The Making of the Atomic Bomb

In the midst of this contretemps all of Little Boy but its U235 target pieces slipped away. With two Army officers in escort, a closed black truck and seven carloads of security guards left Los Alamos Saturday morning for Kirtland Air Force Base in Albuquerque. A manifest describes the truck's expensive cargo:

a. 1 box, wt. about 300 lbs, containing projectile assembly of active material for the gun type bomb.

b. 1 box, wt. about 300 lbs, containing special tools and scientific instruments.

c. 1 box, wt. about 10,000 lbs, containing the inert parts for a complete gun type bomb.

Two DC-3's waiting at Kirtland flew the crates and their officer escorts to Hamilton Field, near San Francisco, from which another security convoy escorted them to Hunter's Point Naval Shipyard to await the sailing of the U.S.S. Indianapolis, the heavy cruiser that would deliver them to Tinian.

At Trinity gloom was everywhere. A physical chemist from Los Alamos, Joseph O. Hirschfelder, remembers Oppenheimer's discomfiture that Saturday evening at the hotel where the guests invited to view the test had begun to assemble: “We drove to the Hilton Hotel in Albuquerque, where Robert Oppenheimer was meeting with a large group of generals, Nobel laureates, and other VIP's. Robert was very nervous. He told [us] about some experimental results which Ed Creutz had obtained earlier in the day which indicated that the [Trinity] atom bomb would be a dud.”

Oppenheimer searched for calm in the midst of this latest evidence of the physical world's relentlessness and found a breath of it in the Bhagavad-Gita, the seven-hundred-stanza devotional poem interpolated into the great Aryan epic Mahabharata at about the same time that Greece was declining from its golden age. He had discovered the Gita at Harvard; at Berkeley he had learned Sanskrit from the scholar Arthur Ryder to set himself closer to the original text and thereafter a worn pink copy occupied an honored place on the bookshelf closest to his desk. There are meanings enough for a lifetime in the Gita, dramatized as a dialogue between a warrior prince named Arjuna and Krishna, the principal avatar of Vishnu (and Vishnu the third member of the Hindu godhead with Brahma and Shiva — a Trinity again). Vannevar Bush records the particular meaning Oppenheimer clutched that desperate Saturday in July:

His was a profoundly complex character… So my comment will be brief. I simply record a poem, which he translated from the Sanscrit, and which he recited to me two nights before [Trinity]:

In battle, in forest, at the precipice in the mountains,
On the dark great sea, in the midst of javelins and arrows,
In sleep, in confusion, in the depths of shame,
The good deeds a man has done before defend him.

Back at Base Camp Oppenheimer slept no more than four hours that night; Farrell heard him stirring restlessly on his bunk in the next room of the quarters they shared, racked with coughing. Chain-smoking as much as meditative poetry drove him through his days.

Sturdy Hans Bethe found a way back from the precipice, Kistia-kowsky remembers:

Sunday morning another phone call came with wonderful news. Hans Bethe spent the whole night of Saturday analyzing the electromagnetic theory of this experiment and discovered that the instrumental design was such that even a perfect implosion could not have produced oscilloscope records different from what was observed. So I became again acceptable to local high society.

When Groves called, Oppenheimer chatted happily about the Bethe results. The general interrupted: “What about the weather?” “The weather is whimsical,” the whimsical physicist said. The Gulf air mass had stagnated over the test site. But change was coming. Jack Hubbard, the meteorologist, predicted light and variable winds the next day.

Stagnation exacerbated the July heat. Camera crews replacing battery packs damaged by a blown circuit burned their hands on metal camera housings. Frank Oppenheimer, thin enough not to suffer the heat unduly, hurried to construct a last-minute experiment less aloof than readings of light and radiation: he set out boxes filled with excelsior and posts nailed with corrugated iron strips to simulate the fragile Japanese houses where LeMay's ubiquitous drill presses lurked. Groves had forbidden the construction of full-scale housing for the test, more scientific tomfoolery, a waste of money and time. Norris Bradbury's instructions for bomb assembly as of Saturday listed “Gadget complete”; for “Sunday, 15 July, all day,” he advised his crews to “look for rabbits' feet and four-leaved clovers. Should we have the Chaplain down there?” Rabbits' feet would turn up, but even chaplains would have had trouble finding a stem of clover on the Jornada.

Oppenheimer, Groves, Bainbridge, Farrell, Tolman and an Army meteorologist met with Hubbard at McDonald Ranch at four that afternoon to consider the weather. Hubbard reminded them that he had never liked the July 16 date. He thought the shot could go as scheduled, he noted in his journal, “in less than optimum conditions, which would require sacrifices.” Groves and Oppenheimer repaired to another room to confer. They decided to wait and see. They had scheduled a last weather conference for the next morning at 0200 hours; they would make up their minds then. The shot was set for 0400 and they let that time stand.

Sometime early that evening Oppenheimer climbed the tower to perform a final ritual inspection. There before him crouched his handiwork. Its bandages had been removed and it was hung now with insulated wires that looped from junction boxes to the detonator plugs that studded its dark bulk, an exterior ugly as Caliban's. His duty was almost done.

At dusk the tired laboratory director was calm. He stood with Cyril Smith beside the reservoir at McDonald Ranch where cattle had watered and spoke of families and home, even of philosophy, and Smith found himself soothed. A storm was blowing up. Oppenheimer looked beneath it to anchorage, to the darkening Oscuras. “Funny how the mountains always inspire our work,” the metallurgist heard him say.

With the weather changing from stagnant to violent and with everyone short of sleep, moods swung at Base Camp. The occasion of Fermi's satire that evening made Bainbridge furious. It merely irritated Groves:

I had become a bit annoyed with Fermi… when he suddenly offered to take wagers from his fellow scientists on whether or not the bomb would ignite the atmosphere, and if so, whether it would merely destroy New Mexico or destroy the world. He had also said that after all it wouldn't make any difference whether the bomb went off or not because it would still have been a well worth-while scientific experiment. For if it did fail to go off, we would have proved that an atomic explosion was not possible.

On the realistic grounds, the Italian laureate explained with his usual candor, that the best physicists in the world would have tried and failed.

Bainbridge was furious because Fermi's “thoughtless bravado” might scare the soldiers, who did not have the benefit of a knowledge of thermonuclear ignition temperatures and fireball cooling effects. But a new force was about to be loosed on the world; no one could be absolutely certain — Fermi's point — of the outcome of its debut. Oppenheimer had assigned Edward Teller the deliciously Tellerian task of trying to think of any imaginable trick or turn by which the explosion might escape its apparent bounds. Teller at Los Alamos that evening raised the same question Fermi had, but questioned Robert Serber, no mere uninformed GI:

Trying to find my way home in the darkness, I bumped into an acquaintance, Bob Serber. That day we had received a memo from our director… saying that we would have to be [at Trinity] well before dawn, and that we should be careful not to step on a rattlesnake. I asked Serber, “What will you do tomorrow about the rattlesnakes?” He said, “I'll take a bottle of whiskey.” I then went into my usual speech, telling him how one could imagine that things might get out of control in this, that, or a third manner. But we had discussed these things repeatedly, and