Nuclear physicist, Robert Carter, describes his time working on the Manhattan Project in Los Alamos, New Mexico.  Photo on the left shows Robert Carter ’42 (far left), posing with Manhattan Project colleagues, nuclear physicists Enrico Fermi (center) and David Inglis.



Interviewee: Robert Carter

Interviewers: Nicholas Coviello, Lorenz Iversen, Liz Wiley

Date of Interview: June 13, 2016

Reaction to Nuclear Bomb

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. 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, 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.

Correspondence and Censoring

We weren’t allowed to tell anyone what we were doing, and all of our mail, we were allowed to exchange mail, but all of our mail was kind of censored. What was done was that there was an office at Los Alamos, and all incoming mail went through that office. Military officers opened up everybody’s mail and incoming mail. They scanned and looked through it for any comments or questions or difficulties that might release, in some way, or might indicate that someone outside knew what was going on at the project. Then the outgoing mail, all the mail that we sent out, we were not allowed to seal the envelopes. We would post it into a special mailbox, which would go through that same office, and they would look through it to make sure we weren’t releasing some kind of classified information. So my mother and I exchanged information letters, I guess not very frequently. I wasn’t a very good correspondent. Well, I was kind of lazy as far as correspondence was concerned, but we exchanged mail.

Oppenheimer to the Rescue

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.  When I got it then, I remember I opened it and 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.”  One of the professor-level people was there with us, and he looked at it and 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 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, who had me by my 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 would probably be a priceless relic from the war.


Life After Los Alamos

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, and 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.  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; he had just taken a leave of absence to work at Los Alamos during the war. So 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, 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.  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; he stayed at Los Alamos the rest of his career. And 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. I was working in the laboratory.