Harold Eugene Edgerton transformed the stroboscope from an obscure laboratory instrument into one of the most important tools in photographic history. Born on April 6, 1903, in Fremont, Nebraska, he earned his doctorate at MIT and joined the electrical engineering faculty, where he spent five decades pushing the boundaries of high-speed photography. His strobe photographs froze moments invisible to the human eye: a bullet piercing an apple, a milk drop creating a perfect coronet, a hummingbird's wings mid-beat. These images became icons of twentieth-century visual culture, published in scientific journals and Life magazine alike. During World War II, Edgerton developed aerial night reconnaissance photography systems for the Allied forces. His strobe units, mounted beneath aircraft, could illuminate entire landscapes from altitude, providing intelligence photographs that were used in planning the D-Day invasion at Normandy. After the war, he collaborated with Jacques Cousteau on underwater photography and sonar systems, helping to locate the wreck of the Civil War ironclad Monitor and the sunken ocean liner Britannic. His students called him "Papa Flash," a nickname he earned through both his pioneering strobe work and his generous mentorship of generations of young engineers. He held 47 patents and received the National Medal of Science in 1973. He continued teaching and researching at MIT until his death on January 4, 1990, at age 86, arriving at his laboratory every morning with the curiosity that had driven him for six decades.