, D.C., it struck Townesthat an extremely small device might be found if he concentrated not upon electrical circuits but rather upon molecules. Since molecules had very specificrates of vibration, and microwaves had very specific wavelengths, molecularvibrations, if somehow converted into radiation, would be equivalent to the essential short-wavelength microwaves.

Frantically writing on the back of an envelope, Townes calculated that it waspossible to produce microwaves if ammonia molecules were " excited" by pumping energy into them and then were stimulated to emit that energy in a controlled, or coherent, pattern. These theories were by no means new; coherence hadbeen studied for years, and stimulated emission was first discussed in depthin Albert Einstein's (1879-1955) theory of relativity. But the application of those two theories for microwaves was unprecedented.

By 1953, Townes, A. L. Schawlow, and Townes' students at Columbia had finallyconstructed a working ammonia maser. One of its first applications was in timekeeping, for the steady, undeviating frequency of the microwaves was far more accurate than any timepiece prior, and was dubbed the " atomic clock." ButTownes and others felt that a more versatile device could be developed if the gaseous ammonia were replaced with a solid crystal.

The resulting solid-state masers were instrumental in the field of radio astronomy, where they were used to amplify very weak signals from distant radio sources. The faint reflected signals from the Echo I satellite were successfully amplified in this manner, as well as radar scannings of the planet Venus.

Perhaps the most important advance in maser technology began in 1957, when Townes and his brother-in-law began speculating on the possibility of creatingan "optical maser," delivering infrared or visible light rather than microwaves. Such light would be coherent; rather than spreading out like normal light, the maser light would maintain a tight beam almost indefinitely. Such a beam could also focus its energy to an extremely fine point, making it a cuttingtool unsurpassed in power and precision.

In 1960 the first ruby maser, or laser (light amplification by the stimulatedemission of radiation), was constructed, paving the way for a technology that would revolutionize engineering, medicine, and communications. For these advances Townes was awarded the 1964 Nobel Prize for physics, sharing it with Prokhorov and Basov (who worked independently in Russia).

In 1959, Townes took a two year leave of absence from Columbia to serve as vice-president and director of research of the Institute for Defense Analyses in Washington, D.C. In 1961, he became provost and professor of physics at theMassachusetts Institute of Technology. He was elected to the National Academy of Sciences in 1956.

Recent Updates

March 9, 2005: It was announced that Townes will receive the 2005 Templeton Prize in a private ceremony held at Buckingham Palace in early May of 2005. The prize, which carries a $1.5 million award, is given annually for progress or research in spiritual matters. In his nomination of Townes for the prize, David Shi, President of Furman University, wrote, "He (Townes) points out that both scientists and theologians seek truth that transcends current human understanding, and because both are human perspectives trying to explainand to find meaning in the universe, both are fraught with uncertainty. Scientists propose hypotheses from postulates, from ideas that ultimately cannot be proven. Thus, like religion, science builds on a form of faith." Source: New York Times, www.nytimes.com, March 10, 2005.May 9, 2006: Townes received one of two 2006 Vannevar Bush Awards bestowed by the National Science Board during a ceremony at the National Museum of Natural History in Washington, D.C. The award recognizes "lifetime contributions to science and long-standing statesmanship in science on behalf of the nation." Source: National Science Foundation, www.nsf.gov, May 3, 2006.



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