Harold Edgerton
Harold Eugene “Doc” Edgerton (1903 – 1990), also known as Papa Flash, was an American scientist and researcher noted for creating high-speed photography techniques that he applied to scientific uses to capture time sequences using multiple cameras.
Edgerton partnered with Kenneth Germeshausen and Herbert Grier to form “Edgerton, Germeshausen, and Grier” (EG&G) in 1947. EG&G became a prime contractor for the Atomic Energy Commission and had a major role in photographing and recording nuclear tests for the US through the fifties and sixties. For this role Edgerton and Charles Wykoff and others at EG&G developed and manufactured the Rapatronic camera .
Atomic Bomb Explosion—1, 1952
Nuclear explosion from the Tumbler-Snapper test series in Nevada, circa 1952 photographed by a rapatronic camera less than 1 millisecond after detonation. In this shot, the fireball is about 20 m (66 ft). The spikes at the bottom of the fireball are known as the rope trick effect.
The detonation of Boltzmann (12 kt)) during Operation Plumbbob – 28 May 1957. In this rapatronic image the spikes below the fireball are the shot tower support cables vaporizing as they absorb thermal radiation – known as the ‘rope trick’ effect. (Photo via sonicbomb)
Harold E. Edgerton, Atomic Bomb Explosion, before 1952, printed 1980, gelatin silver print
Atomic Bomb Explosion, 1952. This photograph, probably of a bomb dubbed “How,” was likely taken on June 5, 1952, as part of Operation Tumbler-Snapper test series at the Nevada Proving Grounds.
The detonation of How (14 kt) during Operation Tumbler-Snapper – 5 June 1952. A millisecond after the previous image, another rapatronic captures a different picture of the detonation. A globe of fire emerges. The Joshua trees silhouetted at the base of the rapidly expanding explosion will quickly be engulfed by the shock and heat waves and incinerated. (Photo via sonicbomb)
The detonation of How (14 kt) during Operation Tumbler-Snapper – 5 June 1952. This rapatronic image captures the expanding plasma ball in all its monstrous majesty. The heat generated through the ‘rope trick’ effect caused the desert floor to turn to glass. (Photo via sonicbomb)
The detonation of Priscilla (37 kt) during Operation Plumbbob – 24 June 1957. Instead of being housed in a shot cab, the Priscilla device was held 700 feet aloft by a balloon with steel cable mooring. This rapatronic image captures the burst of explosive and thermal energy equivalent to 37.000 tons of TNT. The ‘rope trick’ spikes are prominent and dramatic. The spots are fragments of the bomb casing ‘splashing’ against the inside of the expanding shock front. (Photo via sonicbomb)
The detonation of Mohawk (360 kt) during Operation Redwing – 3 July 1956. The thermonuclear Mohawk was a more powerful device than the above three combined. This rapatronic image captures the burst of explosive and thermal energy equivalent to 360.000 tons of TNT. The cloud rose to 65,000ft/~20km. The plasma colossus resembles some sort of strange living organism. (Photo via AtomCentral)
This is an image of a ‘shot cab’ – the housing at the top of the tower that contains the explosive device. (
This is a rapatronic image of a ‘shot cab’ at the moment of an atomic bomb explosion. The cab appears to be fluorescing with X-Ray energy making it transparent. Blogger James Vaughn at ATOMIC-ANNIHILATION made this comment: …the most prominent feature is in the middle-upper (left) which looks like a giant friggin’ eye! Is that the ‘device’ caught in some weird moment of percolating itself into and out of existence before it becomes an … atomic explosion? (Photo via Edgerton Digital Collections, taken at Eniwetok, c. 1952)