The effects could well be called unprecedented, magnificent, beautiful, stupendous, and terrifying. No man-made phenomenon of such tremendous power had ever occurred before. The lighting effects beggared description. The whole country was lighted by a searing light with the intensity many times that of the midday sun. It was golden, purple, violet, gray and blue. It lighted every peak, crevasse and ridge of the nearby mountain range with a clarity and beauty that cannot be described but must be seen to be imagined. It was that beauty the great poets dream about but describe most poorly and inadequately. Thirty seconds after the explosion came first, the air blast pressing hard against people and things, to be followed almost immediately by the strong, sustained, awesome roar which warned of doomsday and made us feel that we puny things were blasphemous to dare tamper with the forces heretofore reserved to the Almighty. Words are inadequate tools for the jobs of acquainting those not present with the physical, mental and psychological effects. It had to be witnessed to be realised [sic].”
Three Years on a Tightrope
BY GENERAL LESLIE R. GROVES
After about an hour’s sleep I got up at 0100 and from that time on until five I was with Dr. Oppenheimer constantly. Naturally he was nervous, although his mind was working at its usual extraordinary efficiency. I devoted my entire attention to shielding him from the excited and generally faulty advice of his assistants who were more than disturbed by their excitement and the uncertain weather conditions. By 0330 we decided that we could probably fire at 0530. By 0400 the rain had stopped but the sky was heavily overcast. Our decision became firmer as time went on. During most of these hours the two of us journeyed from the control house out into the darkness to look at the stars and to assure each other that the one or two visible stars were becoming brighter. At 0510 I left Dr. Oppenheimer and returned to the main observation point which was 17,000 yards from the point of explosion. In accordance with our orders I found all personnel not otherwise occupied massed on a bit of high ground.
At about two minutes of the scheduled firing time all persons lay face down with their feet pointing towards the explosion. As the remaining time was called from the loud speaker from the 10,000 yard control station there was complete silence. Dr. Conant said he had never imagined seconds could be so long. Most of the individuals in accordance with orders shielded their eyes in one way or another. There was then this burst of light of a brilliance beyond any comparison. We all rolled over and looked through dark glasses at the ball of fire. About forty seconds later came the shock wave followed by the sound, neither of which seemed startling after our complete astonishment at the extraordinary lighting intensity.
Dr. Conant reached over and we shook hands in mutual congratulation. Dr. Bush, who was on the other side of me, did likewise. The feeling of the entire assembly was similar to that described by General Farrell, with even the uninitiated feeling profound awe. Drs. Conant and Bush and myself were struck by an even stronger feeling that the faith of those who had been responsible for the initiation and the carrying on of this Herculean project had been justified. I personally thought of Blondin crossing Niagara Falls on his tight rope, only to me this tight rope had lasted for almost three years and of my repeated confident-appearing assurances that such a thing was possible and that we would do it.
U.S. Department of Energy
Brigadier General Thomas F. Farrell was the second-in-command to General Leslie R. Groves. He was stationed at Los Alamos and supervised the Trinity test.
Babysitting the Bomb
Don Hornig remembers the night of July 15, 1945, as he was stationed on top of the tower with the “gadget,” anxiously waiting for a storm to pass over the Trinity site. But he was most worried that his contribution, the electrical switching device, might not work.
From “The Story with Dick Gordon,” WUNC
INTERVIEW WITH DON HORNIG
Oppenheimer was really terribly worried about the fact that the thing was so complicated and so many people knew exactly how it was put together that it would be easy to sabotage. So he thought someone had better baby sit it right up until the moment it was fired. They asked for volunteers and as the youngest guy present, I was selected. I don’t know if it was that I was most expendable or best able to climb a 100-foot tower!
By then there was a violent thunder and lightning storm. I climbed up there, took along a book, Desert Island Decameron, and climbed the tower on top of which there was the bomb, all wired up and ready to go. Little metal shack, open on one side, no windows on the other three, and a 60-watt bulb and just a folding chair for me to sit on beside the bomb, and there I was!
All I had was a telephone. I wasn’t equipped to defend myself, I don’t know what I was supposed to do. There were no instructions! The possibility of lightning striking the tower was very much on my mind. But it was very wet and the odds were the tower would act like a giant lightning rod and the electricity would just go straight down to the wet desert. In that case, nothing would have happened. The other case was that it would set the bomb off. And in that case, I’d never know about it! So I read my book.
I had invented the electrical switching device which came to be used on the bomb. The bomb was itself a sphere of plutonium surrounded by a couple of tons of high explosive, which had to crush that sphere. To do that successfully, the high explosives had to be detonated at 32 points around the sphere. All of those initiations had to take place in a fraction of a millionth of a second.
My switch was a device for doing that, for firing all the 32 detonators well within a millionth of a second. In fact, it was one of the things many people were most skeptical was going to work. And there was a lot of skepticism about whether the “gadget” would work because so many things had never been done before.
All the senior scientists who weren’t actually involved in the test had a betting pool. The betting ran from a complete dud to little explosions to middle-sized explosions. Just a few people were willing to bet that it would produce what it was supposed to produce which was something like 20,000 tons of TNT’s worth. There was a lot of skepticism.
Later, listening to the countdown, I was in the bomb-proof underground control bunker. I had made a point of sitting right next to the door. There was no question at all of it having gone off. The intensity of the light outside was just unbelievable. And so I dashed out the door and saw this great thing ascending into the sky: a million neon lights, orange, green, purple, rising up into the sky, way up. There was no question that it had gone, and gone big.
I just heaved a sigh of relief, because if my thing had failed in any way, the whole national supply of plutonium would have been dumped! We also understood that President Truman was waiting in Potsdam for news about this. He was talking with Stalin and thought he had a trump card for Stalin. Turned out of course he didn’t, because the Russians had good spies.
U.S. Department of Energy
This 100-foot tower was built for the Trinity Test shot.
A Handful of Soldiers at Trinity
In his account of the Manhattan Project, General Groves does not even mention the Special Engineer Detachment. As Val Fitch comments, “Clearly we were not the low men on the totem pole. As carved by our commanding general, we were not on the totem at all.” Later a Nobel laureate, Val Fitch shares the perspective of one the “handful of soldiers” who worked at Los Alamos and witnessed the Trinity test.
From “A Soldier in the Ranks”
BY VAL FITCH
General Thomas F. Farrell, deputy military commander of the Manhattan Project, was at the main control bunker at the time of the first test of the atomic bomb at Alamogordo, July 16, 1945. His impressions are recorded in the Smyth Report.
The scene inside the shelter was dramatic beyond words. In and around the shelter were some twenty odd people concerned with last-minute arrangements. Included were Dr. Oppenheimer, the Director who had borne the great scientific burden of developing the weapon from the raw materials made in Tennessee
and Washington, and a dozen of his key assistants, Dr. Kistiakowsky, Dr. Bainbridge, who supervised the test; the weather expert, and several others. Besides those, there were a handful of soldiers, two or three Army officers and one Naval Officer. The shelter was filled with a great variety of instruments and radios.
I happen to be one of that anonymous “handful of soldiers” mentioned by General Farrell. Here I was, at the focal point of a momentous occasion, by circumstance knowing most of what was going on, seeing all, hearing all, measuring the well-known people who had just arrived on the scene. Still, cloaked in the anonymity of an enlisted man’s fatigue uniform, I was largely ignored by these same people. Somehow the uncertainty principle was being violated. My presence could not have affected the visiting dignitaries less.
Because of this experience early in my life, I developed a special affinity for the individuals present, but outside the spotlight, on historically important occasions. Even when I read, for example, Shakespeare’s Henry V, I tend to pay as much attention to what the soldiers are saying as I do to Henry’s St. Crispin’s Day speech. The soldiers are, after all, only interested in getting the job done and going home. Henry, on the other hand, must devote a large fraction of his time thinking up the memorable phrases expected of him.
I was present at the first test as a member of a military unit known as the Special Engineer Detachment, a group of army enlisted men extracted from regular army units to serve largely in technician capacities in the Manhattan Project. The equipment which concerned me those minutes before the firing was functioning in its automatic mode. We marked time.
About a half a minute before the scheduled moment of detonation my boss, Ernest Titterton, a member of the British Mission to Los Alamos, suggested that since there was nothing more for me to do I might as well go outside the bunker to get a good view. This I did, taking with me the two-by-four inch piece of nearly opaque glass which someone had handed me earlier. (I have, of course, saved the glass as a memento and indeed have watched a number of solar eclipses through it. The envelope in which it came carries the notice, “This welding glass will meet federal specifications covering filter glass for arc welding helmets and hand shields.”)
Out to the east of the bunker I lay on the ground and peered over the top of a mound of earth, my hands tightly cupping the glass in front of my eyes. I was joined by three or four others. I waited with my line of sight not directed due north toward the tower but rather northeast toward the mountains where the dawn was breaking. At the moment of detonation I did not want to be looking directly at the source. Then, 10,000 yards (six miles) to the north that indescribable flash of light occurred. Cautiously, but quickly, I moved my line of sight to the fireball which was still almost blinding even through the nearly opaque glass. As the intensity of the light gradually dimmed I peeked out around the welding glass at the sight and stood up to get a better view. I quickly realized the shock wave had yet to arrive and again lay on the ground and waited for the blast.
The army had sent me to Los Alamos about one year earlier to work on the Manhattan Project. Among my army buddies I was the only one who received travel orders to New Mexico and the orders gave no inkling of what lay in store for me. An enlisted man is a pawn to be moved about, and in the year and a half I had been in the army I had grown accustomed to being ordered to unknown destinations.
The lonely figure that got off the train at Lamy, New Mexico, to shouts of commiseration from a train load of sailors didn’t exactly feel the world was coming up roses. Lamy consisted of little more than a rundown station house in the middle of the desert and there was not a single person in sight. But shortly afterward an army sedan appeared and I was on my way to the “hill” (Los Alamos) to become a member of the Special Engineer Detachment, a SED, with the noncommittal address, P.O. Box 1663, Santa Fe, New Mexico.
At Los Alamos I was assigned to an upper bunk in a recently completed barracks, a spot that was to be home for another year and nine months. I quickly learned the army situation from the SEDs already there. We lived in a single floor barracks, roughly 60 men to a unit. Our mail was censored, both incoming and outgoing. We ate in an army mess hall, but there was no KP, the kitchen help was indigenous labor. We lined up each week to get fresh linen, and once a month to get paid. Reveille came at 6 A.M., and we had calisthenics from 6:30 to 7:00. We could not leave the barracks for work on Saturday mornings until after inspection of quarters, nominally at 8:00. We worked in something called the Tech Area six days a week. It was the army and still it wasn’t the army because in the Tech Area we worked alongside, and were beholden to, civilians.
The usual route up the military ladder, Officer Candidate School, was closed to SEDs, presumably for security reasons. This was a frustrating situation for any reasonably ambitious, intelligent person who happened to find himself in the military. A few SEDs had Ph.D.’s but most had been inducted into the army before, or just after, completion of undergraduate work in some technical field.
On arrival at the Tech Area the first morning I was immediately assigned to work in the group of Ernest Titterton, a young English physicist who had been heavily involved in the radar program in Britain and who was one of the roughly 20 member British Mission to Los Alamos. His group (another SED, Russell Lowry, and two civilian technicians, Gilbert Mathis, and Calvin Linton) was largely concerned with the fast timing measurements of detonation phenomena. My first job was to build a mixing circuit for measuring the degree of simultaneity of several independently initiated explosive shock waves.
Everyone was extremely security conscious and correspondingly circumspect in talking about his work. While nothing was explicitly described to me it was not difficult to perceive rather quickly what was transpiring at Los Alamos. Much earlier I had come to appreciate the reviews by K. K. Darrow in the Bell System Technical Journal and had learned about fission in his 1940 article on the subject. Also, I had by this time read the little book by Ernest Pollard and William Davidson on Applied Nuclear Physics. One could not read the chapter on nuclear fission without being struck by a melodramatic remark uncharacteristic of physicists: “If the reader wakes some morning to read in his newspaper that half the United States was blown into the sea overnight, he can rest assured that someone, somewhere, succeeded.”
As the summer and fall of 1944 progressed the size of the SED contingent continued to increase as fast as new barracks were built. The fundamental dichotomy in the army existence and the work alongside civilians troubled some of the SEDs. They considered themselves miserably exploited by the system. On the other hand, many of us found our work in the laboratory intellectually stimulating, and we spent long hours there working on and learning new things. We considered this army assignment extraordinarily fortuitous.
Our living conditions improved substantially and the army life became less military with the arrival of a new company commander. He was a combat veteran who had some sense of the important. Reveille and the early morning calisthenics were dropped and the latrines were now cleaned by civilian employees. We still had the chore of manning the stoves in the barracks. The barracks were each heated by four iron, pot-bellied, coal-burning stoves spaced the length of the barracks in the center aisle between the bunks. In the tradition of the army, the platoon sergeant was supposed to assign a detail to keep the stoves going. In our barracks we all contributed toward paying one of our willing members to take care of them.
Saturday morning inspection also remained on the schedule but became devoid of spit and polish. The new company commander would stride down the length of the barracks at something less than the speed of light and that was it, for another week. On one morning, however, something struck him on the head as he sped down the aisle. He pulled himself to a stop a few strides later, turned around to see some curious object wildly gyrating on a string from the ceiling of the barracks. “What’s this?” asked the captain. “That’s a bagel, sir,” said my fellow platoon member standing at attention beside his bunk. “
Well it’s pretty dangerous up there, you’d better eat it,” said the captain and continued on his way. My friend had received a box of bagels from his home in New York City. In his rather desperate homesickness he had suspended one of the bagels on a string from the ceiling so he could lie back on his bunk and admire it. It just happened to catch the top of the head of the unusually tall captain.
Those SEDs accustomed to the amenities of city living and unwilling to accept substitutes were an unhappy lot. Those of us who immediately got involved in the hiking, skiing, skating, and folk dancing activities came to love dearly that part of the country. Most of the noted physicists at Los Alamos hiked and skied, and I came to know more of them on the ski slopes than I did at work. Niels Bohr skiing, albeit modestly, was a memorable sight. Being gently chastised by Enrico Fermi for inadequately (in his opinion) filling in the sitzmark from a skiing spill was more an honor for me than a rebuke. Mrs. Rudolph [sic] Peierls, directing traffic over all the ski slopes from the stoop of the warming hut at the bottom, is not to be forgotten. Where else in the army could one, on a moonlit night, go skiing a few hundred yards from his barracks as I did with my friend Gunnar Thornton. And Ernest and Peggy Titterton graciously included me in many of their social gatherings. I knew already that physics was a very special subject. But here at Los Alamos I learned that, by and large, physicists were extraordinary people. The complete intellectual integrity required in the pursuit of physics carried over into the personal relationships of physicists.
During the fall and winter of 1944 I became familiar, first hand, with the speed of propagation of detonations, Kerst’s betatron at “K site,” and the design and construction of better oscilloscopes for recording timing information.
The Manhattan Project Page 30