Four Photographs of an Atomic Bomb

Images of the atom bomb have ceased to shock us. By now, the mushroom cloud has a cozy familiarity; the atomic fireball has been appropriated by Michael Bay and George Lucas. But these 1952 photographs from the Nevada atomic bomb test site still managed to jolt me when I saw them.

 

What are we looking at here? Do these things have legs? Is that a tumor growing out of the side? Are these mile-high fireballs or tiny microscopic bacteria?
In fact, these are photographs of atomic explosions, recorded in the first few microseconds of detonation (a few of the fireballs in these pictures could be as little as 100 feet in diameter, while others are considerably larger). In Pictures of the Body: Pain and Metamorphosis, art historian James Elkins writes
that representations of the human body will always be “unencompassably
strange and irretrievably unruly,” and that’s an equally apt
description of these images.

 

In order to study the rates of fireball expansion during bomb testing, the military employed nearly every type of high-speed camera available at the time. The most successful pictures, though, are the ones you see here, and they resulted from the ingenious “rapatronic” camera designed for the event by Harold “Doc” Edgerton, the MIT engineer who pioneered the use of the stroboscope for flash photography (resulting in this iconic milk drop, among other images). Despite having no moving parts, the complex device solved the two main challenges facing anyone wishing to capture a bomb blast: How do I control shutter speed? And, how do I create a shutter that will bar all light?

 

The issue of speed was solved by using a Kerr cell, triggered magnetically by a delay switch, which allowed for exposures lasting only a few millionths of a second. To block unwanted light, Edgerton created a “fuse wire” shutter, a mesh network of fine wires that vaporized and recondensed across the optical path, effectively blocking light faster than a mechanical shutter could do on its own. The cameras were housed in a “bomb cab,” mounted on towers 75 feet above ground, seven miles from the test site. Each camera was capable of taking only a single picture.

 

These images reveal several peculiar characteristics of these fireballs. For starters, the center of the blast is dark—that’s not an error of film overexposure (a separate yield-recording device was dubbed the “bhangmeter,” after the Indian strain of cannabis, because it was considered slightly daft to even try to measure such a thing). The bulging forms and ghostly cavities on the outer edge are irregularities partly due to the “explosive lenses” surrounding the bomb casing used for detonation. And the limb-like protrusions are “rope tricks,” caused by the instantaneous vaporization of the cables that connected the bomb apparatus to the ground. Some of the other fascinating observations recorded by Edgerton—shock waves, radiation smoke, lightning strikes within the fireball—remain classified, although many of them were of little interest to the military, and have apparently not been preserved.