Lemelson Center Invention Features: Charles Townes

Marvelous Masers: Charles Townes

by Heather Bruce

Townes explains the first maser When he was ten years old, Charles Townes was like most kids; he knew exactly what he wanted for Christmas. But his dream gift was a bit unconventional. "You better buy out a hardware store," he wrote to his 18 year-old sister Mary, requesting a wide assortment of tools. "But just send money for the drill," he continued. "I know exactly which one I want."

Today, at age 83, Townes chuckles at the memory. "I wanted to see how things work," he says, recalling his early interest in science. "I never knew if I would have the chance to build or discover something new. But that was something I thought I might do."

Townes did indeed go on to build something new. As the inventor of the maser (a precursor to the laser) and as the Nobel-Prize winning scientist who conceived the theory behind the laser, he played a crucial role in the development of an instrument that has affected nearly every field in the world, from communications to astronomy. The laser, an instrument in which light radiation drives molecules to give up energy at a single wavelength, produces an intense, steady beam of light. Although it had few practical applications at first, laser technology is now used in fiber optics communications, laser surgery, weapons systems, astronomical measuring tools, compact discs, and bar code scanners.

"People said, 'It's a nice idea, but what can it do?'" Townes recalls. "My view then was that it would touch many applications because it combined electronics and light. But it is amazing how it is used today . . . I've had a number of people come up to me and say 'lasers saved my eyesight.' That's a very emotional experience for me. It's so personal, this connection."

Sketches of the first maser Townes shared the story of his invention and his early interests in science with about 50 middle-school students on Dec. 1, 1998, during an "Innovative Lives" program sponsored by the Lemelson Center. Students from Walker Mill Middle School in Capitol Heights, Md. and Thoreau Middle School in Vienna, Va. attended the program with Townes and then performed science experiments in the Museum's Hands On Science Center to learn more about lasers. Students from South Junior High School in Newburgh, N.Y. participated in the program via video conferencing.

The students, brimming with enthusiasm, peppered him with questions about growing up, learning about science, and his work today in astronomy. Townes showed students drawings and sketches he made when developing the maser and laser, as well as the original maser. He also showed them a replica of the Nobel Prize medal, which he won for physics in 1964 along with Russian scientists N.G. Basov and Aleksandr Prokhorov. The medal's inscription reads, in Latin: "Inventions enhance life, which is beautified through art."

Townes and his wife Frances Townes was joined by his wife Frances during the program. Mrs. Townes showed students a brooch that her husband designed for her for their 25th wedding anniversary. At the brooch's center is the laboratory-made ruby used in the first maser amplifier to get astronomical results. The creative design also features metal in the shape of a parabola--the shape of the maser's reflectors. The ruby maser was used to measure the microwave radiation from Venus. "I guess you could say she's my Venus," Dr. Townes told students as he put his arm around his smiling wife.

Bob Nahory, a former scientist at Bell Laboratories, where Townes worked when he devised the theory for the laser, moderated the program. "Scientists are people who grew up and didn't stop asking questions," Nahory told the students. As a young boy in Greenville, S.C., Townes had lots of questions about science.

Townes says he first got "an appreciation for the universe by getting friendly with the outdoors." He and his older brother would catch insects and frogs, watch the stars, and climb trees. Together they built wagons, kites and rabbit hutches. "I came to feel that everything in nature was a friend of mine," he says. "Learning about nature is a great way to introduce young people to science."

Townes says his parents encouraged their rambunctious sons' interest in science--even when caterpillars got loose in the house. "We had pet frogs, lizards, snakes and caterpillars. My mother was appreciative of that," he says, smiling wryly. "And my father and I would take long walks together in the woods." Little by little, Townes began to learn how things worked in nature--and what their names were. When he was about 15 years old, he found a fish he couldn't identify in his science books. So he sent it to the Smithsonian's National Museum of Natural History, which later verified his opinion that the fish was part of a then-unnamed species, Townes said.

The precocious Townes was just setting off on his path to becoming a great scientist. But some of his teachers may not have recognized his abilities when he was in middle school. "I wasn't doing well in school because I found it boring," Townes says, recalling his parents' decision to let him skip the seventh grade. "And people used to make fun of me because I had unusual hobbies. I got picked on a little bit."

As Townes took on more challenging work, he excelled in school, gaining early admission to Furman University at age 16. He graduated in 1935 with degrees in physics and modern languages. He has studied French, German, Italian, Spanish, and Russian. He has also had a life-long interest in music and has studied the accordion, piano, and voice. "Scientists interact with other people and that interaction is very important," says Townes. He offered this advice to the middle-school students: "Try a lot of things, read a lot and do the things you have the most fun with. Keep exploring and try to learn as much as you can. Don't try to specialize too much because you have more understanding if you know about lots of things." Bob Nahory interviews Townes

Townes also told the students the famous story about the moment when he conceived the theory behind the maser and laser. It was 1951 and Townes was in Washington, D.C., to attend a conference sponsored by the Office of Naval Research. Conference participants were studying the problem of producing high-frequency radio waves to measure matter. The vacuum-tube technology of the time couldn't produce extremely short waves.

Townes decided to take an early-morning walk to ponder the problem that vexed scientists throughout the world. Waiting for a restaurant to open so he could get breakfast, he sat on a park bench in Franklin Square to think. "Sometimes you think and think and it just suddenly hits you," says Townes. "We needed a new way to make waves shorter and shorter. Well, molecules make waves, I thought, and atoms can do it. I knew how molecules worked. And I thought, wait a minute, this will probably work." In a moment most scientists only dream about, he grabbed an envelope from his shirt pocket and began to furiously scribble notes on it. He had conceived the theory behind maser and laser technology.

In an astonishing coincidence, Townes had unknowingly stopped at a park bench located across the street from the former laboratory of Alexander Graham Bell--the man who first showed that light could carry information. "It's a funny coincidence," says Townes, nodding. "There's something almost mystical about it. Maybe he inspired me."

Townes talks to a student Although that moment was a breakthrough, it would take more than two years to produce a working model of the maser. Townes says two of his fellow professors expressed doubt about putting maser theory into practice. One was a Nobel Prize winner and the other went on to win the same prestigious award a few years later. "They told me it wouldn't work," Townes told the middle school students. "And I said, no I think it will, and I'm going to keep going. It's good to have criticism because it makes you think. But if you think you're right, you keep on going."

Townes remembers the exact moment when the maser first worked. James P. Gordon, Townes's doctoral assistant at Columbia University, rushed into Townes's teaching seminar, shouting that the maser was finally working. "I was thrilled," says Townes. "We canceled class that day so we could go see the maser work and celebrate."

Townes said he believes laser technology is "in its adolescence right now." He predicts more advances in communications technology as well as in the study of surfaces and materials. And he predicts that there will be continued advances in biology. "Laser tweezers are used to pick up cells, to stretch cells and chromosomes," says Townes. "It's just beginning to be used in these ways."

Today, Townes is a professor in the graduate school at the University of California at Berkeley. He continues to do astrophysics research, concentrating on the behavior of stars. His main research tool? The laser. "I do enjoy it and for some reason people are willing to pay me," says a smiling Townes. "I have gotten a salary to do what I want to do."

Teachers, explore the history of Nobel Prize further with your students with our "The Nobel Prize: 100 Years of Creativity and Innovation" interactive CD-ROM and teachers' guide. Request the CD-ROM package.