Salam's biographies claim that he was opposed to Pakistan's nuclear weapon programme. This is somewhat strange given that he was the senior Science Advisor to the Pakistan government for at least some of the period between 1972 when the programme was initiated and 1998 when a successful nuclear weapon test was carried out. I look at the evidence for his participation in the programme.
Salam shared the Nobel Prize with Glashow and Weinberg. He is a leading theoretician, although many have questioned what, exactly, was his contribution to the formulation of the electroweak theory of particle physics that Glashow and Weinberg contributed to.
Currently Pakistan's arsenal is ~200 warheads and similar in size to India's. Their largest warhead is estimated to have a yield of ~40kt, compared to ~20kt for the Indians.
What interested me the most was Salam's role in the early stages of the project.
See the paper for more interesting details. Previously I was only aware of Riazuddin through his academic publications, not his weapons work.
I mentioned to Karnad that I had been surprised that some of the Iranin theoreticians assassinated by Israel over the last 10-15 years had quite abstract research interests. They didn't seem the type to be working on bombs - but I suppose you never know!
Bharat Karnad is an Emeritus Professor in National Security Studies at the Center for Policy Research in Delhi. He was a member of India's first National Security Advisory Board and has authored several books on nuclear weapons and Indian security.
Robert Trumbull Crowley, former Deputy Director of Clandestine Operations for the CIA. Recorded conversations (Conversations With The Crow) near the end of his life:
".. their head expert was fully capable of building a bomb and we knew what he was up to. He was warned several times but what an arrogant prick that one was. Told our people to fuck off and then made it clear that no one would stop him and India from getting nuclear parity"
Professor Goldstein recently retired after 20 years of service on the faculty of the U.S. Naval War College (NWC). During his career at NWC, he founded the China Maritime Studies Institute (CMSI) and has been awarded the Superior Civilian Service Medal for this achievement. He has written or edited seven books on Chinese strategy and is at work on a book-length project that examines the nature of China-Russia relations in the 21st century. He has a longstanding interest in great power politics, military competition, and security in the pacific region.
Goldstein is Director of Asia Engagement at the Washington think-tank Defense Priorities, which advocates for realism and restraint in U.S.defense policy, and also a visiting professor at the Watson Institute for International and Public Affairs at Brown University.
He earned a PhD at Princeton, an MA from Johns Hopkins SAIS, and an AB from Harvard. He is fluent in both Chinese and Russian.
Steve and Lyle discuss:
00:00 Early life and background
18:03 Goldstein’s dissertation on China’s nuclear strategy
37:35 Pushback on “Meeting China Halfway”
41:24 Could the U.S. have prevented war in Ukraine?
46:05 How territorial conflicts are influencing China’s relationship with Russia
1:00:16 Analyzing war games with U.S., China, and Taiwan
I've been asked to write something about PRC military buildup and a potential Taiwan (TW) conflict.
1. My perspective and bona fides: My father was a KMT officer, my mother's father was a KMT general and that side of the family is related to Chiang Kai Shek by marriage. I have relatives both in PRC and TW. My wife is a graduate of National Taiwan University. I should be biased in favor of TW and against CPC but I am a realist and rationalist so I call things as I see them.
2. PRC military technology has reached parity with the US and, overall, surpassed Russia. PLARF (dedicated rocket forces) may be decisive in a conflict in the pacific. They may have achieved A2AD and can make it very costly for the US navy to operate anywhere near TW.
3. Specifically, long range missile attack on surface ships, using initial targeting via satellites and drones, and final targeting from sensors on the missile itself, is probably a mature technology now and difficult to defeat with countermeasures / missile defense.
4. US estimates of PRC nuclear weapons stockpile have barely changed in 30y and are likely highly unreliable. Based on production capabilities alone they may already have ~1000 warheads (if not now, in a few years), and the ability to target the entire US. PRC is building up its arsenal to ensure that the US understands that they have a reliable MAD capability.
5. PRC can easily blockade TW if desired, and (at cost of significant escalation) can probably also blockade Japan and S. Korea as well. All of these countries import ~90% of energy and ~50% of food calories, so a protracted blockade would have serious impact.
6. I don’t believe PRC has near term plans to invade TW, but they have to maintain the capability to deter any change in the status quo. Both sides prefer the status quo but accidents can happen.
7. Thanks to stupid US strategy re: Ukraine, PRC can rely on Russian energy in the future and will become much more resistant to naval blockade (e.g., of oil supplies transiting the Malacca Strait). In other words, dumb US neocons solved PRC’s energy security problem for them.
No one talks about this because US strategy has been brain dead for a long time. No one even talks, in the immediate aftermath, about the trillions of dollars and millions of lives wasted over 20y in the Iraq/Afghanistan tragedies. Cui bono?
8. PRC spends a smaller fraction of GDP on defense than the US, but because they have mastered the entire military technology stack cost estimates should be PPP adjusted. After PPP adjustment the PRC economy is substantially larger than the US economy. This, plus the fact that their manufacturing capacity (e.g., ship building) is far beyond that of the US, means that their overall capability to produce war materiel (i.e., to engage in a rapid buildup on, e.g., a 5y timescale) has easily surpassed ours. Anyone following their recent naval or air power or missile or satellite build up can see that this is the case.
I'll be discussing some of these topics with Lyle Goldstein (US Naval War College, Watson China Initiative at Brown University; BA Harvard, PhD Princeton) in a future podcast.
See also this documentary produced by the US Army University Press. Queued to start at discussion of missile technology and nuclear weapons.
More videos from the conference here. (Konrad Zuse!)
See at 50 minutes for an interesting story about von Neumann's role in the implosion mechanism for atomic bombs. vN apparently solved the geometrical problem for the shape of the explosive lens overnight after hearing a seminar on the topic. Still classified?
To solve this problem, the Los Alamos team planned to produce an “explosive lens”, a combination of different explosives with different shock wave speeds. When molded into the proper shape and dimensions, the high-speed and low-speed shock waves would combine with each other to produce a uniform concave pressure wave with no gaps. This inwardly-moving concave wave, when it reached the plutonium sphere at the center of the design, would instantly squeeze the metal to at least twice the density, producing a compressed ball of plutonium that contained about 5 times the necessary critical mass. A nuclear explosion would then result.
Theodore A. Postol is professor emeritus of Science, Technology, and International Security at the Massachusetts Institute of Technology. He is widely known as an expert on nuclear weapons and missile technology.
Educated in physics and nuclear engineering at MIT, he was a researcher at Argonne National Lab, worked at the Congressional Office of Technology Assessment, and was scientific advisor to the Chief of Naval Operations.
After leaving the Pentagon, Postol helped to build a program at Stanford University to train mid-career scientists to study weapons technology in relation to defense and arms control policy.
He has received numerous awards, including the Leo Szilard Prize from the American Physical Society for "incisive technical analysis of national security issues that [have] been vital for informing the public policy debate", the Norbert Wiener Award from Computer Professionals for Social Responsibility for "uncovering numerous and important false claims about missile defenses", and the Richard L. Garwin Award "that recognizes an individual who, through exceptional achievement in science and technology, has made an outstanding contribution toward the benefit of mankind."
Steve and Ted discuss:
0:00 Introduction
2:02 Early life in Brooklyn, education at MIT, work at the Pentagon
20:27 Reagan’s “Star Wars” defense plan
28:26 U.S. influence on Russia and China’s second-strike capabilities
Ted Postol: ... So, you've got to listen to Putin's voice dispassionately. And when you listen to him, he makes it clear numerous times, numerous times that he doesn't think American missile defense is a worth anything, but he also is worried about an American president who might believe otherwise, and who might take steps against Russia, that would then lead to an action-reaction cycle that would get us, get us all killed.
In other words, he's not just worried about the system, whether it can work, he's worried about American political leadership and what they think, or if they think, or if they know. And that was, you know, I was very receptive to understanding that because that's exactly what I went through, you know, 30 years earlier when I was at the Pentagon, looking at this dog of a missile defense.
And so, the Chinese look at this, they know the Americans are lying to them all the time. I could give you a good story about South Korea and the way we lied to the South Koreans and lied to the Chinese.
I was really furious with that. That was under Secretary of State Hillary Clinton.
And my view is...
And my view is if you're lying to an ally and you're lying, you know, I have very good friends. I'm very, very proud to say I have some very good friends who are high-level diplomats, and I've asked every one of them, would you lie in a negotiation? And every one of them has said, no. In other words, your credibility depends on your honesty.
You might not say something that, you know, could be relevant to a negotiation relevant to your adversary's thinking, but you would never lie because your credibility will, you'll never be believed again. That's their view of this.
And here we were under Hillary Clinton lying to an ally and lying to the Chinese, who I knew through my personal contacts, understood that we were lying to them. I know from personal contacts with the Chinese.
So, how do you expect people to treat you when they know you're a liar? To me, it's just simple human relations. And, and I now understand that because I have friends who are both diplomats and soldiers, and I know, if you have to lie to make a point there's something wrong and you're, you're jeopardizing your credibility with other professionals if, if you do that.
So, we should not be surprised that the Chinese are increasing their forces.
And when Putin marched out this horrifying Poseidon underwater torpedo, could potentially carry a hundred megaton warhead. It's nuclear-powered. It can travel at some very high speed, 50, 60 knots or more, and then it can go quiet, sneak into a Harbor, know coastal Harbor and detonate underwater, and destroy out to 30 or 40 kilometers, a complete area, urban area. And he has this weapon. He made it obvious that he had it. He showed plans for it.
Ted Postol: Well, what he was doing is he was saying to an American president who knows nothing. All right, assuming that the president knows nothing, that your missile defenses will not do anything about this weapon. That's what he did it for. He was an insurance policy toward bad decision-making by American political leadership. That's why he built that weapon. That's why he ordered that weapon built.
So not because, I mean, he may be a monster. That's another issue, but it's not because he was a monster, it's because he made a strategic calculation that that kind of weapon would cause any person, even if they were totally without knowledge and thought of how missile defense could work, to understand that you will not escape retribution if you attack Russia. That's why that weapon was built.
Some other recommendations below. I recently re-listened to these podcasts and quite enjoyed them. The interview with Bobby covers brain mapping, neuroscience, careers in science, biology vs physics. With Ted we go deep into free will, parallel universes, science fiction, and genetic engineering. Bruno shares his insights on geopolitics -- the emerging multipolar world of competition and cooperation between the US, Russia, Europe, and China.
A hopeful note for 2022 and the pandemic:
I followed COVID closely at the beginning (early 2020; search on blog if interested). I called the pandemic well before most people, and even provided some useful advice to a few big portfolio managers as well as to Dom and his team in the UK government. But once I realized that
the average level among political leaders and "public intellectuals" is too low for serious cost-benefit analysis,
I got bored of COVID and stopped thinking about it.
However with Omicron (thanks to a ping from Dom) I started to follow events again. Preliminary data suggest we may be following the evolutionary path of increased transmissibility but reduced lethality.
The data from UK and SA already seem to strongly support this conclusion, although both populations have at least one of: high vaccination level / resistance from spread of earlier variants. Whether Omicron is "intrinsically" less lethal (i.e., to a population such as the unvaccinated ~40% of the PRC population that has never been exposed to COVID) remains to be seen but we should know within a month or so.
If, e.g., Omicron results in hospitalization / death at ~1/3 the rate of earlier variants, then we will already be in the flu-like range of severity (whereas original COVID was at most like a ~10x more severe flu). In this scenario rational leaders should just go for herd immunity (perhaps with some cocooning of vulnerable sub-populations) and get it over with.
I'll be watching some of the more functional countries like S. Korea, PRC, etc. to see when/if they relax their strict lockdown and quarantine policies. Perhaps there are some smaller EU countries to keep an eye on as well.
I have an old copy purchased from the Caltech bookstore. When I flip through the book it never fails to reward with a wonderful anecdote from an era of giants.
[Ulam] ... In Israel many years later, while I was visiting the town of Safed with von Kárman, an old Orthodox Jewish guide with earlocks showed me the tomb of Caro in an old graveyard. When I told him that I was related to a Caro, he fell on his knees... Aunt Caro was directly related to the famous Rabbi Loew of sixteenth-century Prague, who, the legend says, made the Golem — the earthen giant who was protector of the Jews. (Once, when I mentioned this connection with the Golem to Norbert Wiener, he said, alluding to my involvement with Los Alamos and with the H-bomb, "It is still in the family!")
One night in early 1945, just back from Los Alamos, vN woke in a state of alarm in the middle of the night and told his wife Klari:
"... we are creating ... a monster whose influence is going to change history ... this is only the beginning! The energy source which is now being made available will make scientists the most hated and most wanted citizens in any country.
The world could be conquered, but this nation of puritans will not grab its chance; we will be able to go into space way beyond the moon if only people could keep pace with what they create ..."
He then predicted the future indispensable role of automation, becoming so agitated that he had to be put to sleep by a strong drink and sleeping pills.
In his obituary for John von Neumann, Ulam recalled a conversation with vN about the
"... ever accelerating progress of technology and changes in the mode of human life, which gives the appearance of approaching some essential singularity in the history of the race beyond which human affairs, as we know them, could not continue."
This is the origin of the concept of technological singularity. Perhaps we can even trace it to that night in 1945 :-)
[p.107] I told Banach about an expression Johnny had used with me in Princeton before stating some non-Jewish mathematician's result, "Die Goim haben den folgenden satz beweisen" (The goys have proved the following theorem). Banach, who was pure goy, thought it was one of the funniest sayings he had ever heard. He was enchanted by its implication that if the goys could do it, then Johnny and I ought to be able to do it better. Johnny did not invent this joke, but he liked it and we started using it.
Below is the closest thing I could find on YouTube -- it has better audio and video quality than the CERN talk.
The amazing story of Bruno Pontecorvo involves topics such as the first nuclear reactions and reactors (work with Enrico Fermi), the Manhattan Project, neutrino flavors and oscillations, supernovae, atomic espionage, the KGB, Kim Philby, and the quote:
I want to be remembered as a great physicist, not as your fucking spy!
This is a nice lecture on Leo Szilard by his biographer William Lanouette. See also ‘An Intellectual Bumblebee’ by Max Perutz.
Wikipedia: Leo Szilard was a Hungarian-American physicist and inventor. He conceived the nuclear chain reaction in 1933, patented the idea of a nuclear fission reactor in 1934, and in late 1939 wrote the letter for Albert Einstein's signature that resulted in the Manhattan Project that built the atomic bomb.
How Alexander Sachs, acting on behalf of Szilard and Einstein, narrowly convinced FDR to initiate the atomic bomb project: Contingency, History, and the Atomic Bomb.
I was just about to lock the door of my hotel room and go to bed when there was a knock on the door and there stood a Russian officer and a young Russian civilian. I had expected something of this sort ever since the President signed the terms of unconditional surrender and the Russians landed a token occupation force in New York. The officer handed me something that looked like a warrant and said that I was under arrest as a war criminal on the basis of my activities during the Second World War in connection with the atomic bomb. There was a car waiting outside and they told me that they were going to take me to the Brookhaven National Laboratory on Long Island. Apparently, they were rounding up all the scientists who had ever worked in the field of atomic energy ...
A number of us discussed it. It was about a war between the USSR and the USA, a very devastating one, which brought victory to the USSR. Szilard and a number of other physicists are put under arrest and then face the court as war criminals for having created weapons of mass destruction. Neither they nor their lawyers could make up a cogent proof of their innocence. We were amazed by this paradox. You can’t get away from the fact that we were developing weapons of mass destruction. We thought it was necessary. Such was our inner conviction. But still the moral aspect of it would not let Andrei Dmitrievich and some of us live in peace.
See also The Many Worlds of Leo Szilard (APS symposium). Slides for Richard Garwin's excellent summary of Szilard's work, including nuclear physics, refrigeration, and Maxwell's Demon. One of Garwin's anecdotes:
Ted Puck was a distinguished biologist, originally trained in physics.
‘With the greatest possible reluctance I have come to the conclusion that it is not possible for me personally to work with you scientifically,’ he wrote Szilard. ‘Your mind is so much more powerful than mine that I find it impossible when I am with you to resist the tremendous polarizing forces of your ideas and outlook.’ Puck feared his ‘own flow of
ideas would slow up & productivity suffer if we were to become continuously associated
working in the same place and the same general kind of field.’ Puck said, ‘There is no
living scientist whose intellect I respect more. But your tremendous intellectual force is a strain on a limited person like myself.’
When Szilard saw in 1954 that biologists Philip Marcus and Theodore Puck were having trouble growing individual cells into colonies, he concluded that “since cells grow with high efficiency when they have many neighbors, you should not let a single cell know it’s alone”. This was no flippant excursion into psychobiology. Rather, Szilard’s idea to use a layered feeder dish worked, while the open dish had not (Lanouette, 1992: 396–397).
After the war Szilard worked in molecular biology. This photo of Jacques Monod and Szilard is in the seminar room at Cold Spring Harbor Lab. Monod credits Szilard for the negative-feedback idea behind his 1965 Nobel prize.
“I have … recorded” in my Nobel lecture, said Monod, “how it was Szilard who decisively reconciled me with the idea (repulsive to me, until then) that enzyme induction reflected an anti-repressive effect, rather than the reverse, as I tried, unduly, to stick to.”
This 1966 documentary on von Neumann was produced by the Mathematical Association of America. It includes interviews with Wigner, Ulam, Halmos, Goldstine, and others.
At ~34m Bethe (leader of the Los Alamos theory division) gives primary credit to vN for the implosion method in fission bombs. While vN's previous work on shock waves and explosive lenses is often acknowledged as important for solving the implosion problem, this is the first time I have seen him given credit for the idea itself. Seth Neddermeyer's Enrico Fermi Award citation gives him credit for "invention of the implosion technique" and the original solid core design was referred to as the "Christy gadget" after Robert Christy. As usual, history is much more complicated than the simplified narrative that becomes conventional.
Teller: He could and did talk to my three-year-old son on his own terms and I sometimes wondered whether his relations to the rest of us were a little bit similar.
Some useful references below on the Ulam-Teller mechanism, Sakharov's Third Idea, and the von Neumann-Fuchs thermonuclear design of 1946. They resolve a mystery discussed previously on this blog:
Sakharov's Third Idea: ... If Zeldovich was already familiar with radiation pressure as the tool for compression, via the Fuchs report of 1948, then perhaps one cannot really credit Teller so much for adding this ingredient to Ulam's idea of a staged device using a fission bomb to compress the thermonuclear fuel. Fuchs and von Neumann had already proposed (and patented!) radiation implosion years before. More here.
It turns out that the compression mechanism used in the von Neumann-Fuchs design (vN is the first author on the patent application; the design was realized in the Operation Greenhouse George nuclear test of 1951) is not that of Ulam-Teller or Sakharov. In vN-F the D-T mixture reaches thermal equilibrium with ionized BeO gas, leading to a pressure increase of ~10x. This is not the "cold compression" via focused radiation pressure used in the U-T / Sakharov designs. That was, apparently, conceived independently by Ulam-Teller and Sakharov.
It is only recently that the vN-F design has become public -- first obtained by the Soviets via espionage (Fuchs), and finally declassified and published by the Russians! It seems that Zeldovich had access to this information, but not Sakharov.
Jeremy Bernstein: When I was an undergraduate at Harvard he [vN] came to the university to give lectures on the computer and the brain. They were the best lectures I have ever heard on anything — like mental champagne. After one of them I found myself walking in Harvard Square and looked up to see von Neumann. Thinking, correctly as it happened, that it would be the only chance I would have to ask him a question, I asked, ‘‘Professor von Neumann, will the computer ever replace the human mathematician?’’ He studied me and then responded, ‘‘Sonny, don’t worry about it.’’
Note added from comments: I hope this clarifies things a bit.
The question of how the Soviets got to the U-T mechanism is especially mysterious. Sakharov himself (ostensibly the Soviet inventor) was puzzled until the end about what had really happened! He did not have access to the vN-F design that has been made public from the Russian side (~2000, after Sakharov's death in 1989; still classified in US). Zeldovich and only a few others had seen the Fuchs information, at a time when the main focus of the Russian program was not the H bomb. Sakharov could never be sure whether his suggestion for cold radiation compression sparked Zeldovich's interest because the latter *had seen the idea before* without fully comprehending it. Sakharov wondered about this until the end of his life (see below), but I think his surmise was not correct: we know now that vN-F did *not* come up with that idea in their 1946 design. I've been puzzled about this question myself for some time. IF the vN-F design had used radiation pressure for cold compression, why did Teller get so much credit for replacing neutrons with radiation pressure in Ulam's staged design (1951)? I stumbled across the (now public) vN-F design by accident just recently -- I was reading some biographical stuff about Zeldovich which touched upon these issues.
Consider the following words in Sakharov’s memoirs, with a note he added toward the end of life:
Now I think that the main idea of the H-bomb design developed by the Zeldovich group was based on intelligence information. However, I can’t prove this conjecture. It occurred to me quite recently, but at the time I just gave it no thought. (Note added July 1987. David Holloway writes in “Soviet Thermonuclear Development,” International Security 4:3 (1979/80), p. 193: “The Soviet Union had been informed by Klaus Fuchs of the studies of thermonuclear weapons at Los Alamos up to 1946. … His information would have been misleading rather than helpful, because the early ideas were later shown not to work.” Therefore my conjecture is confirmed!)
Teller, 1952, August (re Bethe’s Memorandum): The main principle of radiation implosion was developed in connection with the thermonuclear program and was stated at a conference on the thermonuclear bomb, in the spring of 1946. Dr. Bethe did not attend this conference, but Dr. Fuchs did. [ Original development by vN? ]
It is difficult to argue to what extent an invention is accidental: most difficult for someone who did not make the invention himself. It appears to me that the idea was a relatively slight modification of ideas generally known in 1946. Essentially only two elements had to be added: to implode a bigger volume, and, to achieve greater compression by keeping the imploded material cool as long as possible.
The last part ("cool as long as possible") refers to the fundamental difference between the vN-Fuchs design and the U-T mechanism of cold radiation compression. The former assumes thermal equilibrium between ionized gas and radiation, while latter deliberately avoids it as long as possible.
Official Soviet History: On the making of the Soviet hydrogen (thermonuclear) bomb, Yu B Khariton et al 1996 Phys.-Usp. 39 185. Some details on the origin of the compression idea, followed by the use of radiation pressure (Zeldovich and Sakharov).
I always wondered who first worked out the theory of Electromagnetic Pulses (EMP) produced by nuclear weapons. That an EMP would result from a nuclear explosion was known from the beginning:
During the first United States nuclear test on 16 July 1945, electronic equipment was shielded because Enrico Fermi expected the electromagnetic pulse. The official technical history for that first nuclear test states, "All signal lines were completely shielded, in many cases doubly shielded. In spite of this many records were lost because of spurious pickup at the time of the explosion that paralyzed the recording equipment."[2] During British nuclear testing in 1952–1953, instrumentation failures were attributed to "radioflash", which was their term for EMP.
But it's far from obvious that: prompt gamma rays from the nuclear explosion lead to Compton effect ionization, and the resulting Compton current interacts with the Earth's magnetic field to produce coherent synchrotron radiation forming a dangerous EM pulse.
During Cold War years in the 1950’s, a number of mysterious communication disruptions occurred. It was feared that the communications had been sabotaged in some way by the Soviet Union. Robert was at Caltech at the time, but was also a consultant for the Rand Corporation, and became aware of this phenomenon.
For years Robert had been outspoken in his opposition to atmospheric testing of nuclear weapons, and had put a good deal of effort into understanding the effects. At that time the U.S. was still performing atmospheric tests of nuclear weapons. One test involved exploding an atomic bomb at a very high altitude, roughly 20 miles.
It had been known that atomic bombs could sometimes cause problems with electronics in the vicinity, but it was Robert who single-handedly worked out the physics by which atomic explosions in the upper atmosphere would produce an electromagnetic pulse (EMP) that could have catastrophic effects on circuits on the ground at very great distances, and could thereby disrupt communications. He was thus the first to connect the disruption of communications with the high- altitude nuclear explosions. He wrote this up as a classified report. It should be noted, however, that the warning in this report did not prevent the U.S. from carrying out the very-high-altitude “Starfish Prime” test of 1962. In this test a 1.4 megaton bomb was exploded over the Pacific Ocean at an altitude of 250 miles, causing electrical damage in Hawaii (about 900 miles away). The Soviets conducted similar high-altitude tests over Kazakhstan in the same year. These caused even more extensive damage since they were above an inhabited area rather than over the ocean.
The EMP effect of high-altitude atomic explosions is now widely known, but it was Robert Christy who first brought this phenomenon to the attention of the U.S. government. ...
[ See also articles by Longmire and Pfeffer. Perhaps the Soviets were ahead of Christy? Kompaneets, A. S., Radio Emission from an Atomic Explosion, Institute for Chemical Physics, Academy of Sciences, USSR, Journal of Experimental and Theoretical Physics (USSR), English translation in volume 35, 1538-1544 (December 1958); Original article in Russian in JETP, 8, 1076-1080 (1954). ]
... the Los Alamos team discovered that the interface between the detonating explosives and the hollow sphere could become unstable and ruin the crushing power of the blast wave.
Dr. Christy, while studying implosion tests, realized that a solid core could be compressed far more uniformly, and he worked hard in the days that followed to convince his colleagues of its superiority. He succeeded, and the hollow core was replaced with one made of solid plutonium metal.
... Robert Frederick Christy was born May 14, 1916, in Vancouver and studied physics at the University of British Columbia. He was a graduate student at the University of California, Berkeley, under J. Robert Oppenheimer, a leading theoretical physicist who became known as the father of the atomic bomb.
After completing his studies in 1941, Dr. Christy worked at the University of Chicago before being recruited to join the Los Alamos team when Oppenheimer became its scientific director.
After the war, Dr. Christy joined Caltech in theoretical physics and stayed at the university for the rest of his academic career, serving as a faculty chairman, vice president, provost (from 1970 to 1980) and acting president (1977-78). He was elected to the National Academy of Sciences.
... Nonetheless, in the early 1950s, Landau worked on Sakharov’s assignments. True enough, that work was in computational mathematics, not theoretical physics. Odd “material evidence” of this appears in Landau’s Collected Works: placed between the 1958 article about fermions and the 1959 article about quantum field theory is the lecture “Numerical Methods of an Integration of Partial Equations by a Method of Grids.” It was published in 1958 but, as it indicates, describes the methods developed in 1951–1952.
When you look at the article’s unexciting formulas, it’s difficult to imagine what’s behind them. What’s behind them, among other things, is the first thermonuclear bomb in the world and the suicide of the head of the security department. ...
Landau’s group did the calculations for the 1949 A-bomb, for which he received an Order of Lenin and a Stalin Prize of the Second Degree.
Landau’s contribution to the hydrogen bomb was even greater, judging by the fact that he was awarded the title of Hero of Socialist Labor and a Stalin Prize of the First Degree. Landau’s group managed to complete the Sloyka calculations “by hand”; it was the problem akin to the one the Americans postponed until computers appeared. This required devising an entirely new method of calculation.
The processes of a thermonuclear explosion are much more complicated than an atomic one, if only because it includes the atomic one as its first step. Numerical calculations using old methods would have taken years, but the problem had to be solved in months, which ensured a new method needed to be found. However, while developing it at the Institute for Physical Problems, theorists found a serious mathematical problem—the stability of the calculations. Without solving it, they couldn’t be sure that the calculations, no matter how precise, would actually have any relationship to physical reality. The new method solved this problem. But the mathematics group directed by Andrei Tikhonov, which had been created in parallel as a failsafe, denied the problem’s very existence.
Dissent and discussion are common in science, but in this case the science was top secret and super-urgent. Beria could not wait for the problem to be resolved in a free exchange of ideas, so a meeting was convened under the chairmanship of Mstislav Keldysh, the future president of the Academy of Sciences. It lasted for several days and the discussions ended in an unusual way: based on Keldysh’s opinion, the top leadership gave the order regarding which interpretation was to be considered scientific truth—the top leadership was Nikolai Pavlov, the KGB general in charge of nuclear weapons development. And Tikhonov’s group switched to the new method of calculation.
The assignment for the Sloyka calculations sent to the Landau group was “a piece of graph paper, handwritten on both sides in green-blue ink, and it contained all the geometry and data of the first hydrogen bomb.”
This was possibly the most secret document in the Soviet project—and it could not be entrusted to any typist. After a mathematical assignment was prepared on the basis of this document at the Institute of Physical Problems, it was sent on to the Institute of Applied Mathematics where Tikhonov’s group worked. And the page disappeared there. Perhaps it was mistaken for a rough draft—it was a single handwritten page—and it was destroyed along with other drafts. But this action was not recorded, which is what led to the tragedy Sakharov describes:
The head of the Security Department from the Ministry—a man whose mere physical appearance, his stare from under drooping eyelids, elicited physical dread in me—came to investigate the extraordinary incident. Former head of Leningrad State Security during the so-called “Leningrad Affair,” when about 700 top leaders were executed there, he spent nearly an hour on Saturday with the head of Institute Security. The Institute official spent the next day, Sunday, with his family; they say he was cheerful and very affectionate with his children. He came to work on Monday 15 minutes early and shot himself before his co-workers arrived.
The article below illuminates several mysteries concerning the French development of thermonuclear weapons. Why did it take so long? Did the French really need help from the British? Who had the crucial idea of radiation compression?
The original inventors were Ulam and Teller. In the USSR it was Sakharov. The PRC inventor was Yu Min (see Note Added at bottom).
Without men such as these, how long would it have taken to develop breakthrough technologies that defined the modern age?
Nonproliferation Review 15:2 353, DOI 10.1080/10736700802117361
Based on the first-person account of coauthor Pierre Billaud, a prominent French participant, this article describes for the first time in such detail the history of the development of the French hydrogen bomb in the 1960s and the organization of military nuclear research in France. ...
On November 1, 1952, the United States conducted its first thermonuclear test, ‘‘Ivy Mike,’’ seven years and three and a half months after its Trinity test. It took the Soviet Union four years (August 29, 1949 -- August 12, 1953) and the United Kingdom four years and seven months (October 3, 1952 -- May 15, 1957) to achieve thermonuclear capacity. And in the following decade, China did it, with its sixth test, in fewer than three years (October 16, 1964 -- June 17, 1967). Yet after Gerboise Bleue it took France eight and a half years to reach the same landmark, detonating its first thermonuclear device on August 24, 1968. Why such a long delay, especially since the French were pioneers in nuclear research?
1965: What We Knew About the Technical Aspects
From 1955 to 1960, as we prepared for the first French atomic test, we were also pondering thermonuclear weapons. But the prospect of hydrogen weapons seemed so far into the future that we did not work seriously on it. ... Li6D was commonly considered the best fuel for thermonuclear weapons, but we did not have any idea about how to burn it. All the problems with the thermonuclear bomb can be summarized by this question: how to discover the process that will allow the Li6D to undergo a fusion reaction?
... Compared to our American colleagues in 1948, French scientists had many advantages: we knew that hydrogen bombs existed and worked and that they used Li6D, and we understood the reactions at work. We also had powerful computers, of U.S. origin, which were not available in the late 1940s. And we knew, more or less, the dimensions and weights of the nuclear weapons deployed at NATO bases in Europe and their yields. ...
De Gaulle: It’s taking forever! ... I want the first experiment to take place before I leave! Do you hear me? It’s of capital importance. Of the five nuclear powers, are we going to be the only one which hasn’t made it to the thermonuclear level? Are we going to let the Chinese get ahead of us? If we do not succeed while I am still here, we shall never make it! My successors, from whatever side, will not dare to go against the protests of the Anglo-Saxons, the communists, the old spinsters and the Church. And we shall not open the gate. But if a first explosion happens, my successors will not dare to stop halfway into the development of these weapons.
... In January 1967, I published a voluminous report wherein I presented and developed my idea from late 1965, left idle since, explaining why the current studies were going in the wrong direction and producing a ridiculously low thermonuclear efficiency. I proposed a scheme with two consecutive steps: a cold Li6D compression increasing the density, from the normal value of 0.8 g/cm3, by a factor of at least 20, followed by a sufficient temperature increase (the ignition). In this report, I also gave orders of magnitude of the energies involved in each step... [[ One can make the (flawed) analogy of Billaud to Ulam (multi-stage insight, but no mechanism for compression), and Carayol to Teller (proposed the right mechanism for compression, although in Teller's case he may have learned of it from von Neumann and Fuchs!!!). ]]
In early April 1967, Carayol had the idea that the x-rays emitted from the fission explosion could transport the fission energy to the thermonuclear fuel chamber to induce the necessary compression. He published a brief paper wherein he presented, and justified mathematically, his architectural idea. This was the key to the solution for an efficient thermonuclear explosive device, consistent with the current data about U.S. hydrogen weapons. Carayol had rediscovered the radiative coupling concept first introduced by Americans Stanislaw Ulam and Edward Teller in January 1951.
Michel Carayol, the Genuine Father of the French H-Bomb
Michel Carayol was born in 1934 and died in 2003. His father was an industrialist and his mother a teacher. He entered Ecole Polytechnique in 1954, graduated in 1956, and joined the Armament. In 1962, he was part of the DEFA assigned to CEA-DAM at Limeil. In 1967, Carayol was part of the advanced studies branch.
... Soon after, in April 1967, Carayol wrote a brief report describing his proposal for a cylindrico-spherical case in dense metal, containing a fission device on one side and a thermonuclear sphere on the other. The report showed that the photons radiated by the primary *still very hot* in the X-ray frequency range, swept into the chamber rapidly enough to surround completely the thermonuclear sphere before the metal case would be vaporized. Carayol had discovered independently a scheme equivalent to the concept developed by Ulam and Teller in the 50s.
But Carayol's insight was ignored! It was British assistance that alerted project leadership to the value of Carayol's ideas. It is not enough for some isolated genius to make a breakthrough -- the people in charge have to understand its value.
... During the first months of 1967, Viard had told me, ‘‘A British physicist is showing some interest in what we do.’’ At several embassy parties, a first-rate British atomic scientist, Sir William Cook, former director during the 1950s of thermonuclear research at Aldermaston, the British center for atomic military applications, had approached the military attache´ at the French Embassy in London, Andre´ Thoulouze, an Air Force colonel, and had hinted to our nuclear research program. Thoulouze had previously been in charge of an air force base and knew Rene´ David, who would later work at the DAM. For this reason, instead of contacting the French main intelligence services, Thoulouze directly contacted our information bureau at CEA, the BRIS, where David was working at the time. In analyzing the fallout from the French tests, the Americans, the British, and the Soviets knew that we had not made any real progress on the thermonuclear path. In 1966 and 1967 we had tested some combination of fission with light elements. Cook told Thoulouze that we had to look for something simpler.
Two weeks after the Valduc seminar, on September 19, and while the work resulting from the Valduc decisions had not yet concretely gotten under way, Thoulouze came from London bearing information from this qualified source. Jacques Robert immediately convened a meeting, in the DAM’s headquarters in Paris, to debrief this information. Only three other people attended the meeting: Viard, Bonnet (DAM’s deputy), and Henri Coleau (head of the BRIS). The information, very brief and of a purely technical nature, did not consist of outlines or precise calculations. Nevertheless, it allowed Bonnet to declare immediately that the Carayol design, proposed unsuccessfully as early as April 1967, could be labeled as correct.23 Had this outline not already been in existence, we would have had a difficult time understanding the information and might have suspected an attempt to mislead us. In fact, this was a reciprocal validation: Carayol’s sketch authenticated the seriousness of the source, while the latter confirmed the value of Carayol’s ideas. Without realizing it, as very few were aware of Carayol’s discovery (and surely not Cook), he had given us a big tip and unexpected assistance, as this information also freed us from the ministerial harassment to which we had been constantly subjected. From that moment, things moved briskly.
Physicist Michel Carayol laid out what would be the fundamental idea of radiation implosion in an April 1967 paper, but neither he nor his colleagues were immediately convinced that it was the solution, and the search continued.
In late September 1967, Carayol’s ideas were validated by an unlikely source, William Cook, who had overseen the British thermonuclear program in the mid-1950s. Cook, no doubt at his government’s behest, verbally passed on the crucial information to the French embassy’s military attaché in London. Presumably, the British provided this information for political reasons. British Prime Minister Harold Wilson was lobbying for the entry of the United Kingdom into the Common Market (European Economic Community), which was being blocked by de Gaulle.
Note Added: Perhaps someone can translate part of this paper, which gives some details about the Chinese thermonuclear step, credit to Yu Min. Did they invent a mechanism different from Ulam-Teller? I can't tell from this paper, but I suspect the initial Chinese design used U-T. There are claims that Yu Min later developed, in the pursuit of miniaturization and improved safety, a qualitatively different design.
Yu Min was a student of Peng Huanwu (also a key figure in the bomb effort), who was a student of Max Born. Yu Min only recently passed, in early 2019!
[ Financier Alexander Sachs, Look Magazine, March 14, 1950. Article: How FDR Planned to use the A-Bomb ]
Last month I received an astonishing email, partly excerpted below.
Stephen,
By way of introduction, my grandfather, General Groves, led the Manhattan Project. I’m now working on a documentary series about the making of the bomb.
I first came across Robert Jungk’s account of the Sachs-FDR meetings not in Jungk's book, but in your “Contingency, History, and the Atomic Bomb” posting online. Thank you.
It’s an important episode that appears in almost none of the histories, Rhodes’ Making of the Atomic Bomb included. And it’s relevant: anyone who has had to pitch a complicated idea or project knows that getting the initial approval and funding can be more challenging than completing the work proposed.
I’ve since found quite a bit of material pertaining to the story. I thought you might find it interesting.
...
I imagine some graduate history, science, or economics student could turn this into a PhD thesis. (Why did FDR always have time for Sachs? I see some hints that Sachs may have been ahead of his time in macroeconomics.) Or – Szilard and Wigner’s efforts to get the matter in front of FDR could be a management case study.
Anyway, thank you for posting the story. The full version will definitely make it into my production.
How Alexander Sachs, acting on behalf of Szilard and Einstein, narrowly convinced FDR to initiate the atomic bomb project. History sometimes hangs on a fragile thread: had the project been delayed a year, atomic weapons might not have been used in WWII. Had the project completed a year earlier, the bombs might have been used against Germany.
... It was nearly ten weeks before Alexander Sachs at last found an opportunity, on October 11, 1939, to hand President Roosevelt, in person, the letter composed by [Leo] Szilard and signed by [Albert] Einstein at the beginning of August [1939]. In order to ensure that the President should thoroughly appreciate the contents of the document and not lay it aside with a heap of other papers awaiting attention, Sachs read to him, in addition to the message and an appended memorandum by Szilard, a further much more comprehensive statement by himself. The effect of these communications was by no means so overpowering as Sachs had expected. Roosevelt, wearied by the prolonged effort of listening to his visitor, made an attempt to disengage himself from the whole affair. ...
Sachs, however, was able, as he took his leave, to extort from the President the consolation of an invitation to breakfast the following morning. "That night I didn't sleep a wink," Sachs remembers.
...
[ The next morning, at the White House ]
After Sachs finished speaking the President remained silent for several minutes. Then he wrote something on a scrap of paper and handed it to the servant who had been waiting at table. The latter soon returned with a parcel which, at Roosevelt's order, he began slowly to unwrap. It contained a bottle of old French brandy of Napoleon's time, which the Roosevelt family had possessed for many years. The President, still maintaining a significant silence, told the man to fill two glasses. Then he raised his own, nodded to Sachs and drank to him.
Next he remarked: "Alex, what you are after is to see that the Nazis don't blow us up?"
"Precisely."
It was only then that Roosevelt called in his attaché, [Brigadier] General [Edwin] "Pa" Watson, and addressed him—pointing to the documents Sachs had brought—in words which have since become famous:
"Pa, this requires action!
Sachs was a trusted but largely anonymous advisor to Roosevelt. He advised Roosevelt through the Great Depression and foresaw the rise of Hitler and the military threat from Germany. From the profile in Look Magazine:
... only one word describes him: genius. A story about how he helped President Roosevelt to understand the atomic energy problem in 1939 throws light on why Dr. Sachs is so described. ...
... Schooled at Columbia and Harvard, he never left the school of self-education.
Dr. Alexander Sachs' career has been in economics, with a special emphasis on the mathematics of statistics. But the range of his intellectual interests embraces religion, science, history, and politics. ...
Mathematician Peter Lax (awarded National Medal of Science, Wolf and Abel prizes), interviewed about his work on the Manhattan Project. His comments on von Neumann and Feynman:
Lax: ... Von Neumann was very deeply involved in Los Alamos. He realized that computers would be needed to carry out the calculations needed. So that was, I think, his initial impulse in developing computers. Of course, he realized that computing would be important for every highly technical project, not just atomic energy. He was the most remarkable man. I’m always utterly surprised that his name is not common, household.
It is a name that should be known to every American—in fact, every person in the world, just as the name of Einstein is. I am always utterly surprised how come he’s almost totally unknown. ... All people who had met him and interacted with him realized that his brain was more powerful than anyone’s they have ever encountered. I remember Hans Bethe even said, only half in jest, that von Neumann’s brain was a new development of the human brain. Only a slight exaggeration.
... People today have a hard time to imagine how brilliant von Neumann was. If you talked to him, after three words, he took over. He understood in an instant what the problem was and had ideas. Everybody wanted to talk to him.
...
Kelly: I think another person that you mention is Richard Feynman?
Lax: Yes, yes, he was perhaps the most brilliant of the people there. He was also somewhat eccentric. He played the bongo drums. But everybody admired his brilliance. [ vN was a consultant and only visited Los Alamos occasionally. ]
This is the best technical summary of the Los Alamos component of the Manhattan Project that I know of. It includes, for example, detail about the hydrodynamical issues that had to be overcome for successful implosion. That work drew heavily on von Neumann's expertise in shock waves, explosives, numerical solution of hydrodynamic partial differential equations, etc. A visit by G.I. Taylor alerted the designers to the possibility of instabilities in the shock front (Rayleigh–Taylor instability). Concern over these instabilities led to the solid-core design known as the Christy Gadget.
... Unlike earlier histories of Los Alamos, this book treats in detail the research and development that led to the implosion and gun weapons; the research in nuclear physics, chemistry, and metallurgy that enabled scientists to design these weapons; and the conception of the thermonuclear bomb, the "Super." Although fascinating in its own right, this story has particular interest because of its impact on subsequent devel- opments. Although many books examine the implications of Los Alamos for the development of a nuclear weapons culture, this is the first to study its role in the rise of the methodology of "big science" as carried out in large national laboratories.
... The principal reason that the technical history of Los Alamos has not yet been written is that even today, after half a century, much of the original documentation remains classified. With cooperation from the Los Alamos Laboratory, we received authorization to examine all the relevant documentation. The book then underwent a classification review that resulted in the removal from this edition of all textual material judged sensitive by the Department of Energy and all references to classified documents. (For this reason, a number of quotations appear without attribution.) However, the authorities removed little information. Thus, except for a small number of technical facts, this account represents the complete story. In every instance the deleted information was strictly technical; in no way has the Los Alamos Laboratory or the Department of Energy attempted to shape our interpretations. This is not, therefore, a "company history"; throughout the research and writing, we enjoyed intellectual freedom.
... Scientific research was an essential component of the new approach: the first atomic bombs could not have been built by engineers alone, for in no sense was developing these bombs an ordinary engineering task. Many gaps existed in the scientific knowledge needed to complete the bombs. Initially, no one knew whether an atomic weapon could be made. Furthermore, the necessary technology extended well beyond the "state of the art." Solving the technical problems required a heavy investment in basic research by top-level scientists trained to explore the unknown - scientists like Hans Bethe, Richard Feynman, Rudolf Peierls, Edward Teller, John von Neumann, Luis Alvarez, and George Kistiakowsky. To penetrate the scientific phenomena required a deep understanding of nuclear physics, chemistry, explosives, and hydrodynamics. Both theoreticians and experimentalists had to push their scientific tools far beyond their usual capabilities. For example, methods had to be developed to carry out numerical hydrodynamics calculations on a scale never before attempted, and experimentalists had to expand the sensitivity of their detectors into qualitatively new regimes.
... American physics continued to prosper throughout the 1920s and1930s, despite the Depression. Advances in quantum theory stimulated interest in the microscopic structure of matter, and in 1923 Robert Millikan of Caltech was awarded the Nobel Prize for his work on electrons. In the 1930s and 1940s, Oppenheimer taught quantum theory to large numbers of students at the Berkeley campus of the University of California as well as at Caltech. Also at Berkeley in the 1930s and 1940s, the entrepreneurial Lawrence gathered chemists, engineers, and physicists together in a laboratory where he built a series of ever-larger cyclotrons and led numerous projects in nuclear chemistry, nuclear physics, and medicine. By bringing together specialists from different fields to work cooperatively on large common projects, Lawrence helped to create a distinctly American collaborative research endeavor - centered on teams, as in the industrial research laboratories, but oriented toward basic studies without immediate application. This approach flourished during World War II.
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