Posts Tagged ‘Edward Teller’


James B. Conant on Trinity (1945)

Monday, July 16th, 2012

This week, you'll get your weekly document on a Monday, because it's a special occasion. Today, July 16, 2012, is the 67th anniversary of the first test of an atomic bomb: "Trinity." 

A photo negative from the first milliseconds of the nuclear age. The bright spots are where the negative was burnt through by the heat. Photo by Berlyn Brixner; scanned from the National Archives Still Pictures Branch, 454-RF-12A (TR84-1).

A lot has been written about "Trinity." What I thought I'd offer up is a perspective on the test that you've probably never seen — the personal account of James B. Conant, President of Harvard and key figure in the Manhattan Project.

The original document isn't easy to come by — it was withdrawn from the Bush-Conant File when it was microfilmed — but James Hershberg, when writing his great Conant biography (James B. Conant: Harvard to Hiroshima and the Making of the Nuclear Age) managed to get access to it, where it is reprinted as an appendix. It's one of the more gripping of the many personal accounts of the first bomb test, and as far as I've seen, isn't posted anywhere else on the web.

James B. Conant (fourth from left) at a meeting with Uranium Committee principles at UC Berkeley, March 1940. Left to right: Ernest O. Lawrence, Arthur C. Compton, Vannevar Bush, Conant, Karl Compton, Alfred L. Loomis.

This transcription is Hershberg's; the original is no doubt in Conant's impossible handwriting. Any notes italicized in brackets are Hershberg's, any not-italicized are mine.1

Rather than breaking it up with comments, I've added footnotes to highlight little points or add a little depth to things that you might not be familiar with, unless you are a serious Manhattan Project nerd. The footnotes are only visible if you look at this post in "single post" mode, rather than via the main site's front page. If you don't see any footnotes, click on the title of this post at the top. The bolding is by me. Any non sic'd typos are probably by me, too!

Conant and Bush reenact a post-Trinity handshake for the "March of Time" documentary on the atomic bomb. Apparently they were really just in a Boston garage for the reenactment. Via the New York Times.

Notes on the "Trinity" Test Held at Alamogordo Bombing Range

125 miles south east of Alburquerque

5:30 a.m. Monday, July 16

V. Bush, Gen. Groves, and J.B.C. arrived at the Base Camp located 10 miles from the bomb at about 8 p.m. Sunday evening. After dinner at the mess and some brief explanation by [J.R.] Oppenheimer, [R.C.] Tolman, [G.] Kistiakowsky, and [I.I.] Rabbi [sic] in very informal conversation we went to bed. The atmosphere was a bit tense as might be expected but everyone felt confident that the bomb would explode. The pool on the size of the explosion ran from 0 (a few pessimists) to 18,000 (Rabbi [sic]) and perhaps someone at 50,000 [several words censored].2 My own figure was 4400 [tons of T.N.T.] but I never signed up.3 It was a bad night though the weather forecast had been favorable for a clear early morning with light winds (the desired condition). From about 10:30 to 1 a.m., it blew very hard thus preventing sleep in our tent and promising a postponement of the Test. Then it poured for about an hour!

At 1 a.m. General Groves arose and went out to the forward barricade with the key personnel. There were two forward bases located 10,000 yds. N. & S. of the bomb. The [wiring?] from [this?] point to the test and to the camp was fantastic in the [extreme?].4 The instrumentation of the test included a vast array of equipment. At 3:15 a.m., the rain having just ceased, Rabbi [sic]5 came into our tent (V. Bush and JBC) and said that there had been much talk of a postponement because of the weather but reports indicated a 75% chance of going through with it but at 5 a.m. instead of the scheduled 4 a.m.

We got up & dressed and drank some coffee about 4 a.m. and wandered around. The sky was still overcast. It had not rained however at the zero point (the bomb)6 and the [wires? lines?] were O.K. Word then came through about 4:30 that 5:10 would be the time. About 5 p.m. [sic a.m.] or a little after, word came that the firing would occur at 5:30. Shortly after, General Groves came back to the forward area. We prepared to view the scene from a slight rise near the camp. Col. S[tafford]. Warren [was] in charge of health.7 Tolman, Rabbi [sic], Gen. Groves & J.B.C. were more or less together.8 It was agreed that because of the expected (or hoped!) bright flash and the ultra violet light (no ozone to absorb it) it would be advisable to lie flat and look away at the start, then look through the heavy dark glass.

At 5:20 the sirens blew the 10 min signal then another at 5:25 and I think another 2 mins. before. We lay belly down facing 180 [degrees] away from the spot on the tarpaulin. I kept my eyes open looking at the horizon opposite the spot. It was beginning to be light, but the general sky was still dark particularly in the general direction I was looking. Through the loud speaker nearby I heard [Samuel] Allison counting the seconds minus 45, minus 40, minus 30, minus 20, minus 10. (The firing was done by some kind of timing devices started at minus 45 sec.) These were long seconds! Then came a burst of white light that seemed to fill the sky and seemed to last for seconds. I had expected a relatively quick and bright flash. The enormity of the light and its length quite stunned me. My instantaneous reaction was that something had gone wrong and that the thermal nuclear transformational of the atmosphere, once discussed as a possibility and jokingly referred to a few minutes earlier, had actually occurred.9  Slightly blinded for a second, I turned on my back as quickly as possible and raising my head slightly, could see the "fire" through the dark glass. At that stage it looked like an enormous pyrotechnic display with great boiling of luminous vapors, some spots being brighter than others. A picture from memory is as seen through heavy dark glass.

Trinity fireball drawing by James Conant

Very shortly this view began to fade and without thinking the glass was lowered and the scene viewed with the naked eye. The ball of gas was enlarging rapidly and turning into a mushroom. It was reddish purple and against the early dawn very luminous, though I instantly thought of it as colored [somewhere?]. Then someone shouted watch out for the detonation wave (this was 40 sec after zero time). Still on my back I heard the detonation but was not in a position to notice any blast (there was relatively little felt here). The sound was less loud or startling than I expected, but the shock of sensory impression was still dominant in my mind. Then I got up and watched the spread of the colored luminous gas. There was two secondary explosions, after the detonation wave reached us or just before. The cloud billowed upward when these occurred and very soon thereafter [billowed?] up as would an oil fire, the color became [illegible] and the whole looked more like a [unintelligible] fire (though on an enormous scale). The column of smoke then began to spread and took on a Z form which persisted for some time. The spectacular part must have been confined to about 90 seconds. The phases observed by the eve were as follows from memory.

Conant's drawing of the rising and dissipating mushroom cloud

As soon as I had lowered my dark glass and before rising I shook Gen. Groves hand who said "Well, I guess there is something in nucleonics after all."10 Tolman as we rose said, that is something very different from the 100-ton TNT shot,11 "entirely differently, there is no question but what they got a nuclear reaction." Then several people began saying, "Very much larger than expected. Rabbi [sic] said it was 15,000 Tons equivalent at least."

At about 60 sec. as the cloud billowed up, the assembled group including many MPs' gave out a spontaneous cheer.

Then the reports began to come in. Oppenheimer arrived in about 5 or 10 minutes and said the equivalent was 2100 Tons which was greeted with great skepticism. It afterwards turned out he had made an error in converting the first blast measurement and the figure showed 7,000 tons.12

The most exciting news was that the steel tower over "Jumbo" 800 yards away had disappeared.13 This was reported by some one with a telescope and verified by all. This was unexpected and showed a very much more powerful effect than expected.

Before we left at noon, the best estimate seemed to be between 10,000–15,000 though Rabbi [sic] maintain 18,000 would yet prove right.14 Careful exploration of the crater showed 1200 yards again more than expected. The toxicity problem proved not serious. Thought at 10,000 [yards] North evacuated in a hurry as their meter went off the scale almost at once and the cloud of smoke seemed to chase them they declared!15 All evacuation was by car, of course. One man at the Camp Site who looked at the explosion without dark eye glasses got a bad eye burn and was given morphine: the prognosis was that he would not lose his sight. G. Kistiakowsky, all [word illegible], came in to report that the shock wave had knocked him down as he stood outside the barricade at 10,000 S.16 There were reports of two others being knocked down at the same spot.

My first impression remains the most vivid, a cosmic phenomena like an eclipse. The whole sky suddenly full of white light like the end of the world. Perhaps my impression was only premature on a time scale of years!

J.B. Conant, Washington, D.C.
July 17, 1945 4:30 p.m.

  1. Citation: James B. Conant, "Notes on the 'Trinity' Test," (17 July 1945), Bush-Conant File Relating the Development of the Atomic Bomb, 1940-1945, Records of the Office of Scientific Research and Development, RG 227, microfilm publication M1392, National Archives and Records Administration, Washington, D.C., n.d. (ca. 1990), Roll 5, Target 8, Folder 38, "Bush, V. 1944-45." Reprinted in James Hershberg, James B. Conant: Harvard to Hiroshima and the Making of the Nuclear Age(New York: Knopf, 1993), 758-760. []
  2. The yield estimates are questions of how efficient the fission reaction will be — how much plutonium would fission before the bomb blew itself apart? This itself was a question of how effectively the implosion mechanism worked, and how long the bomb could be held in a supercritical state before full explosion. A rough estimate provided by Richard Garwin is that the complete fissioning of 1 kg of Pu-239 produces 17 kt of yield. The "Gadget" contained  6.2 kg of Pu-239 in its core. So obviously zero yield would mean no significant fissioning at all. 18 kt would mean only 17% of the plutonium fissioned. 50 kt would mean 47% fissioned. Conant's estimate, 4.4 kt, would mean 4% fissioned. Perfect efficiency — 100% fissioning — would have been 105 kt. Separately, one wonders what Conant would have to say here that would still be censored today. I suspect it has does have something to do with efficiency questions, and his reasoning on them, because those were considered quite taboo by redactors until relatively recently. I suspect if this was re-reviewed by a classification officer today these lines would be cleared. Note that Rabi's guess was in fact not chosen because of any optimism — he arrived late and it was the only figure left to choose! []
  3. Conant's estimate looks low today — since we know that the bomb was 18 kt was correct. But for the first test, of course, there was no real barometer. The original estimates for the atomic bomb's yield were much, much lower than what the bombs turned out to be — when Roosevelt signed off on the Manhattan Project in 1942, it was under the assumption that the first atomic bomb would be only 2 kt in yield! []
  4. These parenthetical sentences are from Hershberg and are likely good interpretations of Conant's awful handwriting. []
  5. Conant consistently misspells I.I. Rabi's name. But it is amusing to imagine two New England Yankees like Bush and Conant being visited by a rabbi for the Trinity test. []
  6. "Zero point" was the term for where the bomb was located, sometimes just called "Zero" or, eventually, "Ground Zero." This was the original usage of the term, well before it became more commonly used for all manner of targets. The zero obviously came from marking out the distances from the bomb blast site — zero would have been the exact site of the bomb exploding. []
  7. Warren was in charge of making sure that nobody got too much radiation exposure at Trinity, especially from fallout. They actually did have a fallout scare, but more on that another time. []
  8. It's interesting that Rabi was in this group and not any other. Tolman was Groves' personal scientific advisor; Conant and Bush were high-level policy guys; Rabi was more or less just visiting — he wasn't heavily involved in the bomb project, just a consultant, and was spending most of his time working on radar at MIT. It may have been his "outsider" status that got him put into the high-policy bunker. Or maybe Bush and Conant just liked him. I don't know. []
  9. The idea that an atomic bomb might start a thermonuclear reaction in the atmosphere was not quite so seriously considered as a threat as it was later made out to be — and was something that was known to be physically impossible — but it's not surprising that this unlikely fear came back to Conant in this instant of awe. It's also worth remembering that nobody had seen an atomic bomb before, so this must have been fantastically more impressive even than later tests, when you had a general idea of what it ought to look like. I'm also reminded of a comment that Harold Agnew made about watching the first hydrogen bomb explosion in 1952, how it kept getting hotter, and hotter, and hotter, and he actually started to get worried that it would never stop. []
  10. "Nucleonics" was a term coined during World War II to designate the field of nuclear technology. It didn't really catch on. []
  11. The 100-ton TNT shot was a detonation of isotope-laced explosives on May 7, 1945, done as a means of trying to calibrate instrumentation and expectations for the Trinity shot. Read more about it on Carey Sublette's page. []
  12. Oppenheimer was regarded by all as quite brilliant when it came to the physics of these sorts of things, but poor when it came to the mathematics. But I don't know that he actually did these equations — it's unlikely. It's still interesting that the revised estimate was off by 250%. Still, it was an estimate some 15 minutes after the first test, so let's cut them some slack. []
  13. "Jumbo" was a massive containment unit that was initially supposed to have the bomb detonated inside of it, so that if it fizzled, the billion-dollars-worth of plutonium would be recoverable. It was not used, however. Details about Jumbo are here. Jumbo itself survived the blast, though its tower was destroyed. []
  14. And Rabi was, indeed, more or less correct — the final yield was just shy of 19 kt. But, again, he chose 18 kt not because he had any good reason to — he did it because it was the only choice left when he showed up. Now an historical question that I've never seen the answer to is how much money did Rabi win? Apparently it was only a $1 entry fee, and it was restricted to senior scientists, so it probably wasn't much. We know that Oppenheimer (0.3 kt), Teller (45 kt), Kistiakowsky (1.4 kt), Bethe (8 kt), and Ramsey (zero) put in. So that's at least 5 dollars, not counting the one Rabi would have gotten back for admission. (Note that Conant said he did not participate in the pool.) But it must have been more crowded a field than that, given that 18 kt was all that was left to Rabi when he arrived later, and it seems rather arbitrary given the other numbers listed. It may yet be an unsolved mystery... []
  15. This is related to the fallout scare that I mentioned previously — they were somewhat woefully underprepared for fallout issues, though they were aware they might exist. I have a post on this coming up fairly soon... []
  16. So I guess the drawings I posted here weren't completely far-fetched! []

Edward Teller on “Loyalty” (1948)

Wednesday, July 11th, 2012

Edward Teller’s relationship to Cold War loyalty/security hearings is, in a word, infamous. 

Teller famously was one of the few academic scientists to testify against J. Robert Oppenheimer in 1954. The most damning part of Teller’s testimony was thus:

Q. To simplify the issues here, perhaps, let me ask you this question: Is it your intention in anything that you are about to testify to, to suggest that Dr. Oppenheimer is disloyal to the United States?

A. I do not want to suggest anything of the kind. I know Oppenheimer as an intellectually most alert and very complicated person, and I think it would be presumptuous and wrong on my part if I would try in any way to analyze his motives. But I have always assumed, and I now assume that he is loyal to the United States. I believe this, and I shall believe it until I see very conclusive proof to the opposite.

Q. Now, a question which is the corollary of that. Do you or do you not believe that Dr. Oppenheimer is a security risk?

A. In a great number of cases I have seen Dr. Oppenheimer act—I understood that Dr. Oppenheimer acted in a way which for me was exceedingly hard to understand. I thoroughly disagreed with him in numerous issues and his actions frankly appeared to me confused and complicated. To this extent I feel that I would like to see the vital interests of this country in hands which I understand better, and therefore trust more.

In this very limited sense I would like to express a feeling that I would feel personally more secure if public matters would rest in other hands.1

Personally, I’ve long thought that the flack that Teller got for this has been a bit overdone. Teller goes out of his way to keep his testimony pretty respectful and pretty mild, and was hardly the only scientist who opposed Oppenheimer. Behind the scenes Teller did a lot worse stuff than this. There's no evidence that Teller's testimony really directed the Gray Board or the AEC in directions they weren't already going. Oppenheimer didn't lose his security clearance because of Teller. He lost it because he made fairly large political enemies (much larger than Teller), and because he came off as inconsistent and problematic when he got on the witness stand.

"Don't Fence My Baby In." Cartoon by Bill Mauldin, Chicago Sun-Times, 1963; no doubt a reference to Teller's opposition to the Limited Test Ban Treaty.

Still, I understand why Teller gets so much opprobrium: he turned on a (former) friend, and he did so largely because of differences in intellectual opinions. This, coupled with his vigorous advocacy for excessively large weapons and extremely hawkish positions with respects to the arms race, makes him a fairly unlovable figure. But it was Teller’s association with one of the more disturbing “loyalty” hearings that really sealed his position as one of the “bad guys” of the atomic age.

So I was a bit surprised when I came across this week’s document — a letter from Teller to Norris Bradbury (Oppenheimer’s successor as the director of Los Alamos) from 1948. In it, Teller contemplates coming back to Los Alamos, at Bradbury’s request, having retreated to the University of Chicago at the end of World War II.2

Click to view PDF.

Teller was enthusiastic about coming back to the lab, even though he claimed more interest in abstract theoretical physics:

The main reason that attracts me is the great importance of the work on the atomic bomb. I fully realize the menacing international situation and I believe that the United States must develop its military strength to the utmost if we are not to succumb to the danger of communism.

Nothing surprising there — that’s classic Edward Teller for you. Fair enough. But then Teller changes course dramatically from the stereotype:

In considering my proposed position in Los Alamos during the past weeks, I have been disturbed by a problem which can be best summarized by the words “loyalty investigation.”

Wait, what? That’s right: Dr. Strangelove himself was anxious about “loyalty” getting in the way of a security clearance.

Teller continued:

I fully realize the necessity or checking improper dissemination of information. I am convinced of the necessity of checking Russian attempts to obtain classified information about atomic developments from our country. But clearance cases that have occurred in the last months have raised questions in my mind concerning the interpretation or the word “loyalty.”

I feel certain that in my actions and intentions I am loyal to the United States. More specifically I am certain that I would under no conditions want to live under a communist dictatorship and that I shall in every way try to oppose communist-world domination. This, indeed, is the reason why I consider coming to Los Alamos.

On the other hand, I do not want to lose the privilege of reading any publication about Russia — favorable or unfavorable. I consider it my right to make up my own mind about political questions and I feel that it is my intellectual duty to study all sides of a question that is as important as the question or communism. ... I believe, however, that I never could understand the nature or the communist system and could never be convinced of the magnitude of communist danger it I did not inform myself of the arguments in favor of communism as well as of the reasons to reject that system. I should certainly not like to put myself into a position where it would be considered improper for me to read literature favorable to Russia or even to read publications which are Russian propaganda.

In other words, Teller is afraid that the “loyalty” will be assessed in a clunky way , by just looking at what books someone reads, or — more to the later relevance of Oppenheimer — who they “associate” with.

I furthermore do not want to be in a position where it would be necessary for me to avoid an individual merely because he is a convinced communist. It is of course clear that I never discuss classified material with any unauthorized person, whether I agree with his political views or not. In the past I have associated occasionally with individuals whom I believed to be communists. In the following I want to describe to you these cases.

Teller then describes two cases, a Mr. A and a Mr. B (he does not identify them by name), where his friends have had dubious views. He then generalizes the problem:

It is quite possible that some of my other friends or acquaintances had connections with the communist party. I have not discussed politics with all of them and some of them may have been reticent on purpose. In no other cases did I have as clearcut evidence as in those mentioned above.

I certainly do not want to feel that in order to behave properly I must scrutinize the convictions or my friends. I furthermore want to feel free that in case I know of a person that believes in communism I need not avoid him for that reason alone.

Reading Russian literature probably wouldn’t get the FBI too irritated with you, in and of itself. (Subscribing to Communist newspapers is another story.) But acquaintances were definitely a source of judgment — and Teller probably knew this, having followed the well-publicized security issues of other scientists in the late 1940s. (On these, Jessica Wang’s American Science in an Age of Anxiety remains the canonical source.)

Bradbury did write back to Teller in November. He told Teller that what he described would not be a problem... but, if Teller had the chance, the FBI would love the names of that “Mr. A” and “Mr. B” he mentioned, just in case:

This is entirely independent of the Atomic Energy Commission and is only for the purpose of making sure that the position of the United States is as strong as possible with respect to possible unfriendly individuals. The execution of this suggestion is entirely at your discretion, but you can be assured that any information of this nature which you may give the FBI would be kept entirely confidential, that your name would not be involved, and that the rights of the individual concerned would be fully protected.

Thus Teller gets off the hook, but it is not too subtly implied that a truly “loyal” citizen would provide the names. Such is the way of “loyalty” — you can associate with whomever you want... as long as you’re willing to sell them out. 

Edward Teller by Paul Shutzer for LIFE magazine (1957)

Teller isn’t unique in this respect. Oppenheimer did the same thing; anyone who was anyone in the high Cold War reported on their acquaintances. Oppenheimer’s own FBI file is full of “friends” who informed on his every opinion given at his famous cocktail parties. (Teller’s FBI file is mostly devoted to whether he is the same “Edward Teller” who once taught a class on Marxism in New York City.)

But it’s interesting to see that Teller too recoiled at the idea of “loyalty” as something that can be easily measured and assessed. And indeed, as we’ve seen above, Teller went out of his way to express his belief that Oppenheimer was in no way disloyal. But he didn’t see that as being synonymous with not being a security risk.

  1. In the Matter of J. Robert Oppenheimer, 710. []
  2. Citation: Edward Teller to Norris Bradbury (30 August 1948), Nuclear Testing Archive, Las Vegas, NV, document NV0125269. []

Atomic TIME (Magazine)

Friday, April 6th, 2012

Time magazine has featured the bomb on its covers regularly over the years, and its cover archives are actually searchable online. Some of them are pretty iconic, others are just plain weird. Below are a few of my favorites, annotated and in chronological order.

First on the list, chronologically and thematically, is the July 1, 1946 issue featuring Albert Einstein ("All matter is speed and flame") and a mushroom cloud (which is interestingly an amalgam of the Trinity and the Nagasaki clouds) across which, amazingly, "E=mc2" is emblazoned. This is visually fascinating for at least two reasons: 1. Einstein = E=mc2 = the atomic bomb! Has the connection between theoretical physics and nuclear weapons ever been stated in a graphically more oversimplified way? 2. Einstein is wearing a suit! This might not sound very exciting, but consider that in both of Einstein's two other Time covers from his lifetime (19291938), he was exclusively wearing pajamas. Because that's what kooky, head-in-the-clouds theoretical physicists do, right? Until the bomb comes along, and then they get serious and put on a tie. (And shortly thereafter, the FBI shows up.)

Next we have our good buddy J. Robert Oppenheimer ("What we don't understand, we explain to each other"), from November 8, 1948. Here we essentially have the emblematic physicist-of-the-state — a concerned, serious, well-dressed man surrounded by an ocean of equations. The drawing of Oppenheimer (which is on display in the National Portrait Gallery, I can attest) captures his likeness well (compare with this Eisenstaedt photo, which is very similar), and also captures the ice-blue cool of his eyes (something which is not evident in the black and white photos of him, but can be seen in some photos of him when he was elderly). But moreover, it is a stunning contrast to the Oppenheimer depicted in 1954, just after losing his security clearance, who looks drawn and severe. Also note that when Edward Teller got his Time cover, in 1957, the visual scheme was essentially identical. I like to see this parallel as signifying, in a clean, visual way, Oppenheimer's decline and Teller's ascent as the model of what it meant to be a "government scientist" in the early Cold War. Both of these covers are framed in my office — the Yin and Yang of the early atomic age.

There are a lot of other "atomic portrait" photos — David Lilienthal (1947) and a flaming electric horse; Gordon Dean (1952) with a mushroom-cloud periodic table; Lewis Strauss (1953) with a searing radioactive sun, Archbishop Bernadin (1982) using his papal powers to bombard you with ICBMs and doves, just to pick a few creative ones — but none of them "do it for me" as much as the Oppenheimer one does.

The cover for the April 12, 1954, issue of Time is easy to underestimate. It's clearly recognizable as the mushroom cloud from the first hydrogen bomb test, Ivy Mike, from November 1952. But it's being shown in April 1954, not long after the Castle Bravo testing accident (in which an island of Marshallese and a Japanese fishing boat, along with a considerable amount of fish in the Pacific Ocean, were irradiated). Why didn't they put this on the cover in 1952? Because the test was secret, and images from it weren't widely released until April 1954. So even though it was a year and a half late, it still had a lot of symbolic relevance. And notice that Time chose not to depict it in color, but instead went with an austere black, white, and red scheme. (Life magazine also featured an Ivy Mike image on the cover that week, but chose the fireball instead of the cloud.)

Click here to see the rest of them.


The Infamous Teller-Ulam Report (1951)

Wednesday, February 22nd, 2012

Enrico Fermi came up with the basic idea using the power of a fission bomb to ignite fusion reactions -- a thermonuclear or hydrogen bomb -- as early as 1941. He told it to Edward Teller, who, as is well known, ran with it. For the next decade, Teller would commit a significant amount of his time to the effort of trying to figure out how you could make such a thing actually work.

That it took Teller -- and everyone else at Los Alamos -- a full ten years to figure out how to solve the problem is a good indication that it was a very hard problem. At the very least, it required a familiarity with nuclear reactions at energy regimes which had never been achieved previously on Earth. It also required breaking out of several wrong ideas along the way whose wrongness was not obvious.

There has been a lot written about the developments that led to the Teller-Ulam, or Ulam-Teller (as many fashion it), design in the spring of 1951. I find it more than a little fascinating that this old Cold War priority dispute is still alive and well in some circles, and have myself written a talk (which I probably ought to push to publication) with musings on the subject.1

Contemporary portraits of Edward Teller (by George Gamow) and Stanislaw Ulam (by Shatzi Davis).

The most basic form of it is that Stanislaw Ulam, a Polish mathematician, had considered that you could put a fission bomb into a heavy "box," set it off, and use the explosive pressure and heat of the blast to compress a larger piece of fissile material to very high densities. This would result in a very, very powerful (and very "dirty" from a fallout perspective) fission weapon, probably in the megaton range if you did it cleverly enough. Ulam told this to Teller, who jumped on it. As Ulam famously wrote to John Von Neumann: "Edward is full of enthusiasm about these possibilities; this is perhaps an indication they will not work."

Teller realized that the X-rays of the exploding fission "primary" were much faster than explosive forces Ulam was relying on, and could be used to compress fusion fuel to very high densities well before the bulk of the fission bomb's heat reached it. Somewhere along the line he also put a fission "sparkplug" inside the fusion "secondary," adding additional compression of the fusion fuel. Ergo, the multi-megaton hydrogen bomb. (Wikipedia, as you can imagine, has a long article on this thing, should you find my technical description lacking in detail.)

There's much, much more to it than this thumbnail sketch.

The result of all this, though, was a report signed by Teller and Ulam titled "On Heterocatalytic Detonations I. Hydrodynamic Lenses and Radiation Mirrors," report # LAMS-1225, dated March 9, 1951. Quite a mouthful. We'll get to the "heterocatalytic" in a moment, but the "hydrodynamic lenses" are the initial Ulam compression scheme; the "radiation mirrors" is related to Teller's insights with regards to radiation implosion. Presumably.

I've seen this report cited about a million times as "the" report, so I was surprised to find that there was a copy floating around online. Before you get too excited (or before my government readers flip out) the report is heavily redacted. Only a few paragraphs remain unadulterated, but it's still pretty interesting.2

Click to view the full PDF.

Some close-reading thoughts follow, as well as a probably explanation for why the "Ivy Mike" shot cab was called "the Sausage." (It's probably not the reason you'd think it was.)

Read the full post »

  1. The portraits were scanned from George Gamow, My World Line: An Informal Autobiography (New York: Viking Press, 1970), on 153. []
  2. Citation: Edward Teller and Stanislaw Ulam, "On Heterocatalytic Detonations I. Hydrodynamic Lenses and Radiation Mirrors (LAMS-1225)," (9 March 1951), Los Alamos National Laboratory, retrieved from []

Archives Week: Day 3, Edward Teller on the Early History of the “Super”

Wednesday, December 21st, 2011

Studying the past is important. Don't believe me? Well, check this guy out:

Study the Past. Or else this guy's going to be very disapproving.

This guy sits outside the researcher entrance to the National Archives in DC, where I'm still camping out. Apparently he is just meant to be "the past," and not any particular ancient historian. This is probably for the best, because let's be honest — some of those guys were a little sketchy by modern standards.

Anyway, I'm still looking through the Legislative Archives. My little document-of-the-day relates to our good buddy, Edward Teller. If there's one thing I've learned from looking at my blog statistics, it's that the world is still pretty interested in Edward Teller. Gotta give the people what they want, eh? Well, why not — he's always good for something unusual.

"From the Desk of Edward Teller." Did he pre-apply the "SECRET" stamps? It probably would have saved a lot of time.

Read the full post »