Robert "Bob" Carter

Robert “Bob” Carter was a Washington College graduate in 1942 from Berlin, Maryland. A day before being drafted into the Army that year, he was deferred to a graduate school physics program at Purdue University. A year and a half later, his professors invited him and his lab partner to come join them at a secret physics project in New Mexico. By 1945, he and his team had invented history’s first nuclear reactor in Los Alamos as part of the Manhattan Project.

Photo on the left shows Robert Carter (left), posing with Manhattan Project colleagues: nuclear physicists Enrico Fermi (center) and David Inglis (Right).

Trinity Explosion

By the time of the Trinity explosion, there were various members of the Los Alamos laboratory who were designing testing equipment to make measurements of the Trinity test shot: the magnitude of the explosion, the magnitude of the neutron population, neutron density that was formed, the gamma rays and things like that. These various devices had to be calibrated and tested and assurance made that they would function adequately in a microsecond when the explosion went off. And so, a couple of us at the laboratory were in the testing and proofing stage with some equipment, but we were not going to be the ones to take it to the Trinity test. We were the guys at home who had calibrated it and had the basic information of how to interpret the results of the test at Trinity. So we weren’t invited. Two or three of us were not invited to go to the Trinity test but we knew when it was going to be. We knew the schedule. And one of the more senior people, who was going to be at the Trinity test, I asked him to describe what the countryside looked like in the desert of southern New Mexico and where I might be able to sneak in and watch the test. He drew me on the chalkboard pictures of what the hills looked like, the desert area, where a road was, and things like that. So I told him, “Ok, I’m going to try to get there.” There was a woman graduate student with whom I was working on a day-by-day basis at that time. She and I became really good buddies. We did a lot of things together. We skied together, we hiked together, we camped together, we worked together. But anyway, she and I went to southern New Mexico on my motorcycle the day before the test was going to be shot, arriving down there after dark. A couple of other people from Los Alamos who also were interested in seeing the shot, the test, but not directly involved with it, they decided to sneak in with us. So the four of us arrived down there, met up and pushed our vehicles across the desert behind the hill. By that time it was after dark; it was maybe 10 o’clock at night. We hiked further across the desert, found the hills that had been described to me, and we decided which side of the hill to sit on and things like that. We got set up and sat there the rest of the night. I guess none of us had watches so we didn’t know what time it was. And then finally, it started getting a little bit light in the East. And then all of a sudden, the Trinity Test exploded right in front of us but like 15 miles away. So that was how I got there.

Feelings on Seeing the Bomb

It was—I guess overwhelming is a word that might fit, but I‘m not really sure what overwhelming means. It lighted up the whole sky. There was a very, very bright flash and then the cloud of material that was the cause of the explosion or the result of the explosion started rising, and it was visible. Also, it was self-visible, self-lighting, or something I don’t know, self-luminous so we could see the cloud rising. In about a minute, the shock wave arrived because light travels much faster through the atmosphere than sound does so it took about a minute for the sound to arrive after the flash of light. That was almost overwhelming second phase of the whole thing. But it was—I had never really observed a big explosion of any kind before, and so I didn’t quite know what to expect. The whole thing was a surprise to me.

It’s probably the biggest change in human existence that man has been able to create, I think it is about the way we felt. But I remember sort of feeling too what I would guess parents (see I was not married and didn’t have a family and stuff) but I guessed what parents must think when they first see their newborn baby, and they think, “Wow! Look we made a miracle, we did a miracle here. Look at what we made.” And then they think, “Gosh, but we have to protect and take care of this for the rest of our lives.” I think that’s kind of the way I felt at the time because I felt it was a new phenomenon in the existence of mankind. It could be used for good or evil, or good or bad depending on people.

Reactions to the Bomb on Hiroshima

Well, at the beginning of the project there was a lot of uncertainty among the scientists whether a nuclear bomb was even feasible, whether it could be built, or whether the parameters involved were sufficient to make it function as a bomb. And so, that was a large part of the investigations at the beginning. Then when it became more and more certain that a bomb would, in fact, detonate, then we started trying to understand the magnitude of the explosion and the results of it, the mechanical effects of an explosion. So, we realized if it worked as we had predicted, it would be a huge explosion, a bigger explosion than mankind had ever seen before. I guess it was partially scientific inquisition to go ahead and do it if it were possible and then also a little bit of concern how it would be used by the U.S. government if and when it was possible to build one. I don’t remember thinking in terms of it being used to kill a lot of people. I don’t remember thinking that through very much at the time. I guess I was surprised that the United States government had done it, had actually used it on a city. I guess I thought, “Golly, a bomb is supposed to be used on the military installations and military people. It’s not supposed to be used on cities with civilians.” I guess that was my immediate reaction.

Oppenheimer Vs Censors

Actually, one event happened that was kind of unique connected with me, and that is a letter that my mother sent to me. When it went through the security people, they cut out a few words that were in my mother’s letter to me. When I got it then, I remember I opened it, and I held it up. There were three or four of us sitting in an office, and I held it up and said, “Look what they did to my letter.” And one of the professor-level people was there with us, and he looked at it, and he said, “Bob, come on!” And he grabbed me by the hand, and we ran to Robert Oppenheimer’s office. Now, he was the director of the Los Alamos laboratory program, and we ran to his office. And I remember he had an inner office and a secretary in an outer part of his office, and this man and I came running in. She looked up and said, “Can I help you?” This man had me by the hand, said, “No.” And we burst right into Oppenheimer’s office, and my friend held my letter up and said, “Look what they did to Bob’s letter.” And Oppenheimer jumped up. The three of us went over to the office (it was in a different building where the censor people were). And I remember Oppenheimer pointed to the officer who was in charge of that office and said, “Don’t you dare ever do something like this again!” Then he said, “Find all the pieces you cut out of this letter.” The poor man. He was a major, or lieutenant colonel; I forget exactly what his rank was in the army. And he said, “I’m sorry, the pieces were probably put in the trash, and I have no way of locating them now.” So I never did find what was cut out of my letter. But I was not much of a historian. Over the next several months, I threw the letter away, whereas, if I had kept it, these days, it probably would be a priceless relic from the war.

Harry’s Life

Harry, he had done his undergraduate work at Purdue, gotten his bachelor’s degree with a physics major, and then had stayed on as a graduate student in the program at Purdue University. And that’s where I met him. When I first went there, he was already a graduate student in the physics department, and he was already volunteering to work at this cyclotron program. I don’t remember exactly how I met him but when I heard that he was working at the cyclotron, I asked him to take me there and show me. I said, “I’d like to see this device that I’ve heard something about.” And so he took me, introduced me to the professor in charge, and that’s how I got involved there. Well, Harry and I worked together. We were very good friends at Purdue for about a year and a half, and then he was the one that wanted to go to Los Alamos with me, which he did. We worked together there at Los Alamos for about the first year, a little bit less than a year. Then he moved into a different group that was established to do a different kind of work. And the group he moved to was, among other things, the group that tested the nuclear core of bombs to make sure that they met all the specifications and requirements. He was the one who hand carried the nuclear core down to Alamogordo for the Trinity test, for instance. And he helped package the nuclear cores for the Hiroshima and Nagasaki bombs, the ones that were taken overseas. So he was intimately involved in all those things. His new group that he worked in was working in the same building that our group, the first group, was still working in. So we drove together. We were an outlying site at Los Alamos, and so we drove cars together, we worked together and took lunches and other meals together, things like that. But he decided one evening, he wanted to test what would probably have been the next bomb if the U.S. had bombed a third city or third location. He decided to go ahead and test that by himself. That was a little unusual but not unique for him to be working alone on doing the testing. He had an accident. He dropped something, it slipped out of his hand, and it caused the bomb chain reaction to take off. And he was exposed to a large amount of radiation, neutrons and gamma rays, in a very short time. He was the only one working with him so no one else was affected. But it turned out to be a lethal dose. He lived for about three weeks and then died of that radiation exposure.

Well, I guess my feeling was it was too bad that he felt that it was important enough to do those measurements, to go ahead and do them by himself. It was after dinner. We often worked at night in those days. In fact, I was at the other end of the building at my desk doing some calculations on some data when he had this accident at the other end of the building. And I didn’t know about it immediately. The way it happened, I had already gone down to the lab to work, and I was at my desk. This woman with whom I worked a lot came down. Well, I say down because we were down in a canyon, and most of the laboratory space was up on a mesa. She came down somewhat later, was going to join me to work on some calculations,, and Harry had just had his accident. And he ran out of the building into the parking lot, and she had just driven in, and he hollered out to her something like, “I think I just killed myself. Take me to the hospital.” And so, the two of them got back in the car, and she drove him up to the hospital. She stayed there for just a short time ‘till the doctors could take over, and then she came back to the laboratory and told me what had happened. Shortly later we went up to the hospital to see him, and the doctors wouldn’t let us see him. They were still trying to understand what all had happened. So, I guess my feeling was that, as I said, I think, it’s too bad that he felt it was important enough to work alone and had this inadvertent accident.

Japanese Internment Camps

There was one of those [Japanese internment camps] just outside of Santa Fe, New Mexico. Santa Fe was the nearest city of any sort. Every time we went from Los Alamos to Santa Fe, we had to drive past this Japanese internment camp. So, we knew it was there, we were aware of it, we kind of knew why it was there, and as I recall, we sort of accepted it. There were a lot of European scientists who were working at Los Alamos, and some of them, quite a few of them, had left Germany because of Hitler and his Nazi programs in Germany. So, they were aware of sort of displaced persons and getting away from their existing life and moving into a different environment. But I don’t remember any of them mentioning or saying anything negative about the Japanese internment camps. I just don’t remember anybody. We sort of accepted them as part of the war.

Father’s German Friend

My dad had a friend who was German. But his father, this other man’s father, was German and was not a citizen of the US and had lived in this country for quite a few years but did not speak English. He had never learned to speak English. The Germans were required to register with our federal government, and this older man was required to fill out some forms, but he couldn’t read the English. And so, his son asked my dad if I could help him interpret the forms because I had taken a course in German at Washington College my freshman year. So they brought this elderly gentleman, who spoke no English, to talk to me with this form with only English words on it. And so I spent a couple of hours helping him understand and fill out this form.

Life After Manhattan Project

The people in the laboratory on the whole decided, “Okay, our work is finished. The war’s ended, the bombs worked, the war’s ended. That’s what we were here for so now we’ll go back to our real lives.” And a large fraction of the employees at Los Alamos had been professors at universities in various fields like physics, chemistry, mathematics, metallurgy, and things of that sort. There were a lot of various scientific disciplines required to make a successful nuclear bomb. I had decided I wanted to go back to graduate school. And one of the professors I had worked with there at Los Alamos invited me to go to the University of Illinois where he was a full professor. That was his career, and he had just taken a leave of absence to work at Los Alamos during the war. He was going back to the University of Illinois, and I went with him as a graduate student. In about a year, year-and-a-half after I went there, I met a fellow graduate student whom I married. She and I were both graduate students then, and in about a year, we had a baby. And for various reasons, I decided not to continue my graduate work but to go back to work at Los Alamos. The man I had worked with mostly out there wanted me to come back. He stayed; he did not go back. He had been a professor at Purdue, and he stayed at Los Alamos the whole rest of his career. He wanted me to come back, which I did. So I went back to Los Alamos with my wife and child, and we had other children. We stayed there for about fifteen more years while working in the laboratory.