Posts Tagged ‘1940s’

Meditations

Hiroshima and Nagasaki at 70

Friday, August 21st, 2015

This month marked the 70th anniversary of the atomic bombings of Hiroshima and Nagasaki, and the cessation of hostilities in World War II. Anniversaries are interesting times to test the cultural waters, to see how events get remembered and talked about. I was exceptionally busy this summer, doing my part to try to participate in the discourse about these events. In case you missed them and wished you had not, here are a few of my appearances:

I also published a second blog post with the New Yorker on the often-overlooked second use of the atomic bomb: “Nagasaki: The Last Bomb.” I am proud of it as a piece of writing, as I was really trying to pull off something deliberate and subtle with it, and feel that I somewhat accomplished that.

New Yorker - Nagasaki - The Last Bomb

On this latter piece, I would also like to say that very little of what I wrote would come as a surprise to historians, though the particular arrangement of Nagasaki-as-JANCFU (that is, with an emphasis on the less-than-textbook aspects of the operation, as a herald of the later chaotic possibilities of the nuclear age) is usually under-emphasized. We tend to lump Hiroshima and Nagasaki together when we talking about the atomic bombings during World War II, and I think they should probably be separated out a bit in terms of how we regard them. The first use of the bomb, at Hiroshima, was in many ways a very straightforward affair, both in terms of the strategic and ethical considerations, and the tactical operation. Whether one agrees with the strategic and ethical considerations is a separate matter, of course, but a lot of thought went into Hiroshima as a target, and into the first use of the bomb. Nagasaki, by contrast, was less straightforward on all counts — less thought-out, less justified, and was very nearly a tactical blunder. For me, it reflects on the very real dangers that can occur when human judgment gets mixed with the extremely high stakes that come with weapons as powerful as these. Any bomber crew can have a mishap of a mission, but when that mission is nuclear-armed, the potential consequences multiply.

The one notable exception to the “very little would come as a surprise to historians” bit in this piece is that Nagasaki was never put on the “reserved” list. For whatever reason, the idea that both Hiroshima and Nagasaki were “reserved” from conventional bombing is very commonly repeated, but it is just not true. The final “reserved” list contained only Kyoto, Hiroshima, Kokura, and Niigata. Aside from the fact that no documentation exists of Nagasaki being put on the list (whereas we do have such documentation for the others), we also have the documentation actively rescinding the “reserved” status for Hiroshima, Kokura, and Niigata, so that they could become formal atomic targets.1

Detail from a damage map of Nagasaki, produced by the United States Strategic Bombing Survey, 1946. I have the original of this in my possession. I find this particular piece of the map quite valuable to examine up close — one gets a sense of the nature of the area around "Ground Zero" very acutely when examining it. There were war plants to the north and south of the detonation point, but mostly the labeled structures are explicitly, painfully civilian (schools, hospitals, prisons). Click to enlarge.

Detail from a damage map of Nagasaki, produced by the United States Strategic Bombing Survey, 1946. I have the original of this in my possession. I find this particular piece of the map quite valuable to examine up close — one gets a sense of the nature of the area around “Ground Zero” very acutely when examining it. There were war plants to the north and south of the detonation point, but mostly the labeled structures are explicitly, painfully civilian (schools, hospitals, prisons). Click to enlarge. Here is a not-great photo of the whole map, to compare it with, and here is a detail of the legend. At some point, when finances allow, I will get this framed for my office, but it is quite large and not a cheap endeavor.

John Coster-Mullen’s book provided a lot of documents and details about the bombing run. One thing I appreciate about John is his dedication to documentation, even though his views on the meaning of the history are not always the same as mine. I thoroughly believe that rational people can look at the same facts and come up with different narratives and interpretations — the trick, of course, is to make sure you are at least getting the facts right.2

It would be interesting at some point for someone to do a scholarly analysis of the popular discourse surrounding each decade of anniversaries since the bombs were dropped. 1955 was a fairly raw time, right after McCarthyism had peaked and the hydrogen bomb had been developed. 1965 marked an outpouring of new books and revelations from those involved in the bomb project, enabled by new declassifications (allowed, in part, because of the fostering of a civilian nuclear industry) and the fact that some of the major participants (like Groves) were still alive. I have no distinct impressions of 1975 being a major anniversary year, but 1985 resulted in a lot of hand-wringing about the relationship between the birth of the nuclear age and the nuclear fears of the 1980s. 1995, of course, was the first post-Cold War anniversary and one of the “hottest” years of controversy, catalyzing around the Smithsonian’s Enola Gay exhibit controversy and the “culture wars” of the mid-Clinton administration. We are still dealing with the hyper-polarization of the narratives of the atomic bombings that became really prominent in the mid-1990s — where there were only two options available, an orthodox/reactionary view or a critical/revisionist view. The 2005 anniversary did not make a large impression on me at the time, and seemed muted in comparison with 1995 (perhaps a good thing), except for the fact that some very noteworthy scholarship made its appearance to coincide with it.

A small sampling of some of the international press coverage of the NUKEMAP around the Hiroshima anniversary.

A small sampling of some of the international press coverage of the NUKEMAP around the Hiroshima anniversary.

And what of 2015? There were, of course, many stories about the bombings. Nagasaki got a better representation in the discourse than usual, in no small part because Susan Southard’s Nagasaki: Life After Nuclear War received heavy promotion. (I have not read it yet.) The general discussion seemed less polarized than they have been, though I did see a fair share of hand-wringing and defending editorials pop up on my Google Alerts feed. I have speculated that I think anniversaries from this point forward will be somewhat more interesting and reflective than those in the recent past, in part because of the declining influence of American World War II veterans, who were such a strong force in the more recent ones. My (perhaps overly idealistic) hope is that our narratives of the bombings can settle into something more historically informed, more quietly reflective, and less keyed to contemporary politics than in the past.

For my part, I was impressed by the number of people online who were interested in re-creating Hiroshima on their hometowns. The featuring of NUKEMAP on the Washington Post’s Wonkblog drove an incredible amount of traffic to the site. It was one of those stories that could be essentially lifted and re-written to fit a wide variety of different cities or countries, and there were variations of the “What would happen if Hiroshima happened here?” written in dozens of languages over the days leading up to and beyond the anniversary. The result is that NUKEMAP’s traffic had an all-time high spike over 300,000 people on August 6. The traffic is a typical long-tail distribution, so in the week of August 5-12, there were well over 1 million pageviews for the NUKEMAP. There have been other spikes in the past, but none quite as big as this one.

Locations where the Little Boy bomb was "dropped," August 5-12, 2015. These are unweighted (each dot represents an indeterminate number of detonations). Here is a heatmap (capped at 1,000 detonations — the actual cap is 28,116 — to make it easier to see the broader spread) showing where repeat detonations occurred. Here is a version where I have thrown out all locations where fewer than 10 detonations took place, and scaled their size and color by repetition. Total detonations is 266,483.

Locations where the Little Boy bomb was “dropped,” August 5-12, 2015. These are unweighted (each dot represents an indeterminate number of detonations). Here is a heatmap (capped at 1,000 detonations — the actual cap is 28,116 — to make it easier to see the broader spread) showing where repeat detonations occurred. Here is a version where I have thrown out all locations where fewer than 10 detonations took place, and scaled their size and color by repetition. Total detonations is 266,483.

Where do people nuke, when they recreate Hiroshima? Well, all over the world, not surprisingly, though the biggest single draws are New York (which is a NUKEMAP default if it cannot figure out where you probably live) and Hiroshima itself (re-creating the actual bombing). I’ve exported the log data for people using the Little Boy bomb setting (15 kiloton airbursts) for the week of August 5-12, and the maps are shown and linked to above. Obviously it correlates very heavily with both population and Internet access, but still, it is interesting.

Lastly, a week after the anniversary, what more reflection is there to be had? A new poll came out in late July of a thousand Americans, asking them what they thought about the bombings. Overall, 46% of those polled thought that the dropping of the bombs on Japan was the “right decision” to do, while 29% thought it was the “wrong decision,” and 26% said they were “not sure.” Which one can interpret in a number of ways. The feelings appear to correlate directly with age — the older you are, the more likely you think it was “right,” and the younger, with “wrong.” It also correlates with a few other factors, notably political affiliation (Republicans strongly in favor, Democrats and Independents not so much), race/ethnicity, and income. I suspect all of these variables (age, political affiliation, race/ethnicity, and income) to be pretty highly correlated in general. Separately, the gender gap is pretty extreme — men defend the bombings by a very large margin compared to women.

The head of the Nagasaki mushroom cloud — like a monstrous brain.

The head of the Nagasaki mushroom cloud — like a monstrous brain. Source: National Archives/Fold3.com.

None of this is extremely surprising, I don’t think. But I was taken aback by another question in the same poll, a strictly factual one: “Which country was the first country to build a nuclear weapon?” Only 57% of the total polled correctly identified the United States, and it gets very depressing when one looks at how this breaks down by age. Less than half of Americans under the age of 45 could correctly identify that their country was the first country to develop nuclear weapons. I don’t really mind if a lot of people can’t identify when the first weapons were used (another question in the poll); exact years can be hard for people, especially on the spot, and the differences between the options given were not so vast that they represent much, in my view. But 23% were “not sure” who made the first bomb, 15% thought it was the USSR, and 3% thought it was China! (Almost nobody, alas, thought it was France.) This is not a minor factual error — it is a fundamental lack of knowledge about the historical composition of the world. It reflects, I suspect, the waning attention given to nuclear issues in the post-Cold War.

One last reflection: How do I, a historian of these matters, find myself thinking about Hiroshima and Nagasaki these days? Increasingly I find myself uninterested in the question of whether they were “justified” or not, which contain so much predictable posturing, the same old arguments, with very few new facts or analyses. I think the bombings were a very muddy affair from an ethical, strategic, and historical perspective, and I don’t think they fit into any simplistic view of them. I’ve come to feel my position on these could be described as an “inverse moderate,” where a moderate seeks to make everyone feel comfortable, but my goal is to make everyone feel uncomfortable. If you think this history supports some easy, straightforward interpretation, you are probably throwing out a lot of the data and filling it in with what you’d like to believe. It is complex history; it does not boil down easily.

Notes
  1. See Potsdam cable WAR 37683, July 24, 1945, copy in the Harrison-Bundy files, Roll 10, Target 10, Folder 64, “Interim Committee — Potsdam Cables.” []
  2. And, of course, I am not so naive to believe that “getting the facts right” is a simple or straightforward process. Indeed, contextualization of documents is a large part of understanding what the “facts” often are, and that requires narrative and interpretation, and so we end up in a somewhat circular epistemological loop. But there is a difference between people outright getting them wrong and people who are at least trying to get them right. I have been frustrated to see the number of people who still claim that the US warned the Japanese before the atomic bombings, a myth perpetuated in no small part due to shoddy citation by archivists at the Truman Library on their website. []
Meditations

Were there alternatives to the atomic bombings?

Monday, August 3rd, 2015

As we rapidly approach the 70th anniversary of the bombings of Hiroshima and Nagasaki, there have been all sorts of articles, tributes, memorials, and so forth expressed both in print and online. I’ve been busy myself with some of this sort of thing. I was asked if I would write up a short piece for Aeon Ideas about whether there were any alternatives to these bombings, and I figure it won’t hurt to cross-post it here as well.

Unusual photograph of the late cloud of Hiroshima, as seen from the air. This was probably taken by aircraft that arrived several hours after the bombing to do damage reconnaissance; they reported the target was obscured by huge amounts of smoke. Source: National Archives and Records Administration, via Fold3.com.

An unusual photograph of the late clouds of Hiroshima, as seen from the air. This was probably taken by aircraft that arrived several hours after the bombing to do damage reconnaissance; they reported the target was obscured by huge amounts of smoke. Source: National Archives and Records Administration, via Fold3.com.

The point of the piece, I would like to emphasize, is not necessarily to “second guess” what was done in 1945. It is, rather, to point out that we tend to constrain our view of the possibilities generally to one of two unpleasant options. Many of those who defend the bombings seem to end up in a position of believing that 1. there were no other options on the table at the time except for exactly what did occur, and 2. that questioning whether there were other options does historical damage. As a historian, I find both of these positions absurd. First, history is full of contingency, and there were several explicit options (and a few implicit ones) on the table in 1945 — more than just “bomb” versus “invade.” These other options did not carry the day does not mean they should be ignored. Second, I think that pointing out these options helps shape our understanding of the choices that were made, because they make history seem less like a fatalistic march of events. The idea that things were “fated” to happen the way they do does much more damage to the understanding of history, because it denies human influence and it denies choices were made.

Separately, there is a question of whether we ought to “judge” the past by standards of the present. In some cases this leads to statements that are simply non-sequiturs — I think Genghis Khan’s methods were inhumane, but who cares that I think that? But World War II was not so long ago that its participants are of another culture entirely, and those who say we should not judge the atomic bombings by the morality of the present neglect the range of moral codes that were available at the time. The idea that burning civilians alive created a moral hazard was hardly unfamiliar to people in 1945, even if they did it anyway. Similarly, I will note that the people who adopt such a position of historical moral relativism never seem to apply it to nations that fought against their countries in war.

Anyway, all of the above is meant as a disclaimer, in case anyone wonders what my intent is here. It is not to argue that the leaders of 1945 necessarily ought to have done anything different than they did. It is merely to try and paint a picture of what sorts of possibilities were on the table, but were not pursued, and to try and hack away a little bit at the false dichotomy that so often characterizes this discussion — a dichotomy, I might note, that was started explicitly as a propaganda effort by the people who made the bomb and wanted to justify it against mounting criticism in the postwar. I believe that rational people can disagree on the bombings of Hiroshima and Nagasaki.


What options were there for the United States regarding the atomic bomb in 1945?

Few historical events have been simultaneously second-guessed and vigorously defended as the atomic bombings of Hiroshima and Nagasaki, which occurred seventy years ago this August. To question the bombings, one must assume an implicit alternative history is possible. Those who defend the bombings always invoke the alternative of a full-scale invasion of the Japanese homeland, Operation Downfall, which would have undoubtedly caused many American and Japanese casualties. The numbers are debatable, but estimates range from the hundreds of thousands to the millions — an unpalatable option, to be sure.

These unusual before-and-after images come from the Report of the Joint Commission for the Investigation of the Effects of the Atomic Bomb on Japan, Volume I, "Medical Effects of Atomic Bombs," NP-3036 (April 1951). I apologize for the poor image quality. I thought that even so they provide striking contrasts, and are much more easy to grasp that the familiar "view from above" photographs. This one is of the Hiroshima Commercial Museum, only 300 m from ground zero, and now known as the famous "Genbaku dome."

These unusual before-and-after images come from the Report of the Joint Commission for the Investigation of the Effects of the Atomic Bomb on Japan, Volume I, “Medical Effects of Atomic Bombs,” NP-3036 (April 1951). I apologize for the poor image quality. I thought that even so they provide striking contrasts, and are much more easy to grasp that the familiar “view from above” photographs. This one is of the Hiroshima Commercial Museum, only 300 meters from Ground Zero, and now known as the famous “Genbaku dome.” The photographs are not labeled with when they were taken; the “before” photos seem like they are from the late 1930s, the “after” photos are likely no earlier than September 1945, and may be from 1946.

But is this stark alternative the only one? That is, are the only two possible historical options available a bloody invasion of the Japanese home islands, or the dropping of two nuclear weapons on mostly-civilian cities within three days of one another, on the specific days that they were dropped? Well, not exactly. We cannot replay the past as if it were a computer simulation, and to impose present-day visions of alternatives on the past does little good. But part of the job of being a historian is to understand the variables that were in the air at the time — the choices, decisions, and serendipity that add up to what we call “historical contingency,” the places where history could have gone a different direction. To contemplate contingency is not necessarily to criticize the past, but it does seek to remove some of the “set in stone” quality of the stories we often tell about the bomb.

Varying the schedule. The military order that authorized the atomic bombings, sent out on July 25, 1945, was not specific as to the timing, other than saying that the “first special bomb” could be dropped “as soon as weather will permit visual bombing after about 3 August 1945.” Any other available bombs could be used “as soon as made ready by the project staff.” The Hiroshima mission was delayed until August 6th because of weather conditions in Japan. The Kokura mission (which became the Nagasaki mission) was originally scheduled for August 11th, but got pushed up to August 9th because it was feared that further bad weather was coming. At the very least, waiting more than three days after Hiroshima might have been humane. Three days was barely enough time for the Japanese high command to verify that the weapon used was a nuclear bomb, much less assess its impact and make strategic sense of it. Doing so may have avoided the need for the second bombing run altogether. Even if the Japanese had not surrendered, the option for using further bombs would not have gone away. President Truman himself seems to have been surprised by the rapidity with which the second bomb was dropped, issuing an order to halt further atomic bombing without his express permission.

"Komiya street (750 meters [from Ground Zero] before and after bombing. The archlike heavy lamp posts have fallen. One lies at the left of the lower photograph."

“Komiya street (750 meters [from Ground Zero] before and after bombing. The archlike heavy lamp posts have fallen. One lies at the left of the lower photograph.”

Demonstration. Two months before Hiroshima, scientists at the University of Chicago Metallurgical Laboratory, one of the key Manhattan Project facilities, authored a report arguing that the first use of an atomic bomb should not be on an inhabited city. The committee, chaired by Nobel laureate and German exile James Franck, argued that a warning, or demonstration, of the bomb on, say, a barren island, would be a worthwhile endeavor. If the Japanese still refused to surrender, then the further use of the weapon, and its further responsibility, could be considered by an informed world community. Another attractive possibility for a demonstration could be the center of Tokyo Bay, which would be visible from the Imperial Palace but have a minimum of casualties if made to detonate high in the air. Leo Szilard, a scientist who had helped launch the bomb effort, circulated a petition signed by dozens of Manhattan Project scientists arguing for such an approach. It was considered as high as the Secretary of War, but never passed on to President Truman. J. Robert Oppenheimer, joined by three Nobel laureates who worked on the bomb, issued a report, 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.” But was it feasible? More so than most people realize. Though the US only had two atomic bombs in early August 1945, they had set up a pipeline to produce many more, and by the end of the month would have at least one more bomb ready to use, and three or four more in September. The invasion of the Japanese mainland was not scheduled until November. So by pushing back the time schedule, the US could have still had at least as many nuclear weapons to use against military targets should the demonstration had failed. The strategy of the bomb would have changed — it would have lost some of its element of “surprise” — but, at least for the Franck Report authors, that would be entirely the point.

Changing the targets. The city of Hiroshima was chosen as a first target for the atomic bomb because it had not yet been bombed during the war (and in fact had been “preserved” from conventional bombing so that it could be atomic bombed), because the scientific and military advisors wanted to emphasize the power of the bomb. By using it on an ostensibly “military” target (they used scare quotes themselves!), “located in a much larger area subject to blast damage,” they hoped both to avoid looking bad if the bombing was somewhat off-target (as the Nagasaki bombing was), and so that the debut of the atomic bomb was “sufficiently spectacular” that its importance would be recognized not only by the Japanese, but the world at large. But the initial target for the bomb, discussed in 1943 (long before it was ready) was the island of Chuuk (now called Truk), an ostensibly purely military target, the Japanese equivalent of Pearl Harbor. By 1945, Chuuk had been made irrelevant, and much of Japan had already been destroyed by conventional bombing, but there were other targets that would not have been so deliberately destructive of civilian lives. As with the “demonstration,” option had the effect not been as desired, escalation was always available as a future option, rather than as the first step.

"Prefectural Office (900 meters [from Ground Zero]) before and after the bombing. The wooden structure has collapsed and burned. Note displacement of the heavy granite blocks of the wall."

“Prefectural Office (900 meters [from Ground Zero]) before and after the bombing. The wooden structure has collapsed and burned. Note displacement of the heavy granite blocks of the wall.”

Clarifying the Potsdam Declaration. By the summer of 1945, a substantial number of the Japanese high command, including the Emperor, were looking for a diplomatic way out of the war. Their problem was that the Allies had, with the Potsdam Declaration, continued to demand “unconditional surrender,” and emphasized the need to remove “obstacles” preventing the “democratic tendencies” of the Japanese people. What did this mean, for the postwar Japanese government? To many in the high command, this sounded a lot like getting rid of the Imperial system, and the Emperor, altogether, possibly prosecuting him as a “war criminal.” For the Japanese leaders, one could no more get rid of the Emperor system and still be “Japan” than one could get rid of the US Constitution and still be “the United States of America.” During the summer, those who constituted the “Peace Party” of the high council (as opposed to the die-hard militarists, who still held a slight majority) sent out feelers to the then still-neutral Soviet Union to serve as possible mediators with the United States, hopefully negotiating an end-of-war situation that would give some guarantees as to the Emperor’s position. The Soviets rebuffed these advances (because they had already secretly agreed to enter the war on the side of the Allies), but the Americans were aware of these efforts, and Japanese attitudes towards the Emperor, because they had cracked the Japanese diplomatic code. No lesser figures than Winston Churchill and the US Secretary of War, Henry Stimson, had appealed to President Truman to clarify that the Emperor would be allowed to stay on board in a symbolic role. Truman rebuffed them, at the encouragement of his Secretary of State, James Byrnes, believing, it seems, that the perfidy of Pearl Harbor required them to grovel. It isn’t clear, of course, that this would have changed the lack of a Japanese response to the Potsdam Declaration. Even after the atomic bombings, the Japanese still tried to get clarification on the postwar role of the Emperor, dragging out hostilities another week. In the end, the Japanese did get to keep a largely-symbolic Emperor, but this was not finalized until the Occupation of Japan.

Waiting for the Soviets. The planned US invasion of the Japanese homeland, Operation Downfall, was not scheduled to take place until early November 1945. So, in principle, there was no great rush to drop the bombs in early August. The Americans knew that the Soviet Union had, at their earlier encouragement, agreed to renounce their Neutrality Pact with the Japanese and declare war, invading first through Manchuria. Stalin indicated to Truman this would happen around August 15th, to which Truman noted in his diary, “Fini Japs when that comes about.” Aside from cutting Japan off from its last bastion of resources, the notion of possibly being divided into distinct Allied zones of influence, as had been Germany, would possibly be more of a direct existential threat than any damage the Americans would inflict. And, in fact, we do now know that the Soviet invasion may have weighed as heavily on the Japanese high command as did the atomic bombings, if not more so. So why didn’t Truman wait? The official reason given after the fact was that any delay whatsoever would be interpreted as wasting time, and American lives, once the atomic bomb was available. But it may also have been because Truman, and especially his Secretary of State, Byrnes, may have hoped that the war might have ended before the Soviets had entered. The Soviets had been promised several concessions, including the island of Sakhalin and the Kuril Islands (giving them unimpeded access to the Pacific Ocean) for their entry in the war, but by late July 1945, the Americans were having second thoughts. As it was, once Stalin saw that Hiroshima did not provoke an immediate response from the Japanese, he had his marshals accelerate the invasion plans, invading Manchuria just after midnight, the morning of the Nagasaki bombing.

I find this one to be one of the most haunting — by filling in the missing structures, it contextualizes all of the "standard" Hiroshima photos of the rubble-filled wasteland.  "Rear view of Geibi and Sumitomo Buildings before and after bombing. Taken from Fukuya Department Store (700 meters [from Ground Zero]) looking toward center. Complete destruction of wooden buildings by blast and fire. Concrete structures stand." In other places in the text, they usually point out that where you see a concrete structure like this, it has withstood the blast but was gutted by the fire.

I find this one to be one of the most haunting — by filling in the missing structures, it contextualizes all of the “standard” Hiroshima photos of the rubble-filled wasteland.
“Rear view of Geibi and Sumitomo Buildings before and after bombing. Taken from Fukuya Department Store (700 meters [from Ground Zero]) looking toward center. Complete destruction of wooden buildings by blast and fire. Concrete structures stand.” In other places in the text, they usually point out that where you see a concrete structure like this, it has withstood the blast but was gutted by the fire.

What should we make of these “alternatives”? Not, necessarily, that those in the past should have been clairvoyant. Or that their concerns were ours: like it or not, those involved in these choices certainly ranked Japanese civilian lives lower than those of American soldiers, as is typical in war. None of the “alternatives” come with any confidence, even today, much less for those at the time, and those making the choices were working with the requirements, uncertainties, and biases inherent to their historical and political positions.

But by pointing out the alternatives that were on the table, one can see the areas of choice and discretion, the different directions that history might have gone — perhaps for better, perhaps for worse. We should see this history less as a static set of “inevitable” events, or of “easy” choices, but as a more subtle collection of options, motivations, and possible outcomes.

Visions

Trinity at 70: “Now we are all sons of bitches.”

Friday, July 17th, 2015

A quick dispatch from the road: I have been traveling this week, first to Washington, DC, and now in New Mexico, where I am posting this from. Highlights in Washington included giving a talk on nuclear history (what it was, why it was important) to a crowd of mostly-millennial, aspiring policy wonks at the State Department’s 2015 “Generation Prague” conference. A few hours after that was completed, an article I wrote on the Trinity test went online on the New Yorker’s “Elements” science blog: “The First Light of Trinity.”

The First light of Trinity

Being able to write something for them has been a real capstone to the summer for me. It was a lot of work, in terms of the writing, the editing, and the fact-checking processes. But it is really a nice piece for it. I am incredibly grateful to the editor and fact-checker who worked with me on it, and gave me the opportunity to publish it. Something to check off the bucket list.

On the plane to New Mexico, I thought over what the 70th anniversary of Trinity really meant to me. I keep coming back to the post-detonation quote of Kenneth Bainbridge, the director of the Trinity project: “Now we are all sons of bitches.” It is often put in contrast with J. Robert Oppenheimer’s more grandiose, more cryptic, “Now I am become death, destroyer of worlds.” Oppenheimer clearly didn’t say this at the time of test explosion, and its meaning is often misunderstood. But Bainbridge’s quote is somewhat cryptic and easy to misunderstand as well.

The badge photograph of Kenneth Bainbridge, director of the Trinity project. From a photo essay I wrote for the Bulletin of the Atomic Scientists two years ago.

The Los Alamos badge photograph of Kenneth Bainbridge, director of the Trinity project. From a photo essay I wrote for the Bulletin of the Atomic Scientists two years ago.

Bainbridge’s quote first got a lot of exposure when it was published as part of Lansing Lamont’s 1965 book, Day of Trinity, timed for the 20th anniversary of Trinity. Lamont interviewed many of the project participants who were still alive. The book contains many errors, which many of them lamented. (The best single book on Trinity, as an aside, is Ferenc Szasz’s 1984, The Day the Sun Rose Twice, by a considerable margin.) A consequence of these errors is that a lot of the scientists interviewed wrote letters to each other to complain about them, which means they also clarified some quotes of theirs in the book. Bainbridge in particular has a number of letters related to mixed up quotes, mixed up content, and mixed up facts from the Lamont book in his personal papers kept at the Harvard University Archives, which I looked at several years back.

One of the people Bainbridge wrote to was Oppenheimer. He said he wanted to explain his “Now we are all sons of bitches” quote, to make sure Oppenheimer understood he was not trying to be offensive:

The reasons for my statement were complex but two predominated. I was saying in effect that we had all worked hard to complete a weapon which would shorten the war but posterity would not consider that phase of it and would judge the effort as the creation of an unspeakable weapon by unfeeling people. I was also saying that the weapon was terrible and those who contributed to its development must share in any condemnation of it. Those who object to the language certainly could not have lived at Trinity for any length of time.

Oppenheimer wrote back, in a letter dated 1966, just a year before his death, when he was pretty sick and in a lot of pain. It said:

When Lamont’s book on Trinity came, I first showed it to Kitty; and a moment later I heard her in the most unseemly laughter. She had found the preposterous piece about the ‘obscure lines from a sonnet of Baudelaire.’ But despite this, and all else that was wrong with it, the book was worth something to me because it recalled your words. I had not remembered them, but I did and do recall them. We do not have to explain them to anyone.1

I like Bainbridge’s explanation, because it doubles back on itself: people will think we were unfeeling and terrible for making this weapon, which makes it sound like the people are not understanding, but, actually, yes, the weapon was terrible. I think you can get away with that kind of blanket condemnation if you’re one of the people instrumental in its creation.

The original map of fallout from the Trinity test. There are several more "hot spots" to the South and West than are in the later more simplified drawings of it. Click to see the entire map at full resolution.

The original map of fallout from the Trinity test. There are several more “hot spots” to the South and West than are in the later more simplified drawings of it. Click the image to see the entire map at full resolution.

I have been thinking about how broadly one might want to expand the “we” in his quote. Just those at the Trinity test? Those scientists who made the bombs possible? All of the half-million involved in making the bomb, whether they knew their role or not? The United States government and population, from Roosevelt on down? The Germans, the fear of whom inspired its initial creation? The world as a whole in the 1940s? Humanity as a whole, ever?

Are we all sons of bitches, because we, as a species of sentient, intelligent, brilliant creatures have created such terrible means of doing violence to ourselves, to the extremes of potential extinction?

This is probably not what Bainbridge meant, but it is an interesting road to go down. It recalls the recent discussions about whether we live in a new era of time, the Anthropocene, and whether the Trinity test should be seen as the marker of its beginning,

Notes
  1. Regarding Baudelaire, supposedly, according to Lamont, this was going to be the code that Oppenheimer used to tell Kitty that the test was a success: “If the test succeeded, he would send her a brief message, an obscure line from a sonnet by Baudelaire: ‘You can change the sheets.'” []
Meditations

What remains of the Manhattan Project

Friday, June 12th, 2015

What remains of the Manhattan Project? A lot of documents. Some people. A few places. And a handful of artifacts. Maybe less than one might expect, maybe more than one might expect — it was a very large, expensive undertaking, involving a lot of people, so there being some remnants is not surprising. Though given its size, and importance, perhaps one would expect more.

Some of the attending Manhattan Project veterans. Photo by Alex Levy of the Atomic Heritage Foundation.

Some of the attending Manhattan Project veterans. Photo by Alex Levy of the Atomic Heritage Foundation.

The symposium put on by the Atomic Heritage Foundation last week was really excellent — a really important event. The attendance was higher than I would have guessed. At least a dozen Manhattan Project veterans attended, and many children of Manhattan Project veterans (some of whom were born during the war) were there as well. There were also a lot of nuclear historians, scientists, and enthusiasts. I got to spend time talking with a lot of wonderful people who also cared a lot about, and took very seriously, the history of the atomic bomb. Among those who were there included Richard Rhodes (Pulitzer-winning author of The Making of the Atomic Bomb), Stan Norris (biographer of Leslie Groves), Kai Bird and Martin Sherwin (Pulitzer-winning authors of American Prometheus), John Coster-Mullen (major irritant to government censors and author of Atom Bombs), Avner Cohen (author of many books on Israel and the bomb), Ray Smith (the historian at Y-12), and Clay Perkins (physicist and nuclear “collector”), just to name a few. I saw some of my DC friends and former colleagues, and met a lot of nuclear history enthusiasts. All together, it looked like there was well over two hundred people between the two days of it.

There were several themes to the whole event. One was the creation of the Manhattan Project National Historic Park. There were representatives from both the National Park Service and the Department of Energy to talk about the process going forward, and there was also an excellent address by Senator Martin Heinrich of New Mexico.

Richard Rhodes gave the first address of Wednesday by talking about why we save authentic relics of the past. He took a tack I wouldn’t have expected — he started off from the work of the philosopher John Searle on “social reality,” the sorts of facts that exist only by mutual agreement. “When we lose parts of our physical past, we lose part of our social past as well.” Our preference for the originals of things, the “authentic” objects, isn’t just about sentiment, he argued — it is part of what defines us. (And if you don’t believe physical things define you, try losing a wedding ring, or an irreplaceable album of old photographs.) Preserving public memories, spaces of our past, whether positive or negative, help us come to terms with who we are, and what we have done. And he made the point, quite effectively, that we do not just preserve the sites that glorify us — Ford’s Theatre, Manzanar, and the Sand Creek massacre site are all National Historic Sites as well.

Battle deaths in state-based conflicts, 1946-2013, by Max Roser. This is what Rhodes had in mind regarding the decreased amount of deaths from war since World War II. (Note that if WWII was included in this, it would be even more stark: the rate of battle deaths per 100,000 of global population was 300 for the war as a whole.) There are a lot of ways to parse these numbers, as Roser's site makes clear (the raw numbers of wars has been increasing, some of this decline as a unit of population is due to the massive increase in global population), and there are multiple interpretations of the data (whether the bomb has anything to do with it is disputed by scholars), but it is still very interesting. Source: Max Roser, "War and Peace after 1945," OurWorldInData.org

Battle deaths in state-based conflicts, 1946-2013, by Max Roser. This is what Rhodes had in mind regarding the decreased amount of deaths from war since World War II. (Note that WWII’s rate of battle deaths was around 300 per 100,000.) There are a lot of ways to parse these numbers, as Roser’s site makes clear (the raw numbers of wars has been increasing, some of this decline as a unit of population is due to the massive increase in global population), and there are multiple interpretations of the data (whether the bomb has anything to do with it is disputed by scholars), but it is still very interesting. Source: Max Roser, “War and Peace after 1945,” OurWorldInData.org.

Rhodes is no fan of nuclear weapons, and doesn’t believe that the atomic bombs were what caused Japan to surrender in World War II.1 Yet, he argued that when J. Robert Oppenheimer told his recruits that these weapons might end all war, he might not have been wrong. Rhodes noted the marked decrease of deaths by war in the years that followed World War II, paired with the increased risk of a terrible nuclear holocaust. Nuclear weapons, he argued, were the first instance in which science revealed a natural limit to national sovereignty. In Rhodes framing of it, scientists found facts of the natural world which required new political interventions and methods to avoid certain types of war.

As a result, he said, these Manhattan Project sites were potentially among the most significant in the history of the world. It was an interesting way to start things off.

In an event where the participants are present, it is easy to fall into something that feels like just a celebration. And there were those, without a doubt, who felt positively about the Manhattan Project, that it was necessary to end the war, and all of that. There were also those who thought it wasn’t necessary, too. I think my favorite comment came from James Forde, a Manhattan Project veteran who had been employed to clean tubes (later revealed to be gaseous diffusion barriers) near Columbia University during the war. He said that for awhile he felt bad about the atomic bombs, but then he looked more into all of the other damage that non-atomic weapons had done during the war. After that, he lost any enthusiasm for war of any kind. He got solid applause for that.

Age distribution at Los Alamos, May 1945. Top graph is total  civilian personnel, bottom is scientific employees only. Keep in mind this was 70 years ago, so anyone in their 20s then would be in their 90s now. Source: Manhattan District History, Book 8, Volume 2, Appendix, Graph 1.

Age distribution at Los Alamos, May 1945. Top graph is total civilian personnel, bottom is scientific employees only. Keep in mind this was 70 years ago, so anyone in their 20s then would be in their 90s now. Source: Manhattan District History, Book 8, Volume 2, Appendix, Graph 1.

The veterans who were there had all been extremely young at the time. This makes sense, of course — if it is the 70th anniversary, almost nobody older than their early twenties is going to still be around today. And at many of the sites, the youth were in abundance. As a result, most of them had fairly small roles, small jobs, though some of them had rubbed shoulders with the giants. There were a few remarkable anecdotes. Isabella Karle talked about working as a chemist at the Metallurgical Laboratory in Chicago, working on plutonium oxide produced at the Oak Ridge X-10 reactor. She had to move it between buildings, and since it was such a small amount, she just carried it in her pocket. Someone found out she was doing this, and required her, a young woman with pigtails, to be escorted between building by burly guards, attracting more attention than she would have otherwise. She also related a story about carrying a radiation counter around with her, and having it go off next to a Coca-Cola machine. Apparently a deliveryman had forgotten some tubing in his car, and borrow a contaminated tube from a Met Lab office, contaminating the machine with who knows what. Fortunately, she said, she had stumbled across this before anyone had used it.

Ben Bederson told some amazing stories about David Greenglass, who he had bunked with as a member of the Special Engineer Detachment. Greenglass, he said, was a “true believer” of a Communist. Bederson pointed out that he, like many New York Jews at the time, had been interested in Communism for awhile (he had grown up in a part of the Bronx that was considered a “Communist neighborhood”) but that most had become disillusioned with it by the time the US was in the war. Greenglass never seemed to take the hint, though, and thought Bederson was a fellow traveler. It was an amusing contrast to people like Klaus Fuchs and Ted Hall, who hid their politics. Bederson eventually asked to be transferred to a different bunk. Later, Greenglass told the FBI he had wanted to try and recruit Bederson but his courier, Harry Gold, told him not to. The reason Greenglass thought Bederson would be a good recruit is because he gave money to the Roosevelt reelection campaign. “That shows you how smart David Greenglass was,” Bederson remarked with sarcasm.

The arming plugs of the Little Boy bomb.

Holding the arming plugs of the Little Boy bomb.

Along with the veterans and the historians, there were some artifactual pieces of the past there. Clay Perkins had brought the arming switches of the Little Boy bomb, which he purchased over a decade ago. The green (“safe”) one was kept plugged into the bomb until after takeoff. While in flight, the assistant weaponeer, Morris Jeppson, climbed into the unpressurized bomb bay of the Enola Gay and removed it. In its place, he put a red (“armed”) plug, making the bomb electrically “live.” (The red plug that Clay has is a spare, of course — the original was destroyed in the explosion over Hiroshima. Jeppson brought multiple spares with him since if he had dropped one during the operation, it would have aborted the mission.) Clay let me hold them, which was moving.

There was also a very surprising artifact brought by one of the veterans: a lucite hemisphere with pieces of Trinitite embedded in it. The Trinitite is not so rare, but the lucite was cast in the same mold that made the plutonium pits for the Trinity and Fat Man bombs, and included the small hold for the neutron initiator. This is an incredible thing to have kept (and I was also allowed to hold this, as well). I am sure its existence is the result of a violation of untold numbers of security rules. John Coster-Mullen, as I expected would, came up immediately afterwards to trace the dimensions. It looked how we all expected it to, but it still amazing to see something like this, knowing how secret it once was, and even now is supposed to be.2

I knew the plugs existed, I did not know the lucite existed. There is something profound about holding artifacts that had such strong connections to history. That historical empathy I spoke of in my most recent post has something to do with it — the brain suddenly makes this connection with this world that often seems so far away. But of course it really isn’t that far away, and the world we have today is largely a product of it. But sometimes even historians need reminders.

Monthly costs of the Manhattan Project, 1943 through 1946. From the Manhattan District History, Volume 5, Appendix A.

Monthly costs of the Manhattan Project, 1943 through 1946. From the Manhattan District History, Volume 5, Appendix A.

My own contribution to the symposium was a talk about the Manhattan Project as a “Crucible for Innovation.” I didn’t choose the title (it is not really my style, even though I do teach at “The Innovation University“), but it was easy enough to roll with: how much innovation took place during the Manhattan Project, and why was it successful? I talked a bit about the secret Manhattan Project patent program as one way to measure its innovation. By the time the AEC took over, the Manhattan Project patent program approved 2,100 separate secret patent applications for filing, and had already filed 1,250 of them with the US Patent Office. As I noted in an article from a few years ago, that latter number represented 1.5% of all of the patent applications filed in 1946. The Manhattan Project was not just the building of a bomb, but the creation an entirely new industry from scratch.

Why did the Manhattan Project succeed? Well, I argued, it almost didn’t — all you would need for it to have been a “failure” (in the sense of having not produced atomic bombs by the end of World War II) would to have been delayed by likely a few months. Which anyone who has ever tried to run even a small project knows is easy enough to do. I always try to emphasize this lack of an inevitability when I talk about the wartime effort, because it is easy to fall into the fallacy of knowing how the story ends and thus seeing it as predestined. The Manhattan Project was an anomaly: it was not innovation as usual, and it was not the natural or obvious path to take. Which is one reason why the US was the only country who actually went down that path with any seriousness during the war. The Manhattan Project still holds the world record for fastest tested or deliverable nuclear weapon after committing to build one: two and a half years.3

A preview of my forthcoming Manhattan Project sites map. Size is a subjective "prominence" rating given by me, the white dots show the actual location of the sites, and the color corresponds to whether it is government/military, educational institution, or private industry. An interactive version will be unveiled this summer, which will give more information about specific sites and permit zooming in, and etc. This only shows sites in the continental US and lower Canada — there are other non-US sites as well in the final version.

A preview of my forthcoming Manhattan Project sites map. Size is a subjective “prominence” rating given by me, the white dots show the actual location of the sites, and the color corresponds to whether it is government/military, educational institution, or private industry. An interactive version will be unveiled this summer, which will give more information about specific sites and permit zooming in, and etc. This only shows sites in the continental US and lower Canada — there are other non-US sites as well in the final version.

Lastly, I also emphasized the size of the project. I’ve talked on here about the immense cost of the work, and the greater-than-most-people-realize manpower requirements. But I also unveiled a screenshot of a work in progress. For a while now, I’ve been trying to make a database of every site where some sort of work on the Manhattan Project was done. I’ve been combing through the Manhattan District History, through archival files on contracts, and through databases of radioactive Superfund sites. I’ve been keeping a tally of any places listed as having some role in the final outcome, however minor. My current list is well over 200 separate sites. Some of these places were research institutions (about 40 are educational institutions of some nature), some were military or government institutions (some created from scratch, some pre-existing), and about half were private industry. Some places produced materials, some just produced paper. (The symposium took place in the Carnegie Institute of Science, which was where Vannevar Bush’s Office of Scientific Research and Development headquarters were during the war, and I delighted in getting to point this out.) Not all sites were equally important, to be sure. But all played some role, even if most of those places probably did not actually know what their role was. The screenshot above is a preview of the map — it is still a work in progress, and the final version will be fully interactive, sortable into different categories, and so on.

It’s a big list. Bigger than I thought when I started it. It just emphasizes again that the Manhattan Project was responsible for the birth of an industry, not just the bomb. Upon learning about the scale of the project in 1944, Niels Bohr told Edward Teller: “I told you it couldn’t be done without turning the whole country into a factory. You have done just that.” It was an apt observation.

Very little of this infrastructure remains. The Manhattan Project National Historic Park is an important step in the right direction for preservation of this history. There is a long road yet to go in terms of figuring out how to make it available to the public, and how to properly present the material. I remain optimistic that it will be an opportunity to talk about history in a productive way, and to build bridges between the ever-changing present and the ever-receding past.

Notes
  1. Rhodes is explicitly convinced by the Hasegawa thesis. In his words, though, “I find tragedy but no dishonor in having used atomic bombs to hasten the end of the war,” whether they actually hastened that end or not. It is a nuanced point to make. []
  2. John says it is a bit smaller than the actual pit — the initiator would not have been able to fit in the hole given, and the mass would be off by a few percentage points. So either it was cast in an earlier or alternative pit model, or something happened to it in the meantime. My hypothesis is that it was cast in the actual pit mold, but that it shrunk in some way over time, either because it contracted while it cooled originally (the thermal contraction coefficient for acrylic is around 5X that of uranium, just as a point of comparison), or through some other warping mechanism over the last 70 years. []
  3. The decision to produce nuclear weapons was made in December 1942. The work prior to this was of an exploratory or pilot nature, not a production program. The “Gadget” was ready by mid-July 1945, the other bombs were ready by the end of the month. []
Redactions

What did Bohr do at Los Alamos?

Monday, May 11th, 2015

In the fall of 1943, the eminent quantum physicist Niels Bohr managed a dramatic escape from occupied Denmark, arriving first in Sweden, then going to the United Kingdom. He was quickly assimilated into the British part of the Manhattan Project, then well underway. Bohr’s institute in Copenhagen had long been considered the world center of theoretical physics, and in the 1920s, young students from around the world flocked to work with him there. Now, in December 1943, Bohr and his son Aage made their pilgrimage to what was quickly becoming the new, stealth center of nuclear expertise: Los Alamos. At age 59, he would be the oldest scientist on “the Hill,” a place where the average age was 29.

Bohr skiing at Los Alamos, January 1945, seemingly without a care in the world. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

Bohr skiing at Los Alamos, January 1945, seemingly without a care in the world. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

This much is a standard part of Manhattan Project lore. Bohr’s contributions are usually spoken of primarily in psychological and moral terms. Bohr inspired the physicists to think about the consequences of their work, and laid the seeds of what would become the effort for postwar international control. He also spoke with both Churchill and Roosevelt, ineffectively, about the need to avoid an arms race. Bohr was a notoriously poor oral communicator, typically being barely audible. His deeply alienated and disturbed Churchill, who thought he might be proposing to tell the Soviets about the weapon. He probably just bored Roosevelt.

Some of the stories of his conduct at Los Alamos are adorably absent-minded. One of my favorite memos in the Manhattan Project archives is a February 1944 letter from Lt. Col. John Lansdale, head of MED security, to Richard Tolman, a physicist who was a good friend of the Bohrs. “Subject: Nicholas Baker,” it starts out, using Bohr’s wartime codename, and explains that in the process of following Bohr around, to make sure he was safe, some, well, deficiencies in his judgment were encountered:

“Both the father and son appear to be extremely absent-minded individuals, engrossed in themselves, and go about paying little attention to any external influences. As they did a great deal of walking, this Agent had occasion to spend considerable time behind them and observe that it was rare when either of them paid much attention to stop lights or signs, but proceeded on their way much the same as if they were walking in the wood. On one occasion, subjects proceeded across a busy intersection against the red light in a diagonal fashion, taking the longest route possible and one of greatest danger. The resourceful work of Agent Maiers in blocking out one half of the stream of automobile traffic with his car prevented their possible incurring serious injury in this instance.”

… I understand that the Bakers will be in Washington in the near future, at which time you will unquestionably see them. If the opportunity should present itself, I would appreciate a tactful suggestion from you to them that they should be more careful in traffic.1

Nobel-Prize winning physicist nearly run over by a car, because he treats American streets like paths in a forest, saved from disaster only by a trailing secret agent blocking the road with his car? You can’t make this stuff up. These kinds of stories reinforce the playful, harmless, “Uncle Nick” character that Bohr has come to represent in this period.

Bohr and General Groves' personal technical advisor, Richard Tolman, attending the opening of the Bicentennial Conference on "The Future of Nuclear Science," circa 1947. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

Bohr and General Groves’ personal technical advisor, Richard Tolman, attending the opening of the Bicentennial Conference on “The Future of Nuclear Science,” circa 1947. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

But the truth is a little more complicated. For his part, Bohr would later downplay his role in the actual creation of nuclear weapons. He told another physicist in 1950, for example, that he had spent most of his time while in the United States trying to forestall a nuclear arms race. “That is why I went to America… They didn’t need my help in making the atom bomb,” he later said.2

Did they need Bohr? Probably not — they probably would have managed well enough without him. But this is an odd standard for talking about one’s role in making a weapon of mass destruction. They didn’t need almost any individual who worked on the bomb, in the sense that they could have salvaged on without them.3

And not being “needed” does not really get one off the hook, does it? Which gets at what I think is a key point here: in the postwar, Bohr never relied on his contributions to the bomb as a means of claiming moral superiority, responsibility, or political leverage. He was active in attempts to promote international control and avoid an arms race, but he didn’t do so in a way that ever owned up to his own role in making the bomb. As a result, a lot of people seem to believe that Bohr didn’t really do that much at Los Alamos other than provide the aforementioned moral support and provocative questions.

In fact, Bohr did work on the bomb. And not just on esoteric aspects of the physics, either; one of his role was concerned with the very heart of the “Gadget.”

Niels Bohr (r) conversing animatedly with his son Aage in front of a board full of equations. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

Niels Bohr (r) conversing animatedly with his son Aage in front of a board full of equations. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

One of the key parts of the implosion design for the atomic bomb (the same sort of bomb detonated at Trinity and over Nagasaki) is the neutron initiator that sits at the absolute center of the device. It is a deceptively tricky little contraption. At the instance of maximum compression, it needs to send out a small burst of neutrons, to get the whole chain reaction started. It’s not even that many neutrons, objectively speaking — on the order of a hundred or so in the first bombs. But conjuring up a hundred neutrons, at the center of an imploding nuclear assembly, at just the right moment, was a tricky technical problem, apparently.

The details are still classified-enough that figuring out exactly what the nature of the problem is proves a little tough in retrospect. In an interview many years later, the physicist Robert Bacher, head of G (Gadget) Division during the war, recalled that for whatever reason, Enrico Fermi had become particularly focused on the initiator as the lynchpin of the bomb, and maybe his own conscience:

I think Fermi began to be very worried about the fact that this terrific thing that he’d sort of been the father of was going to turn into a great big weapon. I think he was terribly worried about it. … I think he [Fermi] was worried about the whole project, not just the initiator. But focusing on the initiator was the one thing that he thought he could look at. The thing really might not work.

And I think he also felt an obligation to take something that was as hare-brained as this was and try to find a way in which it really wouldn’t work. So he did look into every sort of thing, and I think every second day or so for a period, I’d see him and he’d come up or he’d see Hans [Bethe] and come up with a new reason why the initiator wouldn’t work. …4

Bacher got sick of Fermi’s interference, and eventually went to Oppenheimer to complain. Bacher recalled:

I said, “What I’d like to do is, Uncle Nick is here now, and I’d like to go and explain to him about the initiator and say I’d like his advice and counsel on whether he thinks it will work or not. We’ll answer any question that he puts to us, that we know the answer to.” So we did and he agreed with us and I told him quite frankly, “One of the reasons that we want to do this is that Fermi has so many misgivings about initiators.”

So I talked to him for a long while and then he spent about two days with his son Aage going over every single thing that had been done on this business. I saw him after this and he said, “My that’s very impressive. I think that will work.” I said, “Well now comes the test. Will you talk to Fermi about this? The two of you talk together and give me some counsel of what’s up on this?” So he did. And it made a lot of difference to have Uncle Nick talk to Fermi, because he felt that this wasn’t somebody you had working on some particular model and so on. It was sort of somebody from the outside, and I think it made Fermi feel a lot happier. And it certainly made it a lot easier for us.5

The initiator that “Uncle Nick” convinced Fermi of, the one that they ended up using in the Trinity and Nagasaki bombs, was the “Urchin.”

A schematic of the “Urchin,” as imagined by me, based on a postwar British account.

It was a hollow sphere of beryllium, a mere two centimeters in diameter. The inner side of the sphere was machined with grooves, facing inwards. At the center of these grooves was another sphere of beryllium, centered by pins embedded in the outer shell. On both the inner grooves of the outer shell, and the outer surface of the inner sphere were coated with nickel and gold. Onto the nickel of the inner sphere was a thin film of virulently radioactive polonium. Polonium emits alpha particles; in the non-detonated state of the “Urchin,” these would be absorbed harmlessly by the gold and nickel. But when the bomb came imploding in around it, the beryllium and polonium would be violently mixed, producing a well-known reaction (beryllium + an alpha particle = carbon + neutron) that produced the necessary neutrons.6

Margrethe and Niels Bohr converse in Copenhagen, 1947, in this extremely rare color photo. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

Margrethe and Niels Bohr converse in Copenhagen, 1947, in this extremely rare color photo. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

“Urchin” wasn’t the only initiator design on the table. Fermi apparently favored a design with the codename “Grape Nuts.” What was “Grape Nuts”? I have no idea — it’s still classified. Presumably these names meant something, since “Urchin” seems to reference the internal spikes. A topic listing for a May 1945 laboratory colloquium at Los Alamos discussed three initiator designs and their creators: “Urchin,” attributed to James Tuck and Hans Bethe; “Melon-Seed,” attributed to James Serduke; and, lastly, “Nichodemus,” attributed to… Nicholas Baker, the codename for Niels Bohr.7

In the recently-declassified Manhattan District History, there are several paragraphs on Bohr. Most of them describe theoretical work he did on the physics of nuclear fission after arriving at the lab, which “cleared up many questions that were left unanswered before.” His work affected their understanding the nuclear properties of tamper materials, and he apparently gave them ideas for “new and better methods… of alternative means of bomb assembly.” (All of which apparently just pointed to the superiority of implosion, in the end, but still.)

MHD Bohr contributions to bomb

At least one sentence in the Manhattan District History is still completely blacked out. Maybe it refers to the initiator design (which the previous sentence refers to), maybe it refers to something else. It’s interesting that seven decades later, something of what Bohr worked on was still considered too classified to reproduce — evidence that Bohr’s influence on the bomb was less trivial than he would later make it out to be.8

Why does it matter? In Michael Frayn’s Copenhagen, there is, towards the end of the play, an implied asymmetry between Bohr and Heisenberg. Heisenberg is criticized throughout the play for potentially making an atomic bomb for Hitler. The play ultimately says Heisenberg didn’t make an atomic bomb in part because he wasn’t trying to make a bomb. (It does so with perhaps a little bit too much credence to the “he didn’t do it because he was sabotaging it thesis,” which I think there is no evidence for and no reason to believe, but anyway.) Driven by his fears, Bohr goes to the United States and actually does work on the bomb, does contribute to the killing of over a hundred thousand people, and so on. And so there is some irony there, where Heisenberg, supposedly the one in a state of moral jeopardy, is the one who actually contributes to the death of no one, where Bohr, supposedly the moral authority, is the one who helps build the bomb.

Bohr with Elisabeth and Werner Heisenberg in Athens, Greece, 1956. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

Bohr with Elisabeth and Werner Heisenberg in Athens, Greece, 1956. Source: Emilio Segrè Visual Archives, Niels Bohr Library, American Institute of Physics.

Do Bohr’s contributions to the atomic bomb, however major or minor, weaken his moral authority? I don’t really think so. Bohr’s strongest and most lasting contribution was putting the bug of international control into the heads of people like Oppenheimer. That bug might have come up on its own (when they learned about Bohr’s scheme, Vannevar Bush and James Conant were surprised to find that they had been thinking along almost exactly the same lines, completely independently), but Bohr’s influence on openness, candor, the moral obligation of scientists, and so on had a profound effect on postwar political discourse, even if his dreaded arms race was not avoided. In this light, I think Bohr still comes off pretty well, even if the bomb still does contain traces of his fingerprints.

Notes
  1. John Lansdale to Richard Tolman, “Subject: Nicholas Baker,” (5 February 1944), Manhattan Engineer District (MED) records, Records of the Army Corps of Engineers, RG 77, National Archives and Records Administration, College Park, MD, Box 64, “Security.” []
  2. J. Rud Nielson, “Memories of Niels Bohr,” Physics Today 16, no. 10 (Oct. 1963), 28-29. []
  3. I am occasionally drawn into a game of “who is so important that you absolutely couldn’t remove them and still expect it to be successful?” I am inclined to think that almost everyone would be more or less replaceable, as individuals, though there are a few whose contributions were so pivotal that removing them would create serious issues. Someday I will post some concrete thoughts on this on this. []
  4. Robert Bacher interview with Lillian Hoddeson and Alison Kerr (30 July 1984), Robert Bacher papers, Caltech Institute Archives, Pasadena, CA, Box 48, Folder 5. []
  5. Ibid. []
  6. Accounts of the exact dimensions of the “Urchin” vary from source to source. John Coster-Mullen’s book, Atom Bombs, gives what I find to be convincing evidence that it was 0.8 in./2 cm in diameter. There was 20 curies of polonium deposited in them, and they had to be replaced frequently because of polonium’s low half-life. The inner core of the plutonium pit was about 1 in. in diameter, and apparently both the core and the initiator would be expected to expand slightly due to the heat generated by their radioactivity. Apparently James Tuck gave it the name “Urchin,” on account of its inner ridges. There is some question as to how the grooves were machined, whether they were pyramids (as in the British account) or ridges (e.g. like a theatre in the round). It’s always nice to be reminded that there are still a few secret details out there. []
  7. The list of wartime colloquia comes from the Klaus Fuchs FBI File, Part 49 of 111, available on the FBI’s website, starting on page 49 of the PDF. The only other “Nicholas Baker” contribution mentioned in the document is a November 1944 talk on “nuclear reactions of heavy elements and particularly the various results obtained when a neutron comes in contact with heavy nuclei, such as Uranium 238.” []
  8. Manhattan District History, Book 8 (Los Alamos Project), Volume 2 (Technical), pages II-2 to II-3. []