Excerpted from “The Devil Reached Toward the Sky: An Oral History of the Making and Unleashing of the Atomic Bomb” by Garrett M. Graff ’03.

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Wisconsin physicist Joseph O. Hirschfelder: It was time to get ready for the explosion. There were 300 of us assembled at our post. These included soldiers, scientists, visiting dignitaries, etc. We were all cold and tired and very, very nervous. Most of us paced up and down. We all had been given special very, very dark glasses to watch the explosion.

Rice physicist Hugh T. Richards: I was at Base Camp, 9.7 miles from ground zero. The shot was scheduled for 2:00 a.m. July 16. However, around 2:00 a.m. a heavy thunderstorm hit the base camp area and on advice of the meteorologist, the test was postponed until 5:30 a.m. to let the bad weather pass the area.

Harvard chemistry professor George B. Kistiakowsky: The thing was ready to be fired. Just before the time counting came to zero I went up to the top of the control bunker, put on dark glasses and turned away from the tower. I was rather convinced that the physicists exaggerated what would happen from a nuclear point of view. Well, I was wrong.

Brig. Gen. Thomas F. Farrell, Manhattan Project field operations chief: Dr. [J. Robert] Oppenheimer held on to a post to steady himself. For the last few seconds, he stared directly ahead.

Maj. Gen. Leslie Groves, Manhattan Project director: The blast came promptly with the zero count on July 16, 1945.

Trinity test site director Kenneth T. Bainbridge: The bomb detonated at 5:29:45 a.m.

Farrell: In that brief instant in the remote New Mexico desert the tremendous effort of the brains and brawn of all these people came suddenly and startlingly to the fullest fruition.

Los Alamos physicist Robert Christy: Oh, it was a dramatic thing!

Los Alamos technician Val L. Fitch: It took about 30 millionths of a second for the flash of light from the explosion to reach us outside the bunker at S-10.

N.Y. Times reporter William L. Laurence: There rose from the bowels of the earth a light not of this world, the light of many suns in one.

Hirschfelder: All of a sudden, the night turned into day.

Groves: My first impression was one of tremendous light.

Physicist Warren Nyer: The most brilliant flash.

British physicist Otto R. Frisch: Without a sound, the sun was shining—or so it looked. The sand hills at the edge of the desert were shimmering in a very bright light, almost colorless and shapeless. This light did not seem to change for a couple of seconds and then began to dim.

Nuclear physicist and radio chemist Emilio Segrè: In fact, in a very small fraction of a second, that light, at our distance from the explosion, could give a worse sunburn than exposure for a whole day on a sunny seashore. The thought passed my mind that maybe the atmosphere was catching fire, causing the end of the world, although I knew that that possibility had been carefully considered and ruled out.

British physicist Rudolf Peierls: We had known what to expect, but no amount of imagination could have given us a taste of the real thing.

Physicist Richard P. Feynman: This tremendous flash, so bright that I duck.

Los Alamos physicist Joan Hinton: It was like being at the bottom of an ocean of light. We were bathed in it from all directions.

Los Alamos physicist Marvin H. Wilkening: It was like being close to an old-fashioned photo flashbulb. If you were close enough, you could feel warmth because of the intense light, and the light from the explosion scattering from the mountains and the clouds was intense enough to feel.

Bainbridge: I felt the heat on the back of my neck, disturbingly warm.

Richards: Although facing away from ground zero, it felt like someone had slapped my face.

Kistiakowsky: I am sure that at the end of the world—in the last millisecond of the earth’s existence—the last man will see what we have just seen.

Nyer: I knew instantly that the whole thing was a success.

Physicist Lawrence H. Johnston: At count zero we dropped our parachute gauges. There was a flash as the bomb went off and we prepared for the shock wave to reach our microphones hanging in the air from the parachutes to be recorded. The flash was pretty bright, even at 20 miles. The white light lit the ceiling of our plane, faded to orange and disappeared. My immediate reaction was, “Thank God, my detonators worked!”

Hinton: The light withdrew into the bomb as if the bomb sucked it up.

Groves: Then as I turned, I saw the now familiar fireball.

Los Alamos physicist Boyce McDaniel: The brilliant flash of an ever-growing sphere was followed by the billowing flame of an orange ball rising above the plain.

Frisch: That object on the horizon, which looked like a small sun, was still too bright to look at. I kept blinking and trying to take looks, and after another 10 seconds or so it had grown and dimmed into something more like a huge oil fire, with a structure that made it look a bit like a strawberry. It was slowly rising into the sky from the ground, with which it remained connected by a lengthening gray stem of swirling dust; incongruously, I thought of a red-hot elephant standing balanced on its trunk.

Farrell: Oppenheimer’s face relaxed into an expression of tremendous relief.

Laurence: I stood next to [physics Nobel laureate] Professor [James] Chadwick when the great moment for the neutron arrived. Never before in history had any man lived to see his own discovery materialize itself with such telling effect on the destiny of man, for the immediate present and all the generations to come. The infinitesimal neutron, to which the world paid little attention when its discovery was first announced, had cast its shadow over the entire earth and its inhabitants. He grunted, leaped lightly into the air, and was still again.

Groves: As [Vannevar] Bush [director of the Office of Scientific Research and Development], [Harvard President James] Conant, and I sat on the ground looking at this phenomenon, the first reactions of the three of us were expressed in a silent exchange of handclasps. We all arose so that by the time the shock wave arrived we were standing.

Fitch: It took the blast wave about 30 seconds. There was the initial loud report, the sharp gust of wind, and then the long period of reverberation as the sound waves echoed off the nearby mountains and came back to us.

Laurence: Out of the great silence came a mighty thunder.

Los Alamos theoretical physicist Edward Teller: Bill Laurence jumped and asked, “What was that?” It was, of course, the sound of the explosion. The sound waves had needed a couple of minutes to arrive at our spot 20 miles away.

Frisch: The bang came minutes later, quite loud though I had plugged my ears, and followed by a long rumble like heavy traffic very far away. I can still hear it.

Princeton physicist Robert R. Wilson: The memory I do have is when I took the dark glasses away, of seeing all the colors around and the sky lit up by the radiation—it was purple, kind of an aurora borealis light, and this thing like a big balloon expanding and going up. But the scale. There was this tremendous desert with the mountains nearby, but it seemed to make the mountains look small.

Laurence: For a fleeting instant the color was unearthly green, such as one sees only in the corona of the sun during a total eclipse. It was as though the earth had opened and the skies had split.

Hirschfelder: The fireball gradually turned from white to yellow to red as it grew in size and climbed in the sky; after about five seconds the darkness returned but with the sky and the air filled with a purple glow, just as though we were surrounded by an aurora borealis. For a matter of minutes we could follow the clouds containing radioactivity, which continued to glow with stria of this ethereal purple.

Christy: It was awe-inspiring. It just grew bigger and bigger, and it turned purple.

Hinton: It turned purple and blue and went up and up and up. We were still talking in whispers when the cloud reached the level where it was struck by the rising sunlight so it cleared out the natural clouds. We saw a cloud that was dark and red at the bottom and daylight on the top. Then suddenly the sound reached us. It was very sharp and rumbled and all the mountains were rumbling with it. We suddenly started talking out loud and felt exposed to the whole world.

Hirschfelder: There weren’t any agnostics watching this stupendous demonstration. Each, in his own way, knew that God had spoken.

Groves: Unknown to me and I think to everyone, [Nobel laureate physicist Enrico] Fermi was prepared to measure the blast by a very simple device.

Physicist Herbert L. Anderson: Fermi later related that he did not hear the sound of the explosion, so great was his concentration on the simple experiment he was performing: he dropped small pieces of paper and watched them fall.

Groves: There was no ground wind, so that when the shock wave hit it knocked some of the scraps several feet away.

Anderson: When the blast of the explosion hit them, it dragged them along, and they fell to the ground at some distance. He measured this distance and used the result to calculate the power of the explosion.

Groves: He was remarkably close to the calculations that were made later from the data accumulated by our complicated instruments.

Hirschfelder: Fermi’s paper strip showed that, in agreement with the expectation of the Theoretical Division, the energy yield of the atom bomb was equivalent to 20,000 tons of TNT. Professor [Isidor] Rabi, a frequent visitor to Los Alamos, won the pool on what the energy yield would be—he bet on the calculations of the Theoretical Division! None of us dared to make such a guess because we knew all of the guesstimates that went into the calculations and the tremendous precision which was required in the fabrication of the bomb.

Optical engineer and photographer Berlyn Brixner: The bomb had exceeded our greatest expectations.

Bainbridge: I had a feeling of exhilaration that the “gadget” had gone off properly followed by one of deep relief. I got up from the ground to congratulate Oppenheimer and others on the success of the implosion method. I finished by saying to Robert, “Now we are all sons of bitches.” Years later he recalled my words and wrote me, “We do not have to explain them to anyone.” I think that I will always respect his statement, although there have been some imaginative people who somehow can’t or won’t put the statement in context and get the whole interpretation. Oppenheimer told my younger daughter in 1966 that it was the best thing anyone said after the test.

Chicago physics grad student Leona H. Woods: The light from Trinity was seen in towns as far as 180 miles away.

Physicist Luis Alvarez: Arthur Compton told of a lady who visited him after the war to thank him for restoring her family’s confidence in her sanity. She had visited her daughter in Los Angeles and was driving home across New Mexico early one morning to avoid the midday heat. She told her family that she saw the sun come up in the east, set, and then reappear at the normal time for sunrise. Everyone was sure that Grandma had lost her marbles, until the story of the Trinity shot was reported in the newspapers on August 4, 1945.

Elsie McMillan: [At home in Los Alamos,] I had to try to get some more sleep. There was a light tap on my door. There stood Lois Bradbury, my friend and neighbor. She knew. Her husband [physicist Norris] was out there too. She said her children were asleep and would be all right since she was so close and could check on them every so often. “Please, can’t we stay together this long night?” she said. We talked of many things, of our men, whom we loved so much. Of the children, their futures. Of the war with all its horrors. Lois watched out of the window. It was 5:15 a.m. and we began to wonder. Had weather conditions been wrong? Had it been a dud? I sat at the window feeding [physicist] Ed’s and my baby. Lois stood staring out. There was such quiet in that room. Suddenly there was a flash and the whole sky lit up. The time was 5:30 a.m. The baby didn’t notice. We were too fearful and awed to speak. We looked at each other. It was a success.

Woods: The most important problem given to Herb was to measure the yield of the Trinity test of the plutonium bomb. Herb converted some Army tanks with thick steel shielding to drive out into the desert after the Trinity explosion for scooping up samples of surface dirt. After the successful firing at Trinity, the tanks scooped up desert sand now melted to glass, containing and also covered with fallout.

Anderson: The method worked well. The result was important. It helped decide at what height the bomb should be exploded.

Farrell: All seemed to feel that they had been present at the birth of a new age.

Los Alamos Director J. Robert Oppenheimer: We knew the world would not be the same. A few people laughed, a few people cried. Most people were silent. I remembered the line from the Hindu scripture, the Bhagavad-Gita; Vishnu [a principal Hindu deity] is trying to persuade the prince that he should do his duty, and to impress him, takes on his multi-armed form and says, “Now I have become death, the destroyer of the worlds.” I suppose we all thought that, one way or another.

Kistiakowsky: I slapped Oppenheimer on the back and said, “Oppie, you owe me $10 dollars” because in that desperate period when I was being accused as the world’s worst villain, who would be forever damned by the physicists for failing the project, I said to Oppenheimer, “I bet you my whole month’s salary against $10 dollars that implosion will work.” I still have that bill, with Oppenheimer’s signature.

Groves: Shortly after the explosion, Farrell and Oppenheimer returned by jeep to the base camp, with a number of the others who had been at the dugout. When Farrell came up to me, his first words were, “The war is over.” My reply was, “Yes, after we drop two bombs on Japan.” I congratulated Oppenheimer quietly with “I am proud of all of you,” and he replied with a simple “Thank you.” We were both, I am sure, already thinking of the future.

Oppenheimer: It was a success.

Hirschfelder: If atom bombs were feasible, then we were glad that it was we, and not our enemy, who had succeeded.

Teller: As the sun rose on July 16, some of the worst horrors of modern history—the Holocaust and its extermination camps, the destruction of Hamburg, Dresden, and Tokyo by fire-bombing, and all the personal savagery of the fighting throughout the world—were already common knowledge. Even without an atomic bomb, 1945 would have provided the capstone for a period of the worst inhumanities in modern history. People still ask, with the wisdom of hindsight: “Didn’t you realize what you were doing when you worked on the atomic bomb?” My reply is that I do not believe that any of us who worked on the bomb were without some thoughts about its possible consequences. But I would add: How could anyone who lived through that year look at the question of the atomic bomb’s effects without looking at many other questions? The year 1945 was a melange of events and questions, many of great emotional intensity, few directly related, all juxtaposed. Where is the person who can draw a reasonable lesson or a moral conclusion from the disparate events that took place around the end of World War II?

Cmdr. Norris Bradbury, physicist and head of E-5, the Implosion Experimentation Group: Some people claim to have wondered at the time about the future of mankind. I didn’t. We were at war, and the damned thing worked.

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