Posts Tagged ‘H-bomb’


Oppenheimer, Unredacted: Part II – Reading the Lost Transcripts

Friday, January 16th, 2015

This is the second and final part (Part II) of my story about the lost Oppenheimer transcripts. Click here for Part I, which concerns the origin of the transcripts, the unintuitive aspects of their redaction, and the unorthodox archival practice that led me to find their location in 2009.

Oppenheimer photograph courtesy of the Emilio Segrè Visual Archive.

The Oppenheimer security hearing transcript is not exactly beach reading. Aside from its length (the redacted version alone is some 690,000 words, which makes it considerably longer than War and Peace), it is also a jumble of witnesses, testimonies, and distinct topics. It is also somewhat of a bore, as there is incredible repetition, and unless you know the context of the time very well, the specific arguments that are focused on can seem arbitrary, pedantic, and confusing, even without the additional burden of some of the content having been deleted by the censor.

The most damning problem for Oppenheimer at his 1954 hearing involved his conduct during the so-called “Chevalier incident,” in which a fellow-traveler colleague of his at Berkeley, Haakon Chevalier, approached Oppenheimer at a party in late 1942 or early 1943 at the behest of another scientist (a physicist named George Eltenton) who wanted to see if Oppenheimer was interested in passing on classified information to the Soviet Union. Oppenheimer, in his recollection, told Chevalier in no uncertain terms that this was a bad idea. Later, Oppenheimer went to a member of the Manhattan Project security team and told him about the incident, calling attention to Eltenton as a security risk, but also trying to not to make too big of a deal of the entire matter. Confronted with the idea of Soviet spying on the atomic bomb project, the security men of course did not take it so lightly, and pressed Oppenheimer for more details, such as the name of the intermediary, Chevalier, which Oppenheimer did not want to give since he claimed Chevalier had nothing truly to do with Soviet spying. Over the course of several years, the security agents re-interviewed Oppenheimer, trying to clarify exactly what had happened. Oppenheimer gave contradictory answers, seemingly to shield his friends from official scrutiny and its consequences. At his hearing, when asked whether he had lied to security officials, Oppenheimer admitted that he had. When asked why, Oppenheimer gave what was become the most damning testimony at a hearing about his character: “Because I was an idiot.” Not a good answer to have to give under any context, much less McCarthyism, much less when you are known to be brilliant.

I mention this only to highlight the difference between what is in the published transcript and what is not. The newly unredacted information does not touch on the Chevalier incident much at all. That is, it does not shed any new light on the central question of relevance towards Oppenheimer’s security clearance. What does it shed light on? We can lump its topics into roughly three categories.

One of the censor's trickier redactions, in which he removed a trouble word, and substituted a different word in its place. "Principle" was too close to a secret, but"idea" was acceptable.

One of the censor’s trickier redactions, in which he removed a trouble word, and substituted a different word in its place. “Principle” was too close to a secret, but”idea” was acceptable. (JB = James Beckerley.)

The first category concerns the creation of the hydrogen bomb. Oppenheimer had been on a committee that had opposed a “crash” program to build the H-bomb in 1949. This was at a time when it was unclear that such a weapon could be built at all. The then-favored design (later dubbed the “Classical Super”) had many problems with it, and didn’t seem like it was likely to work. It seemed to also require huge quantities of a rare isotope of hydrogen, tritium, the production of which could only be done in nuclear reactors at the expense of producing plutonium.For Oppenheimer and many others, there was a strong technical reason to not rush into an H-bomb program: it wasn’t clear that the bomb could be built, and preparing the materials for such a bomb would decrease the rate of producing regular fission bombs.

How much plutonium would be lost in pursuing the Super? This is an area the newly-reduced transcript does enlighten us. Gordon Dean, Chairman of the Atomic Energy Commission from 1950 to 1953, explained that:

You don’t decide to manufacture something that has never been invented. Nothing had been invented. No one had any idea what the cost of this thing would be in terms of plutonium bombs. As the debate or discussions waged in the fall of 1949, we had so little information that it was very difficult to know whether this was the wise thing to do to go after a bomb that might cost us anywhere from 20 plutonium bombs up to 80 plutonium bombs, and then after 2 or 3 years effort find that ft didn’t work. That was the kind of problem. So there were some economics in this thing.

The underlined section was removed from the published transcript. This does contribute to the debate at the time — if researching the Super meant depriving the US stockpile of 20-80 fission bombs, that is indeed a high price. We might ask: Why was it redacted? Because the censor wanted to undercut Oppenheimer’s position? Probably not — if the censor had wanted to do that, he would have removed a lot more than just those numbers. More likely it is because you can work backwards from those numbers how much plutonium was in US nuclear weapons at that time, or, conversely, how much tritium they were talking about. My understanding is that every gram of tritium you make is a gram of plutonium you don’t make; if you know that the bombs at the time had about 6 kg of plutonium in them, then you can see they are talking about producing between 120 and 480 kg of tritium. Should this have been classified? It seems benign at the moment, but this was still a period of a “race” for thermonuclear weapons, and nearly everything about these weapons was, rightly or wrongly, classified.

Redaction of a long section on the development of the Teller-Ulam design. Ulam's name was almost totally (but not entirely) removed from the transcript, sometimes very deliberately and specifically. The orange pencil shows the mark of the censor, as does the "Delete, JB" on the right.

Redaction of a long section on the development of the Teller-Ulam design. Ulam’s name was almost totally (but not entirely) removed from the transcript, sometimes very deliberately and specifically. The orange pencil shows the mark of the censor, as does the “Delete, JB” on the right.

But the hydrogen bomb could be built. In the spring of 1951, physicists Edward Teller and Stanislaw Ulam hit upon a new way to build a hydrogen bomb. It was, from the point of view of the weapons physicists, a totally different approach. Whereas the “Classical Super” required using an atomic bomb to start a small amount of fusion reactions that would then propagate through a long tube of fusion fuel, the “Equilibrium Super,” as the so-called Teller-Ulam design was known at the time, involved using the radiation of an atomic bomb to compress a capsule of fusion fuel to very high densities before trying to ignite it. To a layman the distinction may seem minor, but the point is that many of the scientists involved with the work felt this was really quite a big conceptual leap, and that this had political consequences.

The differences between the redacted and un-redacted transcript shows a censor who tried, perhaps in vain, to dance around this topic. The censor clearly wanted to make sure the reader knew that the hydrogen bomb design developed in 1951 (the “Equilibrium Super”) was a very different thing than the one on the table in 1949 (the “Classical Super”), because this is a clear part of the argument in Oppenheimer’s favor. But the censor also evidently feared being too coy about what the differences between the 1949 and 1951 designs were, as such was the entire “secret” of the hydrogen bomb. For example, here is a section where Oppenheimer testified on this point, early on in the hearing:

In the spring of 1951, there were some inventions made. They were not discoveries, really; they were inventions, new ideas, and from then on it became clear that this was a program which was bound to succeed. It might not succeed at first shot; you might make mistakes, but for the first time it was solid. It was not on the end; it wasn’t so that every time you calculated it it was yes or not, but it came out that you knew that you could do not. It was just a question of how rapidly and how well and I am amazed at the speed at which this actually went after we learned what to do. Ulam and Teller had some very bright ideas; why none of us had them earlier, I cannot explain, except that invention is a somewhat erratic thing.

Again, what is underlined above was removed from the original. Read the sentences without them and they still have the same essential meaning: Oppenheimer is arguing that the 1951 design was very different than the 1949 one. Put them back in, and the meaning only deepens a little, adding a little more specifics and context, but does not change. One still understands Oppenheimer’s point, and much is left in to emphasize its import — Oppenheimer only opposed the H-bomb when it wasn’t clear that an H-bomb could be made.

Why remove such lines in the first place? A judgment call, perhaps, about not wanting to reveal that the “secret” H-bomb was not a new scientific fact, but a clever application of a new idea. The censor could have probably justified removing more under the security guidelines, but took pains to maintain coherency in the testimony. In one place, the physicist Hans Bethe referred to Teller and Ulam’s work as a new “principle,” and the censor re-worded this to “idea” instead. A subtle change, but certainly done in the name of security, to shift attention away from the nature of the H-bomb “secret.”

Early 1954 was a tricky time for hydrogen bomb classification. The US had detonated its first H-bomb in 1952, but not told anyone. In March 1954, a second hydrogen bomb was detonated as the “Bravo test.” Radioactive fallout rained down on inhabited atolls in the Marshall Islands, as well as a Japanese fishing boat, making the fact of it being a thermonuclear test undeniable. The Soviet Union had detonated a weapon that used fusion reactions in 1953, but did not appear to know about the Teller-Ulam design. As a result, US classification policy on the H-bomb was extremely conservative and sometimes contradictory; that the US had tested an H-bomb was admitted, but whether it was ready to drop any of them was not.

JRO redaction Rabi mermaids

In this category I would also attribute I.I. Rabi’s “mermaids” redaction, mentioned earlier. As published, it was:

We have an A-bomb and a whole series of it, *** and what more do you want, mermaids?

Restored, it is:

We have an A-bomb and a whole series of it, and we have a whole series of Super bombs, and what more do you want, mermaids?

To the censor, the removed section implied, perhaps, that there was no single H-bomb design, but rather a generalized arrangement that could be applied to many different weapons (which were being tested during Operation Castle, which was taking place at the same time as these hearings). This is a tricky distinction for a layman, but important for a weapons designer — and it is the eyes of the weapon designer that the censor feared, in this instance.

The censor’s fear of foreign scientists scouring the Oppenheimer hearing transcripts for clues as to the H-bomb’s design was not, incidentally, unwarranted. In the United Kingdom, scientists compiled a secret file full of extracts from the (redacted) Oppenheimer transcript that reflected on the nature of the successful H-bomb design. So at least one country was watching. As for the Soviet Union, they detonated their first H-bomb in 1955, having figured out the essential aspects of the Teller-Ulam design by the spring of 1954 (there is still scholarly uncertainty as to the exact chronology of the Soviet H-bomb development, and whether it was an entirely indigenous creation).

Project Vista cover page

The second major category of deletions pertained to Oppenheimer’s role in advising on the use of tactical nuclear weapons in Europe. This involved his participation in Project Vista, a study conducted in 1951-1952 by Caltech for the US Army. Vista was about the defense of continental Europe against overwhelming Soviet ground forces, and Oppenheimer’s section concerned the use of atomic bombs towards this end. (It was named after the hotel that the summer study took place in.)

Oppenheimer’s chapter (“Chapter 5: Atomic Warfare”) concluded that small, tactical fission bombs could be successfully used to repel Soviet forces. In doing so, it also argued against a reliance on weapons that could only be used against urban targets — like the H-bomb. The US Air Force attempted to suppress the Vista report, because it seemed to advocate that the Army into their turf and their budget. It was one of the many things that made the Air Force sour on Oppenheimer.1

In order to emphasize that Oppenheimer was not opposed to the hydrogen bomb on the basis of entirely moralistic reasons, a lot of the discussions at the hearing initiated by his counsel related to his stance on tactical nuclear weapons. They wanted it to be clear that Oppenheimer was not “soft” on Communism and the USSR. Arguably, Oppenheimer’s position was sometimes more hawkish than those of the H-bomb advocates. Oppenheimer wanted a nuclear arsenal that the US would feel capable of using, as opposed to a strategic arsenal that would only lead to a deterrence stalemate.

Another classic Cold War redaction: what we know about the enemy, even if we don't know anything.

Another classic Cold War redaction: what we know about the enemy, even if we don’t know anything.

The debate of strategic arms versus tactical nukes is one that would become a common point of discussion from the 1960s onward, but in 1954 it was still confined largely to classified circles because they pertained to actual US nuclear war plans in place at the time and the future of the US nuclear arsenal. Much of this discussion is still visible in the redacted transcript, but with less emphasis and detail than in the un-redacted original. The essential point — that in the end, the US military pursued both of these strategies simultaneously, and that Oppenheimer was no peacenik — gets filled out a more clearly in the un-redacted version.

Among the sentences that got redacted are long portions that describe the Vista project, its importance, and the fact that it was taken very seriously. It is unfortunate that these were removed, because they would definitely have changed the perception that Oppenheimer was acting on purely “moral” reasons against the hydrogen bomb. Oppenheimer opposed the hydrogen bomb, but he did so, in part, because he advocated making hundreds of smaller fission bombs. Other statements removed is a remark by General Roscoe Charles Wilson about something he heard Curtis LeMay say: “I remember his saying most vigorously that they couldn’t make them too big for him.” One can appreciate why the censor might want to remove such a thing, as a rather unflattering bit of hearsay about the head of the Strategic Air Command. Lest one think that these removals would only help Oppenheimer’s case, many of the other lines removed from Wilson’s testimony concerned the fact that the Air Force did find that they had plenty of strategic targets for multi-megaton bombs — removed, no doubt, because it shed light on US targeting strategy, but the sort of thing that generally went against Oppenheimer’s argument.

Similarly, John McCloy testified that Oppenheimer’s views were fairly hawkish at the time:

I have the impression that he [Oppenheimer], with one or two others, was somewhat more, shall I say, militant than some of the other members of the group. I think I remember very well that he said, for example, that we would have to contemplate and keep our minds open for all sorts of eventualities in this thing even to the point of preventative war.

Did Oppenheimer really advocate preventative nuclear war with the Soviet Union? It’s not impossible — his views in the 1950s could be all over the place, something that makes him a difficult figure to fit into neat boxes. In retrospect, we have made Oppenheimer into an all-knowing, all-rational sage of the nuclear age, but the historical record shows someone more complicated than that. Why would the censor remove the above? Probably because it would be seen as inflammatory to US policy, potentially because it might shed light on actual nuclear policy discussions. In this case, this line potentially could have had a strong impact on the post-hearing memory of Oppenheimer, had it been released, but probably not a positive one.

JRO redaction Groves on Rosenbergs

Lastly, there are a few removals for miscellaneous reasons relating to the conduct of the hearings themselves. As I pointed out at the beginning, when the witnesses at the security hearing took the stand, they were told that their responses would be “strictly confidential,” and not published. This was to encourage maximum candor on their part. When the decision was made to publish the transcript, each of the witnesses were contacted individually to be told this and were asked if there was anything they would not want made public. There is evidence of a few removals for this reason.

General Leslie Groves, the head of the Manhattan Project during World War II, said a number of things that were not classified but would have been embarrassing or controversial if they appeared in print. For example, he was emphatic that “the British Government deliberately lied about [Klaus] Fuchs,” the German physicist who had been part of the British delegation to Los Alamos and was, as it later became known, a Soviet spy. Groves also opined on the importance of Fuchs’ espionage versus that of the Rosenbergs:

I think the data that went out in the case of the Rosenbergs was of minor value. I would never say that publicly. Again that is something while it is not secret, I think should be kept very quiet, because irrespective of the value of that in the overall picture, the Rosenbergs deserved to hang, and I would not like to see anything that would make people say General Groves thinks they didn’t do much damage after all.

Even Groves’ comment at the time made it clear that this was not something he wanted circulated publicly. Should this information have been removed? It is a tricky question. If Groves had known what he said would be printed, he never would have said any of it. Ultimately this becomes not an issue of classification, but one of propriety. Its inclusion does not affect issues relating to Oppenheimer’s clearance. It is part of a much longer rant on Groves’ part about the British, something he was prone to do when confronted with the fact that the worst cases of nuclear secrets being lost occurred on his watch.

In one slightly smaller category, there is at least evidence of one erroneous, accidental removal. There is a line, on page 129 of the GPO version, which, when restored, looks like this: “Having that assumption in mind at the time Lomanitz joined the secret project, did you tell the security officers anything that you knew about Lomanitz’s background?” The restored material contains nothing classified, or even interesting, and its removal is not noted in the official “concordance” of deleted material produced by the Atomic Energy Commission censor. So why was it removed? Looking at the originals, we find that the entire contents of the deleted material comprise the last line of the page. It looks like it got cut off on accident, and marked as a redaction. Such is perhaps further evidence of the rushed effort that resulted in the transcript being published.

* * *

Does the newly released material give historians new insight into J. Robert Oppenheimer? In my view: not really. At best, they may address some persistent public misconceptions about Oppenheimer, but ones that have long since been redressed by historians, and ones that even the redacted transcript makes clear, if one takes the time to read it carefully and deeply. The general public has long perceived Oppenheimer to be a dovish martyr, but even a cursory reading of the actual transcripts makes it clear that this is not quite right — he was something more complex, more duplicitous, more self-serving.

Oppenheimer's two TIME magazine covers: as ascendent atomic expert (1948), and casualty of the security state (1954).

Oppenheimer’s two TIME magazine covers: as ascendent atomic expert (1948), and casualty of the security state (1954).

If the redacted sentences had been released in 1954, they would have fleshed out a little more of the story behind the H-bomb and behind Oppenheimer’s advocacy for tactical nuclear weapons. They would have emphasized more strongly that Oppenheimer opposed the H-bomb not just for moral reasons, but for technical reasons, and that rather than opposing the development of atomic armaments, Oppenheimer supported them vigorously — and even supported using them in future conflicts. The latter aspect, in particular, might have changed a bit the public’s perception of Oppenheimer at the time. Oppenheimer was not a dove, he was just a different sort of hawk, which somewhat reduces the idea of Oppenheimer as a martyr against the warmongers. This latter notion (Oppenheimer as anti-nuke) is a common perception of Oppenheimer, even today, though much scholarly work has tried to go against this notion for several decades.

The recent declassification of the transcript does not tell us anything we essentially did not already know from other sources, including the many of the wonderfully-researched histories of this period published in recent years by scholars such as Jeremy BernsteinKai Bird, David Cassidy, Gregg Herken, Priscilla McMillan, Richard Polenberg, Richard Rhodes, Sam SchweberMartin Sherwin, and Charles Thorpe, among others. These new revelations do not drastically revise our understanding of Oppenheimer or his security clearing. He looks no more nor less of a “security risk” than he did in the redacted version of the transcripts.

At the same conference where I initially was inspired to search for the conference, Polenberg asked the group assembled: how would we remember Oppenheimer today, if he had not had his security clearance stripped after the hearing? His own answer is that we would probably have longer focused on the more negative aspects of Oppenheimer’s personality and perspectives. We’d see him not as a dove, but as a different flavor of hawk. He’d see him as someone who was willing to turn in his friends to the FBI, if it served his interests. We’d see him as someone who, again and again, wanted to be accepted by the politicians and the generals. We would see more of his role as an enabler of the Cold War arms race, not just his attempts at tamping it down. By revoking the clearance, Oppenheimer’s enemies may have crushed his soul, but they made him a martyr in the process.

Headlines from 1954 regarding Beckerley and his split with the Atomic Energy Commission — and his turn as a secrecy critic.

Headlines from 1954 regarding Beckerley and his split with the Atomic Energy Commission — and his turn as a secrecy critic.

But just because these transcripts don’t give us much of a revision on Oppenheimer, or the conduct of his security hearing, doesn’t mean they are not  instructive. For one thing, they shed a good deal of light on the process of secrecy itself — and it is only by getting the full story, the record of deletions, that one can pass judgment on whether the secrecy was used responsibility or inappropriately.

In my view, the erasures appear to have been done responsibly. They do not greatly obscure the ultimate arguments for or against Oppenheimer’s character, and primarily hew to legitimate security concerns for early 1954. The choice of what to remove and what to keep was done not by one of Oppenheimer’s enemies, but by Dr. James G. Beckerley, a physicist who was at the time the Director of the Atomic Energy Commission’s Division of Classification. His initials (“JB”) can be found next to many of the specific deletions in some of the volumes. Beckerley was no rabid anti-Communist or promoter of secrecy. He was a moderate, one who often felt that the AEC’s security rules were highly problematic, and believed that only careful and sane application of classification rules (as opposed to zealous or haphazard) would lead to a stronger nation. As it was, he resigned his job in May 1954, not long after the Oppenheimer hearing, and became an outspoken critic of nuclear secrecy. We do not know Beckerley’s personal opinions on Oppenheimer, but in every other aspect of his work he seems not to be the classification villain that one expects of a Cold War drama.

So it is perhaps not surprising that his deletions from the Oppenheimer transcript are, in retrospect, pretty reasonable, if viewed in context. They do not seem overtly politicized, especially in the way that Beckerley carefully carved up some of the problematic statements so that their ultimate argument still came out, even if the classified details did not. Most were plausibly done in the name of security, according to the security concerns of early 1954. In fact, the amount of discussion of the H-bomb’s development allowed in the final transcript is rather remarkable — very little has in fact been removed on this key topic. A few of the removals, were done in the name of propriety, removed because of the changing status of the transcript from “confidential” to public record. None of the comments removed for non-security reasons seem to have had any bearing on the question of Oppenheimer’s character and loyalty, though they are certainly interesting. Groves’ comments on the Rosenbergs, for example, is completely fascinating — but not relevant to Oppenheimer’s case.

Two frames from a 1961 photo session with Oppenheimer by Ulli Steltzer. "He was shy of the camera and I never got more than 12 shots. It is hard to say which expression is most typical." More on this image, here.

Two frames from a 1961 photo session with Oppenheimer by Ulli Steltzer. “He was shy of the camera and I never got more than 12 shots. It is hard to say which expression is most typical.” More on this image, here.

In this case, I disagree with the conclusions given by the other historians in the New York Times article about the release. I don’t think the removals bolster Oppenheimer’s case, and I don’t think there is any evidence to suggest that the redactions were made to aid the government’s case. We are accustomed to a story about classification that involves bad guys hiding the truth. Sometimes that is a narrative that works well with the facts — classification can, and has often been, abused. But in my (someday) forthcoming book, I argue that part of this impression of “the censor” as a shadowy, faceless, draconian “enemy” is just what happens when we, on the outside, are not privy to the logic on the “inside.”

It is somewhat tautological to say that secrecy regimes hide their own logic by the very secrecy they impose, but it is actually a somewhat subtle point for thinking about how they work. When you are outside of a secrecy regime, you can’t always see why it acts the way it does, and it is easy to see it as an oppositional entity designed to thwart you. Peeling back the layers, which is what historians can do many years after the fact, often reveals a more subtle and complex organizational discussion going on. In the case of these transcripts, it is clear, I think, that Beckerley was trying his best to satisfy both the security requirements of the day regarding the key features of the newly-invented hydrogen bomb, as well as avoid saying too much about US nuclear force postures in Europe. And, just as key, he was juggling the problem of witnesses who had been told their original testimony would be confidential. There is no evil intent in these actions, that I can see.

Did these redacted sentences need to be kept classified for 60 years? Of course not. And by releasing them in full, the Department of Energy explicitly agrees that these transcripts contain nothing classified as of today. But they weren’t being hoarded for decades because of their lasting security relevance — they were just forgotten about. These volumes probably could have been fully declassified at least as early as 1992, and probably would have, had the declassification effort not gotten shelved.

Still, it is important that they are finally released. Even a negative result is a result, and even an empty archive can tell us something positive. Knowing that the un-redacted transcripts contain nothing that would either exculpate, nor incriminate, J. Robert Oppenheimer is itself something to know. Secrecy does not just hide information: it creates a vacuum into which doubt, paranoia, fear, and fantasy are harbored. Removing the secrecy here has, at least, removed one last veil and source of uncertainty from the Oppenheimer affair.

  1. On Vista, see esp. Patrick McCray, “Project Vista, Caltech, and the dilemmas of Lee DuBridge,” Historical Studies in the Physical and Biological Sciences 34, no. 2: 339-370. The Vista cover page image comes from a heavily redacted copy of the report that was given to me by Sam Schweber. []
News and Notes

Public lecture: “The Secret Histories of Laser Fusion”

Thursday, October 16th, 2014

Sorry for the radio silence last week! A lot has been going on over here. More on all that pretty soon. Tomorrow morning I will be putting up a post on the death of David Greenglass.

I wanted to let people in the greater New York City metro area know about a public lecture I am giving on Wednesday, October 29, 2014, as part of the New York City History of Science Society Consortium, at Columbia University.

Meeting of the New York City History of Science Society Consortium

Wednesday, October 29th, 2014, 6:00-7:30 PM

Faculty House, Columbia University, 64 Morningside Drive

Wellerstein - Laser fusion talk

“Clean, Limitless, Classified: The Secret Histories of Laser Fusion”

Alex Wellerstein, Stevens Institute of Technology

The invention of the laser and its proliferation in scientific settings created a unique problem for the United States government starting in the 1960s. The Cold War regime of nuclear secrecy had required an absolute legal distinction between “peaceful” civilian technology and “dangerous” military technology: the former needing wide dissemination and development by the private sector, the latter being tightly regulated under penalty of imprisonment and death. But the emergent technology of laser fusion began to challenge and blur these Cold War categories. For its proponents, which included both international scientists and private entrepreneurs, laser fusion held out the hope of clean, limitless power generation during a time of increasing energy instability. But at its heart was a form of physics that was, for government censors, far too near to the methods used in the design of advanced thermonuclear weapons. This talk will use newly declassified files to tell the international history of laser fusion in the 1960s and 1970s as a case study for looking at the unusual classification problems of late Cold War nuclear technology. 

This is a very fun talk, one I’ve been working on (and workshopping on) for a few years now. It is based on interviews with some of the pioneers of laser fusion technology, and a whole lot of documents I got declassified by the Department of Energy relating to the declassification of laser fusion technology in the 1970s, the KMS Fusion affair, and international development of inertial confinement fusion. In a world where some new fusion hype seems to be bursting out (or petering out) on a weekly basis, this is a history with more relevance than ever, and has some moments in it that are sure to shock and delight. For those who are more interested in the weapons side of the nuclear picture, there’s a lot going on related to that in this as well, in describing the back-and-forth between the work of H-bomb designs and the work on “civilian” applications, and the complete mess that this put the Atomic Energy Commission in as they tried to figure out their classification policies and priorities. There’s a lot going on in this one.

All are welcome — there doesn’t seem to be a need to RSVP. I don’t know if it is being recorded. I don’t think it is being streamed.

News and Notes

John Wheeler and the Terrible, Horrible, No Good, Very Bad Day

Monday, July 14th, 2014

Just a quick plug: as noted previously, I’m moving out of the Washington, DC, area very soon, to start a new job at the Stevens Institute of Technology in the New Jersey/NYC area. My last talk as a DC denizen is going to be next Monday, July 21st, at the American Institute of Physics in College Park, Maryland, from 12-1:30pm.


Here’s the information:

The AIP History Programs invites you to an ACP Brown Bag Lunch-Time Talk:

John Wheeler’s H-bomb blues:
Searching for a missing document
at the height of the Cold War

by Alex Wellerstein, Postdoctoral Fellow at the Center for History of Physics

Monday, July 21, 2014
12–1:30 pm

Conference Room A
American Center for Physics
1 Physics Ellipse
College Park, MD 20740

There’s never a right time to lose a secret document under unusual circumstances. But for the influential American physicist John Archibald Wheeler, there might not have been a worse time than January, 1953. While on an overnight train ride to Washington, D.C., only a month after the test of the first hydrogen bomb prototype, Wheeler lost, under curious circumstances, a document explaining the secret to making thermonuclear weapons.

The subsequent search for the missing pages (and for who to blame) went as high as J. Edgar Hoover and President Eisenhower, and ended up destroying several careers. The story provides a unique window into the precarious intersection of government secrecy, competing histories of the hydrogen bomb, and inter-agency atomic rivalry in the high Cold War. Using recently declassified files, the AIP Center for History of Physics’ outgoing Associate Historian will trace out the tale of  how Wheeler ended up on that particular train, with that particular document, and the far-reaching consequences of its  loss—or theft—for both Wheeler and others involved in the case.

It’s a very fun paper, drawing heavily on John Wheeler’s FBI file, and one that I will be turning into an article fairly soon. It is open to the public if you RSVP. If you’re in town and want to see me before I go, please feel free to come! To my knowledge it will not be live-streamed or recorded or anything like that.


Castle Bravo at 60

Friday, February 28th, 2014

Tomorrow, March 1, 2014, is the 60th anniversary of the Castle Bravo nuclear test. I’ve written about it several times before, but I figured a discussion of why Bravo matters was always welcome. Bravo was the first test of a deliverable hydrogen bomb by the United States, proving that you could not only make nuclear weapons that had explosive yields a thousand times more powerful than the Hiroshima bomb, but that you could make them in small-enough packages that they could fit onto airplanes. It is was what truly inaugurated the megaton age (more so than the first H-bomb test, Ivy Mike, which was explosively large but still in a bulky, experimental form). As a technical demonstration it would be historically important even if nothing else had happened.

One of the early Bravo fallout contours. Source.

One of the early Castle Bravo fallout contours showing accumulated doses. Source.

But nobody says something like that unless other things — terrible things — did happen. Two things went wrong. The first is that the bomb was even more explosive than the scientists thought it was going to be. Instead of 6 megatons of yield, it produced 15 megatons of yield, an error of 250%, which matters when you are talking about millions of tons of TNT. The technical error, in retrospect, reveals how grasping their knowledge still was: the bomb contained two isotopes of lithium in the fusion component of the design, and the designers assumed only one of them would be reactive, but they were wrong. The second problem is that the wind changed. Instead of carrying the copious radioactive fallout that such a weapon would produce over the open ocean, where it would be relatively harmless, it instead carried it over inhabited atolls in the Marshall Islands. This necessitated evacuation, long-term health monitoring, and produced terrible long-term health outcomes for many of the people on those islands.

If it had just been natives who were exposed, the Atomic Energy Commission might have been able to keep things hushed up for awhile — but it wasn’t. A Japanese fishing boat, ironically named the Fortunate Dragon, drifted into the fallout plume as well and returned home sick and with a cargo of radioactive tuna. One of the fishermen later died (whether that was because of the fallout exposure or because of the treatment regime is apparently still a controversial point). It became a major site of diplomatic incident between Japan, who resented once again having the distinction of having been irradiated by the United States, and this meant that Bravo became extremely public. Suddenly the United States was, for the first time, admitting it had the capability to make multi-megaton weapons. Suddenly it was having to release information about long-distance, long-term contamination. Suddenly fallout was in the public mind — and its popular culture manifestations (Godzilla, On the Beach) soon followed.

Map showing points (X) where contaminated fish were caught or where the sea was found to be unusually radioactive, following the Castle Bravo nuclear test.

Map showing points (X) where contaminated fish were caught or where the sea was found to be unusually radioactive, following the Castle Bravo nuclear test. This sort of thing gets public attention.

But it’s not just the public who started thinking about fallout differently. The Atomic Energy Commission wasn’t new to the idea of fallout — they had measured the plume from the Trinity test in 1945, and knew that ground bursts produced radioactive debris.

So you’d think that they’d have made lots of fallout studies prior to Castle. I had thought about producing some kind of map with all of the various fallout plumes through the 1950s superimposed on it, but it became harder than I thought — there are just a lot fewer fallout plumes prior to Bravo than you might expect. Why? Because prior to Bravo, they generally did not map downwind fallout plumes for shots in Marshall Islands — they only mapped upwind plumes. So you get results like this for Ivy Mike, a very “dirty” 10.4 megaton explosion that did produce copious fallout, but you’d never know it from this map:

Fallout from the 1952 "Ivy Mike" shot of the first hydrogen bomb. Note that this is actually the "back" of the fallout plume (the wind was blowing it north over open sea), and they didn't have any kind of radiological monitoring set up to see how far it went. As a result, this makes it look far more local than it was in reality. This is from a report I had originally found in the Marshall Islands database.

To make it even more clear what you’re looking at here: the wind in this shot was blowing north — so most of the fallout went north. But they only mapped the fallout that went south, a tiny amount of the total fallout. So it looks much, much more contained than it was in reality. You want to shake these guys, retrospectively.

It’s not that they didn’t know that fallout went further downwind. They had mapped the Trinity test’s long-range fallout in some detail, and starting with Operation Buster (1951) they had started mapping downwind plumes for lots of tests that took place at the Nevada Test Site. But for ocean shots, they didn’t their logistics together, because, you know, the ocean is big. Such is one of the terrible ironies of Bravo: we know its downwind fallout plume well because it went over (inhabited) land, and otherwise they probably wouldn’t have bothered measuring it.

The publicity given to Bravo meant that its fallout plume got wide, wide dissemination — unlike the Trinity test’s plume, unlike the other ones they were creating. In fact, as I mentioned before, there were a few “competing” drawings of the fallout cloud circulating internally, because fallout extrapolation is non-trivially difficult:

BRAVO fallout contours produced by the AFSWP, NRDL, and RAND Corp. Source.

But once these sorts of things were part of the public discourse, it was easy to start imposing them onto other contexts beyond islands in the Pacific Ocean. They were superimposed on the Eastern Seaboard, of course. They became a stock trope for talking about what nuclear war was going to do to the country if it happened. The term “fallout,” which was not used even by the government scientists as a noun until around 1948,1 suddenly took off in popular usage:

Google Ngram chart of the usage of the word "fallout" in English language books and periodicals. Source.

Google Ngram chart of the usage of the word “fallout” in English language books and periodicals. Source.

The significance of fallout is that it threatens and contaminates vast areas — far more vast than the areas immediately affected by the bombs themselves. It means that even a large-scale nuclear attack that tries to only threaten military sites is also going to do both short-term and long-term damage to civilian populations. (As if anyone really considered just attacking military sites, though; everything I have read suggests that this kind of counter-force strategy was never implemented by the US government even if it was talked about.)

It meant that there was little escaping the consequences of a large nuclear exchange. Sure, there are a few blank areas on maps like this one, but think of all the people, all the cities, all the industries that are within the blackened areas of the map:

Oak Ridge National Laboratory estimate of "accumulated 14-day fallout dose patterns from a hypothetical attack on the United States," 1986. I would note that these are very high exposures and I'm a little skeptical of them, but in any case, it represents the kind of messages that were being given on this issue. Source.

Oak Ridge National Laboratory estimate of “accumulated 14-day fallout dose patterns from a hypothetical attack on the United States,” 1986. I would note that these are very high exposures and I’m a little skeptical of them, but in any case, it represents the kind of messages that were being given on this issue. Source.

Bravo inaugurated a new awareness of nuclear danger, and arguably, a new era of actual danger itself, when the weapons got big, radiologically “dirty,” and contaminating. Today they are much smaller, though still dirty and contaminating.

I can’t help but feel, though, that while transporting the Bravo-like fallout patterns to other countries is a good way to get a sense of their size and importance, that it still misses something. I recently saw this video that Scott Carson posted to his Twitter account of a young Marshallese woman eloquently expressing her rage about the contamination of her homeland, at the fact that people were more concerned about the exposure of goats and pigs to nuclear effects than they were the islanders:

I’ve spent a lot of time looking at the reports of the long-term health effects on the Marshallese people. It is always presented as a cold, hard science — sometimes even as a “benefit” to the people exposed (hey, they got free health care for life). Here’s how the accident was initially discussed in a closed session of the Congressional Joint Committee on Atomic Energy, for example:

Chairman Cole: “I understand even after they [the natives of Rongelap] are taken back you plan to have medical people in attendance.”

Dr. Bugher: “I think we will have to have a continuing study program for an indefinite time.”

Rep. James Van Zandt: “The natives ought to benefit — they got a couple of good baths.”

Which is a pretty sick way to talk about an accident like this, even if all of the facts aren’t in yet. Even for a classified hearing.

What’s the legacy of Bravo, then? For most of us, it was a portent of dangers to come, a peak into the dark dealings that the arms race was developing. But for the people on those islands, it meant that “the Marshall Islands” would always be followed by “where the United States tested 67 nuclear weapons” and a terrible story about technical hubris, radioactive contamination, and long-term health problems. I imagine that people from these islands and people who grew up near Chernobyl probably have similar, terrible conversations.

A medical inspection of a Marshallese woman by an American doctor. "Project 4," the biomedical effects program of Operation Castle was initially to be concerned with "mainly neutron dosimetry with mice" but after the accident an additional group, Project 4.1, was added to study the long-term exposure effects in human beings — the Marshallese. Image source.

A medical inspection of a Marshallese woman by an American doctor. “Project 4,” the biomedical effects program of Operation Castle was initially planned to be concerned with “mainly neutron dosimetry with mice” but after the accident an additional group, Project 4.1, was added to study the long-term exposure effects in human beings — the Marshallese. Image source.

I get why the people who made and tested the bombs did what they did, what their priorities were, what they thought hung in the balance. But I also get why people would find their actions a terrible thing. I have seen people say, in a flip way, that there were “necessary sacrifices” for the security that the bomb is supposed to have brought the world. That may be so — though I think one should consult the “sacrifices” in question before passing that judgment. But however one thinks of it, one must acknowledge that the costs were high.

  1. William R. Kennedy, Jr., “Fallout Forecasting—1945 through 1962,” LA-10605-MS (March 1986), on 5. []

Sakharov’s turning point: The first Soviet H-bomb test

Friday, January 31st, 2014

The Soviets set off their first megaton-range hydrogen bomb in November 1955. It was the culmination of many years of effort, in trying to figure out how to use the power of nuclear fission to release the power of nuclear fusion in ways that could be scaled up arbitrarily.1 The Soviet bomb was designed to be a 3-megaton warhead, but they set it off at half strength to avoid too much difficulty and fallout contamination. Unlike the US, the Soviets tested their version version by dropping it out of a bomber — it was not a big, bulky, prototype like the Ivy Mike device. But it was not an uneventful test. The details are little talked about, but it serves as an impressive parable about what can go wrong when you are dealing with science on a big scale.

Andrei Sakharov, from nuclear weapons designer to aged dissident.

Andrei Sakharov, from young nuclear weapons designer to aged dissident. Source.

Andrei Sakharov has a stunning chapter on it in his memoirs. It makes for an impressive story in its own right, but Sakharov also identifies the experience as a transformative one in his own thinking about the responsibility of the scientist, as he made his way from nuclear weapons designer to political dissident.2

Sakaharov starts out by talking about going to Kazakhstan to see the test. He had by this time been assigned two armed KGB officers, known euphemistically as “secretaries,” whose jobs were to act as bodyguards and “to prevent undesirable contacts.” Sakharov claims not to be have been too bothered by them. They lived next door.

The test of the device, code-named RDS-37, was to be the 24th Soviet nuclear test, and was the largest ever tested at the Semipalatinsk test site. This created several logistical difficulties. In order to avoid local nuclear fallout, it was going to be an airburst. The size of the bomb, however, brought up the possibility that it might accidentally blow the bomber that delivered it out of the sky. To avoid this, the bomber was painted white (to reflect the thermal radiation), and a big parachute was applied to the bomb so that the bomber could get away fast enough. Sakharov was satisfied enough with the math on this that he asked if he could ride along on the bomber, but the request was denied.

Sakharov’s account lingers on the incongruity between testing nuclear weapons in beautiful, wild places. Siberia was “a new and spellbinding experience for me, a majestic, amazingly beautiful sight.” He continued: “The dark, turbulent waters of the Irtysh, dotted with a thousand whirlpools, bore the milky-blue ice floes northward, twisting them around and crashing them together. I could have watched for hours on end until my eyes ached and my head spun. Nature was displaying its might: compared to it, all man’s handiwork seems paltry imitation.

The RDS-37 test device. Source.

The RDS-37 test device. Source.

A test trial-run on November 18th went smoothly, but the first test attempt, on November 20th, did not. As David Holloway recounts in Stalin and the Bomb, that same Siberian wintery majesty that dazzled Sakharov made for difficult testing conditions.3 The fully-loaded Tu-16 bomber had to abort when the test site was unexpectedly covered by clouds, making them unable to see the target aiming point and rendering the optical diagnostic systems inoperable. The plane was ordered to land, only now it had a fully-armed experiment H-bomb on board. There was concern that if it crashed, it could result in a nuclear yield… destroying the airfield and a nearby town. The airfield had meanwhile iced over. Igor Kurchatov, the lead Soviet nuclear weapons scientist, drove out to the airfield himself personally to see the airfield. Sakharov assured him that even if it crashed, the odds of a nuclear yield were low. An army unit at the airfield quickly worked to clear the runway, and so Kurchatov ordered the plane to land. It did so successfully. Kurchatov met the crew on the field, no doubt relieved. Sakharov recalls him saying, “One more test like [this one] and I’m retiring.” As for Sakharov, he called it “a very long day.”

Two days later, they gave it another go. This time the weather cooperated, as much as Siberian weather cooperates. The only strange thing was a temperature inversion, which is to say, at higher altitudes it was warmer than at lower altitudes, the opposite of the usual. The meteorologists gave the go-ahead for the testing.

Sakharov stayed at a laboratory building on the outskirts of a small town near the test site. An hour before the test, Sakharov saw the bomber rising above the town. It was “dazzling white,” and “with its sweptback wings and slender fuselage extending far forward, it looked like a sinister predator poised to strike.” He recalled that “for many peoples, the color white symbolizes death.” An hour later, a loud-speaker began the countdown.

The white bomber. Source.

The white bomber. Source.

Sakharov described the test in vivid detail:

This time, having studied the Americans’ Black Book4, I did not put on dark goggles: if you remove them after the explosion, your eyes take time to adjust to the glare; if you keep them on, you can’t see much through the dark lenses. Instead, I stood with my back to ground zero and turned around quickly when the building and horizon were illuminated by the flash. I saw a blinding, yellow-white sphere swiftly expand, turn orange in a fraction of a second, then turn bright red and touch the horizon, flattening out at its base. Soon everything was obscured by rising dust which formed an enormous, swirling grey-blue cloud, its surface streaked with fiery crimson flashes. Between the cloud and the swirling durst grew a mushroom stem, even thicker than the one that had formed during the first [1953] thermonuclear test. Shock waves crisscrossed the sky, emitting sporadic milky-white cones and adding to the mushroom image. I felt heat like that from an open furnace on my face — and this was in freezing weather, tens of miles from ground zero. The whole magical spectacle unfolded in complete silence. Several minutes passed, and then all of the sudden the shock wave was coming at us, approaching swiftly, flattening the feather-grass.

“Jump!” I shouted as I leaped from the platform. Everyone followed my example except for my bodyguard (the younger one was on duty that day); he evidently felt he would be abandoning his post if he jumped. The shock wave blasted our ears and battered our bodies, but all of us remained on our feet except for the bodyguard on the platform, who fell and suffered minor bruises. The wave continued on its way, and we heard the crash of broken glass. Zeldovich raced over to me, shouting: “It worked! It worked! Everything worked!” Then he threw his arms around me. […]

The test crowned years of effort. It opened the way for a whole range of devices with remarkable capabilities, although we still sometimes encountered unexpected difficulties in producing them.

But they soon learned that a bruised bodyguard was the least of the injuries sustained in the test. Scientists and soldiers had been stationed far closer to the blast than Sakharov was. The scientists were fine — they were lying flat on the ground and the blast wave caused them no injury. One of them lost his cool and ran away from the blast, but he was only knocked down by it. But a nearby trench held a platoon of soldiers, and the trench collapsed. One young soldier, in his first year of service, was killed.

RDS-37 detonation

RDS-37, detonating. This is considerably sped up; it shows about 50 seconds of footage compressed into only a few seconds. Video source here.

There was also a nearby settlement of civilians affected by the blast wave. In theory it was at a distance remote enough to avoid anything serious; this had been calculated. But the aforementioned inversion layer reflected the shock wave back down to Earth with unusual vehemence — underscoring how even a little misunderstanding of the physics can translate into real problems when you are talking about millions of tons of TNT (something learned by the US a year earlier, at the Castle Bravo test). The inhabitants of the town were in a primitive bomb shelter. After the flash, they exited to see the cloud. Inside the shelter, however, was left a two-year-old girl, playing with blocks. The shock wave, arriving well after the flash, collapsed the shelter, killing the child. 

The ceiling of a woman’s ward of a hospital in another nearby village collapsed, seriously injuring many people. Glass windows broke at a meat-packing plant a hundred miles from the test site, sprinkling ground beef with splinters. Windows broke throughout the town where Sakharov was stationed.

RDS-37, seen from a local town. Also sped up. Same source as the previous.

The consequences of an explosion are hard to predict,” Sakharov concluded.

Had we been more experienced, the temperature inversion would have caused us to delay the test. The velocity of the shock wave increases as the temperature does: if the air temperature rises with altitude, the shock wave bends back towards the ground and does not dissipate as fast under normal conditions. This was the reason the shock wave’s force exceeded our predictions. Casualties might have been avoided if the test had been conducted as scheduled on November 20, when there was no temperature inversion.

As with Castle Bravo, there was a grim, almost literary connection between technical success and human disaster. They had shown the way forward for deployable, multi-megaton hydrogen bombs, but with a real cost — and that cost only an insignificant hint of what would happen if the weapons were used in war. Sakharov concluded:

We were stirred up, but not just with the exhilaration that comes with a job well done. For my part, I experienced a range of contradictory sentiments, perhaps chief among them a fear that this newly released force could slip out of control and lead to unimaginable disasters. The accident reports, and especially the deaths of the little girl and the soldier, heightened my sense of foreboding. I did not hold myself personally responsible for their deaths, but I could not escape a feeling of complicity.

That night, the scientists, the politicians, and the military men dined well. Brandy was poured. Sakharov was asked to give the first toast. “May all of our devices explode as successfully as today’s, but always over test sites and never over cities.”

Sculpture of Andrei Sakharov by Peter Shapiro, outside the Russia House Club & Restaurant on Connecticut Ave in Washington, DC. Image source.

Sculpture of Andrei Sakharov by Peter Shapiro, outside the Russia House Club & Restaurant on Connecticut Ave in Washington, DC. Image source.

The immediate response was silence. Such things were not to be said. One of the military higher-ups flashed a crooked grin, and stood to give his own toast. “Let me tell a parable. An old man wearing only a shirt was praying before an icon. ‘Guide me, harden me. Guide me, harden me.’ His wife, who was lying on the stove, said: ‘Just pray to be hard, old man, I can guide it myself.’ Let’s drink to getting hard.

Sakharov blanched at the crudity (“half lewd, half blasphemous”), and its serious implications. “The point of his story,” he later wrote, “was clear enough. We, the inventors, scientists, engineers, and craftsmen, had created a terrible weapon, the most terrible weapon in human history; but its use would lie entirely outside our control. The people at the top of the Party and military hierarchy would make the decisions. Of course, I knew this already — I wasn’t that naive. But understanding something in an abstract way is different from feeling it with your whole being, like the reality of life and death. The ideas and emotions kindled at that moment have not diminished to this day, and they completely altered my thinking.

  1. The Soviets tested their first thermonuclear bomb in 1953, the RDS-6s, which used fusion reactions. But it was not a true, multi-megaton capable hydrogen bomb. The 1953 device was “just” a very, very big boosted bomb, where 40 kilotons of fissioning produced 80 kilotons of fusioning which in turn produced another 280 kilotons of fissioning, for 400 kilotons total. The design could not be scaled up arbitrarily, though, and it did not use radiation implosion (like the Teller-Ulam design, known in the USSR as the “Third Idea.” It was a big bomb, but the 1955 test was the design that became the basis for their future nuclear warheads. []
  2. Andrei Sakharov, Memoirs, trans. Richard Lourie (New York: Knopf, 1990), 188-196. []
  3. David Holloway, Stalin and the bomb: The Soviet Union and atomic energy, 1939- 1956 (New Haven: Yale University Press, 1994), 314-316. []
  4. From elsewhere in the Memoirs, it seems that Sakharov may be referring here to the 1950 edition of Samuel Glasstone’s The Effects of Atomic Weapons. There was a hardcover edition that apparently had a black cover. Sakharov notes that the nick-name only “partly” came from the cover; he implies that the contents are “black” as well. However there is nothing about goggles or glare in the version of the text I have, so maybe it is something different. []