Posts Tagged ‘Metallurgical Laboratory’

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To demonstrate, or not to demonstrate?

Friday, March 6th, 2015

As the atomic bomb was becoming a technological reality, there were many scientists on the Manhattan Project who found themselves wondering about both the ethics and politics of a surprise, unwarned nuclear attack on a city. Many of them, even at very high levels, wondered about whether the very threat of the bomb, properly displayed, might be enough, without the loss of life that would come with a military attack.

1945-06-12 - Franck Report

The Franck Report, written in June 1945 by scientists working at the University of Chicago Metallurgical laboratory, put it perhaps most eloquently:

the way in which nuclear weapons, now secretly developed in this country, will first be revealed to the world appears of great, perhaps fateful importance. … It will be very difficult to persuade the world that a nation which was capable of secretly preparing and suddenly releasing a weapon, as indiscriminate as the rocket bomb and a thousand times more destructive, is to be trusted in its proclaimed desire of having such weapons abolished by international agreement…. 

From this point of view a demonstration of the new weapon may best be made before the eyes of representatives of all United Nations, on the desert or a barren island. The best possible atmosphere for the achievement of an international agreement could be achieved if America would be able to say to the world, “You see what weapon we had but did not use. We are ready to renounce its use in the future and to join other nations in working out adequate supervision of the use of this nuclear weapon.”

They even went so far as to suggest, in a line that was until recently totally etched out of the historical record by the Manhattan Project censors, that “We fear its early unannounced use might cause other nations to regard us as a nascent Germany.” 

The evolution of the "Trinity" test fireball, at constant scale, with the Empire State Building for additional scale reference.

The evolution of the “Trinity” test fireball, at constant scale, with the Empire State Building for additional scale reference.

The idea of a “demonstration” was for many scientists a compelling one, and news of the idea spread to the various project sites. The idea would be to let the Japanese know what awaited them if they did not surrender. This would be more than just a verbal or textual warning, which could be disregarded as propaganda — they would set the bomb off somewhere where casualties would be low or minimal, but its nature easy to verify. If the demonstration did not work, if the Japanese were not receptive, then the bomb could be used as before. In the eyes of these scientists, there would be no serious loss to do it this way, and perhaps much to gain.

Of course, not all scientists saw it this way. In his cover letter forwarding the Franck Report to the Secretary of War, the physicist Arthur Compton, head of the Chicago laboratory, noted his own doubts: 1. if it didn’t work, it would be prolonging the war, which would cost lives; and 2. “without a military demonstration it may be impossible to impress the world with the need for national sacrifices in order to gain lasting security.” This last line is the more interesting one in my eyes: Compton saw dropping the bomb on a city as a form of “demonstration,” a “military demonstration,” and thought that taking a lot of life now would be necessary to scare the world into banning these weapons in the future. This view, that the bombs were something more than just weapons, but visual arguments, comes across in other scientists’ discussions of targeting questions as well.

Truman was never asked or told about the demonstration option. It is clear that General Groves and the military never gave it much thought. But the Secretary of War did take it serious enough that he asked a small advisory committee of scientists to give him their thoughts on the matter. A Scientific Panel, composed of J. Robert Oppenheimer, Arthur Compton, Enrico Fermi, and Ernest Lawrence, weighed in on the matter formally, concluding that: “we can propose no technical demonstration likely to bring an end to the war; we see no acceptable alternative to direct military use.”1

"Recommendations on the Immediate Use of Atomic Weapons," by the Scientific Panel of the Interim Committee, June 16, 1945. The full report (which also discusses the possibility of the H-bomb and many other things) is extremely interesting, as well — click here to read it in its entirety.

“Recommendations on the Immediate Use of Atomic Weapons,” by the Scientific Panel of the Interim Committee, June 16, 1945. The full report (which also discusses the possibility of the H-bomb and many other things) is extremely interesting, as well — click here to read it in its entirety.

I find this a curious conclusion for a few reasons. For one thing, are these four scientists really the best experts to evaluate this question? No offense, they were smart guys, but they are not experts in psychological warfare, Japanese political thought, much less privy to intercepted intelligence about what the Japanese high command was thinking at this time. That four physicists saw no “acceptable alternative” could just be a reflective of their own narrowness, and their opinion sought in part just to have it on the record that while some scientists on the project were uncomfortable with the idea of a no-warning first use, others at the top were accepting of it.

But that aside, here’s the other fun question to ponder: were they actually unanimous in their position? That is, did these four physicists actually agree on this question? There is evidence that they did not. The apparent dissenter was an unlikely one, the most conservative member of the group: Ernest Lawrence. After the bombing of Hiroshima, Lawrence apparently told his friend, the physicist Karl Darrow, that he had been in favor of demonstration. Darrow put this into writing on August 9, 1945, to preserve it for posterity should Lawrence come under criticism later. In Darrow’s recollection, Lawrence debated it with the other scientists for “about an hour” — a long-enough time to make it seem contentious. On August 17, after the bomb had “worked” to secure the peace, Lawrence wrote back to Darrow, somewhat denying this account, saying that it was maybe only ten minutes of discussion. Lawrence, in this later account, credits Oppenheimer as being the hardest pusher for the argument that unless the demonstration took out a city, it wouldn’t be compelling. I’m not sure I completely believe Lawrence’s later recant, both because Darrow seemed awfully convinced of his recollection and because so much changed on how the bomb was perceived after the Japanese surrendered, but it is all an interesting hint as some of the subtleties of this disagreement that get lost from the final documents alone. In any case, I don’t know which is more problematic: that they debated for an hour and after all that, concluded it was necessary, or that they spent no more than ten minutes on the question.2

1945-08-10 - Groves memo on next bombs

As an aside, one question that sometimes gets brought up at this point in the conversation is, well, didn’t they only have two bombs to use? So wouldn’t a demonstration have meant that they would have only had another bomb left, perhaps not enough? This is only an issue if you consider the timescale to be as it was played out — e.g., using both bombs as soon as possible, in early August. A third plutonium bomb would have been ready by August 17th or 18th (they originally thought the 24th, but it got pushed up), so one could imagine a situation in which things were delayed by a week or so and there would have been no real difference even if one bomb was expended on a demonstration. If they had been willing to wait a few more weeks, they could have turned the Little Boy bomb’s fuel into several “composite” core implosion bombs, as Oppenheimer had suggested to Groves after Trinity. I only bring the above up because people sometimes get confused about their weapon availability and the timing issue. They made choices on this that constrained their options. They had reasons for doing it, but it was not as if the way things happened was set in stone. (The invasion of Japan was not scheduled until November 1st.)3

So, obviously, they didn’t choose to demonstrate the bomb first. But what if they had? I find this an interesting counterfactual to ponder. Would dropping the bomb in Tokyo Bay have been militarily feasible? I suspect so. If they could drop the bombs on cities, they could probably drop them near cities. To put it another way: I have faith they could have figured out a way to do it operationally, because they were clever people.4

But would it have caused the Japanese high command to surrender? Personally, I doubt it. Why? Because it’s not even clear that the actual atomic bombings were what caused the Japanese high command to surrender. There is a strong argument that it was the Soviet invasion of Manchuria that “shocked” them into their final capitulation. I don’t know if I completely buy that argument (this is the subject of a future blog post), but I am convinced that the Soviet invasion was very important and disturbing to the Japanese with regards to their long-term political visions for the country. If an atomic bomb dropped on an actual city was not, by itself, entirely enough, what good would seeing a bomb detonated without destruction do? One cannot know, but I suspect it would not have done the trick.

The maximum size of a 20 kiloton mushroom cloud in Tokyo Bay, as viewed from the roof of the Imperial Palace today, as visualized by NUKEMAP3D. Firebombed Tokyo of 1945 would have afforded a less skyscraper-cluttered view, obviously.

The maximum size of the mushroom cloud of a 20 kiloton nuclear detonation in Tokyo Bay, as viewed from the roof of the Imperial Palace today, as visualized by NUKEMAP3D. Firebombed Tokyo of 1945 would have afforded a less skyscraper-cluttered view, obviously.

Of course, the Chicago scientists suspected that as well, but said it was necessary from a moral point of view. Sure, the Japanese might not surrender, but then, at least, you can say you showed them what was coming first.  As it was, we gave no real warning whatsoever before dropping it on Hiroshima. But here’s the question I come to next: could you demonstrate it, and then drop it on a city? That is, could the United States really say: “we have made this apocalyptic weapon, unleashed the atom, and many other peril/hope clichés — and we have chosen not to use it to take life… yet. But if you don’t give in to our demands, we will unleash it on your people.” How could that not look like pure blackmail, pure terrorism? Could they then turn around and start killing people by the tens of thousands, having announced their capability to do so? Somehow I suspect the public relations angle would be almost impossible. By demonstrating it first, they would be implying that they knew that it was perhaps not just another weapon, not just another way to wage war. And that acknowledgment would mean that they would definitely be seen as crossing a line if they then went on to use it.

As it was, that line, between the bomb as “just another weapon” and something “special,” was negotiated over time. I think the demonstration option was, for this reason, never really going to be on the table: it would have forced the American policymakers to come to terms with whether the atomic bomb was a weapon suitable for warfare on an earlier schedule than they were prepared to. As it was, their imagery, language, and deliberations are full of ambiguity on this. Sometimes they thought it would have new implications for “man’s position in the universe” (and other “special bomb” notions), sometimes they thought it was just an expedient form of firebombing with extra propaganda value because it would be very bright and colorful. Secrecy enabled them to hedge their bets on this question, for better or worse.

Without imagery like this, would the world fear nuclear weapons more, or less?

Without imagery like this, would the world fear nuclear weapons more, or less? When, if ever, would the first use of nuclear weapons in warfare have been?

So who was right? I don’t know. We can’t replay history to see what happened, obviously. I think the idea of a demonstration is an interesting expression of a certain type of ethical ideal, though it went so far against the practical desires of the military and political figures that it is hard to imagine any way it would have been pursued. I am not sure it would even have been successful, or resolved the moral bind of the atomic bomb.

I do find myself somewhat agreeing with those scientists who said that perhaps it was better to draw blood with the smaller, cruder bombs, before the really big ones came around — and they knew those were coming. If we didn’t have Hiroshima and Nagasaki, what would we point to, to talk about why not to use nuclear weapons? Would people think the bombs were not that impressive, or even more impressive than they were? I don’t know, but there is something to the notion that knowing the gritty, gruesome reality (and its limitations) is better than not. It took the Holocaust for the world to (mostly) renounce genocide, maybe it took Hiroshima and Nagasaki for the nuclear taboo to be established (arguably). That, perhaps, is the most hopeful argument here, the one that sees Hiroshima and Nagasaki as not just the first cities to be atomic bombed, but the last, but I am sure this is little solace to the people who were in those cities at the time.

Notes
  1. This was part of a larger set of recommendations these scientists made, including those which touched on the “Super” bomb, future governance of the atom, and other topics of great interest. Report of the Scientific Panel of the Interim Committee (16 June 1945), Harrison-Bundy Files Relating to the Development of the Atomic Bomb, 1942-1946, microfilm publication M1108 (Washington, D.C.: National Archives and Records Administration, 1980), Roll 6, Target 5, Folder 76, “Interim Comittee — Scientific Panel.” []
  2. Karl Darrow to Ernest Lawrence (9 August 1945), copy in Nuclear Testing Archive, NV0724362 [note the NTA has the wrong name and date on this in their database]; Ernest Lawrence to Karl Darrow (17 August 1945), copy in Nuclear Testing Archive,NV0724363. []
  3. On the composite core question, see J. Robert Oppenheimer to Leslie Groves (19 July 1945), copy in Nuclear Testing Archive, NV0311426; Leslie Groves to J. Robert Oppenheimer (19 July 1945), Correspondence (“Top Secret”) of the Manhattan Engineer District, Roll 1, Target 6, Folder 5B: “Directives, Memorandums, etc to and from Chief of Staff, Secretary of War, etc.” []
  4. To answer one other question that comes up: would such a demonstration create deadly fallout? Not if it was set to detonate high in the air, like at Hiroshima and Nagasaki. If it was detonated underwater the fallout would be mostly limited to the area around the bomb detonation itself. It would be hard to actually create a lot of fallout with a bomb detonated over water and not land, in any case. “Local fallout,” the acutely deadly kind, is caused in part by the mixing of heavier dirt and debris with the radioactive fireball, which causes the fission products to descend very rapidly, while they are still very “hot.” []
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Fears of a German dirty bomb

Friday, September 6th, 2013

For good reason, much has been made of the initial fear of a German atomic bomb. But there was another, lesser-known atomic fear as well. If the Germans could make nuclear reactors — which the Americans thought they were probably doing — could they not take the dangerously-radioactive spent-fuel out of them and use them to make dirty bombs? 

Hanford spent fuel rods — the sort of thing that could have been weaponized during World War II as a radiological weapon.

Hanford spent fuel rods — the sort of thing that could have been weaponized during World War II as a radiological weapon.

In the summer of 1942, Arthur Compton, head of the University of Chicago’s Metallurgical Laboratory, wrote a memo to Harvard President and atomic-bomb big-wig James B. Conant expressing the need for “protection against ionizing bombs”:

We have become convinced there is real danger of bombardment by the Germans within the next few months using bombs designed to spread radio-active materials in lethal quantities. … Since protection against the danger from such bombs will be primarily a matter of detection of radiation and instruction with regards to the dangers, it is essential that the matter be brought at once to the attention of the appropriate military officers.1

Compton and his scientists were, at the time, working under the assumption that the Germans were ahead of the Americans, and had already gotten a nuclear reactor running. They estimated that with a 100 kilowatt reactor, 100,000 Curies of radioactivity could be produced daily for bomb usage.

A radiation survey device of the sort produced during World War II by the Victoreen Instrument Company in Cleveland, in collaboration with the University of Chicago scientists.

A radiation survey device of the sort produced during World War II by the Victoreen Instrument Company in Cleveland, in collaboration with the University of Chicago scientists.

A result of this was that in the fall of 1942, the first steps were taken to, at a minimum, detect whether the Germans used any kind of radiological attack against the Allies. Survey meters were developed that would trigger alarms if they detected high levels of radioactivity. These were secretly dispersed to Manhattan District offices in Boston, Chicago, New York, San Francisco, and Washington, DC. At each location, a small number of officers were trained in their use. Further instruments were held in reserve in case they needed to be deployed further. If the alarms went off,  or if there were other suspicious signs (like reports of a large-scale blackening of photographic film), scientists at the University of Chicago were kept on the ready to be brought in to assess the situation.2

This was a fairly small program, as far as they go. Those involved were acutely aware that the secrecy of the atomic bomb made it impossible to adequately prepare for this possibility. They were stuck in a bind that was very common during the wartime period. The atomic bomb was, at that time, what I like to call an “absolute secret”: the fact that there was a “secret” at all was itself a secret. They could not draw attention to matters relating to atomic energy without drawing attention to the fact that they were engaged in a secret research program with regards to atomic energy. This is a very peculiar situation, one primarily specific to the war, when the secrecy of the project could not be acknowledged (they could not simply say, “oh, the details are secret,” as they could in the Cold War).

What did they think the Germans would do with such a radiological weapon? They considered four possibilities. First, it could be used as an “area-denial” weapon, by making areas uninhabitable. Second, it could be used to contaminate critical war infrastructure (e.g. airports). Third, it could be used as a “radioactive poison gas” to attack troops. Fourth, it could be used “against large cities, to promote panic, and create casualties among civilian populations.”3 Their assessment of the effects, by 1943, was grim:

Areas so contaminated by radioactive material would be dangerous until decay of the material took place, perhaps for weeks or months. … As a gas warfare instrument the material would be ground into particles of microscopic size to form dust and smoke and distributed by a ground-fired projectile, land vehicles, or aerial bombs.  In this form it would be inhaled by personnel.  The amount necessary to cause death to a person inhaling the material is extremely small.  It has been estimated that one millionth at a gram accumulating in a person’s body would be fatal.  There are no known methods of treatment for such a casualty.4

In the time-honored method of worrying about threats, they also then immediately realized that maybe the United States should be weaponizing fission products: “It is the recommendation of this Subcommittee that if military authorities feel that the United States should be ready to use radioactive weapons in case the enemy started it first, studies on the subject should be started immediately.” Note that this isn’t really a deterrent capability, it is a response capability. Deterrence requires your enemy knowing that you have the capability to respond, and secrecy precluded true deterrence.

1943 - Oppenheimer to Fermi

In this context, there is an interesting letter in the J. Robert Oppenheimer papers at the Library of Congress, where Oppenheimer is writing to Enrico Fermi in May 1943 on “the question of radioactively poisoned foods.” From the context, it is clear that both Edward Teller and Fermi had devoted time to this project. The full document is available here. Two parts stand out. One is that one of the acute problems in looking into the issue was, as Oppenheimer put it, difficult to study the subject “without telling anyone about it.” That is, it would be hard to investigate some of the substances in question “without letting a number of people into of the secret of why we want” the substances. The “absolute secret” bind again.

The other is Oppenheimer’s criteria for the project being worth looking into:

…I think that we should not attempt a plan unless we can poison food sufficient to kill a half a million men, since there is no doubt that the actual number affected will, because of non-uniform distribution, be much smaller than this.5

Frank Oppenheimer later called this a very “bloodthirsty” statement by his brother; the historian Barton Bernstein instead argued that this was just scientists trying to help the war effort.6 Either way, it makes Oppenheimer look like a very cold fish indeed. And not much of a “dove.” Even if one isn’t clear how much of a “non-uniform distribution” he was assuming.

1943 - Oppenheimer to Fermi - quote

The offensive angle was basically dropped — they didn’t think they’d need it, and they were focused intently on making the actual atomic bomb, a much more devastating weapon. But defensive measures did proceed. By late 1943, it was thought that the use of radioactive poisons against the UK by the Germans was of low probability, but an unpleasant possibility.7 To avoid being completely taken by surprise in such an event, General Groves (with the concurrence of General Marshall) had four officers from the European Theater of Operations staff briefed on the subject “under most complete secrecy,” and a Manual on Use of Radioactive Materials in Warfare was drawn up for these four officers. Signals officers were instructed to report any “peculiar or unexplained effects” on photographic films or personnel, and the officers in question were given radiation detection instruments to use in the case of suspected cases.

In March 1944, General Groves had the matter brought to the attention of General Dwight D. Eisenhower, commanding general of the Supreme Headquarters Allied Expeditionary Force, fearing that the Nazis might use such weapons to prevent an Allied invasion of Europe. Eisenhower concluded that since the Combined Chiefs of Staff had not brought up the issue, that they must consider that “the enemy will not implement this project.” To keep secrecy, in order to “to avoid a possible scare,” Eisenhower informed only a handful of people, which he acknowledged was not really enough to counter “enemy action of this nature”: “No US or British Commander participating in OVERLORD [the landing at Normandy] has been briefed.” However, radiation detectors were being kept in the UK for deployment on short notice, and a “cover” letter was sent out with symptoms of radiation poisoning listed as a “mild disease of unknown etiology” that was going around, requesting any medical officers to report further cases.8

Dry-run of using radiation detection equipment during a beach landing, as part of "Operation Peppermint." Source.

Team performing a dry-run of a beach landing with radiation detection equipment, as part of “Operation Peppermint.” Source.

The plan to deploy radiation monitoring during the D-Day invasions was dubbed “Operation Peppermint,” one of the more amusing code-names of the war. Dry runs of the detection apparatus were taken before D-Day, and German bomb craters were surveyed for radioactive residues, but since no evidence of German radiological weapons preparations or use were uncovered, the “Peppermint” preparations were never put into effect. 

We now know that the Germans never got anywhere near this kind of plan. They didn’t even get a reactor running by the end of the war, the necessary prerequisite for this kind of operation. It wasn’t a totally crazy fear, though. There are aspects of radiological warfare which would make it preferable to, say, chemical warfare from the German point of view. Still, there’s an aspect to this of the old saying, “when the only tool you have is a hammer, every problem looks like a nail.” When you’re studying radioactive hazards intently, every threat looks like a radioactive hazard.

The secrecy angle is what intrigues me the most about this story: the secrecy of the bomb made it difficult to enact serious preparation from this related, but separate threat. The secrecy of one fear made addressing another fear difficult, because the relevant information of both fears were too deeply entangled. 

Notes
  1. Arthur H. Compton to James B. Conant (15 July 1942), Bush-Conant file, Roll 7, Target 10, Folder 75, “Espionage.” []
  2. Manhattan District History, Book 1, Volume 14, Foreign Intelligence Supplement No. 2 (Peppermint), 31 July 1952. []
  3. Use of Radioactive Material as a Military Weapon” (n.d., c.a. early 1943). []
  4. Ibid. []
  5. J. Robert Oppenheimer to Enrico Fermi (25 May 1943), J. Robert Oppenheimer Papers, Library of Congress. []
  6. Barton J. Bernstein, “Oppenheimer and the Radioactive Poison Plan,” Technology Review, 88 (May-June 1985), 14-17. There is also some follow-up in Barton J. Bernstein, “Four physicists and the bomb: The early years, 1945-1950,” Historical Studies in the Physical and Biological Sciences, 18, No. 2 (1988), pp. 231-263, on 252-253. []
  7. Leslie Groves to George C. Marshall (30 November 1944), Manhattan Engineer District (MED) records, Records of the Army Corps of Engineers, RG 77, National Archives and Records Administration, Box 64, “Security.” []
  8. Dwight D. Eisenhower to George Marshall (11 May 1944), Correspondence (“Top Secret”) of the Manhattan Engineer District, 1942-1946, microfilm publication M1109 (Washington, D.C.: National Archives and Records Administration, 1980), Roll 5, Target 8, Folder 18, “Radiological Defense.” []
Meditations | News and Notes

Three losses

Friday, January 25th, 2013

There were three Manhattan Project losses that I heard about over the last week that I thought were worth briefly commenting on. They highlight, in different ways, how the living history of the Manhattan Project is rapidly vanishing.

Erwin Hiebert, 1972. From the Radcliffe Archives.

Erwin Hiebert, 1972. From the Radcliffe Archives.

Erwin Hiebert had worked as a chemist at the Chicago Metallurgical Laboratory. He passed away last November, though a notice was just recently sent around. I interviewed him a few years back, though not about his bomb work (connected with doing some local Harvard history). I believe I recall him telling me he had worked with Harold Urey on diffusion research. He later became an historian of science, and this was the capacity I knew him in. He was a charming old man, very helpful, very friendly. He wasn’t a major figure on the Manhattan Project, but it’s sometimes worth remembering how many people were involved in the project other than the main, well-known scientists and the thousands of construction workers or miscellaneous technicians. I recently had a chance to look up just how many people working at the Met Lab — we normally only hear about the 20 or so people who worked on the pile, but at its height, there were around 2,000 people working at Chicago on the bomb, with some 750 of them doing it in a scientific (as opposed to administrative or construction) capacity.

Assembling the Trinity device: Louis Slotin, Herb Lehr, and — I believe, at top right — Donald F. Hornig. It looks a lot like him, to me.

Assembling the Trinity “Gadget”: Louis Slotin, Herb Lehr, and — I believe, at top right — Donald F. Hornig (magnified). It looks a lot like him, to me, but I don’t have confirmation of this. The “Gadget” is at far left, of course; on top of the box next to it is the container with its plutonium core.

Donald F. Hornig also recently passed away. He worked at Los Alamos during the war, and was heavily involved in the instrumentation work that was required for the implosion bomb. He was credited as the inventor of the triggered spark-gap switch (a “low-impedance switch”), which was the switch necessary to divert a high-voltage signal to the 32 detonators on the “Gadget” with a simultaneity tolerance of only nanoseconds. (A patent application for this switch had been filed in his name in late 1945; it was declassified and granted in 1976. Hornig told me he had no awareness of it being filed or granted when I talked to him a few years back.) He was also one of the last people in the “Trinity” tower before its detonation, checking the electrical connections, which proved to be a somewhat hair-raising experience. He describes his work at “Trinity” in some detail here. It’s worth a read:

I think I was the last person down from the tower although there might be a little bit of argument about that. I won’t go into any detail, but Oppenheimer had gotten worried about nine o’clock the night before about how easy the thing was to sabotage by anyone who really knew anything about it, and so I believe it was Kistiakowsky, Bainbridge and I who each took a turn sitting with it up on the tower. My turn came from around nine o’clock until midnight, in the midst of a violent thunder and lightning storm. You get philosophical in those circumstances. You know, either you do get hit by lightning or you don’t and either way you won’t know what happens.

He had many later achievements, including being LBJ’s science advisor.

The Oak Ridge K-25 plant in 1945.

The Oak Ridge K-25 plant in 1945.

Lastly, the K-25 plant has been completely destroyed. The Oak Ridge facility, which had been used during and after World War II to enrich uranium via the gaseous diffusion method, was the largest factory under one roof at the time it was constructed. It had been long since shut down, and, a few years back, all but one “cell” of its building had been destroyed. A number of people had been trying to keep the cell preserved as an historic site, but it came to naught. It took only 20 minutes to permanently knock down the last piece of it, the last indication of the scale of this site.

I think this is really too bad — a completely missed opportunity. I know that there are people who have mixed feelings about preserving the Manhattan Project sites — they think that they will be used as excuses to glorify the atomic bomb. I think this is entirely misguided. These sites are ambiguous and they provoke different reactions from different people. By analogy, there can be controversy over how the Enola Gay should be presented to the public, but the answer is not to melt the Enola Gay into scrap. Destroying these sorts of legacies is a permanent act, whereas the act of interpretation is an always changing one. Erasing history is not the right response to the fact that we still disagree over it. Destroying the sites where the atomic bomb was made will not change the fact that we made the atomic bomb.

The last generation of people who worked on the first atomic bombs is passing away. The bomb still exists. We should be doing more to preserve these sites, even if they make us uncomfortable, even if we are unsure how they will be used by people in the present or the future.