Harold Eugene "Doc" Edgerton (April 6, 1903 - January 4, 1990) was an
electrical engineer, MIT professor, co-founder of the EG&G company,
and most famously, a pioneer in high-speed photography and the visualization of high-speed phenomena.
Edgerton was born in Fremont, Nebraska to parents Frank and Mary Edgerton.
Edgerton first learned about photography from his uncle as a teenager, but
he eventually took up electrical engineering at the University of Nebraska
after summer jobs with his local electrical company. He graduated from there
in 1925, moved to Schenectady, New York to continue working in the
electrical industry, and then enrolled at MIT for graduate studies.
He was awarded his Master's Degree in 1927 for his thesis on
stroboscopic imaging of motors, and finished his Doctorate
in 1931. He became a member of the faculty at MIT at that time.
In the 1930's, Edgerton began his most famous work, using a stroboscopic
camera to photograph high-speed phenomena. In this technique, a camera with
a high-speed shutter is coupled to a very bright, fast strobe light.
The camera is triggered in such a way as to catch the event as it is
happening, usually using a piezoelectric microphone or a light detector
as the switch. In this way, Edgerton was able to catch the fine details of
rapid events like the splash of a milk droplet, or a bullet piercing a
balloon, an apple, or a playing card. Edgerton also began using multiple,
rapid strobe flashes on a single exposure to capture motion (for example, a
golfer swinging a driver). In this way, he was able to bring
out the fine details of dynamical phenomena for human study. In 1940,
Edgerton et al. worked on a short film, Quicker Than A Wink, which
won an Academy Award for best short film that year.
In the late 1930's and 1940's, Edgerton, along with Kenneth Germeshausen and
Herbert Grier (two of Edgerton's students at MIT) began a long affiliation
with the United States military, eventually forming the company EG&G
in 1947. In 1939, they developed very powerful camera flashes to be used
from airplanes for night-time reconnaissance and
aerial photography. This system was used several times during
World War II, including D-Day.
EG&G was also involved with nuclear weapons design and research. First,
EG&G supplied the triggering system which detonated the device. The proper
detonation of an atomic bomb requires that the core of the device
implode rapidly and in as spherically symmetric way as possible. Therefore,
the high explosive jacket covering the fissionable material has to be
detonated at multiple points within much less than a microsecond of one
another. EG&G also supplied the photographic equipment which allowed
scientists to film nuclear tests at very early stages of the explosion.
One striking photograph of the early moments of a nuclear test shows a fireball only a few hundred
feet across, not yet large enough to engulf the tower from which it was
fired. Such photographs require extremely fast exposure times --
much less than a microsecond, and new technology had to be used. For example,
their Rapitronic cameras used magnetic shutters rather than mechanical
ones, because mechanical parts could not work at the speeds required.
The shutter has no moving parts -- it works by passing a magnetic field
between two crossed polarizing filters. A brief magnetic
pulse causes Faraday rotation in the incoming light, allowing it to pass
through the normally opaque second filter. They also developed motion picture
of recording millions of frames per second, in order to record the
progress of explosions in fine detail.
Edgerton is also famous for his work on underwater photography and sonar,
including collaborations with Jacques Cousteau. He worked with Cousteau
starting in 1953, to develop underwater cameras which used sonar as a
rangefinder near the ocean floor. He also worked on side-scan sonar, and
a low-frequency sonar capable of penetrating the ocean floor to search for
buried rocks and debris. He helped to explore the sunken Achaean city of
Helice in 1966, and in 1973 helped to find the U.S.S. Monitor off
Cape Hatteras in North Carolina. His penetrating sonar was used to
find the English warship The Mary Rose dating from the reign of
King Henry VIII, which accidentally sank in 1545 during an engagement
with the French navy in the English Channel.
Edgerton retired from EG&G in 1975, though he remained affiliated
both with the company and with MIT until his death. He died in 1990
of a heart attack while dining at the faculty club at MIT.
During his life, he received several awards for his work, including an
Academy Award (1940), the War Department Medal of
Freedom for his work on aerial reconnaissance, the National Medal of
Science in 1973.
Sources: Most of the biographical information was obtained from the web
biography at http://www.edgerton.org/biography.html, and from
http://www.egginc.com/. The rest is from (somewhat fuzzy) memory.