The Apocalypse Factory

by Steve Olson

  At the beginning of July, Szilard drafted a petition to President Truman. The development of atomic bombs “places in your hands, as Commander-in-Chief, the fateful decision whether or not to sanction the use of such bombs in the present phase of the war against Japan,” the final version of the petition stated. Gone was any mention of demonstrating the bomb. Instead, Szilard wanted the president simply to think hard about the forthcoming decision. The United States should make public the terms it planned to impose on Japan after the war, the petition stated. Once these terms were announced, Japan should be given an opportunity to surrender. “If Japan still refused to surrender,” the petition went on, “our nation might then, in certain circumstances, find itself forced to resort to the use of atomic bombs. Such a step, however, ought not to be made at any time without seriously considering the moral responsibilities which are involved.” These moral responsibilities were paramount, the petition observed: “A nation which sets the precedent of using these newly liberated forces of nature for purposes of destruction may have to bear the responsibility of opening the door to an era of devastation on an unimaginable scale.”

  Sixty-nine people at the Met Lab signed the petition—an act of great bravery, given the government’s control over their current and future careers. Lacking a friend or acquaintance who could deliver a document to the president, Szilard gave the signed petition to Compton, who in turn gave it to Kenneth Nichols, Matthias’s counterpart at Oak Ridge. Nichols then sent the petition to Groves.

  Meanwhile, Szilard arranged for several people he knew at Los Alamos to distribute the petition there, where it quickly came to the attention of Oppenheimer. Despite his own involvement in political decision making, the lab director was annoyed that Szilard was trying to influence policy, and he banned drafts of the petition from being distributed in Los Alamos. He also informed Groves about the petition, so that Groves knew what was coming.

  Groves had no reason to act on the petition right away, though he knew he would have to deal with it at some point. He had already been discussing with the Interim Committee ways of eliminating “certain scientists of doubtful discretion and uncertain loyalty”—by whom he meant Szilard—from the Manhattan Project. But Groves knew that immediately firing or imprisoning Szilard would trigger a revolt by other scientists that he could not afford at this critical juncture in the project. He would bide his time.

  Not until August 1 did Groves forward Szilard’s memo to Stimson’s office. By then Stimson was caught up in other affairs and gave the petition no notice. It sat unread among the papers on his desk.

  ON FRIDAY, JULY 13—a date chosen by George Kistiakowsky in the hope that it would bring the project good luck—the scientists and engineers at the Trinity test site south of Los Alamos began the final assembly of the test device.* That afternoon, shortly after 3:00, working beneath the tower in the Jornada del Muerto desert, they removed a brass plug from the center of the assembly. At the very center of the high explosives was a cylindrical void about the size of a small fire extinguisher. The men assembling the bomb readied a cylinder of the same size that contained Hanford’s plutonium. But as they lowered the cylinder into the center of the bomb, it got stuck. Something had gone wrong.

  The men thought for a while. Then one of the physicists realized that the bomb had been sitting in the shade beneath the tower while the assembly containing the plutonium had been exposed to the desert heat, which had caused it to expand. “Let it stick there for a few minutes and the heat will be conducted away,” he said. Less than a minute later the assembly fell into place—the crisis was over. The team placed the final explosive lenses into the bomb, covering the now-filled hole at its center, and sealed the bomb up.

  The next morning they attached a metal cable to a U-shaped bracket holding the bomb, lifted the bomb a few feet into the air, and stacked a pile of mattresses beneath it. If the cable had broken, the mattresses would not have protected the bomb from damage. Still, they made the men feel better.

  A hoist raised the bomb to a wooden platform at the top of the tower. An electronics team then climbed the tower to install electrical cables, monitoring devices, and other equipment. It was the afternoon of Saturday, July 14, by the time they had finished. After one final test of the connections, the electrical leads to the bomb were disconnected. They would be reconnected to the five thousand pounds of high explosives and 13 pounds of plutonium when the test was ready to go.

  That weekend, various Manhattan Project dignitaries began to arrive in New Mexico. Groves flew to Albuquerque with Bush after the two of them had toured various project facilities, including Hanford. There they met Conant, and the three of them drove south to the Trinity base camp. Three of the four members of the Scientific Panel attended the test. Since the previous fall, Fermi had been living and working at Los Alamos, where he had proved to be a calming influence on the younger scientists. Lawrence had traveled with Groves to New Mexico after joining him on the last part of his West Coast swing. But Compton, whose National Academy of Sciences committee had helped set the Manhattan Project in motion, stayed in Chicago. “I could not absent myself at that time without giving rise to questions,” he later wrote. Seaborg was not invited from Chicago to attend the first test of the element he had discovered. He wrote in his journal about the test only after it occurred.

  The world’s first atomic bomb was detonated atop this tower in central New Mexico. Courtesy Palace of the Governors Photo Archives (NNHM/DCA), 147362.

  James Chadwick, the discoverer of the neutron and the head of the British Mission to the Manhattan Project, had flown to New Mexico from Washington, DC. William Laurence, a science writer at the New York Times whom Groves had hired to write about the project, was upset at having to watch the test from 20 miles away rather than from the south bunker, where the shot was being controlled. He had already written his own obituary in case the explosion was larger than anticipated.

  The dignitaries arrived not to the hot dry weather they might have expected but to rain, wind, and thunderstorms. A monsoon pattern had set in Saturday that promised to persist for at least two days. By late Sunday night, heavy rains and high winds were lashing the test site, and many of the scientists were convinced that the test, which had originally been scheduled for 2:00 a.m. Monday morning, had to be postponed. Oppenheimer, who had contracted chicken pox a few weeks earlier and now weighed just 115 pounds, was a physical and emotional wreck. He smoked incessantly as he and Groves discussed the weather and the timing of the test. “Groves stayed with the Director, walking with him and steadying his tense excitement,” wrote Groves’s assistant, Thomas Farrell. “Every time the Director would be about to explode because of some untoward happening, General Groves would take him off and walk with him in the rain, counseling with him and reassuring him that everything would be all right.”

  Groves was adamant that the test go ahead. He had promised Stimson and other members of the president’s delegation in Germany, who were beginning the Potsdam Conference with Churchill and Stalin even as he and Oppenheimer were talking that night, that he would conduct the test as soon as possible. That way, Truman would know whether he had the atomic bomb in his pocket while negotiating with Stalin about ending the war. If the test were delayed, it would take at least several days to re-create the fevered pitch of activity required of the Los Alamos test group, and that would be too late for Truman. Also, Groves was fearful that a saboteur somewhere among the people at Los Alamos was waiting until the last possible minute to disrupt the test. Already he had Manhattan Project scientists stationed at the base of the tower and on the platform with the now fully armed bomb to make sure that no one meddled with it. A delay would just give the saboteur more time to act.

  At about 11:00 p.m. Sunday night, Groves urged Oppenheimer to get a couple of hours of sleep before the test, which by then had been rescheduled for 4:00 a.m. Groves drove back to the base camp 10 miles south of the tower, where he was sharing a tent with Bush and Conant. Th
e tent had been poorly staked, which irritated Groves, and Bush and Conant did not sleep a wink with the canvas flapping in the wind. But Groves fell asleep within minutes and slept soundly for about an hour.

  At 1:00 a.m., Groves was back with Oppenheimer at the control bunker. By two o’clock the weather forecast had improved slightly, and Groves decided that the test would occur at 5:30 a.m. rather than 4:00. As he later wrote, “There was only one dissenting vote that could have called off the test and that was my own. This operation was not run like a faculty meeting. Advice was sought and carefully considered but then decisions were made by those responsible. There was no one but myself to carry this responsibility.”

  At 5:10 Monday morning, as the night sky continued to clear, Groves returned to base camp, leaving Farrell with Oppenheimer. Farrell was Groves’s understudy on the Manhattan Project. If anything happened to Groves, Farrell was supposed to know enough to step in and finish the job. They had agreed that they should not be in the same place in dangerous situations.

  Forty-five seconds before the test was scheduled to occur, Sam Allison, who had been building piles in Chicago before Fermi arrived from New York, began calling out over an intercom the number of seconds left until the test. “Fifty-five, fifty-four, fifty-three, . . .” he said. Allison later said that it was the first time he had ever heard of someone counting backward.

  At 5:29:45, Allison reached zero. “Now!” he shouted. Inside the bomb, 32 detonators fired simultaneously atop wedge-shaped pieces of high explosives. The shock wave from the explosives traveled inward and compressed the apple-sized sphere of plutonium at the bomb’s core to a bit less than half its original volume—from a diameter of 3.6 inches to 2.6 inches, which is about the size of a tennis ball. At that instant, the initiator in the middle of the plutonium loosed a flood of neutrons into the supercritical plutonium. In the next millionth of a second, more than a million-million-million-million atoms fissioned, each of them painstakingly forged in Hanford’s nuclear furnaces.

  Several hundred people on the Jornada del Muerto witnessed the explosion of the world’s first nuclear bomb that Monday morning. What many of them remembered best was the light. When an atomic bomb explodes, it emits an incredibly bright flash of white light, many times brighter than the sun, the brightest light ever created on Earth, a light bright enough to be easily seen from the moon and nearby planets. Those who were looking away from the tower saw the desert and surrounding mountains lit with a vivid intensity. Every stone, mesquite bush, and crevasse stood out as if illuminated by a flashbulb. Those who were looking in the direction of the tower without the dark welder’s lenses they had been issued were temporarily blinded. They missed most of what happened next.

  As the bright flash of light faded, a huge white fireball, a thousand feet across, appeared on the horizon at the vaporized tower’s former location. Dust kicked up from the ground momentarily obscured the bottom half of the fireball. But then the fireball began to rise, a roiling, bulbous, fearsome sphere of light and gas and dust. After a few seconds the white light began to fade and change color, to red, orange, and purple. A thin stem extended from the rising fireball to the ground, connecting the monstrous sphere to its earthly origins. The churning fireball rose higher and higher, above a layer of clouds, gradually darkening in the predawn sky. As George Kistiakowsky, who watched the test with Oppenheimer at the control bunker, later reflected, “at the end of the world—in the last millisecond of the Earth’s existence—the last men will see what we saw.”

  The tremendous heat of a nuclear explosion compresses the air around the bomb, which creates a shock wave that propagates in all directions. This shock wave was so powerful that it knocked Kistiakowsky down six miles away from the blast. The sound of the explosion reached the observers as a loud crack. The sound then began reverberating off the surrounding mountains. For several minutes the Earth roared as the fireball rose higher into the sky.

  At the base camp, Fermi was so focused on an experiment he was doing that he paid little attention to the light or sound from the explosion. He waited about 40 seconds for the shock wave to travel the 10 miles from the explosion. He then began dropping scraps of paper from his hand. He measured the distance they were blown sideways with his shoe. From this measurement, he calculated that the yield of the blast was equivalent to 10,000 tons of TNT. His estimate was off by only about a factor of two.

  An hour or so after the test, as the sun began to light the desert, Oppenheimer and Farrell drove back to base camp. When the two of them met Groves, Farrell said, “The war is over.”

  “Yes,” Groves replied, “after we drop two bombs on Japan.”

  * Technically it was not a bomb, since it was not configured for that use, but it was essentially the same device used later as a bomb.

  Chapter 15

  TINIAN ISLAND

  CHARLES SWEENEY EASED OFF THE BRAKE, AND THE OVERLOADED B-29, its four 18-cylinder engines roaring, lurched down the runway. Someone had turned off the lights at the runway’s far end, though Sweeney didn’t know why. He would have to assume that he could get his plane in the air before the macadam gave way to the Pacific Ocean. The previous evening he had watched a heavily loaded B-29 crash on takeoff, its napalm-filled bombs and fuel tanks bursting into flames. But Sweeney’s flight was different. If his plane crashed, the 13 pounds of Hanford plutonium it carried could vaporize much of the air base on Tinian Island.

  Sweeney desperately wanted this mission to go perfectly. Three days earlier, on August 6, his friend and commanding officer Paul Tibbets had flown a different B-29, the Enola Gay, to drop the uranium-based bomb on Hiroshima, and that mission had been flawless. The weather had been ideal, Tibbets had dropped the bomb on his first run, and much of the city had been destroyed. Sweeney had also been flying a B-29 over Hiroshima on that mission, The Great Artiste, which was filled with instruments to measure the effects of the blast. Looking back on the city, Sweeney had seen Hiroshima covered with a roiling brown cloud interspersed with flames. Above the city, and far above his plane, rose a thin vertical column of smoke filled with colors, colors Sweeney had never seen before. It was a beautiful and terrible thing to see.

  As Sweeney had rolled The Great Artiste to a stop back on Tinian Island, he had glimpsed, through the plexiglass window of the B-29, the commander of the army air forces pinning the Distinguished Service Cross on Tibbets’s flying coveralls. Sweeney was proud to be associated with the commander of the 509th Composite Group. Tibbets had been leading the group for less than a year, but in that time he had fashioned it into a tight-knit, efficient operation. Just 30 years old, reserved, and soft-spoken, Tibbets had the assurance of a man many years older. Sweeney had wanted to join his outfit from the first day they met.

  The evening of the Hiroshima bombing, amidst a raucous celebration party, Tibbets had pulled Sweeney aside. What Tibbets had to say shocked Sweeney. Tibbets wanted the younger man—Sweeney was just 25—to command the mission to drop a second atomic bomb on Japan. Sweeney had always assumed that Tibbets would lead all the missions. Now Tibbets was turning the job over to him. As Sweeney later said, “I’d rather face the Japanese than Tibbets in shame if I made a stupid mistake.”

  Accelerating down the runway, Sweeney glanced at the Bockscar’s speedometer—125 miles an hour. He kept the yoke pushed forward, the wheels down. The B-29, with its 10 regular crew members, three additional men to monitor the 10,300-pound bomb, and 7,250 gallons of fuel, was way above Boeing’s weight guidelines. Sweeney would have to use the entire runway to get the plane aloft. He glanced again at the speedometer—140 miles an hour. In the darkness, he could feel rather than see the water approaching. At 155 miles an hour he eased up on the yoke. The plane rose slowly from the end of the runway and soared out over the Pacific Ocean.

  Three days earlier, for the Hiroshima mission, the weather had been calm and clear. Now the skies were filled with clouds and distant flashes of lightning—a bad omen, Sweeney thought. Already this miss
ion had encountered more problems than the entire mission to Hiroshima. During preflight checks, Sweeney had discovered that a pump connected to two 320-gallon reserve fuel tanks in the rear bomb bay was not working. He had gotten off the plane to discuss the situation with Tibbets. Replacing the fuel pump would take at least several hours, and the bomb could not be moved to another plane. If they waited until the pump was fixed, the mission would likely have to be postponed for a day. But the mission had already been moved up two days, to Thursday, August 9, because the weather was supposed to turn stormy on Friday and stay bad for at least five days. Sweeney knew that even without the fuel in the reserve tank, he should have enough to fly to Japan, drop the bomb, and return to Tinian Island. Tibbets had said, “It’s your call, Chuck.”

  Technicians on Tinian Island prepare the bomb, nicknamed Fat Man, that was dropped on Nagasaki on August 9, 1945. Courtesy of the US National Archives and Records Administration.

  “The hell with it. I want to go.”

  The Bockscar had no choice but to fly through the thunderstorms on the way to Japan. The plane yo-yoed through the sky, the crew bucking within their four-point restraints. Lightning backlit the clouds; St. Elmo’s fire played along the props and wingtips. Sweeney, his copilot, and a third pilot on the flight tried not to jostle the bomb hanging from a shackle in the forward bomb bay of the plane, but there was nothing they could do. The bomb was egg-shaped, about 10 feet long and five feet around, with a set of boxy fins attached to one end. It was painted yellow, like the practice bombs they had been dropping for months, with black sealant spray-painted on its metal seams. The tail fins of the bomb were covered with signatures and messages to the Japanese from the Tinian ground crew. “A second kiss for Hirohito,” wrote Rear Admiral Purnell, whose arguments had convinced Groves that two bombs would be necessary to defeat Japan.