The Man Who Stopped Time

ON DECEMBER 19, 1937, THE HARTFORD Courier described a demonstration that Harold Edgerton had just given at the local Bushnell Motion Pictures and Lecture Course: “About 2000 persons sat for about two hours in Bushnell Memorial last night and saw things happen that happened a long time before they reached the hall, but which really happened at the time they saw them happen. S’elp us, that’s what happened! In other words they saw what a booby a high-speed camera and a little stroboscopic light will make out of time.”

The reporter’s amused perplexity was just what the lecturer had wanted. Edgerton played with the human sense of time, a sense that had already been transformed from a natural rhythm of day and night into a segmented commodity regulated by the clock. His stroboscopic light further upset time by making infinitesimally short bits of it visible, giving the unaided eye a glimpse into an unseen world.

HAROLD EDGERTON WAS BORN IN NEBRASKA in 1903 and headed to Cambridge and the Massachusetts Institute of Technology in 1926. He had had summer jobs at Nebraska Power and Light, earned a bachelor’s degree in electrical engineering from the University of Nebraska, and spent a year in General Electric’s test course; now his ambition was to run an electricity-generating plant. As a graduate student at the institute he studied the large electric motors found in power plants.

He was most interested in what happened when a sudden change, such as a surge caused by a lightning strike on power lines, hit a motor, but parts of the machine spun so fast that there was no way to see what occurred. He noticed that a mercury-arc rectifier, a tube he was using to generate surges, flashed brightly as the power peaked. When the repeating flash synchronized with the motor’s turning parts, it made them look as if they were standing still.

By 1931 Edgerton had turned his experiments with motors and mercury tubes into a commercial product that he called the stroboscope. It had three basic components. First, a power supply—an electrical outlet or battery—would send electricity into the second component, a capacitor, which collected the energy. Then at some point the stored-up energy would be dumped into the third component, a tube filled with a rare gas, and the excited gas molecules would produce a blast of brilliant light and heat. What made the stroboscope especially useful was that the flash was renewable; as soon as the capacitor recharged, it could go again. Adjusting the flashing rate made it possible to measure the speed of machinery in motion and spot any irregularities in the mechanism’s operation.

Edgerton’s stroboscope was not a completely new thing; he did not see a vision of it and shout “Eureka!” In fact, he never claimed to have invented it at all. When he first turned a strobe on a motor in motion and photographed what it revealed, he was building on the work of others who had earlier devised mechanical or electrical means of arresting time in the camera’s eye.

When photography was introduced, in 1839, exposure times could be measured in minutes. Cameras did not need shutters; a photographer simply uncovered the lens, waited, and put the lens cap back to end the exposure. Most photographs were portraits and landscapes. But within a dozen years practitioners of the new art were finding ways to catch life in motion.

In 1851, scarcely twelve years after introducing photography using negatives, William Henry Fox Talbot produced the first known flash picture. He fastened a piece of newspaper onto a disk and set it spinning as fast as possible. Then he discharged a spark and exposed his glass plate. “An image was found of a portion of the words printed on the paper,” he reported to the Royal Society in London. “They were perfectly well-defined and wholly unaffected by the motion of the disc.” He declared, “It is in our power to obtain the pictures of all moving objects, no matter in how rapid motion they may be, provided we have the means of sufficiently illuminating them with a sudden electric flash.”

Other photographers soon began capturing motion. The camera became a tool for dissecting the movements of humans and animals and tackling unanswered questions about them. One such inquiry led to a set of experiments that has become legend. As the probably apocryphal story goes, the railroad magnate Leland Stanford hired Eadweard Muybridge in 1872 to settle a bet: Do all four of a trotting horse’s hooves leave the ground simultaneously? To record the gait of a horse, Muybridge devised a complicated arrangement of boards, springs, lenses, and a camera. His first photographs have not survived, but success was reported in the press: The horse had indeed been airborne. In 1878 Muybridge produced a series of photographs of running horses that conclusively proved the point.

DURING THE 1870s AND 1880s MUYBRIDGE continued to photograph all sorts of sequences of men, women, children, and animals in motion. Others shared his interest. Five years before the first trotting-horse photos, the French physiologist Etienne-Jules Marey began his own study of locomotion. At first Marey designed mechanical and graphic devices to measure and trace in ink on paper people’s and animals’ movements. When Muybridge’s trotting-horse photographs were published in 1878, Marey was astounded; he had dismissed photography as too slow. Now he began to realize the potential of the medium.

Marey designed and built some ingenious devices for seeing motion over time. One of the first used a clockwork mechanism to rotate a glass-plate negative behind two spinning slotted disks. The apparatus produced a sequence of exposures around the perimeter of the plate, making it resemble the View-Master disks of later generations.

But he didn’t like missing the fragments of movement between the exposures, so he gave up the rotating negative for a stationary one, replaced the two-disk shutter with a single slotted one, left the lens open, and created “chronophotographs”—multiple exposures on a single plate. As the subject—a man walking, for example—moved along, he would be in a different location each time the revolving shutter exposed the negative and would leave a sequential image on the plate. The faster the disk spun, the closer the individual images would be on the negative, since less time would elapse between them and the subject would cover less ground. To emphasize the motion of particular body parts, Marey often dressed his subjects in black—even if they were animals—and painted white lines on their arms and legs. The eerie, skeleton-like lines and angles that resulted were for Marey the “clean” data he was seeking.

Throughout the late 1880s and the 1890s, experimenters tried to capture ever-smaller increments of time by using the electric spark that Talbot had introduced to photography. In Great Britain Frederick J. Smith dropped his cat upside down and took a series of multiple-spark photographs of the pet as it righted itself to land on its feet. (“His cats do not seem to like the experiments,” an acquaintance reported.) Arthur Mason Worthington studied splashes of all sorts: water drops, falling marbles, even artillery shells striking armor plate. In Germany Ernst Mach photographed bullets in flight, as did C. Vernon Boys in England. In the United States Charles Steinmetz photographed high-voltage sparks themselves, as part of his research on lightning.

MANY OF THESE IMAGES WERE SHADOW PHOTO graphs—the spark exposing the image directly onto the emulsion, without the use of any lens. While some researchers were using induction coils to get strong, bright electric sparks, most still relied on Leyden jars and electrostatic machines. But that was about to change. People were beginning to look at the behavior of electrified elements enclosed in glass, including discharges of electricity through gases in evacuated tubes. In so doing, they were starting down the path to the electronic stroboscope.

Étienne Oehmichen and the Peugeot Automobile Company received French and Swiss patents around 1920 for an intermittent light source for examining motors in motion. In 1926 and 1927 two brothers named Laurent and Augustin Seguin obtained patents in France, Switzerland, and the United States for an early strobe that they marketed as the Stroborama. By the early 1930s they had won industrial, government, and university laboratories around the world as their customers. One of these was the General Electric Company in Schenectady, New York, where Harold Edgerton had worked in 1925 and 1926.

Edgerton later recalled that he had learned about strobes while he was at G.E., though he probably didn’t mean from the Seguins’ Stroborama. “I’d seen it before in General Electric,” he told an oral historian in 1975. “They had strobes there, little neon strobes.” But they were not very powerful, the flash lasted too long, and the light they gave off was quite red. Edgerton called those strobes “a solution to the problem, but… not a good solution to the problem.” He spent the rest of his life building better solutions.

Like its predecessors, Edgerton’s stroboscope originally found use in direct visual observation. But he also combined it with a high-speed motion-picture camera to make movies of machinery in operation. His pioneering technique produced ultra-slow-motion movies in a new way. Instead of having the shutter open and close repeatedly with the film advancing one frame at a time, as in traditional motion pictures, Edgerton’s camera used continuously moving film, racing along at seventy-five feet per second. In a darkened room the crisp blinking of the stroboscopic light acted as a shutter, starting and stopping the exposures.

He used this tool to study moving machinery in various industrial settings. Operators of all sorts of equipment got the chance to see their belt drives slipping, their gears not meshing properly, and other faults that were obvious only when a machine was at work. But Edgerton did not reserve the strobe for industrial uses alone. He turned his light on everyday events and common sights, and in all of them his scrutiny revealed uncommon beauty and wonder.

Most of us are familiar with some of the results—wellknown photographs produced either under contract or out of curiosity by Edgerton and his colleagues. But other images that hold just as significant a place in his work are usually overlooked. These are the films and photographs that he used to work out his ideas. They amount to a kind of photographic sketchbook for his visual thinking.

The historian of technology Eugene Ferguson has written persuasively about engineers’ use of the “mind’s eye” to solve design problems, emphasizing the importance of technical drawings but passing over photography as a less precise method of representing three-dimensional objects. Edgerton, however, found that photography made the most of his analytical mind’s eye. For each of his fine, finished photographs, he made scores of negatives that show how he worked out a problem. He photographed the setups he used. He photographed the flashes of new lamps. He photographed different arrangements of the variables in a situation, helping him puzzle out whatever mystery he was trying to solve.

IN A WAY THESE PHOTOGRAPHIC sketches are easier to explain than the finished images, like the milk drop, that have become part of our visual vocabulary. Edgerton thought of himself as an engineer first and foremost, and this is visible in his rough laboratory photographs. But there is more to his work than that.

Many of his photographs were produced under contract. He was marvelous at self-promotion, and within a few years of putting his strobe on the market he was working for a long list of companies and government agencies. His consulting projects ranged from barrel and bolt tests on automatic rifles to studies of the erosion resistance of different kinds of soil and examinations of textile- and paper-mill machinery. But he never approached a job as a mere job.

For example, in 1940 he was hired by Fisher Body to test safety glass for car windshields. Basically this meant simply photographing the glass in the process of breaking, a natural application of strobe photography. But he did not just break the glass; he brought in a New York Yankees pitcher, Bump Hadley, to hurl baseballs at a Buick windshield.

Edgerton’s lab notes describe the experience: “On Wed. I … made arrangements to experiment with the cutaway Buick 1939 model. … On thursday the three light studio unit was taken to the Buick Bldg and set up for the evening for Mr. Bumps [sic] Hadley—NYY pitcher. He came at 10:30 and threw several balls at the windshield. None penetrated the glass. Two cameras were used for this. I operated one at the side and Barstow the other in back. A microphone trip was used to start the lights.”

This sense of the theatrical carried through much of Edgerton’s work. His lifetime fascination with water drops led to some especially unusual experimental setups. In 1936 he put his camera and strobe at the base of an elevator shaft and photographed drops released through a hole in the elevator floor. Again he described it in his notes: “Spent all day with Kiethly taking photos of H 2 O Drops in the elevator shaft. The dropper was on the elevator, dripping through a hole in the floor. Pictures were taken with the elevator at 5 ft 1st 2nd 3rd 4th 5th and 8th floor. The camera was at the level of the basement floor. A photocell method of tripping was used. From the 8th floor the drops were in a 8” circle. 40 photos taken to get 2 pictures of drops! The-drops do not break up in falling this distance. Wt of drops about 0.9 grams.”

THE PLAYFULNESS EDGERTON BROUGHT TO PROB lem solving bears out the historian George Basalla’s view of “technological dreams” and fantasy as important to technological accomplishment. Basalla refers to “the great pleasure taken in playing with technological possibility for its own sake.” Edgerton’s pleasure in his work is obvious, as are his sense of wonder and his entrepreneurial bent. He took his show on the road, introducing the strobe to industrial corporations, research laboratories, professional photographers, naturalists, and anyone else who would look at it. In pushing the strobe’s capabilities in ever-changing directions for diverse purposes, he blurred the line between technology and art. His photographs themselves became a kind of technological dream.

Edgerton could have had a comfortable life just teaching at MIT until his death in 1990, while earning extra income from the sale of stroboscopes. He did stay involved with the institute all his life, but at the same time he made himself a true pioneer. He expanded the use of the strobe from direct observation into photography. And while so doing, he consciously paid homage to the scientists and photographers who preceded him. Like Marey, he created multiple exposures on a single negative and draped his subjects in black to emphasize their specific movements. His bullet photography showed the influence of Mach’s and Boys’s shadow techniques. He honored Worthington with milk drops and Smith with twisting cats. But ultimately the art and technology of Harold Edgerton stand on their own, the products of a lifetime of insatiable curiosity and wonder. In both still photographs and motion pictures, the leitmotif of his work was an unending search to make time visible. As he summed it up, “I like to see the real thing.”