Remember when we all went wild because The Matrix brought out "bullet-time"? They were about half a century behind Harold Edgerton. He was an engineer who first started looking into the idea of photographing fast motion. He let people see exploding apples and coronets made of droplets. And he made the world a much cooler place.
Harold "Doc" Edgerton was an engineer with an amazing idea. It would be easier for scientists to describe the phenomena they studied if they could actually see them. He decided to put his idea into practice with some special cameras and a stroboscope, and on the way he discovered sunken ships, photographed nuclear bombs, and made an Oscar-winning film.
Edgerton started out as an engineering student at the University of Nebraska before going to MIT in the early 1930s. To help him out with his thesis, which required him to study a working engine, he used a stroboscope. Look at a fast-moving object in continuous light and it's a blur. Time a stroboscope to flash light at only certain periods, and it will visually freeze an engine, or the blades of a fan, or any other repetitive motion in place. Change the frequency of the flash a little more, and it will show the object moving forward very, very slowly, as each flash of light catches it later in its cycle of motion. For motion that's unique, and can't be repeated, this is no good. For repetitive motion, in which each cycle is more or less like the last, it changes lightning fast motion to a slow crawl.
After college, Edgerton worked with this technology a lot, and incorporated cameras that used high-speed photography equipment in sync with a strobe light to eliminate the blur in motion photography. In 1940, he won an Oscar for his short film, Quicker 'n a Wink, which features shots of how air moves in the wake of a fan, how an egg shatters on fan blades, and how milk forms a little coronet when it drips into a bowl. All of these segments are still fascinating today. (The decision to close the film with footage of a dentist's drill working on teeth is questionable, though.)
He went into business for himself developed a special camera that let scientists take still images of the first few milliseconds of a nuclear explosion. He then went nautical and developed side-scan sonar. This type of sonar shoots out sound waves in a kind of cone from a central point, and measures the intensity of the returning sound. The sonar is tugged across an area by a boat, until it has tested it with sound from all angles. It then takes all those different returning sounds and knits them into a picture of the ocean floor. By developing ths type of sonar, Edgerton helped locate the wreck of the HMHS Britannic.
Despite his many technical accomplishments, he is best known for his relatively simple still photos. The milk drop coronet image gained enduring popularity, and since then people have taken many photos of the coronet that liquid droplets make when they fall. His second most popular picture was dubbed the how to make applesauce at MIT - a picture of a bullet going through an apple, the splatter at both ends frozen. He put a microphone between the apple and the gun. When it picked up the sound of the gun, it relayed an electronic signal that set off a microflash, timed to go off just as the bullet hit the apple. It's still used in demonstrations.
Edgerton won a lot of awards - besides that paltry Oscar. He got the Royal Photographic Society's Bronze Medal, and a lot of acclaim for his work as a photographer. But he thought of himself as an engineer first, and so perhaps the posthumous dedication of the MIT Edgerton Center, which was to concentrate on applied engineering, would have pleased him most.
Coronet Image: JJ Harrison
Nuclear Bomb Image: Atom Central