Harold E. Edgerton

• Born: April 6, 1903
• Birthplace: Fremont, Nebraska
• Died: January 4, 1990
• Place of death: Cambridge, Massachusetts

American electrical engineer

Edgerton was an electrical engineer who pioneered the development of high-speed photography, employing and perfecting the electronic flash. He used the electronic flash to study motions as diverse as the splash of a milk drop and the flapping of the wings of a bat.

Primary field: Electronics and electrical engineering

Primary inventions: Electronic flash strobe light; high-speed photography

Early Life

Harold Eugene Edgerton was born on April 6, 1903, in Fremont, Nebraska, the eldest of three children to Frank Eugene Edgerton and Mary Nettie (Coe). His father was the high school principal and coached the football team. Edgerton’s family moved several times. First, they moved to Washington, D.C., where his father served as a correspondent for the Lincoln, Nebraska, newspaper; then they moved to Lincoln, and finally to Aurora, Nebraska, where Edgerton attended high school. During that period, his uncle, Ralph Edgerton, a studio photographer, taught Edgerton the basics of photography. Edgerton bought his first camera when he was fourteen years old and set up a darkroom in his house so he could develop and process his own images.

As a child, Edgerton enjoyed taking apart mechanical devices to figure out how they worked and fixing those that were broken. While in high school, he worked for the Nebraska Power and Light Company. Although he was hired to perform janitorial and maintenance tasks in the office, many of the men who repaired the power lines were called into military service during World War I, and Edgerton was assigned to repair power lines. He described this job as challenging, because he had to solve different kinds of problems each day.

Edgerton decided to pursue a career in electrical engineering and entered the University of Nebraska, Lincoln, in 1921. He was awarded a bachelor of science degree in electrical engineering in 1925 and spent the next year working at General Electric in Schenectady, New York. In 1926, Edgerton began graduate studies in electrical engineering at the Massachusetts Institute of Technology (MIT), in Cambridge, Massachusetts.

Life’s Work

Edgerton received his master’s degree in electrical engineering from MIT in 1927. He was appointed an instructor in electrical engineering at the university, beginning a more than fifty-year association with the research institute. He also continued to work toward his Ph.D., investigating the effects of sudden changes, such as the power surge caused by a lightning strike on a power line, on the rotation of large electric motors. However, the motor rotated too fast for his eye to see the effects. Edgerton noticed that the device he was using to send power surges to the motor produced a flash of light accompanying each power surge. He realized that if he synchronized these light flashes with the rotation rate of the motor, its parts appeared to stand still.

In 1929, Edgerton asked Kenneth Beardsley, one of his graduate students, to use a pulsing mercury-arc lamp to examine motor rotation and to try to record the results photographically. Edgerton recognized that each light flash would expose an image, recording the motor’s position in a photograph. By 1930, Edgerton was using a mercury arc that emitted sixty flashes per second, each having a duration of only 1/100,000 second, to study the behavior of a motor as it began to rotate.

Edgerton and Beardsley were not the first people to combine a light flash with photography. The first flash photograph, made using a spark to expose the image, was made in 1851 by William Fox Talbot, shortly after photography was invented. At the time, photographs required very long exposures, so only stationary objects were suitable subjects. Talbot said that combining electric sparks with photography had the potential for obtaining photographs of moving objects. However, the spark photography technique was treated simply as a curiosity until Edgerton developed it as a serious research tool and a new art form.

Edgerton was awarded a doctor of science degree in electrical engineering in 1931, and his stroboscope was described in the May, 1931, issue of the research journal Electrical Engineering. Edgerton saw the value of his device as a tachometer, an instrument used to measure rotation rates, and submitted a patent application in 1933. In 1934, he contracted with the General Radio Company to produce his suitcase-size mercury-arc stroboscope, the Strobotach.

In 1928, Edgerton married Esther May Garrett, whom he first met when her family moved to Aurora, Nebraska, in 1915. They had three children, Mary, William, and Robert. During the summer of 1934, Edgerton and his family drove back to Nebraska for a visit. Edgerton stopped at factories on the route, trying to interest them in his Strobotach.

As word spread of his success in photographing rapidly moving objects, people visited Edgerton’s laboratory seeking assistance on their own projects—initially, other faculty members who had research that might benefit from Edgerton’s electronic flash. Edgerton credited MIT professor Charles Stark Draper with suggesting that he explore other uses for the strobe light. Draper told Edgerton, “The whole world is moving,” inspiring Edgerton to take photographs of everyday objects and events. His first such photograph was a high-speed picture of water running from a faucet, highlighting the complexity of the motion. From then on, as Edgerton said, “it was just looking at one problem after another.”

Edgerton and Kenneth Germeshausen, his research assistant, were both amateur photographers, so they began making still and motion pictures of all kinds of objects in rapid motion. These photographs showed everyday events in a way never before been seen. One photograph, taken in 1934, showing a football being placekicked, recorded the distortion of the football as the kicker’s foot penetrated nearly halfway into the ball.

Three of Edgerton’s photographs were included in the Royal Photographic Society’s annual exhibition in London in 1933, the first time his photography was exhibited. Edgerton’s most famous image is “Coronet,” which shows in fine detail the symmetry of the splash made by a drop of milk striking a flat surface. That photograph was featured in the first-ever exhibit of photography at the Museum of Modern Art in New York City in 1937. Edgerton went on to photograph athletes in action; hummingbirds in flight; and bullets bursting balloons, cutting through playing cards, and penetrating a light bulb. Many of Edgerton’s photographs were used as illustrations for articles in National Geographic and in Life magazines. In 1940, Edgerton was invited to Hollywood by MGM Studios to describe how his stop-action photography could be used in movies. This resulted in a short film, titled Quicker than a Wink! and starring Edgerton, which won an Academy Award.

Edgerton had formed a business partnership with Germeshausen in 1931. Together they improved on his original device. They wanted a brighter flash with an even shorter duration than the mercury arc could deliver. This effort resulted in the development of the xenon flashtube as a replacement for the mercury-arc source used in the original device.

Edgerton’s electronic flash opened new avenues for the scientific study of the dynamics of fluids, air currents, and engines. During World War II, the U.S. Army sought Edgerton’s help in developing an extremely bright flash for night aerial photography. The system Edgerton developed was used to monitor the night movement of enemy troops during the Battle of Monte Cassino in Italy and in the weeks before the Allied invasion of Normandy.

After World War II, Edgerton founded a company with Germeshausen and another of his research assistants, Herbert Grier. The company, now EG&G, received a contract from the Atomic Energy Commission to design timing and firing systems for atomic bomb testing. EG&G also developed a high-speed shutter for a camera that was used to photograph the explosion of atomic bombs, showing the structure of the intense fireball that developed as the atomic explosion propagated down the wires of the tower on which it was detonated.

In 1952, Edgerton developed an underwater camera for an expedition led by the underwater explorer Jacques Cousteau. Edgerton and Cousteau photographed the Romanche Trench, a deep trench in the Atlantic Ocean. Cousteau’s crew nicknamed Edgerton “Papa Flash.” On later expeditions with Cousteau, Edgerton participated in the location of the wreckage of the Britannic, a sister ship of the Titanic that was sunk by a German mine during World War I, as well as ancient wrecks. Edgerton faced the problem of determining the position of a camera when it was deep underwater. To solve this problem, he developed a special sonar, an underwater radar that sends out sound waves and detects their reflections. This led to Edgerton’s pioneering work on side-scan sonar, which can profile the shapes of objects on the bottom of the sea.

Edgerton retired from MIT in 1968, when he reached the mandatory retirement age of sixty-five. However, he continued to teach and work in his research laboratory, called “Strobe Alley,” for another two decades. In 1973, he recorded changes in the light and color of the solar eclipse in Akjoujt, Mauritania. That same year, he assisted a group using side-scan sonar to locate the wreck of the Monitor, the U.S. Navy’s Civil War armored gunboat. Edgerton also participated in the search for the Loch Ness Monster in Scotland, using both special underwater cameras and sonar. As late as 1989, he was working on the design of a camera to be placed at the bottom of Loch Ness. Edgerton died of a heart attack in 1990.

Impact

Edgerton’s work influenced science and engineering, artistic photography, and the public’s perception of the world around them. The War Department awarded Edgerton the Medal of Freedom for this work during World War II. The strobe light that he developed has been incorporated into most cameras, from inexpensive models to sophisticated professional designs. His underwater cameras and side-scan sonar revolutionized undersea exploration. In 1988, the National Geographic Society awarded Edgerton its Centennial Award, naming him one of fifteen people worldwide who made major contributions to the knowledge of the earth, its inhabitants, and the natural environment during the first one hundred years of the society’s existence. MIT preserved his Strobe Alley laboratory as a place for students and researchers to continue to explore applications of high-speed photography.

Bibliography

Bruce, Roger R., ed. Seeing the Unseen: Dr. Harold E. Edgerton and the Wonders of Strobe Alley. Cambridge, Mass.: MIT Press, 1994. A well-illustrated, eighty-nine-page account of Edgerton’s life, including information on his scientific and engineering achievements and his long career as an educator.

Ray, Sidney F., ed. High-Speed Photography and Photonics. Boston: Focal Press, 1997. A large collection of articles tracing the history of high-speed photography and describing its applications in commercial, industrial, and military settings.

Vandiver, J. Kim, and Pagan Kennedy. Harold Eugene Edgerton, 1903-1990. Biographical Memoirs 86. Washington, D.C.: National Academies Press, 2005. A twenty-three-page account of Edgerton’s life and his exploits using high-speed photography. Written by one of Edgerton’s former teaching assistants.

Zwingle, Erla. “Doc Edgerton: The Man Who Made Time Stand Still.” National Geographic 172, no. 4 (October, 1987): 464-483. An excellent account of Harold Edgerton’s life, his development of the strobe light, and the diversity of projects he undertook. Well illustrated with many of Edgerton’s most famous photographs.