by Donald Hunt
Oppenheimer proceeded to pull together some of the best minds the fields of physics and chemistry had to offer. The only man who turned him down was Linus Pauling, a pacifist. The rest, all world class leaders in their respective fields, accepted. The group was an international mix, some of them Jewish scientists who had escaped Europe. Among those was Leo Szilard, the avuncular Hungarian physicist. In 1933, Szilard was struck by the idea that an element might be found, if struck by a neutron, could emit two neutrons and thus sustain a chain reaction. Under the direction of Enrico Fermi, a sustained nuclear chain reaction had been achieved in Chicago.
In June, 1942, eight physicists working with Oppenheimer at Berkley had determined that a fission bomb was feasible. The calculations for ‘critical mass’ of the fissile material was to be worked out. The next question was how to find a suitable location for a laboratory. Groves and Oppenheimer settled on an obscure site in northern New Mexico – Los Alamos.
The goal had always been to find a physical location that could be guaranteed safety from both domestic curiosity and foreign attack. This was not so simple a place to find. Groves had scoured the western part of the country and at one time, toyed with the idea of Jemez Springs, New Mexico. But he and Oppenheimer both rejected it in the end. Transportation would be a problem and the area was too confined by canyon walls.
It was Oppenheimer who finally suggested Los Alamos. The site of a boys’ school, the Los Alamos Ranch School sat atop a mesa overlooking the Rio Grande Valley and the Sangre de Cristo mountains. The hilltop was isolated and yet easily accessible by routes that could be controlled. Another plus was the landscape itself. The area was dotted with canyons that could serve as excellent test sites. The War Department approved it. When the academic term ended in 1943, Los Alamos swapped its boys for bomb making.
The other major project sites chosen were Oak Ridge, Tennessee for the production of uranium-235, and the Hanford site near Richland, Washington for the production of plutonium-239. The chemical element plutonium had been discovered in 1940 by Glenn Seaborg working at Cal-Berkley. It had been kept a secret and its isotope, Pu-239 was developed as a fissile fuel for a nuclear bomb. A fissile substance was something that was stable and would undergo fission, the release of huge amounts of energy when bombarded with neutrons, in accordance with Einstein’s equation E= mc2.
Los Alamos served as the epicenter of bomb production. A part of its charm was its beauty and isolation. It was the perfect irony. The efforts at Los Alamos were centered on developing weapons of mass destruction. But the land tucked quietly beneath the mesa served as the ancestral homeland and sacred grounds of six of New Mexico’s northern pueblo nations. Here, people had lived simple lives for hundreds of years. Eschewing technology and urban lifestyles, the people of the pueblos spent their days in communal fashion, their lives revolving around family and traditions. They were farmers and pottery makers. They baked bread and celebrated feast days. They believed all of nature to be sacred. It was in this pastoral setting that the Manhattan Project was launched.
The mesa was only about 25 miles west of Santa Fe. Oppenheimer called the location a dream come true, and several times he stated that the two things he loved most in life were physics and the high desert of New Mexico.
The men and the families of Los Alamos lived a confined existence. Security was an obsession. They had no telephones, no bright lights, no night spots or outside contacts. They all had one postal box, # 1663, Santa Fe. Their leisure activities were limited to fishing and mountain climbing, soft ball and poker, and of course, their own parties. The scientists did have one outlet - the house at Otowi Bridge. There, just a few miles below Los Alamos and adjacent to the San Iledefonso Pueblo, a woman named Edith Warner ran a small tea room. Oppenheimer, Bohrs and many of the other nuclear scientists could remove themselves from the tensions inside the laboratory and sit quietly in conversation, viewing the high desert vista and feasting on Warner’s specialties - spicy tea and chocolate cake. But for the rest of families of Los Alamos, there was no getaway. Only the tiny community and each family’s home. They found their own reprieves. Lots and lots of babies were born at Los Alamos.
The Oppenheimer’s moved to Los Alamos in March 1943. By April, the first wave of new residents had arrived. The orientation lectures were given to the scientists by Robert Serber, a physicist who had worked with Oppenheimer at Berkley. The gist of these lectures was that there would be no compartmentalization of information. Everything would be shared. Most of the men were not fully aware of the mission of the project until they got there. Over the next twelve months the remainder of the collaborators arrived.
One of the last to set foot in Los Alamos was Enrico Fermi, his wife Laura and their children. Life on ‘the hill’ as it was called, was soon known as mesa life. The mixture of citizenship and birthplaces was broad. They were both Machiavellian and convivial to their core. But not everyone was enamored with mesa life. When Leo Szilard first saw Los Alamos, he is known to have said, “Nobody can think straight in a place like this….everyone that comes will go crazy!”
Enrico Fermi – nuclear physicist who engineered the first
‘chain reaction’ Chicago Pile-1
Quickly, Robert Oppenheimer morphed into a powerful, unctuous leader. The power of his intellect and personality convinced everyone around him that their hard work could accomplish something nothing else could - the shortening of the war and the saving of thousands of lives. But these men of science soon became aware that saving lives would cost lives. They were in the business, at least indirectly, of massive death and destruction.
In September, 1944, as substantial progress was secretly being made at Los Alamos, the American and British Combined Military Chiefs had set a time table for ending the war in the Pacific. Tentatively, it was 18 months after the defeat of Germany. Central to that goal was the invasion of Japan. Major General Curtis LeMay had command of the 20th Bomber Command, based in India with forward air fields in China to reach targets in Japan. Fuel supply for the missions was being flown over the Himalayas. But it wasn’t working. Every gallon of fuel used for the bombing missions required 12 gallons to fly the fuel from India to China.
The U.S. had a better option, but one achieved at a high price. The Mariana Islands in the archipelago in the north-western Pacific, was a volcanic group that was for the most part, uninhabited. The southern section was occupied by the Japanese military and was invaded, island by island, by the U.S. Marines. The island of Tinian was selected as the ideal place to build the support air fields for the B-29 Superfortress to be used to attack the Japanese mainland. The B-29’s began arriving in the Mariana Islands in October 1944. They were there to begin precision bombing of key enemy industries. Along with precision bombing, efforts were also being made to accomplish what was referred to as ‘incendiary’ bombing, meaning the goal was to set large areas of Japanese cities on fire. Most of the structures in their cities were made of wood.
LeMay was given command of the B-29’s in the Marianas. He was a tough, two- fisted man who hated failure. And he felt he was failing. But it was not for lack of effort. Six out of seven days weather was an issue over the Japanese mainland. Japanese radar installations on the island of Iwo Jima were giving the mainland early warning of the U.S. attacks, and the 29’s were flying into 140 mph headwinds. This caused the engines to overheat. Finally, enemy fighter-bombers from Iwo Jima began attacking his bases.
Iwo Jima was a mass of volcanic ash only seven miles square. A large volcano, Mt. Suribachi, was on one end. The Japanese understood the strategic importance of the island and defended it with 20,000 troops dug in to 5,000 pill boxes, bunkers, tunnels and caves. American writer and journalist, William Manchester described the intent:
“They meant to make the conquest of Iwo so costly, that the Americans would recoil from the thought of invading their homeland.”
Washington was deeply concerned and gave seri
ous consideration to the concept of ‘sanitizing’ the island using poisonous gas. Neither the U.S. nor Japan had signed the Geneva Convention prohibiting such use. Still, Roosevelt would not agree. He believed world opinion would turn against America.
After a week of heavy naval bombardment, the invasion began on February 19, 1945. It was the only battle during the war in which U.S. casualties exceeded those of the enemy. Of the 60,000 troops committed by the U.S., 27,909 were killed or wounded. Of the 21,000 defenders, an estimated 20,703 died, either having been killed or due to
suicide. Only 216 were captured.
It appeared that bombing the mainland combined with a naval blockade would not bring an end to the war. Thus, another plan became an option.
Dozens of men played key roles in the development of the atomic bomb. They all were instrumental in supplying various pieces to the puzzle. A central component was the Frisch-Peierls memorandum, developed in March 1940, and kept highly secret. Working at Birmingham University, Otto Frisch and Roudolf Peierls made new calculations detailing the critical mass required. It was estimated to be about a pound of enriched uranium-235. The previous amount was thought to be several hundred pounds, a much harder achievement. This led to the formal effort by Britain in the following year, to establish a bomb project, code named the MAUD Project. Eventually the MAUD Project was combined with the Manhattan Project and moved to the U.S. At that time, James Chadwick, who had discovered the neutron in 1932, moved to Los Alamos to head up the British delegation. Before its move to the U.S., the MAUD Committee’s code name for their bomb was ‘Tube Alloys.’
In late August 1943, Churchill and Roosevelt met in Quebec City, Canada and hammered out an agreement of non-proliferation between their two countries concerning nuclear weapons. They agreed never to use this agent against each other; not to use it against a third party without each other’s consent; and not to communicate any information about ‘Tube Alloys’ to third parties except by mutual consent. This agreement established a combined Policy Committee to oversee and coordinate weapons development.
The following November, Chadwick invited Otto Frisch, the nephew of Jewish physicist Lisa Meitner, to join his team in New Mexico. In less than a week, Frisch was made a British citizen and was on his way. He was briefed by General Groves in Washington D.C., then was boarded on a train for New Mexico. Frisch was driven the 75 miles from Albuquerque, then he and a colleague were met on the mesa by a tall, emaciated looking man smoking a pipe. The man reached out to shake hands and said, “Welcome to Los Alamos and who the devil are you?”
Oppenheimer had become an iconic leader of the lab. Hans Bethe, head of the Theoretical Division of the bomb project would later say the following:
“He knew everything that went on in the laboratory, whether it was chemistry, or theoretical physics or machine shop. He could keep it all in his head and coordinate it. It was clear also at Los Alamos that he was intellectually superior to us.”
It was evident from the beginning that only one test of the bomb would be possible. Sometime before the summer of 1944, Oppenheimer code-named the test and the test site. He called it Trinity. In clarifying why this name was chosen, he explained that he was influenced by a John Donne poem expressing the idea that dying ends in death but could result in resurrection - the bomb was a weapon of death that might also redeem mankind. The paradox of the bomb was an ever-present thought of the scientists.
The site chosen for Trinity was in the Alamogordo Bombing Range, some 200 miles south of Los Alamos. Immediately, work began to build reinforced concrete camera bunkers, two 100-foot towers, and miles of communication wire with optics and expensive seismic instruments to measure blast. One of the towers was at ground zero and would suspend the test bomb. The other was 800 yards south of zero. It was filled with 100-tons of high explosives which were detonated to test the blast monitors. There were ionization chambers and instruments to reveal the explosive yield radiochmeically. The various teams had the bomb physics well in hand by November 1944. Oppenheimer set a tentative target test date of July 4the of the following summer.
As weapons grade plutonium-239 and uranium-235 were being delivered to Los Alamos, the ‘Target Committee’ held their first meeting in Lauris Norstad’s conference room at the Pentagon. Their objective was to select four target options within the guidelines of the B-25 range of 1,500 miles and the essential of visual bombing. They were briefed by the top Air Force meteorologist who informed the group that June brought the worst weather to Japan. This meant he could only forecast a good day for bombing operations 24 hours in advance. Target selection would consider only cities that had not had previous significant damage and places that would most adversely affect the will of the Japanese people to continue the war. It was also critical that there be no POW camps near the targets.
By the end of May 1945, enough plutonium had been shipped to Los Alamos to begin critical-mass experiments. Theoretical bomb design calculations were being finalized for configurations. The uranium bomb was code named ‘Little Boy’ and the plutonium bomb ‘Fat Man’.
The detonation device for the plutonium bomb was much more complex than the device for uranium. Thus, ‘Fat Man’ would not be used before testing it first. In the meantime, plans were made to ship ‘Little Boy’ to the Pacific by sea. Because of the complexity of devising the detonation details of ‘Fat Man’, Trinity was pushed back to July 16. In compliance with the Quaker Agreement, the Combined Policy Committee met in Washington on July 4th, and the British officially gave their approval to use the weapons against Japan.
The sudden death of Franklin Roosevelt on April 12th jolted the scientists in New Mexico, particularly Oppenheimer and the Americans. Without the bold vision and trust of Roosevelt, the Manhattan Project would never have begun. He had remained a talisman of support and was steadfast in his encouragement to the team. Oppenheimer scheduled a memorial service for the following Sunday and opened it to the entire community. Shortly after mid-night on Saturday, a steady snow began. By morning the mesa was adorned with a blanket of white frosting. The theater was packed. Oppenheimer was eloquent.
“When, three days ago, the world had word of the death of President Roosevelt, many wept who are unaccustomed to tears, many men and women, little enough accustomed to prayer, prayed to God. Many of us looked with deep trouble to the future; many of us felt less certain that our works would be to a good end; all of us were reminded of how precious a thing human greatness is.
We have been living through years of great evil and of great terror. Roosevelt had been our President, our Commander-in-Chief and, in an old and un-perverted sense, our leader. All over the world men have looked to him for guidance and have seen symbolized in him their hope that the evils of this time would not be repeated; that the terrible sacrifices which have been made, and those that are still to be made, would lead to a world more fit for human habitation….
In the Hindu scripture, in the Bhagavad-Gita, it says, ‘Man is a creature whose substance is faith. What his faith is, he is.’ The faith of Roosevelt is one that is shared by millions of men and women in every country of the world. For this reason, it is possible to maintain the hope, for this reason it is right that we should dedicate ourselves to the hope that his good works will not have ended with his death.”
Harry Truman was now president. He had known almost nothing of the Manhattan Project, and now the awesome burden of this most terrible of weapons was directly on his shoulders.
With the war in Europe won, all focus was on the Pacific Theater of Operations. Truman had agreed to meet with Stalin and Churchill in the Berlin suburb of Potsdam. He wanted to know the results of Trinity before facing Stalin so the meeting was put off until the week of July fifteenth. Trinity was set for July sixteenth.
In the two weeks leading up to Trinity, the tension at Las Alamos became palpable. Silently, men asked themselves, ‘what if the bomb fails?’ ‘What if the tw
o billion spent and the employment of over 100,000 is all for naught?’
Everything hinged on the implosion device for the plutonium. The detonation of ‘Little Boy’ had never been an issue. There was great confidence in that design. But ‘Fat Man’ was another story. The uranium bomb would be set off by a ‘gun assembly’ that was simple in concept and operation. But plutonium fission could not be started by the same mechanism. It required a more violent start – in essence, an explosion to produce the explosion. It had never been done. It was all theoretical. The mood at Trinity was gloomy.
The evening of July fifteenth everything was in place. The plutonium bomb had been lifted by a giant crane and was suspended on the 100-foot tower. Later that night the bomb would be armed. The shot was set for 4:00 a.m. the following day. Oppenheimer was standing at base camp with Cyril Smith, the head of the metallurgy division. As the sun was ducking behind the mountains, Smith heard him say, “Funny how the mountains always inspire our work.”
Fat Man would be fired through cables from the S-10000 control bunker. About 2:00 a.m. a fierce thunderstorm hit base camp and dumped several inches of rain in one hour. Then the storm evaporated. But since everything depended on the weather, the rain delayed the shot until 5:30 a.m. Several men had veto over the timing, but all agreed on the delay. A B-29 was to fly directly over ground zero at 30,000 feet to get data on the blast effects at that altitude.
The main viewing site was at Compania Hill some 20 miles away. A number of physicists and Trinity staff were there. A short-wave radio broadcast the countdown. Everyone had eye protection so they could look directly at the flash. The final 10 seconds were automatic...four…three…two…one…zero.
The fission multiplied its energy over one millionth of a second, generating millions of degrees and millions of pounds of pressure. The initial hot sphere was cooled to about half a million degrees in a ten-thousandth of a second – then the shock wave formed. It moved out like a water wave expanding from a rock thrown into a still pool. The fireball formed and over the next 10 to 15 seconds its buoyancy took it up thousands of feet. All of the men witnessing Trinity were profoundly affected. Oppenheimer’s response was laconic. He described the moment: