Authors: Brian Van DeMark
Pandora's Keepers (34 page)
Fermi had gazed over the desert the day before “at the world on the eve of its disintegration.”
81
Now he stood at base camp, making some final calculations on his slide rule. He tore up scraps of paper and stuffed them into his pockets. A brilliant and methodical physicist with a mordant wit, he had annoyed Groves by offering to take wagers from other scientists on whether or not the bomb would ignite the atmosphere and destroy the world. Whatever the outcome, Fermi said, the test would be a worthwhile scientific experiment. If the bomb failed, they would have proved that an atomic explosion was impossible. Some of Fermi’s colleagues interpreted his remark as thoughtless bravado, but to Fermi it was black satire.
Rabi had spent the night playing poker. Now he stood beside Fermi at base camp. The intermittent lightning and thunder made Rabi fear that the “gadget” might be set off accidentally. A warning siren, fired one minute before the explosion, signaled him, Fermi, and others to go into shallow trenches that had been bulldozed below a reservoir at base camp. Rabi lay down, facing away from Zero. “We were lying there, very tense, in the early dawn, and there were just a few streaks of gold in the east; you could see your neighbor very dimly,” he recalled of the final moments. “Those ten seconds were the longest ten seconds that I ever experienced.”
82
The nervous announcer brought the countdown to zero with a scream.
PANDORA’S
BOX
A
T
5:29:45
A.M.
Mountain War Time on July 16, 1945, just as the first faint signs of dawn appeared above the eastern horizon, a pinprick of blinding white light materialized atop the tower that spurted upward in a flaming jet. The light, at its core many times brighter than the midday sun, instantly replaced the sky’s subtle pastels with a blazing flash. It was so intense that it could be seen in Albuquerque, Santa Fe, and even El Paso—180 miles away. The heat at the center of the blast was so great that six miles away it felt like standing in front of a roaring fireplace. In milliseconds, charges imploding inward had compressed the plutonium core beyond critical mass, causing it to explode in a furious frenzy of energy-releasing fissions that instantly vaporized the steel tower.
A white-hot fireball spilled across the desert, kicking up a swirl of radioactive debris that boiled and billowed upward in a massive mushroom. Every living thing within a mile’s radius was annihilated. The flash left behind shadows of tiny creatures incinerated in the hard-packed sand. The fireball gouged out a twelve hundred foot crater ranging in depth from ten feet at the periphery to twenty-five feet in the center. Sand in the crater melted into a jadelike substance the color of emerald. Fifteen hundred feet away, a stout four-inch iron pipe, sixteen feet high and set in concrete, had completely disappeared. Slowly the fireball lifted from the desert, a furnace of mammoth, violent, roiling flames. Up it went, a convulsive, quivering mushroom a mile in diameter, changing colors from gold to purple to violet to gray to blue, expanding, growing and rising until it touched the clouds, pushed through them, and kept rising higher and higher.
The mushroom stem appeared twisted like a left-hand threaded screw, and below it, the color of the Jornada was an unearthly green. The whole sky glowed with an intense violet hue for half a minute. Then came a shock wave of hot wind closely followed by a strong, sustained, awesome roar of thunder. The sound reverberated for miles across the desert, mounting in resonance as it raced to the very rim of the Jornada’s bowl and ricocheted off the peaks. The ground trembled as in an earthquake.
Across the test site everyone felt infinitely small. The moment was uplifting and crushing, exhilarating and devastating, full of great promise and great foreboding. The spectacle was so overwhelming that most observers’ first reaction was speechlessness. No one moved or said a word for several moments. All was silence. They were in awe and at a loss for words. Yet all of them had the feeling that they had just witnessed one of the great events of history. “It was,” said an eyewitness, “as awesome a thing as I’ve ever seen.”
1
Oppenheimer’s face relaxed into an expression of tremendous relief as he sensed the flash of light. All his pent-up emotions and burdens evaporated in that instant. He waited until the blast had passed, then stepped out of the control bunker. He watched and listened in silence, then simply muttered, “It worked. It worked.” He thought of the immediate future. The success of the test seemed to signal an end to the war against Japan and a promise of life for many American soldiers. It was “terrifying” and “not entirely undepressing,” he told the
New York Times
science correspondent who was at Trinity to chronicle the event, adding: “Lots of boys not grown up yet will owe their life to it!”
2
But in the next moments he thought of the longer future, which made him feel “extremely solemn.” “We knew the world would not be the same,” he said of the explosion many years later, then recalled lines from the Bhagavad Gita: Vishnu is trying to persuade the Prince that he should do his duty, and to impress him he takes on his multi-armed form and says, “If the radiance of a thousand suns / Were to burst forth at once in the sky, / That would be like the splendor / of the Mighty One…. / I am become Death, the destroyer of worlds.” “I suppose we all thought that, one way or another,” he remembered.
When Oppenheimer returned to base camp shortly after the explosion, he was strangely quiet. He appeared distant and distracted, not in a frame of mind to discuss anything. Still shaken, Oppenheimer asked to be driven in a jeep into the surrounding hills for an hour or so in order to calm down. He felt deeply relieved that the bomb had worked—that his creation was a success—and yet terribly frightened by what he had done.
The other scientists at Trinity shared Oppenheimer’s feelings. The mushroom cloud symbolized a giant question mark to Teller. Bethe felt overwhelmed by exhilaration and accomplishment. Then he began to feel shock and fear. “What have we done?” he whispered to himself. “What have we done?”
3
Lawrence reacted by slapping another scientist on the back and leaping in the air. Then he began to feel solemn. “The grand, indeed almost cataclysmic proportions of the explosion produced a kind of solemnity in everyone’s behaviour,” he wrote later that day. “There was restrained applause, but more a hushed murmuring bordering on reverence.”
4
Deeply moved, Lawrence still could talk of nothing else even two days later. “The awesome spectacle was an experience I shall never forget.”
5
Even the cool and matter-of-fact Fermi felt its emotional impact. At first, Fermi played the scientist, trying to measure the force of the blast by dropping the scraps of paper from his pocket into the air before, during, and after the shock wave hit base camp. He was so absorbed in his bits of paper that he did not hear the tremendous noise.
6
Then he felt jolted and drained. He confessed that he did not feel capable of sitting behind the wheel of his sand-colored Chevrolet, and asked a friend to drive him back to Los Alamos—something he had never done before. When his wife saw him, “he seemed shrunken and aged, made of old parchment, so entirely dried out and browned was he by the desert sun and exhausted by the ordeal.”
7
Rabi felt jubilant at first. He passed around cups of bourbon as a congratulatory offering. Then he began to notice little things: horses whinnying in fright, the slowly spinning paddle of the windmill above the reservoir, the toads that had stopped croaking. Rabi felt gooseflesh break out all over him. He sensed, he later wrote, “a chill, which was not the morning cold; it was a chill that came to one when one thought, as for instance when I thought of my wooden house in Cambridge, and my laboratory in New York, and of the millions of people living around there, and this power of nature which we had first understood it to be—well, there it was.”
8
When the scientists piled into buses to return to Los Alamos, they sprawled exhausted in their seats and grew solemn. “It was quiet,” recalled one who made the ride back. “We were busy with our own thoughts. We were still absorbing the impact of it.”
9
The full import of Trinity was beginning to register. A physicist at Los Alamos vividly remembered seeing the grim, silent expressions on the faces of the scientists as they stepped from the buses that evening. “I saw that something very grave and strong had happened to their whole outlook on the future.”
10
At last they had a chance to pause and think about what they had done, to face the awesome and chilling consequences of their labors. They realized—because they had seen and felt it—just how terrifying was the force they had unleashed. The bomb’s power turned out to be far greater than they had imagined. They sensed the world would never be the same again.
Meanwhile, planning for dropping the bomb on Japan ground forward relentlessly. By July twenty-fourth, plans were set. The bombs would be used when they were ready. Beforehand, Japan would be given a generally phrased warning of total destruction unless it surrendered. This “last chance” warning, included in the Potsdam Declaration of July twenty-sixth, was dismissed by the Japanese. Groves notified Stimson that a uranium bomb would be available soon after August first. The first plutonium bomb, the type tested at Trinity, would be ready for delivery about August sixth, and a second was expected by August seventeenth or eighteenth. Additional ones would be produced at an accelerated rate from possibly three in September to perhaps seven or more in December. A specially trained B-29 unit in the South Pacific, the 509th Composite Air Group, was to deliver the first bomb as soon as weather permitted visual bombing after August third. The list of targets included Hiroshima and Nagasaki.
Hiroshima was chosen as a target for the atomic bomb because its landscape was flat and it was one of the few Japanese cities left by the summer of 1945 that had not yet been firebombed to ashes. These conditions would afford the most dramatic demonstration of the weapon’s power and the most accurate measurement of its destructiveness. There was some military rationale, too: the city was the headquarters of the Second Japanese Army, which commanded the defense of southern Japan. From here the Japanese general staff prepared to direct the defense of the island of Kyushu against an impending American invasion. But it was also the home of more than 300,000 noncombatants. In Hiroshima, civilians outnumbered soldiers by more than six to one.
On July twenty-third Oppenheimer informed Navy Captain Deak Parsons, the Los Alamos ordnance specialist who would ride aboard the attacking aircraft, that the bombs were expected to perform well. “As a result of the Trinity shot we are led to expect a very similar performance from the first Little Boy [U-235 bomb] and the first plutonium Fat Man.” Oppenheimer predicted that the energy release of each bomb would fall between twelve to twenty thousand tons, and that the blast effect would be equivalent to eight to fifteen thousand tons of TNT. The fireball would be of greater brilliance and longer duration than the Trinity shot, since no dust would be mixed with it when it detonated at altitude. Yet lethal radiation from the bomb would reach the ground.
11
At 2:45
A.M.
on August 6, 1945, three B-29s belonging to the 509th lifted off from the island of Tinian in the Marianas and headed for the Japanese home islands fifteen hundred miles to the north. In the belly of the lead plane, the
Enola Gay
, was Little Boy—chosen because it had been readied first. It contained twenty-five kilograms of U-235 encased within cordite, steel tamper, casing, and firing controls.
*
By 7:30
A.M.
the bomb had been armed. Fifteen minutes later the plane was over the Japanese mainland.