About the Strobe Light
& it's inventor Harold Edgerton
A strobe light is a fast-flashing lamp which is used for "freezing" the movements of certain objects. These can be propagating water waves or a revolving fan or a horse galloping on a treadmill. When the flashing frequency (i.e., how many times a second the lamp flashes) is the same as that of the moving object (e.g., the same as the frequency of the water wave) the object will appear to be "frozen" (in this case, the water wave seems "suspended in air"). Once we've matched the frequencies by seeing when the object "freezes", we can figure out the objects frequency as being the same as the frequency of the flashing strobe. So a strobe basically makes things seem to be moving in slow motion and we can take advantage of this to slow down and observe those things that are usually moving too quickly for us to study.
Dr. Harold Edgerton is recognized internationally as the scientist who developed the stroboscope and electronic flash for high-speed photographic images. He is also known for his extraordinary career as a professor at the Massachusetts Institute of Technology, where students were inspired by his ability to turn science into a theatre of excitement.
Harold Eugene Edgerton born April 6th, 1903 in Fremont, Nebraska. He works summers at the Nebraska Power and Light Company. Develops an interest in electrical generation. While working at an electric company in Schenectady, New York, he continues his study on the turbines that produce electrical generation.
In 1926 he enters the Massachusetts Institute of Technology (MIT). In his graduate studies uses the strobe light to study whirling rotor engines. By controlling the frequency of strobe flashes synchronized with the spinning rotors, he is able to see rotors clearly. He developed and perfected the stroboscope for use in both ultra-high-speed and still (or stop-motion) photography.
High-speed photography still had two limiting factors in the early 20th century: there were limits to the speed of a mechanical camera shutter, and a very brief exposure required intense light to produce an image on film. In the 1930's Harold Edgerton solved both problems when he invented the electronic flash, an intense light that could be as brief as a millionth of a second. In 1938 he perfects multiflash photography of athletes in action. Unsuccessfully attempts to sell the concept of electronic flash to major U.S. camera manufacturers. Contacts sports photographers and offers them his services and equipment. By 1940, sports photography is revolutionized by Edgerton's technique, which allows the camera to capture high-speed motion and preserve an unprecedented degree of detail. Electronic flash photographs of sports events are regularly published in major newspapers after 1940.
The first of his many articles for National Geographic magazine is published. "Hummingbirds in Action" contains high-speed photographs that illustrate for the first time the wing movement and flight patterns of these tiny birds.
In 1953 he began a long association with French underwater explorer Jacques-Yves Cousteau, accompanying him on numerous expeditions aboard the research vessel Calypso. They explore and photograph sea floors from the Mediterranean to Lake Titicaca in the Andes Mountains. To position underwater cameras on these expeditions, Edgerton designs a "pinger" device that attached to a submerged camera. Sound waves, emitted from the pinger and returning as echoes from the ocean floor, indicate how close the camera is to the bottom. On these expeditions, Edgerton also experiments with the side-scan sonar, an acoustic device used to locate objects lying on the ocean floor.
!n 1973, using a side-scan sonar, Edgerton and colleagues locate the sunken Civil War battleship USS Monitor, lost since 1862, off Cape Hatteras, North Carolina. The battleship lies upside down in 220 feet of water.
IN 1982 he was named "New England Inventor of the Year" by MIT, the Boston patent Law Association, and the Museum of Science in Boston. Citation reads: "He has pressed back the frontiers of our knowledge of vision and motion with his stroboscopic photography, and, through his marvelous medium, he has captured and revealed new beauty and order in both nature and industry."
Jeff Danger, Science
Cool Science Show For Kids