Posts Tagged ‘Manhattan Project’

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General Groves’ secret history

Friday, September 5th, 2014

The first history of the Manhattan Project that was ever published was the famous Smyth Report, which was made public just three days after the bombing of Nagasaki. But the heavily-redacted Smyth Report understandably left a lot out, even if it did give a good general overview of the work that had been done to make the bomb. Deep within the secret files of the Manhattan Project, though, was another, classified history of the atomic bomb. This was General Leslie Groves’ Manhattan District History. This wasn’t a history that Groves ever intended to publish — it was an internal record-keeping system for someone who knew that over the course of his life, he (and others) would need to be able to occasionally look up information about the decisions made during the making of the atomic bomb, and that wading through the thousands of miscellaneous papers associated with the project wouldn’t cut it.

Manhattan District History - Book 2 - Vol 5 - cover

Groves’ concern with documentation warms this historian’s heart, but it’s worth noting that he wasn’t making this for posterity. Groves repeatedly emphasized both during the project and afterwards that he was afraid of being challenged after the fact. With the great secrecy of the Manhattan Project, and its “black” budget, high priority rating, and its lack of tolerance for any external interference, came a great responsibility. Groves knew that he had made enemies and was doing controversial things. There was a chance, even if everything worked correctly (and help him if it didn’t!), that all of his actions would land him in front of Congress, repeatedly testifying about whether he made bad decisions, abused public trust, and wasted money. And if he was asked, years later, about the work of one part of the project, how would he know how to answer? Better to have a record of decisions put into one place, should he need to look it up later, and before all of the scientists scattered to the wind in the postwar. He might also have been thinking about the memoir he would someday write: his 1962 book, Now it Can Be Told, clearly leans heavily on his secret history in some places.

Groves didn’t write the thing himself, of course. Despite his reputation for micromanagement, he had his limits. Instead, the overall project was managed by an editor, Gavin Hadden, a civil employee for the Army Corps of Engineers. Individual chapters and sections were written by people who had worked in the various divisions in question. Unlike the Smyth Report, the history chapters were not necessarily written near-contemporaneously with the work — most of the work appears to have been started after the war ended, some parts appear to have not been finished until 1948 or so.

General Groves not amused

In early August 1945 — before the bombs had been dropped — a guide outlining the precise goals and form of the history was finalized. It explained that:

Tho purpose of the history is to serve as a source of historical information for War Department officials and other authorized individuals. Accordingly, the viewpoint of the writer should be that of General Groves and the reader should be considered as a layman without any specialized knowledge of the subject who may be critical of the Department or the project.

Which is remarkably blunt: write as if Groves himself was saying these things (because someday he might!), and write as if the reader is someone looking for something to criticize. Later the guide gives some specific examples on how to spin problematic things, like the chafing effect of secrecy:

For example, the rigid security restrictions of the project in many cases necessitated the adoption of unusual measures in the attainment of a local objective but the maintenance of security has been recognized throughout as an absolute necessity. Consequently, instead of a statement such as, “This work was impeded by the rigid security regulations of the District,” a statement such as, “The necessity of guarding the security of the project required that operations be carried on in — etc.” would be more accurate.1

This was the history that Groves grabbed whenever he did get hauled in front of Congress in the postwar (which happened less than he had feared, but it still happened). This was the history that the Atomic Energy Commission relied upon whenever it needed to find out what its predecessor agencies had done. It was a useful document to have around, because it contains all manner of statistics, technical details, legal details, and references to other documents in the archive.

"Dante's Inferno: A Pocket Mural" by Louis C. Anderson, a rather wonderful and odd drawing of the Calutron process. From Manhattan District History, Book 5, "Electromagnetic Project," Volume 6.

“Dante’s Inferno: A Pocket Mural” by Louis C. Anderson, a rather wonderful and odd drawing of the Calutron process. From Manhattan District History, Book 5, “Electromagnetic Project,” Volume 6.

The Manhattan District History became partially available to the general public in 1977, when a partial version of it was made available on microfilm through the National Archives and University Publications of America as Manhattan Project: Official History and Documents. The Center for Research Libraries has a digital version that you can download if you are part of a university that is affiliated with them (though its quality is sometimes unreadable), and I’ve had a digital copy for a long time now as a result.2 The 1977 microfilm version was missing several important volumes, however, including the entire book on the gaseous diffusion project, a volume on the acquisition of uranium ore, and many technical volumes and chapters about the work done at Los Alamos. All of this was listed as “Restricted” in the guide that accompanied the 1977 version.3

I was talking with Bill Burr of the National Security Archive sometime in early 2013 and it occurred to me that it might be possible to file a Freedom of Information Act request for the rest of these volumes, and that this might be something that his archive would want to do. I helped him put together a request for the missing volumes, which he filed. The Department of Energy got back pretty promptly, telling Bill that they were already beginning to declassify these chapters and would eventually put them online.

Manhattan Project uranium production flow diagram, from book 7, "Feed materials."

Manhattan Project uranium production flow diagram, from Manhattan District History, Book 7, “Feed materials.”

The DOE started to release them in chunks in the summer of 2013, and got the last files up this most recent summer. You can download each of the chapters individually on their website, but their file names are such that they won’t automatically sort in a sensible way in your file system, and they are not full-text searchable. The newly-released files have their issues — a healthy dose of redaction (and one wonders how valuable that still is, all these years — and proliferations — later), and some of the images have been run through a processor that has made them extremely muddy to the point of illegibility (lots of JPEG artifacts). But don’t get me started on that. (The number of corrupted PDFs on the NNSA’s FOIA website is pretty ridiculous for an agency that manages nuclear weapons.) Still, it’s much better than the microfilm, if only because it is rapidly accessible.

But you don’t need to do that. I’ve downloaded them all, run them through a OCR program so they are searchable, and gave them sortable filenames. Why? Because I want people — you — to be able to use these (and I do not trust the government to keep this kind of thing online). They’ve still got loads of deletions, especially in the Los Alamos and diffusion sections, and the pro-Groves bent to things is so heavy-handed it’s hilarious at times. And they are not all necessarily accurate, of course. I have found versions of chapters that were heavily marked up by someone who was close to the matter, who thought there were lots of errors. In the volumes I’ve gone the closest over in my own research (e.g. the “Patents” volume), I definitely found some places that I thought they got it a little wrong. But all of this aside, they are incredibly valuable, important volumes nonetheless, and I keep finding all sorts of unexpected gems in them.

You can download all of the 79 PDF files in one big ZIP archive on Archive.org. WARNING: the ZIP file is 760MB or so. You can also download the individual files below, if you don’t want them all at once.

Statistics on the ages of Los Alamos employees, from Ted Hall (19) to Niels Bohr (59). From Manhattan District History, Book 8.

Statistics on the ages of Los Alamos employees, May 1945, from the young spy, Ted Hall (19), to the old master, Niels Bohr (59). From Manhattan District History, Book 8.

What kinds of gems are hidden in these files? Among other things:

And a lot more. As you can see, I’ve drawn on this history before for blog and Twitter posts — I look through it all the time, because it offers such an interesting view into the Manhattan Project, and one that cuts through a lot of our standard narratives about how it worked. There are books and books worth of fodder in here, spread among some tens of thousands of pages. Who knows what might be hidden in there? Let’s shake things up a bit, and find something strange.


Below is the full file listing, with links to my OCR’d copies, hosted on Archive.org. Again, you can download all of them in one big ZIP file by clicking here, (760 MB) or pick them individually from below. Items marked with an asterisk are, as far as know, wholly new — the others have been available on microfilm in one form or another since 1977. Read the full post »

Notes
  1. E.H. Marsden, “Manhattan District History Preparation Guide,” (1 August 1945), copy in the Nuclear Testing Archive, Las Vegas, Nevada, accession number NV0727839. []
  2. In fact, I used portions of it — gasp! — on actual microfilm very early on my grad school career, when you still had to do that sort of thing. The volume on the patenting program was extremely useful when I wrote on Manhattan Project patent policies. []
  3. Some of the Los Alamos chapters were later published in redacted form as Project Y: The Los Alamos Story, in 1983. []
Meditations

The luck of Kokura

Friday, August 22nd, 2014

On the morning of August 9th, 1945, a B-29 bomber left the island of Tinian intending to drop an atomic bomb on the city of Kokura, the location of one of the largest arsenals still standing in Japan. On arriving at the target, the plane found it obscured by clouds. It turned south and went to its secondary target: Nagasaki. 

Supposedly, some in Japan still refer to the “luck of Kokura” in reference to this time in which some bad weather saved the lives of tens of thousands of people there. But what really happened that morning? Was it bad weather, or something else, that obscured, and thus saved, Kokura? 

Surprisingly, there are actually a few different theories floating around, and the uncertainty over the matter is generally not realized or acknowledged.

Model of the Kokura arsenal made for targeting purposes, ca. 1945. North is in the lower-right hand corner. Source: USAAF photos, via Fold3.com.

Model of the Kokura arsenal made for targeting purposes, ca. 1945. North is in the lower-right hand corner. Source: USAAF photos, via Fold3.com.

But first, let’s review the basics of the mission. The Kokura/Nagasaki mission (dubbed CENTERBOARD II), as with the Hiroshima mission before it (CENTERBOARD I), did not involve the bomber flying on its lonesome to the target, as is sometimes imagined. There were a total of six planes involved in the mission, all B-29 bombers. One of them was the strike plane that carried the Fat Man implosion bomb (Bockscar).1  Two other planes (The Great Artiste and Big Stink) were instrument and observation planes. One other plane was a “standby” plane (Full House) that was to serve as backup if the three bombing planes ran into air resistance — because they didn’t, it instead flew back to Iwo Jima instead of on to the target after a rendezvous with the bombing plane. Lastly, there were two weather planes that flew out in advance, one to Nagasaki (the Laggin’ Dragon), the other to Kokura (the Enola Gay, the same plane that had dropped the atomic bomb on Hiroshima a few days earlier, but with a different crew). The weather planes would check out bombing conditions and then circle back, helping the bomber plane determine whether the primary or secondary target would be used. Niigata, a third atomic bombing target, was not considered on this mission because of its great geographical distance from Kokura and Nagasaki.

Bockscar was being piloted by Major Charles Sweeney. It had taken off from the island of Tinian at 3:47am, Tinian time. They had arrived at a rendezvous point at Yakushima Island around 9:15am. It rendezvoused with one of the other B-29s (the instrument plane), but did not spot the other one (the photo plane). At 9:50am, the pilot of Bockscar, Charles Sweeney, gave up and continued on to Kokura, having waited some 30 minutes longer than he was supposed to. At 10:44am, they arrived at Kokura. The flight log records that “Target was obscured by heavy ground haze and smoke.” A crew member of Bockscar rated it as “7/10 clouds coverage – Bomb must be dropped visually but I don’t think our chances are very good.”2

Three bombing runs on Kokura were attempted, but “at no time was the aiming point seen,” as the flight log recorded. Visual bombing had been made a mandatory requirement (they did not trust the accuracy of radar-assisted bombing), so this made Kokura a failed mission. Since Bockscar had limited fuel, Sweeney decided to continue on to the secondary target, Nagasaki. They arrived at Nagasaki at 11:50am, which they also found obscured by smoke and clouds, to the degree that they made the target approach entirely by radar. Right at the last possible moment, the clouds parted just enough for the bombardier to site the target and drop the bomb. (It missed the intended target by a significant margin.) Bockscar circled the target once and then, at 12:05pm, took off for Okinawa, and from there, after refueling, Tinian.

Care about the details of the Hiroshima and Nagasaki bombings? Get this book.

Care about the details of the Hiroshima and Nagasaki bombings? Get John’s book. I’m not just saying that because he says nice things about my blog, either.

An aside: For anyone interested in the nitty-gritty details of the Hiroshima and Nagasaki missions, my go-to reference these days is John Coster-Mullen’s Atom Bombs: The Top Secret Insider Story of Little Boy and Fat Man. I first got a copy of John’s book in 2006 or so. John sent me a new copy a few months ago, and I have been impressed with how much new material he has added over the last 8 years. (And I have managed to find a few useful things for him over the years, which have made it into his book as well — duly credited!) If you’re interested in the history of the Manhattan Project, you can’t not have a copy of John’s book… and if your copy is over 5 years old, considered getting an updated edition! All of these little details about times and planes and whatnot come from John’s book.

So what caused the “heavy ground haze and smoke”?

Theory #1: Bad weather

The most common explanation for the obscuring of Kokura is one of weather. It seems to me to be a valid possibility, but let’s pick it apart a bit.

As noted, the Enola Gay had flown ahead to Kokura to scope out the visual conditions. They had radioed back that the visibility was “3/10 low clouds, no intermediate or high clouds, and forecast of improving conditions.”3 That was a favorable-enough weather report that Kokura, the primary target, was chosen as the first run. Upon arriving, however, Bockscar found the weather conditions were now 7/10 — too obscured to bomb. Is this plausible?

Summer weather patterns in Japan, map made in early 1945. Not great for bombing. Source: Produced for the USAAF's IMPACT magazine, high-res version via Fold3.com.

Summer weather patterns in Japan, map made in early 1945. Not great for bombing. Source: Produced for the USAAF’s IMPACT magazine, high-res version via Fold3.com. There is another wonderful map for winter weather as well.

General Groves, in his 1964 memoir, suggests that it might have been the case that the change in weather conditions was simply a matter of how much time had passed between the forecast and arrival of Bockscar. The strike plane was, as noted, delayed by around half an hour. Groves also implies that there may have been a difference between how visual the target was at an angle — how a bombardier sees it — and how it looks from straight above — how a weather plane sees it). He concludes that the reasons for the haze were “never determined.”4

On the face of it, it’s hard to know whether such a rapid change in visibility is possible through entirely natural causes. In some parts of the world, the weather can be very volatile. Japan is one of these parts of the world, especially around the late fall. The variability of Japanese weather conditions was something that the US Army Air Forces knew very well, and was one of the bane of their bombing plans. It was a major issue in the atomic bombing discussions as well since very early on. At the first Target Committee meeting in April 1945, weather was a major point of discussion:

…it was pointed out that the months in which the initial mission will be run constitute the worst weather months of Japan. […] Dennison pointed out that all weather maps indicated that there were only an average of 6 good bombing days in August and that of those 6 days a conservative estimate would probably result in safely predicting that we would have 3 good days in the month of August but these 3 good days could not be positively predicted in advance of more than 48 hours. 

Elsewhere in the memo it remarks that “3/10ths or less” cloud coverage was considered acceptable for visual bombing. It also notes that “only once in 6 years have there ever been 2 successive good visual bombing days of Tokyo,” which gives some indication of the weather’s variability.

Weather from the nearby city of Shimonoseki for August 8-9, 1945. Click to enlarge, or click here for the Excel file. Source: Japanese M

Weather from the nearby city of Shimonoseki for August 8-9, 1945. Click to enlarge, or click here for the Excel file. Source: Courtesy of the Japanese Meteorological Agency.

So it doesn’t seem impossible that it could have just been according to the weather, though the big difference between the conditions reported by the weather plane and the observed conditions by the strike plane seem, on the face of it, beyond what a half hour’s delay would accomplish. One question I don’t have the answer for is when the weather plane radioed those conditions back. In the case of the Hiroshima run, the weather plane was only 30 minutes earlier than the strike plane. If we assume that was a similar attempt on the second mission, it would mean that the strike plane was reaching the target over an hour after the weather plane had seen it, which could be a significant-enough delay for a serious change in visibility. (And another possibility is that the weather plane could have been, for whatever reason, incorrect — either at the wrong place or had its message garbled.)

There aren’t good weather records from this period, at least none I have seen. The closest site for state weather recording was in Shimonoseki, some 7 miles / 11 km northeast of Kokura. I asked the Japan Meteorological Agency for any records they had from that period and they sent me the above data.5 It is not especially helpful towards answering this question that I can see, but I’m not a meteorologist in the slightest. For me, the big take-away from the data is that it could go from totally clear to totally obscured over the course of an hour, which at least supports the plausibility of the weather theory.

Theory #2: Smoke from firebombing

One of the other causes put forward is that the “smoke and haze” seen over Kokura was actually a result of nearby firebombing. On August 8th, 1945, the 20th AF had sent 221 B-29s to the nearby city of Yahata (Yawata) to drop incendiary bombs.6 Yahata had been bombed several times during the war. It was, in fact, the site of the first B-29 attack on the Japanese homeland in June 1944, and indeed the first bombing attack against the Japanese homeland at all since the Doolittle raid. It had been bombed again in August 1944. The USAAF considered Yahata to be the largest steel producing center in the country, and dubbed it “the Pittsburgh of Japan.” It was the last Japanese city to be hit by a massive B-29 raid, a “night burn job” as a USAAF writer put it, and it was considered “leftover business” that had been scheduled to take place much earlier but delayed because of bad weather.7

Yahata/Yawata target map, March 1945. Kokura arsenal is visible to the east. Source: JapanAirRaids.org. Click here for the uncropped, unadjusted version.

Yahata/Yawata target map, March 1945. Kokura arsenal is visible to the east. Source: JapanAirRaids.org. Click here for the uncropped, unadjusted version.

The weather at Yahata had been 4/10 clouds over the target, but this didn’t matter for B-29 firebombing raids, because accuracy was not as big a concern as with the atomic bombs. The planes had arrived at Yahata around noontime. I’ve found very little in terms of documentation about how much of Yahata was burned out with this raid — perhaps because it was so late in the war, many of the traditional sources for information about incendiary bombing results (especially those contained on the invaluable website JapanAirRaids.org) essentially omit any discussion of this final big raid.

Could the bombing of Yahata have been the cause of the smoke that obscured Kokura? It doesn’t seem impossible, but it seems to me to be somewhat unlikely.

Approximate areas of interest in Yahata and Kokura, as seen on Google Earth today.

Approximate areas of interest in Yahata and Kokura, as seen on Google Earth today.

Bockscar was flying over Kokura just a little under 24 hours after the Yahata raid began. Incendiary raids did produce extreme amounts of smoke cover, as other photographic evidence indicates clearly. Yahata was only around 6 miles / 9 km west of Kokura (and their proximity is emphasized by the fact that both are today just considered wards of a larger city, Kitakyushu).

It seems odd that the Yahata smoke would have caught them off-guard. Wouldn’t the weather plane have noticed that there was smoke over Yahata rolling towards Kokura, or at least threatening it? Yahata is close enough that at the 30,000 feet or so that a weather plane would be flying over Kokura, all they would have to do is glance in its direction to see if there was heavy cloud cover. (One can easily replicate this experience with Google Earth if one chooses.) Could the smoke cloud have been lagged behind by just the amount of time that the weather plane wouldn’t see it, then rush ahead to obscure Kokura an hour later? Could the smoke have gone from non-obscuring to obscuring in just an hour? At the wind speeds measured at Shimonoseki (around 2-12 mph), it doesn’t strike me as super likely, but I’m not an expert in this kind of thing.

Theory #3: Japanese smokescreen

One last, more obscure theory. I first read of this in John Coster-Mullen’s book. I will quote him here:

When [Bockscar] finally arrived at 10:44 AM, smoke and industrial haze had obscured Kokura. Yahata had been firebombed by over 200 of LeMay’s B-29’s the previous day and the smoke had drifted over nearby Kokura. There was also a POW camp right next door to the main downtown power plan. An American prisoner in this camp reported later the Japanese had installed a large pipe that went from the power plant down to the river. He stated that whenever B-29’s were sighted over Kokura, the steam in the plant was diverted through this pipe and into the river. This created enormous condensation clouds that also helped to obscure the city.

John himself seems to have interviewed the POW camp survivor in question, and notes in a footnote that he thinks this was the first time this claim had surfaced in print. I certainly hadn’t seen it anywhere prior to John’s book. John asked Commander Ashworth about this in 1995, and Ashworth replied that this seemed possible, and added “if the Japanese really did that, then they were damn clever!”

German smokescreen use at Wilhelmshaven in June 1943. Caption: "Despite a smoke screen, 168 B-17s of the Eighth Air Force attacked Wilhelmshaven on 11 June. There are three lines of generators to windward of the area covered when the wind is in the north, as it was in this case. Generator boats are at the upper left. Despite the extent of the smoke screen hits are observed inside the circle..." Source: USAAAF IMPACT magazine, vol. 1, No. 5, August 1945, page 18.

German smokescreen use at Wilhelmshaven in June 1943. Caption: “Despite a smoke screen, 168 B-17s of the Eighth Air Force attacked Wilhelmshaven on 11 June. There are three lines of generators to windward of the area covered when the wind is in the north, as it was in this case. Generator boats are at the upper left. Despite the extent of the smoke screen hits are observed inside the circle…” Source: USAAAF IMPACT magazine, vol. 1, No. 5, August 1943, page 18.

A few weeks ago, there was a story carried by Japanese newspapers along these lines:

As the 69th anniversary of the Nagasaki atomic bombing approaches, a former mill worker in the present-day city of Kitakyushu, Fukuoka Prefecture, spoke about his untold story on how he burned coal tar to block the view of U.S. aircraft as they were about to drop the A-bomb on the city. … Of the three workers, Oita resident Satoru Miyashiro, 85, who worked at a can factory in the steel mill at around the end of the war said he burned coal tar to lay a smoke screen on Aug. 9, 1945. … Miyashiro said about two days before the Nagasaki attack Yawata steel workers learned that Hiroshima had been wiped out by the “new bomb” from their colleagues who had come back to Yawata via Hiroshima. He thought the next target would be his city as there were arms factories located in the area.

Note that this isn’t quite the same thing — this is someone in Yahata who was burning coal tar after hearing an air raid drill, and the smoke going downwind (east) to Kokura. I find it a little odd that the worker in question doesn’t mention that Yahata itself was firebombed less than a day before he decided to do this.

Are either of these theories plausible? In terms of, could they have done these things — of course. Turning on an incinerator is not an implausible action, and neither is the steam cloud scenario.

But would this have reduced the visibility over Kokura from 3/10 to 7/10 in the time it took the strike plane to get there? I’m not an atmospheric scientist, so I wouldn’t want to hazard a strong position on this. One can presumably model both of these scenarios and see if either were possible. I would be extremely interested if anyone wanted to that!

Susquehanna Steam Electric Station — just an example of what a very large nuclear power plant can generate in terms of steam. It's a lot of steam. Could it obscure a city downwind of it from a B-29 bomber? Image source.

Susquehanna Steam Electric Station — just an example of what a very large nuclear power plant can generate in terms of steam. It’s a lot of steam. Could it obscure a city downwind of it from a B-29 bomber? Image source.

My gut thought is that they were not super likely to be wholly responsible for the cloud cover. If it had been steam from a single plant, I suspect someone on Bockscar would have noted it as such. We have lots of experience with steam-generating power plants — think of the clouds created by nuclear cooling towers. They certainly can put out a lot of steam. Would it be enough to block off the entire city? I’m kind of dubious.

What about the coal tar possibility? I’m especially dubious that this would have been enough. Setting up honest-to-god smokescreen for an entire city is hard work, even if you are a professional. When the Germans wanted to protect individual places (like plants) from bombers they set up dozens to hundreds of smoke pots to do the job, or used multiple dedicated smoke generators. Some of the larger smokescreen images I have found clearly involve lots of smoke sources placed at good intervals upwind of the target they are meant to protect. So I don’t know.

On the other hand, if the smoke from Yahata was not from the firebombing but instead something deliberate, it would explain the time delay issue. If the wind was going due east at around 5 mph, that would in fact be perfect for putting a smoke cover over Kokura. So it has its merits as a theory.

Conclusion

There are narrative aspects of each theory that appeal, and each of them change what is meant by the “luck of Kokura.” If bad weather is what saved Kokura, then it becomes a metaphor for how serendipitously life and death are dealt out by the hands of fate. If it was smoke from the firebombing of Yahata, then it becomes an ironic story about the Army Air Forces’ zeal for destruction could become counterproductive. If it was the result of deliberate action on behalf of the Japanese, then it becomes something much more complicated, a story about how individual action may have led to the saving of some lives… and the dooming of others. It also would change the standard story of how defenseless the Japanese were against these weapons.

The bombing of Nagasaki. Original source. Slightly edited to improve foreground/background distinction.

Of course, what was lucky for Kokura was not so for Nagasaki.

Looking at these three options, I find the weather theory the easiest one to stomach. Japanese weather patterns were notoriously hard to predict and it was known as the worst season for bombing conditions. That they could change over an hour seems unsurprising to me, especially for a coastal city, where clouds can come and go which impressive rapidity (as someone who has lived in the Berkeley, Boston, and New York areas can attest). I like the irony of the Yahata story, but there are things that just don’t add up — I don’t see why the weather plane would not have mentioned it, and it seems implausible to me that it would take almost exactly 24 hours for the heavy cloud cover to have migrated a mere 5-10 miles. And for reasons indicated, I’m not sure I buy the smokescreen story — it would have been really difficult to pull off that degree of cloud cover reliably. It would have taken tremendous foresight and luck. And it is strange that this story would be “buried” for so long. This doesn’t mean that someone didn’t try it (I am emphatically not calling anyone a liar!). It just means that I’m not sure it would have worked even if they did try it.

A separate possibility is “all of the above.” Maybe the weather was bad. Maybe there was haze from the Yahata bombing. Maybe someone did try to release steam or smokescreen. Maybe all of these things occurred at once, making “the luck of Kokura” something that was the result of multiple causes. That would make Kokura extra lucky, I suppose, and not fit into any of the above pat narratives. And make Nagasaki extra un-lucky in turn.

In the end, it doesn’t really matter which of these things happened. The bare fact is that Kokura didn’t get bombed and Nagasaki did. But I find looking into these kinds of questions useful as a historian. Too often it is easy to take for granted that the explanations given in narrative works of history are “settled,” when really they are often resting on very thin evidence, thinner perhaps than the historian who writes them realizes. I don’t think we really know what happened at Kokura, and I’m not sure we ever truly will.

Notes
  1. Sometimes you see it as “Bock’s Car,” but it said “Bockscar” on the side of the B-29. This is one of those places where I say, “who cares?” but purists are concerned with this kind of detail. []
  2. Flight diary of Lt. Fred Olivi, quoted in Coster-Mullen’s book. []
  3. Bockscar flight log by Commander Frederick Ashworth, included in Norman F. Ramsey, “History of Project A,” (27 September 1945). A full of copy of Ramsey’s report is included in Coster-Mullen’s Atom Bombs book. []
  4. Leslie Groves, Now it Can Be Told, 345: “At Kokura, they found that visual bombing was not possible, although the weather plane had reported that it should be. Whether this unexpected condition was due to the time lag, or to the difference between an observer looking straight down and a bombardier looking at the target on a slant, was never determined.” []
  5. Here is the original Excel file they sent me. []
  6. Most US sources list the city as “Yawata,” but it apparently corresponds with what is today transliterated as the city of Yahata, in Fukoka prefecture, and there is an entirely different city known as Yawata in Kyoto Prefecture. The kanji is the same. Yahata has since been absorbed by Kitakyushu, along with Kokura. []
  7. Tom Prideaux, “Mission to Yawata, 7 Aug. 1945,” IMPACT, vol. 3, no. 9 (September-October 1945), 53. []
Meditations

A bomb without Einstein?

Friday, June 27th, 2014

If Albert Einstein had never been born, would it have changed when nuclear weapons were first produced? For whatever reason, I’ve seen this question being asked repeatedly on Internet forums, as odd as it is. It’s kind of a silly question. You can’t go in and tweak one variable in the past and then think you could know what the outcome would be. History is a chaotic system; start removing variables, who knows what would happen. Much less a variable named Albert Einstein, one of the most influential physicists of the 20th century, and whose importance extended well past the equations he wrote… and those were pretty important equations, at that!

1946 - Einstein Time magazine - detail

Einstein’s 1946 cover of Time magazine. The mushroom cloud is a beautifully executed combination of the Trinity and Nagasaki mushroom clouds.

On the other hand, this kind of science-fiction counterfactual can have its usefulness as a thought experiment. It isn’t history, but it can be used to illustrate some important aspects about the early history of the atomic bomb that a lot of people don’t know, and to undo a little bit of the “great man” obsession with bomb history. Albert Einstein has been associated with the bomb both through his famous mass-energy equivalence calculation (E=mc²) and because of the famous Einstein-Szilard letter to Roosevelt in 1939. On the face of it, this gives him quite a primary role, and indeed, he usually shows up pretty quickly at the beginning of most histories of the Manhattan Project. But neither E=mc² nor the Einstein-Szilard letter were as central to the Manhattan Project’s success as people realize — either scientifically or historically.

In terms of the science, E=mc² gets a lion’s share of attention, most perfectly expressed by Einstein’s portrait on the cover of Time magazine in 1946 (above) with his equation emblazoned on a mushroom cloud. A lot of people seem to think that E=mc² played a key role in the development of the bomb, that the weapon just falls out of the physics. This is wrong. The equation can help one understand why atomic bombs work, but it doesn’t really tell you how they work, or whether you would expect them to even be possible.

The way I like to put it is this: E=mc² tells you about as much about an atomic bomb as Newton’s laws do about ballistic missiles. At some very “low level” the physics is crucial to making sense of the technology, but the technology does not just “fall out” of the physics in any straightforward way, and neither of those equations tell you whether the technology is possible. E=mc² tells you that on some very deep level, energy and mass are equivalent, and the amount of energy that mass is equivalent is gigantic. But it says nothing about the mechanism of converting mass into energy, either whether one exists in the first place, or whether it can be scaled up to industrial or military scales. It gives no hints as to even where to look for such energy releases. After the fact, once you know about nuclear fission and can measure mass defects and things like that, it helps you explain very concisely where the tremendous amounts of energy come from, but it gives you no starting indications.

Eddington's famous plate of the 1919 solar eclipse, which helped confirm Einstein's theory of General Relativity. Very cool looking, and interesting science. But not relevant to atomic bombs. Source.

Eddington’s famous plate of the 1919 solar eclipse, which helped confirm Einstein’s theory of General Relativity. Very cool looking, and interesting science. But not relevant to atomic bombs. Source.

What about the rest of Einstein’s main theoretical work, both Special and General Relativity Theory? They are pretty irrelevant to bomb-making. The physical processes that take place inside atomic bombs are what physicists call “non-relativistic.” Relativity theory generally only shows its hand when you are talking about great speeds (e.g. large fractions of the speed of light) or great masses (e.g. gravitational fields), and neither of those come into play with fission bombs. You can neglect relativity when doing the math to make a bomb.1

An intelligent follow-up question might be: “well, just because relativity theory didn’t play a role in the bomb process itself doesn’t answer the question of whether it started physics on a path that led to the bomb, does it?” Without getting into a long timeline of the “science that led to the bomb,” here, I think we could reasonably summarize the situation like this: Einstein’s 1905 papers (of which E=mc² was one) did indeed play a role in the subsequent developments that followed, but perhaps not as direct a one as people think. E=mc² didn’t inspire physicists to start looking into processes that converted mass to energy — they were already looking into those through an entirely separate (and earlier) line of development, namely the science of radioactivity and particle physics. The fact that huge amounts of energy were released through nuclear reactions, for example, had already been studied closely by the Curies, by Ernest Rutherford, and by Frederick Soddy prior (but only just) to 1905.

Arguably, the most important work Einstein did in this respect was his work on the photoelectric effect (for which he was awarded the Nobel Prize in Physics for 1921), which helped establish the physical reality of Max Planck’s idea of a quantum of energy, which helped kick off investigations into quantum theory in earnest. This had a big influence on the later direction of physics, even if Einstein himself was never quite comfortable with the quantum mechanics that developed in subsequent decades.

The Hahn-Meitner-Strassman experiment apparatus, at the Deutsches Museum in Munich. My own photo.

The Hahn-Meitner-Strassman experiment apparatus, at the Deutsches Museum in Munich. My own photo.

Did any of the relativity work lead, though, down the path that eventually arrived at the discovery of fission in 1939? I don’t think so. The experiments that Hahn, Meitner, and Strassman were doing in Berlin that lead to the discovery of fission in uranium were themselves careful replications of work that Fermi had done around 1934. Fermi’s work came directly out of an experimentalist, nuclear physics context where physicists were bombarding substances with all manner of subatomic particles to see what happened. It was most directly influenced by the discovery of the neutron as a new sub-atomic particle by Chadwick in 1932. This came out of work on atomic theory and atomic modeling that was being done by Rutherford and his students from the early 1910s-1920s. And this early nuclear physics came, most directly, out of the aforementioned context of radioactivity and experimental physics of the late 19th century.

None of which has a strong, direct connection to or from Einstein’s work in my mind. They have some overlaps of interest (e.g. Bohr was a student of Rutherford’s), but the communities working on these sorts of experimental problems are not quite the same as the more theoretical circle that Einstein himself worked in.2 If we somehow, magically, removed Einstein’s early work from the equation here, does the output change much? There would be some reshuffling, probably, but I sort of think that Rutherford would still be doing his thing anyway, and from that much of the other work that led to the bomb would eventually come out, even if it had a somewhat different flavor or slightly different timeline.

My least favorite way of depicting the fission process, where energy (E) is a magic lightning bolt coming out of the splitting atom. In reality, most of the energy comes in the form of the two fission products (F.P. here) repelling from each other with great violence. Source.

This is my least-favorite way of depicting the fission process, where energy (E) is a magic lightning bolt coming out of the splitting atom. In reality, most of the energy comes in the form of the two fission products (F.P. here) repelling from each other with great violence. Source.

Do you even need to know that E=mc² to make an atomic bomb? Perhaps surprisingly, you don’t! There are other, more physically intuitive ways to calculate (or measure) the energy release from a fission reaction. If you treat the fission process as being simply based on the electrostatic repulsion of two fission products, you get essentially the same energy output in the form of kinetic energy. This is how the physics of fission is often taught in actual physics classes, because it gives you a more concrete indication of how that energy is getting released (whereas E=mc² with the mass-defect makes it seem like a magical lightning bolt carries it away). There are other more subtle physical questions involved in making a bomb, some of which have Einstein’s influence on them in one way or another (e.g. Bose–Einstein statistics). But I think it is not totally crazy to say that even if you somehow imagine a world in which Einstein had never existed, that the physics of an atomic bomb would still work out fine — Einstein’s specific technical work wasn’t central to the problem at all. We also have not brought up the question of whether without Einstein, relativity in some form would have been discovered anyway. The answer is probably “yes,” as there were people working on similar problems in the same areas of physics, and once people started paying a close attention to the physics of radioactivity they were bound to stumble upon the mass-energy relationship anyway. This isn’t to denigrate or underestimate Einstein’s influence on physics, of course. What makes Einstein “Einstein” is that he, a single person, pulled off a great number of theoretical coups all at once. But if he hadn’t done that, there’s no reason to think that other people wouldn’t have come up with his theoretical insights individually, if slightly later.

A postwar re-creation of the genesis of the Einstein-Szilard letter.

A postwar re-creation of the genesis of the Einstein-Szilard letter.

What about Einstein’s most direct role, the famous Einstein-Szilard letter of 1939 that influenced President Roosevelt to set up the first Uranium Committee? This is a tricky historical question that could have (and may at some point) an entirely separate blog post relating to it. Its writing, contents, and influence are more complex than the standard “he wrote a letter, FDR created the Manhattan Project” understanding of it that gets boiled down in some popular accounts. My feeling about it, ultimately, is this: if the Einstein-Szilard letter hadn’t been written, it isn’t clear that anything would be terribly different in the outcome in terms of making the bomb. Something like the Uranium Committee might have been started up anyway (contrary to popular understanding, the letter was not the first time Roosevelt had been told about the possibility of nuclear fission), and even if it hadn’t, it isn’t clear that the Uranium Committee was necessary to end up with a Manhattan Project. The road from a fission program whose primary output was reports and a fission program whose primary output was atomic bombs was not a direct one. By early 1941, the Uranium Committee had failed to convince scientist-administrators that atomic bombs were worth trying to build. They had concluded that while atomic bombs were theoretically feasible, they were not likely to be built anytime soon. Had things stayed there, it seems unlikely the United States would have built a bomb ready to use by July/August 1945.

The “push” came from an external source: the British program. Their MAUD Committee (an equivalent of the Uranium Committee) had concluded that a nuclear weapon would be much easier to build than the United States had concluded, and sent an emissary (Mark Oliphant) to the United States to make sure this conclusion was understood. They caught Vannevar Bush’s ear in late 1941, and he (along with Ernest Lawrence, Arthur Compton, and others) wrested control of the uranium work out of the hands of the Uranium Committee, accelerated the work, and morphed it into the S-1 Committee. The name change is significant — it is one of the more vivid demonstrations of the increased degree of seriousness with which the work was taken, and the secrecy that came with it. By late 1942, the wheels for the full Manhattan Project were set into motion, and the work had become a real bomb-making program.

Einstein wasn’t involved with any of the later work that actually led to the bomb. He almost was, though: in late 1941, Bush considered consulting Einstein for help on the diffusion problem, but opted not to push for it — both because Einstein wasn’t regarded as politically reliable (he had a fat FBI file), and his approach to physics just wasn’t very right for practical problems.3 Bush decided that Einstein would stay out of the loop.

Usual, rare anti-Nazi propaganda postcard from 1934, showing Hitler expelling Einstein from Germany, titled "The Ignominy of the 20th Century." It is one of the most blatant visual renderings of Einstein as a "scientific saint." Source.

Unusual, rare anti-Nazi propaganda postcard from 1934, showing Hitler expelling Einstein from Germany, titled “The Ignominy of the 20th Century.” It is one of the most blatant visual renderings of Einstein as a “scientific saint.” Source.

Let’s sum it up. Did Einstein play a role in the creation of the atomic bomb? Of course — his physics isn’t irrelevant, and his letter to Roosevelt did start one phase of the work. But both of these things are less prominent than the Time-magazine-cover-understanding makes them out to be. They weren’t central to what became the Manhattan Project, and if you could somehow, magically, remove Einstein from the equation, it isn’t at all clear that the atomic bomb wouldn’t have been built around the time it actually was built. I don’t think you can really credit, or blame, Einstein for the atomic bomb, in any direct fashion. Einstein did play a role in things, but that role wasn’t as crucial, central, or direct as a lot of people imagine. If you could magically drop him out of history, I think very little in terms of atomic bombs would have been affected.

So why does the Einstein and the bomb myth persist? Why does everybody learn about the Einstein letter, if it wasn’t really was sparked the Manhattan Project? There are two answers here, I think. One is that Einstein was, even before the war, one of the best-known, best-recognized physicists of the 20th century, and was synonymous with revolutionary science and genius. Having him “predict” the atomic bomb with equations in 1905 — 40 years before one was set off — is the kind of “genius-story” that people love, even if it obscures more than it enlightens. It also has a high irony quotient, since Einstein was forced to flee from Germany when the Nazis took power.

But there’s another, perhaps more problematic aspect. In many early copies of the Smyth Report that were distributed by the government, copies of the Einstein letter were mimeographed and loosely inserted. The magnification of Einstein’s role was purposefully encouraged by the government in the immediate period after using the weapon. (And it was even a convenient myth for Einstein, as it magnified his own importance and thus potential influence.) Hanging the atomic bomb on Einstein’s head was an act of self-justification, of sorts. Einstein was the world’s greatest genius in the eyes of the public, and he was a well-known pacifist, practically a scientific saint. After all, if Einstein thought building a bomb was necessary, who could argue with him?

Notes
  1. As Robert Serber puts it: “Somehow the popular notion took hold long ago that Einstein’s theory of relativity, in particular his famous equation E = mc², plays some essential role in the theory of fission. Albert Einstein had a part in alerting the United States government to the possibility of building an atomic bomb, but his theory of relativity is not required in discussing fission. The theory of fission is what physicists call a non-relativistic theory, meaning that relativistic effects are too small to affect the dynamics of the fission process significantly.” Robert Serber, The Los Alamos Primer: The First Lectures on How to Build an Atomic Bomb (University of California Press, 1992), 7. []
  2. For a good, non-teleological, non-bomb-centric approach to the context of 19th- and 20th-century physics, Helge Kragh’s Quantum Generations: A History of Physics in the Twentieth Century (Princeton University Press, 2002), is excellent. []
  3. Einstein wasn’t entirely a head-in-the-clouds physicist, of course. He worked at the patent office, and as Peter Galison has written about, even his famous thought experiments were often motivated by experience with practical problems of time synchronization. And he did help invent a refrigerator with Leo Szilard. But his work on diffusion physics was too abstract, too focused on first-principle analysis, for use in producing a practical outcome. []
Meditations

Feynman and the Bomb

Friday, June 6th, 2014

Richard Feynman is one of the best-known physicists of the 20th century. Most of those who know about him know he was at Los Alamos during the Manhattan Project — some of the best “Feynman stories” were set there. But Feynman’s own stories about his wartime hijinks were, like most of his stories about himself, half just-for-laughs and half lookit-mee! Feynman’s always got to either be a lucky average Joe, or the one brilliant mind in a sea of normals. His Los Alamos antics are mostly just tales of a genius man-child running around a secret laboratory, picking safes and irritating security guards. They aren’t very good gauges of what he actually did towards making the bomb. So what did Feynman actually do with regards to making the bomb? And does it matter, for thinking about his later career, especially the work that won him a Nobel Prize two decades later? 

Los Alamos colloquium from 1946, featuring (foreground, from left-to-right), Norris Bradbury, J. Robert Oppenheimer, John Manley, Richard Feynman, and Enrico Fermi. This version is cropped from the scanned copy at the Emilio Segrè Visual Archives. I will note that unlike the more common copies of this photo that have circulated, you can actually get a sense for how many other people were in the room — it looks like a really packed house.

Los Alamos colloquium from 1946, featuring (foreground, from left-to-right), Norris Bradbury, J. Robert Oppenheimer, John Manley, Richard Feynman, and Enrico Fermi. This version is cropped from the scanned copy at the Emilio Segrè Visual Archives. I will note that unlike the more common copies of this photo that have circulated, you can actually get a sense for how many other people were in the room — it looks like a really packed house.

Feynman’s own stories of his wartime work are centered around things other than the work itself. So he describes doing calculations, but doesn’t really say what they were for. He describes going to Oak Ridge, but only as a pretext for a story about dealing with generals and engineers. He describes the Trinity test, but a lot of that is about his claim to being the only person who saw it without welding glass on. And so on. These give glimpses, but not a very complete picture.

The historian of physics (and my advisor) Peter Galison wrote an article on “Feynman’s War” several years back, looking closely at what it actually was that Feynman was doing at the lab, and how it played into the style that he later became famous for in physics.1 Galison argues that Feynman’s postwar work is uniquely characterized by being “modular, pictorial, and proudly unmathematical.” He contrasts this with the work of several of his contemporaries, including Julian Schwinger, who came up with equivalent solutions to the same physical problems but through a very different (much more mathematical) approach. Feynman’s famous diagrams, which had a huge influence on the teaching and practice of postwar physics, exemplify this approach. What in Schwinger and Tomonaga’s hands (the other people Feynman shared his Nobel Prize with in 1965) was solvable only through massive, lengthy, laborious math could, in Feynman’s hands, be solved through a series of clever diagrams which came up with equivalent results. Feynman’s solutions to quantum electrodynamics weren’t the only way to do it — but they were easier to comprehend, to teach, and to apply to new questions.

The first Feynman diagram, published in R. P. Feynman, "Space—Time Approach to Quantum Electrodynamics,"Physical Review 76 (1949), 769-789, on 772.

The first published Feynman diagram, from Richard P. Feynman, “Space-Time Approach to Quantum Electrodynamics,”Physical Review 76 (1949), 769-789, on 772.

OK, so what does this have to do World War II? Well, Galison’s argument is that you can see the same sort of thinking at work in what Feynman did at Los Alamos, and he argues that it is during the war that he really started applying this mode of physics. He divides Feynman’s work into several “projects.” They were:

  • Neutron measurements for determining critical mass (including the famous “tickling the dragon’s tail” experiment” involving creating brief, barely-subcritical masses)
  • Work on the “Water Boiler” reactor at Los Alamos, which provided further data on nuclear chain reactions
  • Work as a safety supervisor at Oak Ridge, Tennessee, at Oppenheimer’s request (which in his own writings is distilled down to a single humorous anecdote where Feynman is simultaneously clueless and brilliant)
  • Developing formulae relating to criticality and implosion efficiency (including the Bethe-Feynman formula)
  • His work on the hydride bomb, an abortive, Teller-inspired approach to make a “cheaper” fission weapon which involved devilishly difficult calculation (because not all of the neutrons produced in the weapon would be of the same energy)

Galison argues that in each of these instances, you can see the germs of his later approaches. He credits this to both Feynman’s own personal scientific style and inclinations as a theorist (Feynman didn’t seem to like to work with fundamental equations, but with “shortcuts” that lead to quicker, more efficient solutions, for example), but also to the requirements of the wartime goal, where theorists had to come up with tangible, practical results in a very short amount of time.  For example, Galison notes that the formulae relating to how the implosion bomb worked “brought the abstract differential equations to the bottom line: how hot, how fast, how much yield?” The practical needs of the war favored a particular “theoretical style” in general, Galison argues, one that could be most easily meshed with engineering concerns, rapid prototyping, and the lack of time to ruminate on fundamental physics questions.2

The "Water Boiler" reactor at Los Alamos. Source: Los Alamos Archives (12784), via Galison 1998.

The “Water Boiler” reactor at Los Alamos that Feynman worked on. Source: Los Alamos Archives (12784), via Galison 1998, p. 404.

Galison’s article is fairly technical. He goes through Feynman’s work (what of it that is declassified, anyway) and tries to follow his thinking in a very “internal” way, and then match that up with the requirements imposed by the specific wartime context. If you are well-versed in physics you will probably find the details interesting. I’m more of a big-picture person myself, and I like the structure of Galison’s argument even if I don’t feel fully capable of digesting all of the physics involved. One small example of Galison’s work can probably suffice. Feynman was sent to Oak Ridge, as noted, to serve as a safety supervisor. He was taking over for Robert Christy, who got pneumonia in April 1944. The safety question was not a general one, but a very specific one: how many barrels of uranium (in various degrees of enrichment) could be safely stored in a room without running a risk of a criticality accident? Feynman himself relates the problem like this in his famous bit, “Los Alamos from Below” (reproduced in Surely You’re Joking, Mr. Feynman):

It turned out that the army had realized how much stuff we needed to make a bomb — twenty kilograms or whatever it was — and they realized that this much material, purified, would never be in the plant, so there was no danger. But they did not know that the neutrons were enormously more effective when they are slowed down in water. In water it takes less than a tenth — no, a hundredth — as much material to make a reaction that makes radioactivity. It kills people around and so on. It was very dangerous, and they had not paid any attention to the safety at all.

In Feynman’s account, he more or less walks in and figures out what the problems were and how to fix them. The story is about ignorance — in particular systemic ignorance due to secrecy — and Feynman’s attempts to cut through it.

Feynman's diagrammatic sketch of storage of barrels of uranium at Oak Ridge, prepared for his "Safety Report." Source: Galison 1998, p. 408.

Feynman’s diagrammatic sketch of storage of barrels of uranium at Oak Ridge, prepared for his “Safety Report.” Source: Galison 1998, p. 408.

Galison’s account is more technical. Feynman told them that pretty much any amount of unenriched uranium could be stored safely in the facility, but that 5% enriched and 50% enriched had to be handled fairly carefully. 50% enriched uranium in water, for example, would dangerous at a mere 350 grams of material unless there was a neutron absorbing material (cadmium) present. Feynman developed a series of safety recommendations for all grades of enrichments, and had to use reasonable safety margins to make up for potential errors in the calculations. He became the “point man” for safety questions involving fissionable materials, and developed (as Galison puts it) “visualizable” methods for answering basic (but important) questions about hypothetical systems (e.g. for “Gunk storage tanks,” whether they had to be coated with cadmium or not). His methods, Feynman himself emphasizes, were “only approximate, as accuracy has been sacrificed to speed and simplicity in calculation” — the kind of computational “short cut” that was both needed for the practical requirements, but also was common to Feynman’s general approach to physics. Galison concludes the section thus:

The admixture of approximation methods, neutron diffusion, nuclear cross sections, floods, fires and wooden walls marked Feynman’s correspondence with the Oak Ridge engineers. From April of 1944 to September 1945, whatever else Feynman was doing, he was also deeply enmeshed in the barely-existing field of nuclear engineering. Out of this interaction came characteristic rules and modular reasoning: visualizable, approximate, from-the-ground-up calculations applied to neutrons, pans, sheds and sludge. Visionary statements reinterpreting established laws of physics ceded to the exigencies of living in a world he had to reach outside the home culture of theoretical physics as he knew it before the war. Now a billion dollar plant was churning out U-235, and only a calculation stood between thousands of workers and nuclear disaster.

Which is a lot more serious-sounding that Feynman’s own somewhat jokey accounts of the work. In the latter part of the article, Galison connects all of these methods for thinking — and sometimes even the specific problems — with Feynman’s postwar work, showing the influence of his time at Los Alamos.

Diagram of neutron fluctuations from a report by F. de Hoffmann, R.P. Feynman, and R. Serber. Galison notes: "Significantly, Feynman and his collaborators captured the situation in a spacetime diagram drawn with time in the vertical direction and space horizontal. Such an image must be kept in mind when viewing Feynman's early postwar spacetime 'Feynman diagrams,' where again particles are absorbed, emit other particles, and scatter as reckoned by a concatenation of independent algebraic rules." Galison 1998, 405-406.

Diagram of neutron fluctuations from a report by F. de Hoffmann, R.P. Feynman, and R. Serber. Galison notes: “Significantly, Feynman and his collaborators captured the situation in a spacetime diagram drawn with time in the vertical direction and space horizontal. Such an image must be kept in mind when viewing Feynman’s early postwar spacetime ‘Feynman diagrams,’ where again particles are absorbed, emit other particles, and scatter as reckoned by a concatenation of independent algebraic rules.” Galison 1998, 405-406.

Feynman stayed at Los Alamos until the fall of 1946, when he relocated to Cornell University. He never worked on weapons again, but he never took a particularly strong stand on it. What did Feynman think about nuclear weapons, and his role in making them? There is some evidence in his private correspondence, much of which was published not too long ago,3 but it is scant. Most of his responses to inquiries were along the lines of “we feared the Nazis would get one first.”4That’s it. No comment on their use at all, or the end of the war, or any of the other common responses from Los Alamos veterans. When asked in the 1970s about his thoughts on nuclear weapons in general, he demurred: “Problems about the atomic bomb and the future are much more complicated and I cannot make any short  statement to summarize my beliefs here.”5

Feynman gave an interview in 1959 where he was asked directly about the bomb. His response was a little lengthier then, but still said very little:

Now, with regard to our own things as human beings, naturally—I myself, for example—worked on the bomb during the war. Now how do I feel about that? I have a philosophy that it doesn’t do any good to go and make regrets about what you did before but to try to remember how you made the decision at the time. …if the scientists in Germany could have developed this thing, then we would be helpless, and I think it would be the end of the civilization at that time. I don’t know how long the civilization is going to last anyway. So the main reason why I did work on it at the time was because I was afraid that the Germans would do it first, and I felt a responsibility to society to develop this thing to maintain our position in the war.6

This, of course, ignores the question of “so why did you continue when the Germans were known not to have made much progress?” and much more.

Charles Critchfield, Richard Feynman, J. Robert Oppenheimer, and an unidentified scientist, at Los Alamos. Source: Emilio Segrè Visual Archives, via Los Alamos.

Charles Critchfield, Richard Feynman, J. Robert Oppenheimer, and an unidentified scientist, at Los Alamos. Source: Emilio Segrè Visual Archives, via Los Alamos.

During the interview, Feynman was asked, point blank, whether he worked on any secret projects. Feynman said no, and that this was “out of choice.” Pushed further, he elaborated:

I don’t want to [do secret work] because I want to do scientific research—that is, to find out more about how the world works. And that is not secret; that work is not secret. There’s no secrecy associated with it. The things that are secret are engineering developments which I am not so interested in, except when the pressure of war, or something else like that, makes me work on it. … Yes, I am definitely anti-working in secret projects. … I don’t think things should be secret, the people developing this. It seems to me very difficult for citizens to make a decision as to what’s going on when you can’t say what you’re doing. And the whole idea of democracy, it seems to me, was that the public, where the power is supposed to lie, should be informed. And when there’s secrecy, it’s not informed. Now, that’s a naive point of view, because if there weren’t secrecy, there’d be the Russians who would find out about it. On the other hand, there’s some awfully funny things that are secret. It becomes secret that we know what the Russians are keeping secret from us, for instance, or something like that. It seems to me that things go too far in the secrecy.7

After that point in the interview, he steered away from political opinions, explaining that he had strong ones, but he didn’t think they were any more valuable than anyone else’s opinions.

There were those, of course, who did try to recruit Feynman for military work. John Wheeler, his doctoral advisor at Princeton, and the man who had roped him into Los Alamos in the first place, appealed to him strongly to join the Princeton work on the hydrogen bomb (Matterhorn) in late March 1951. Wheeler had heard the Feynman was trying to spend his sabbatical in Brazil, but Wheeler thought the chance of global war was “at least 40%,” and that Feynman’s talents might be better spent helping the country. It was a long, emotional letter, albeit a variation on one that Wheeler sent to many other scientists as well. Wheeler tried to win him (and others) with flattery as well, telling Feynman that “You would make percentage-wise more difference there than anywhere else in the national picture.” In response to Wheeler’s long, many-pointed letter, Feynman simply responded that he didn’t want to make any commitments until he found out whether the Brazil idea would work out. End of story. Nothing specific about the hydrogen bomb one way or the other.

High resolution detail of Feynman's Los Alamos security badge photograph. A this resolution you can see a lot more strain on his face than the one I posted awhile back. Source: Los Alamos National Laboratory Archives.

High-resolution detail of Feynman’s Los Alamos security badge photograph. At this resolution you can see potentially more strain on his face than the one I posted awhile back. Source: Los Alamos National Laboratory Archives.

What should we make of this? Feynman is a complicated man. Much more complicated than the zany stories let on — and I suspect the stories themselves were some kind of defense mechanism. As Feynman’s friend Murray Gell-Mann said at Feynman’s memorial service, Feynman “surrounded himself with a cloud of myth, and he spent a great deal of time and energy generating anecdotes about himself.” They were stories “in which he had to come out, if possible, looking smarter than anyone else.”8 He was not a moralizer, though. His work on the bomb fit into his stories only as a context. He no doubt drew many lessons from his work on nuclear weapons, and he no doubt had many opinions about them in the Cold War, but he kept them, it seems, much to himself.

Oppenheimer famously said that, “In some sort of crude sense, which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin…” Perhaps Feynman agreed — perhaps no more humor could be wrung out of the bomb after Hiroshima and Nagasaki. Maybe it’s harder to write a zany story about the hydrogen bomb. And maybe he was just truly not interested in them from a technical standpoint, or, as he said in 1959, just didn’t think his opinions on these matters, one way or another, were worth a damn, going against the notion held by many of his contemporaries that those who made the bomb had a special knowledge and a special responsibility. To me, he’s still something of an enigma, just one that wrapped himself in jokes, rather than riddles.

Notes
  1. Peter Galison, “Feynman’s War: Modelling Weapons, Modelling Nature,” Stud. Hist. Phil. Mod. Phys. 29, No. 3 (1998), 391-434. []
  2. This is an argument that Galison also makes at length about wartime work in his 1997 book Image and Logic: A Material Culture of Microphysics, both for Los Alamos and for the MIT Rad Lab, which if you’re interested in this kind of thing, is a must-read. []
  3. Michelle Feynman, ed., Perfectly Reasonable Deviations from the Beaten Track: The Letters of Richard P. Feynman (Basic Books, 2005). []
  4. See e.g., Ibid., 268: “I did work on the atomic bomb. My major reason was concern that the Nazi’s would make it first and conquer the world.” []
  5. Ibid., 305. []
  6. Ibid., 421. []
  7. Ibid., 422-423. []
  8. James Gleick, Genius: The Life and Science of Richard Feynman (Pantheon, 1992), on 11. []
Visions

Silent Nagasaki

Friday, February 7th, 2014

Teaching and other work has bogged me down, as it sometimes does, but I’m working on a pretty fun post for next week. In the meantime, here is something I put together yesterday. This is unedited (in the sense that I didn’t edit it), “raw” footage of the loading of the Fat Man bomb into the Bockscar plane on the island of Tinian, August 9th, 1945. It also features footage of the bombing of Nagasaki itself. I got this from Los Alamos historian Alan Carr a while back. I’ve added YouTube annotations to it as well, calling out various things that are not always known.

You have probably seen snippets of this in documentaries and history shows before. But I find the original footage much more haunting. It was filmed without sound, so any sound you hear added to this kind of footage is an artifact of later editing. The silent footage, however, makes it feel more “real,” more “authentic.” It removes the Hollywood aspect of it. In that way, I find this sort of thing causes people to take the events in the footage more seriously as an historical event, rather than one episode in “World War II, the Movie.”

I posted it on Reddit as well, and while there was some share of nonsense in the ~700 comments that it accrued, there was also a lot of expression of empathy and revelation, and a lot of good questions being asked (e.g. Did the people loading Fat Man into the plane know what they were loading? Probably more than the people who loaded Little Boy did, because they knew what had happened at Hiroshima). So I think some learning has happened, and I think the fact that this has gotten +100,000 views in just a day is some sign that there is quite an audience out there for this sort of stripped-down history.

There is also Hiroshima footage, but it isn’t quite as good, on the whole. It is largely concerned with the crew of the plane taking off and arriving. Which is interesting, in a sense, but visually doesn’t mean much unless you know who everybody is.

There is a lot of Trinity test footage as well which I will upload and annotate in the future as well.

Until next week!