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What John von Neumann did at Los Alamos (2020)

242 points by fanf2 3y ago

credit_guy 3y ago
Personal speculation: without John von Neumann's contributions to the Plutonium bomb, there's a good chance we would not have hydrogen bombs to this day. Here's why: the US had already had a feasible bomb design, the Uranium-235 based bomb, that was dropped at Hiroshima. Not only that, but it had an alternative to the Plutonium bomb too, the U-233 bomb. Glenn Seaborg, the guy who discovered Plutonium and a bunch of other elements, was tasked with doing a feasibility study of a bomb with U-233. He found out it can be done, and sure enough, a few years after the war the US build such a bomb and tested it. It was not done because the Plutonium bomb became possible (with von Neumann's help). But again, if von Neumann had decided to spend his time on other problems, then the US could have focused on the U-233 bomb instead. This leaves us at the end of the war, when the Soviets decided to steal the secret and build their own bomb. Stalin decided they'll build an exact replica of the Nagasaki bomb, which they did and tested in 1949. If only U-233 and U-235 were on the table, they would have picked one of those, rather than explored an uncertain design. From uranium bombs to boosted uranium bombs there's a small step. So the world would have seen much bigger bombs than the ones dropped on Japan. Fission bombs were built and tested that got close to one megaton. But the hydrogen bomb is fundamentally an implosion bomb. The hydrogen bomb was a side-effect of the deeper understanding of the implosion design. In particular, the US figured out that if you can do implosion with conventional explosives, you can do it even better with nuclear explosives, so it designed and tested a two stage fission bomb, the Castle Nectar bomb. It's the only non-thermonuclear bomb ever detonated that had a yield above 1 MT (it was 1.8 MT). The research into this two-stage bomb is what Ulam was doing, and he told Teller that maybe what works for a second stage that is a fission bomb could work for a second stage that's a fusion bomb. Teller added his own insights, and eventually it was done.
- philwelch 3y ago
  Wikipedia claims that Von Neumann and Klaus Fuchs also had a preliminary design for a hydrogen bomb that also used the implosion bomb as a first stage, though in a different way than the Teller-Ulam design. Fuchs leaked the Neumann-Fuchs design to the Soviets along with everything else, but just like the US, the Soviets set it aside and independently came up with the Teller-Ulam design instead. So it would seem that, despite Teller and Ulam winning out, Von Neumann was still deeply involved in hydrogen bomb development beyond simply developing the prerequisite plutonium implosion bomb.
  - refset 3y ago
    > Von Neumann was still deeply involved in hydrogen bomb development beyond simply developing the prerequisite plutonium implosion bomb This. https://en.wikipedia.org/wiki/John_von_Neumann https://en.wikipedia.org/wiki/John_von_Neumann > In 1955, von Neumann became a commissioner of the Atomic Energy Commission (AEC) > He used this position to further the production of compact hydrogen bombs suitable for intercontinental ballistic missile (ICBM) delivery > He was adamant that H-bombs delivered deep into enemy territory by an ICBM would be the most effective weapon possible It seems much of his life was dedicated to applying Game Theory.
- barelyauser 3y ago
  This is an absurd take, to say the least. It offends the intelligence of virtually everyone involved in the bomb development. Plutonium usefulness would be noticed eventually. Implosion of fusion fuel using X-Rays thermal transport would have been discovered as well. The world does not have a single point of failure based on a single person, like you paint it.
  - silverquiet 3y ago
    Absurd isn't really the word I would use. I think it's more of a naive/common misconception about how science advances. People tend to think of a single genius making breakthroughs when in fact a lot of ideas were building on prior work and in collaboration with others; essentially the ideas eventually have their time, and you get a sense that the specific people who discovered them, while impressive, are a bit of a historical detail rather than an essential ingredient. To me, the biggest example would be evolution - Darwin was famous for it, but you will find others speculating about it before him, and famously he sat on his work and only published it once Alfred Russel Wallace was about to independently publish his discovery of the same phenomena "Connections" by James Burke is a wonderful documentary that first helped me to really understand this.
  - credit_guy 3y ago
    Slow down a bit. First: it took many years for the Ulam-Teller design to be discovered. Teller came up with the idea of a fusion bomb in 1942. The actual Ulam-Teller design was invented in March 1951, basically 9 years later. In this 9 years, for at least 2 years, people were searching frantically for a workable design. It's very easy to say, after the fact, that "X-Rays thermal transport would have been discovered as well" because we know this is what worked in the end. But before the fact, nobody was looking for X-Ray implosion. Second: During WW2, plutonium was considered superior to uranium because it was cheaper to manufacture. U-235 was being manufactured via a very expensive separation process. But U-233 can be bred in a thorium reactor just like Plutonium is bred in a uranium reactor. They both come with their challenges (U-232 for U-233, Pu-240 for Pu-239), but in a scenario where the Manhattan project did not figure the implosion design in a hurry, the US would have shifted the resources to U-233. Here's a quote from wikipedia [1] > A declassified 1966 memo from the US nuclear program stated that uranium-233 has been shown to be highly satisfactory as a weapons material, though it was only superior to plutonium in rare circumstances. It was claimed that if the existing weapons were based on uranium-233 instead of plutonium-239, Livermore would not be interested in switching to plutonium. Now, I have no doubts that fission boosting would have been discovered. But with fission boosting, bombs would have gotten to the 1 MT yield, and that is plenty destructive for all war scenarios. Crucially, such a weapon did not need to use any type of implosion. In a scenario where the US does not develop the implosion knowledge because it can build a 1 MT weapon without, then it is not at all a given that someone else would have looked for an implosion-based design of a thermonuclear weapon. We would still have had the layer-cake design, but that is not a game changer, and it's not clear that the extra yield was worth the extra complexity. Now, in today's world: Most of US's nukes have yields around 100 kT [2]. They are thermonuclear but the same effect can be achieved with (boosted) fission bombs. The largest current US nuke, the B83, has a yield of 1.2 MT, but the US is looking to retire it, and replace it with B61, with a maximum yield of 400 kT. My point is that a superpower can service all its deterrence needs with nuclear weapons with yields that are achievable with boosted fission. Why did we then go and build thermonuclear monster bombs in the 50's and 60's? Because at the time the ICBM precision was limited, and you needed something with a mile-sized fireball to make up for the lack of precision. But the ICBM technology advanced at an incredible pace. If we had been 10 years late coming with the design for a thermonuclear bomb, it would not have been needed at all. Yet another thing is this: the destructive power of a nuke does not grow linearly with its yield. Ten bombs with a 100 kT yield are more destructive than on single bomb with a 1 MT yield. Oppenheimer knew that, and advised the US to focus on more rather than bigger. He was not listened to, and the US build both more and bigger. But we do know that you can devastate the world with 100 kT bombs, just as much as you can devastate it with 1 MT bombs. [1] https://en.wikipedia.org/wiki/Uranium-233#Weapon_material https://en.wikipedia.org/wiki/Uranium-233#Weapon_material [2] https://en.wikipedia.org/wiki/W76 https://en.wikipedia.org/wiki/W76
- dilyevsky 3y ago
  Implosion design would have been worked out eventually with JN or not. Computer models make this a lot easier and they probably could have gotten there even without via trial and error.
  - Animats 3y ago
    There was a lot of trial and error involved. Huge numbers of explosive tests were made out in the desert. A technique was developed of taking X-ray movies of implosions to see what was going on in there.
    - dilyevsky 3y ago
      It think x-ray were early tests and later they switched to ionization chambers with a La-140 radioactive source aka RaLa experiments[0]. Wiki says they conducted a total of 254 tests which is huge amount of work but hardly huge number of tests. Guessing if they had to determine the shape and composition of charges experimentally, it would've probably taken thousands of tests and a few more years. [0] - https://en.wikipedia.org/wiki/RaLa_Experiment https://en.wikipedia.org/wiki/RaLa_Experiment
- temporarely 3y ago
  > the Soviets decided to steal the secret Did they decide or was it gifted to them? My speculation is that USSR supported creation of Israel as a quid pro quo.
082349872349872 3y ago
see also https://en.wikipedia.org/wiki/Klára_Dán_von_Neumann https://en.wikipedia.org/wiki/Klára_Dán_von_Neumann Lagniappe: http://anappendage.blogspot.com/2010/02/autofac-by-phillip-k.html http://anappendage.blogspot.com/2010/02/autofac-by-phillip-k...
- CamperBob2 3y ago
  She died in 1963 when she drove from her home in La Jolla to the beach and walked into the surf and drowned. Well, that got dark towards the end.
  - aebtebeten 3y ago
    10 Nov 1963 (1 day before Armistice Day) to be specific. Maybe it was something personal, but (as someone who spent their youth worrying that the Big One might arrive anytime in the next 5-30 minutes, depending upon flight time) I see a lot of geopolitics going on around that date. Now I was fortunate: the US was already out of Vietnam before I was draftable, and I emigrated early in this century, before it was apparent that Afghanistan and Iraq would become slogs, so my life has had a lot of peace, with only minor engagements[0] of either of my countries. Compare KDvN: born in 1911, WWI+Kun 1914-1919, Hitler+WWII 1933-1945, Cold War 1947-, Korea 1950-1953, US involvement in Vietnam 1961-, plus Bay of Pigs 1961, Cuban Missile Crisis 1962, and chaos in Vietnam mid 1963[1]; worked on at least the A-bomb[1,5] and therefore knew what the H-bomb was capable of, but had no empirical evidence that MAD[2] would turn out to be effective, as that acronym was only coined in 1962 and doctrine announced sometime after. If I try to take her priors (as someone who had already started fleeing communism at 8, and had had, it seems, a life full of hope only between the ages of 9 and 22?) I wouldn't have put a lot of weight on peaceful outcomes then either. (then again, Stefan Zweig also committed suicide[3], so I'm not sure how much of a culture shock the New World was to former Austro-hungarians in general) [0] Lebanon, Grenada, Tanker War, Panama, Gulf I, Somalia, Bosnia&Croatia, Haiti, Kosovo (+ Libya raid & misc. no-fly's) [1] https://en.wikipedia.org/wiki/Vietnam_War#Kennedy's_escalation,_1961–1963 https://en.wikipedia.org/wiki/Vietnam_War#Kennedy's_escalati... ; she fortunately missed Kennedy getting cancelled by 11 days. [1,5] EDIT: JvN died young from cancer, which, as an atomic scientist, leads to obvious suspicions. [2] https://en.wikipedia.org/wiki/Mutual_assured_destruction https://en.wikipedia.org/wiki/Mutual_assured_destruction [3] having left The World of Yesterday as a book-length note?
ChrisArchitect 3y ago
(2020) Some discussion then: https://news.ycombinator.com/item?id=28673376 https://news.ycombinator.com/item?id=28673376
- literallycancer 3y ago
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- dang 3y ago
  Thanks! Macroexpanded: What John von Neumann Did at Los Alamos - https://news.ycombinator.com/item?id=28673376 https://news.ycombinator.com/item?id=28673376 - Sept 2021 (152 comments)
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nmwnmw 3y ago
Highly recommend The Man from the Future: The Visionary Life of John von Neumann by Ananyo Bhattacharya. Talks about this time plus many of his other contributions to e.g. game theory.
- stevenwoo 3y ago
  I read that and really wanted more details on the science stuff so I guess it's a good intro to get one started investigating, and the part where the author introduces the woman who was the love of his life (up to that point) and then they were married was unintentionally hilarious because she was not mentioned up to that point in the book despite knowing each other since childhood and prior pages had stories about him carousing at university, IIRC.
- serjester 3y ago
  Personally I found this underwhelming- the book read like a long CV. I wish it talked more about him as a person. But to each their own.
surprisetalk 3y ago
If you’re looking for a dramatic, fictionalized biography of Von Neumann and surrounding characters, I highly recommend The MANIAC: https://bookshop.org/p/books/the-maniac-benjamin-labatut/19622872 https://bookshop.org/p/books/the-maniac-benjamin-labatut/196...
jonplackett 3y ago
I’m curious, since I never studied maths past A level. Is there a difference to the way it’s taught now compared to whenever von Neumann was studying. What I mean is, the way I was taught maths and science in general was with a feeling of “look we basically know everything just learn this and you’ll be fine”. Rather than that there are MASSIVE open questions and things we don’t understand at all. Please learn maths and physics and fix them, will you? I’m basically curious how a fairly young person gets into their head a thought like “Hey, why don’t I just revolutionise a few things? That seems totally reasonable for me to do that.”
- tekla 3y ago
  Some people just seem to be born with the gift and are simply better. I recommend reading about Srinivasa Ramanujan https://en.wikipedia.org/wiki/Srinivasa_Ramanujan https://en.wikipedia.org/wiki/Srinivasa_Ramanujan
  - jonplackett 3y ago
    This is fascinating. Thanks for sharing.
  - hakdbha 3y ago
    [dead]
  - mycologos 3y ago
    Ramanujan is an interesting comparison. He was an outstanding mathematician, but it feels like his prowess came from a deep love of math and concomitant time spent on it. There's an anecdote somewhere about child Ramanujan working his way through thousands of elementary lemmas for fun, and I wonder if this gave him the almost occult intuitive ability reported by his collaborators. The stories about him have a tone of awe, but not fear. In some contrast, von Neumann seems to have been able to take his enormous fluid intelligence and speed and apply it to pretty much whatever problem he decided, and he did it across many areas, including non-scientific ones. The stories about him are tinged with a little unease, and it's a little harder to see the human underneath his achievements.
randcraw 3y ago
BTW, the author of this piece is an amazing writer. The rest of his blog and the blog roll at 3quarksdaily are worth a closer look.
RcouF1uZ4gsC 3y ago
von Neumann was the genius's genius. Even the people a at Los Alamos had a suspicion that von Neumann operated on a different level from themselves. From wikipedia: Nobel Laureate Hans Bethe said "I have sometimes wondered whether a brain like von Neumann's does not indicate a species superior to that of man".[29] Edward Teller observed "von Neumann would carry on a conversation with my 3-year-old son, and the two of them would talk as equals, and I sometimes wondered if he used the same principle when he talked to the rest of us."
- TMWNN 3y ago
  Unsurprisingly, von Neumann was one of The Martians. <https://en.wikipedia.org/wiki/The_Martians_(scientists) https://en.wikipedia.org/wiki/The_Martians_(scientists)>
- zero_k 3y ago
  I am 100% with you. I have infinite admiration for von Neumann's talents. He was the genius of the geniuses. I wish I could have a 10 minute chat with him. He'd blow my mind, I'm sure. I'd love to explain some of the research issues I'm working on to him, I have a feeling he'd nail them to the ground. His resume is absolutely insane. The dude invented merge sort and it's an effin' side-note to his work. Like, WAT. His achievements could fill the resume of 50 Nobel Laureate scientists. Plus apparently he had a CHARACTER, like a real one. Would have loved to shoot the sh&t with him.
  - satori99 3y ago
    There were others in his league who have been mostly lost in history. When von Neumann first published a description of a stored-program binary computing machine in 1945, he cited only one paper -- which was co-authored by Walter Pitts; https://nautil.us/the-man-who-tried-to-redeem-the-world-with-logic-235253/ https://nautil.us/the-man-who-tried-to-redeem-the-world-with...
    - cmehdy 3y ago
      Thank you for sharing this, beautiful and tragic as it is.
AlbertCory 3y ago
> “Using a term like nonlinear science is like referring to the bulk of zoology as the study of non-elephant animals.” Gotta remember that one. Even though it wasn't JvN.
- pfdietz 3y ago
  The JvN quote I remember is from Ulam. In this story, Ulam and vN are at seminar, watching a presentation where the speaker has put up a cloud of data points on a slide and has, with great hope, stated they fall on a line. JvN leans over to Ulam and whispers, "well, at least they lie on a plane."
tyre 3y ago
Minor side point, did anyone else find it odd that the author almost exclusively referred to the subject as "Johnny"?
- deleted 3y ago
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- mycologos 3y ago
  IIRC that's the name that friends and colleagues used to refer to him. It pops up in a lot of their quotes.
  - mkl 3y ago
    Many of the quotes are from https://web.archive.org/web/20200626032839/https://www.youtube.com/watch?v=Y2jiQXI6nrE&feature=youtu.be https://web.archive.org/web/20200626032839/https://www.youtu..., where they do say Johnny a lot.
deleted 3y ago
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unsigner 3y ago
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- deleted 3y ago
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- awestroke 3y ago
  I would not want to live in a world where nobody opposes the US
- skrebbel 3y ago
  I’ll never understand this sentiment. You’re actually for killing all the Russians? Everything the Nazis did pales in comparison, how can anyone be this evil? I don’t understand it about von Neumann and I don’t understand it about comments like these.
  - unsigner 3y ago
    Not all Russians, no. I think the suffering during the Cold War, and the current war in Europe (which has so far only reached Georgia. Moldova, and Ukraine, with a satellite conflict simmering in Bosnia) is due to only one of the evils being defeated in WWII, and the other left to grow and pretend to be an esteemed citizen of the world.)
- archagon 3y ago
  You're OK with tens of millions murdered civilians? Shame on you.
  - unsigner 3y ago
    I’m not okay with the German and Japanese civilian casualties during WWII either, but I think the world is better off with Hitler defeated. Similarly, I think we would be in a better place if Stalin was defeated, and Russia rebuilt in a western image like Germany and Japan were.
hilux 3y ago
Interesting: Oswald Veblen, the recipient of the von Neumann letter, was the nephew of Thorstein Veblen, who gave a name to "conspicuous consumption," among other things.
mkl 3y ago
The YouTube video linked in reference 11 has been taken down, but I found it on the Internet Archive: https://web.archive.org/web/20200626032839/https://www.youtube.com/watch?v=Y2jiQXI6nrE&feature=youtu.be https://web.archive.org/web/20200626032839/https://www.youtu... I've just watched it, and it was very interesting (though a low quality copy). From 1966, it has many people who knew him talking about him.
justanotherjoe 3y ago
What a wonderfully written article. Anyone knows why exactly it's such an easy read? I wish I can write this well and this clearly
Mikhail_K 3y ago
I have searched the article (and another one that the author linked) for the clarity regarding what, specifically, were the original contributions of von Neumann to the computer science. The best I could gather was that he was a "generalist" and that he popularized the principles developed during the work on ENIAC and EDVAC wider, than the engineers who designed those machines intended (to their displeasure). The specifics of computer architecture do not seem to be his idea. I welcome corrections to the impression that I've formed. Program stored in the same memory as data, particularly, strikes me as mixed blessing, given that it has proved over the years to be a never-drying wellspring of security vulnerabilities.
- OskarS 3y ago
  It may seem like a mixed blessing now, but without von Neumann architectures computers would not be what they are now. It's an ingenious, and non-obvious idea, that there should be no essential distinction between "program" and "data" (indeed, Turing machines are based on this idea as well). von Neumann was enormously important in early Computer Science, his contributions cannot be understated. Indeed, Knuth credits him with the one of the most fundamental concepts in all of programming, subroutines (Turing had similar ideas in England around the same time). For more specific examples, von Neumann also came up with the concept of the PRNG, and the first practical algorithm (the "middle square" method). PRNGs are not obvious: before von Neumann, people had only tried generating random numbers using a table or primitive hardware RNGs. He was the one who came up with the idea to generate random numbers using arithmetic methods already present in computers. He also came up with the worlds first practical computer algorithm for sorting, merge sort. There's a huge number of other examples, early CS is riddled with ideas that can from von Neumann.
  - Mikhail_K 3y ago
    > without von Neumann architectures computers would not be what they are now. He did not develop that architecture. It is not his idea. The article is pretty clear on that. The subroutines were not original, as Turing also came up with them.
Oarch 3y ago
What a wonderful read. Makes me slightly bothered he didn't get so much as a cameo in the Oppenheimer film. The book the author referenced, Turing's Cathedral, is a great read for anyone who enjoyed this and wants to know more.

242 points by fanf2 3y ago

Personal speculation: without John von Neumann's contributions to the Plutonium bomb, there's a good chance we would not have hydrogen bombs to this day. Here's why: the US had already had a feasible bomb design, the Uranium-235 based bomb, that was dropped at Hiroshima. Not only that, but it had an alternative to the Plutonium bomb too, the U-233 bomb. Glenn Seaborg, the guy who discovered Plutonium and a bunch of other elements, was tasked with doing a feasibility study of a bomb with U-233. He found out it can be done, and sure enough, a few years after the war the US build such a bomb and tested it. It was not done because the Plutonium bomb became possible (with von Neumann's help). But again, if von Neumann had decided to spend his time on other problems, then the US could have focused on the U-233 bomb instead. This leaves us at the end of the war, when the Soviets decided to steal the secret and build their own bomb. Stalin decided they'll build an exact replica of the Nagasaki bomb, which they did and tested in 1949. If only U-233 and U-235 were on the table, they would have picked one of those, rather than explored an uncertain design. From uranium bombs to boosted uranium bombs there's a small step. So the world would have seen much bigger bombs than the ones dropped on Japan. Fission bombs were built and tested that got close to one megaton. But the hydrogen bomb is fundamentally an implosion bomb. The hydrogen bomb was a side-effect of the deeper understanding of the implosion design. In particular, the US figured out that if you can do implosion with conventional explosives, you can do it even better with nuclear explosives, so it designed and tested a two stage fission bomb, the Castle Nectar bomb. It's the only non-thermonuclear bomb ever detonated that had a yield above 1 MT (it was 1.8 MT). The research into this two-stage bomb is what Ulam was doing, and he told Teller that maybe what works for a second stage that is a fission bomb could work for a second stage that's a fusion bomb. Teller added his own insights, and eventually it was done.

philwelch 3y ago
Wikipedia claims that Von Neumann and Klaus Fuchs also had a preliminary design for a hydrogen bomb that also used the implosion bomb as a first stage, though in a different way than the Teller-Ulam design. Fuchs leaked the Neumann-Fuchs design to the Soviets along with everything else, but just like the US, the Soviets set it aside and independently came up with the Teller-Ulam design instead. So it would seem that, despite Teller and Ulam winning out, Von Neumann was still deeply involved in hydrogen bomb development beyond simply developing the prerequisite plutonium implosion bomb.
- refset 3y ago
  > Von Neumann was still deeply involved in hydrogen bomb development beyond simply developing the prerequisite plutonium implosion bomb This. https://en.wikipedia.org/wiki/John_von_Neumann https://en.wikipedia.org/wiki/John_von_Neumann > In 1955, von Neumann became a commissioner of the Atomic Energy Commission (AEC) > He used this position to further the production of compact hydrogen bombs suitable for intercontinental ballistic missile (ICBM) delivery > He was adamant that H-bombs delivered deep into enemy territory by an ICBM would be the most effective weapon possible It seems much of his life was dedicated to applying Game Theory.
barelyauser 3y ago
This is an absurd take, to say the least. It offends the intelligence of virtually everyone involved in the bomb development. Plutonium usefulness would be noticed eventually. Implosion of fusion fuel using X-Rays thermal transport would have been discovered as well. The world does not have a single point of failure based on a single person, like you paint it.
- silverquiet 3y ago
  Absurd isn't really the word I would use. I think it's more of a naive/common misconception about how science advances. People tend to think of a single genius making breakthroughs when in fact a lot of ideas were building on prior work and in collaboration with others; essentially the ideas eventually have their time, and you get a sense that the specific people who discovered them, while impressive, are a bit of a historical detail rather than an essential ingredient. To me, the biggest example would be evolution - Darwin was famous for it, but you will find others speculating about it before him, and famously he sat on his work and only published it once Alfred Russel Wallace was about to independently publish his discovery of the same phenomena "Connections" by James Burke is a wonderful documentary that first helped me to really understand this.
- credit_guy 3y ago
  Slow down a bit. First: it took many years for the Ulam-Teller design to be discovered. Teller came up with the idea of a fusion bomb in 1942. The actual Ulam-Teller design was invented in March 1951, basically 9 years later. In this 9 years, for at least 2 years, people were searching frantically for a workable design. It's very easy to say, after the fact, that "X-Rays thermal transport would have been discovered as well" because we know this is what worked in the end. But before the fact, nobody was looking for X-Ray implosion. Second: During WW2, plutonium was considered superior to uranium because it was cheaper to manufacture. U-235 was being manufactured via a very expensive separation process. But U-233 can be bred in a thorium reactor just like Plutonium is bred in a uranium reactor. They both come with their challenges (U-232 for U-233, Pu-240 for Pu-239), but in a scenario where the Manhattan project did not figure the implosion design in a hurry, the US would have shifted the resources to U-233. Here's a quote from wikipedia [1] > A declassified 1966 memo from the US nuclear program stated that uranium-233 has been shown to be highly satisfactory as a weapons material, though it was only superior to plutonium in rare circumstances. It was claimed that if the existing weapons were based on uranium-233 instead of plutonium-239, Livermore would not be interested in switching to plutonium. Now, I have no doubts that fission boosting would have been discovered. But with fission boosting, bombs would have gotten to the 1 MT yield, and that is plenty destructive for all war scenarios. Crucially, such a weapon did not need to use any type of implosion. In a scenario where the US does not develop the implosion knowledge because it can build a 1 MT weapon without, then it is not at all a given that someone else would have looked for an implosion-based design of a thermonuclear weapon. We would still have had the layer-cake design, but that is not a game changer, and it's not clear that the extra yield was worth the extra complexity. Now, in today's world: Most of US's nukes have yields around 100 kT [2]. They are thermonuclear but the same effect can be achieved with (boosted) fission bombs. The largest current US nuke, the B83, has a yield of 1.2 MT, but the US is looking to retire it, and replace it with B61, with a maximum yield of 400 kT. My point is that a superpower can service all its deterrence needs with nuclear weapons with yields that are achievable with boosted fission. Why did we then go and build thermonuclear monster bombs in the 50's and 60's? Because at the time the ICBM precision was limited, and you needed something with a mile-sized fireball to make up for the lack of precision. But the ICBM technology advanced at an incredible pace. If we had been 10 years late coming with the design for a thermonuclear bomb, it would not have been needed at all. Yet another thing is this: the destructive power of a nuke does not grow linearly with its yield. Ten bombs with a 100 kT yield are more destructive than on single bomb with a 1 MT yield. Oppenheimer knew that, and advised the US to focus on more rather than bigger. He was not listened to, and the US build both more and bigger. But we do know that you can devastate the world with 100 kT bombs, just as much as you can devastate it with 1 MT bombs. [1] https://en.wikipedia.org/wiki/Uranium-233#Weapon_material https://en.wikipedia.org/wiki/Uranium-233#Weapon_material [2] https://en.wikipedia.org/wiki/W76 https://en.wikipedia.org/wiki/W76
dilyevsky 3y ago
Implosion design would have been worked out eventually with JN or not. Computer models make this a lot easier and they probably could have gotten there even without via trial and error.
- Animats 3y ago
  There was a lot of trial and error involved. Huge numbers of explosive tests were made out in the desert. A technique was developed of taking X-ray movies of implosions to see what was going on in there.
  - dilyevsky 3y ago
    It think x-ray were early tests and later they switched to ionization chambers with a La-140 radioactive source aka RaLa experiments[0]. Wiki says they conducted a total of 254 tests which is huge amount of work but hardly huge number of tests. Guessing if they had to determine the shape and composition of charges experimentally, it would've probably taken thousands of tests and a few more years. [0] - https://en.wikipedia.org/wiki/RaLa_Experiment https://en.wikipedia.org/wiki/RaLa_Experiment
temporarely 3y ago
> the Soviets decided to steal the secret Did they decide or was it gifted to them? My speculation is that USSR supported creation of Israel as a quid pro quo.

082349872349872 3y ago

see also https://en.wikipedia.org/wiki/Klára_Dán_von_Neumann https://en.wikipedia.org/wiki/Klára_Dán_von_Neumann Lagniappe: http://anappendage.blogspot.com/2010/02/autofac-by-phillip-k.html http://anappendage.blogspot.com/2010/02/autofac-by-phillip-k...

CamperBob2 3y ago
She died in 1963 when she drove from her home in La Jolla to the beach and walked into the surf and drowned. Well, that got dark towards the end.
- aebtebeten 3y ago
  10 Nov 1963 (1 day before Armistice Day) to be specific. Maybe it was something personal, but (as someone who spent their youth worrying that the Big One might arrive anytime in the next 5-30 minutes, depending upon flight time) I see a lot of geopolitics going on around that date. Now I was fortunate: the US was already out of Vietnam before I was draftable, and I emigrated early in this century, before it was apparent that Afghanistan and Iraq would become slogs, so my life has had a lot of peace, with only minor engagements[0] of either of my countries. Compare KDvN: born in 1911, WWI+Kun 1914-1919, Hitler+WWII 1933-1945, Cold War 1947-, Korea 1950-1953, US involvement in Vietnam 1961-, plus Bay of Pigs 1961, Cuban Missile Crisis 1962, and chaos in Vietnam mid 1963[1]; worked on at least the A-bomb[1,5] and therefore knew what the H-bomb was capable of, but had no empirical evidence that MAD[2] would turn out to be effective, as that acronym was only coined in 1962 and doctrine announced sometime after. If I try to take her priors (as someone who had already started fleeing communism at 8, and had had, it seems, a life full of hope only between the ages of 9 and 22?) I wouldn't have put a lot of weight on peaceful outcomes then either. (then again, Stefan Zweig also committed suicide[3], so I'm not sure how much of a culture shock the New World was to former Austro-hungarians in general) [0] Lebanon, Grenada, Tanker War, Panama, Gulf I, Somalia, Bosnia&Croatia, Haiti, Kosovo (+ Libya raid & misc. no-fly's) [1] https://en.wikipedia.org/wiki/Vietnam_War#Kennedy's_escalation,_1961–1963 https://en.wikipedia.org/wiki/Vietnam_War#Kennedy's_escalati... ; she fortunately missed Kennedy getting cancelled by 11 days. [1,5] EDIT: JvN died young from cancer, which, as an atomic scientist, leads to obvious suspicions. [2] https://en.wikipedia.org/wiki/Mutual_assured_destruction https://en.wikipedia.org/wiki/Mutual_assured_destruction [3] having left The World of Yesterday as a book-length note?

ChrisArchitect 3y ago

(2020) Some discussion then: https://news.ycombinator.com/item?id=28673376 https://news.ycombinator.com/item?id=28673376

literallycancer 3y ago
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dang 3y ago
Thanks! Macroexpanded: What John von Neumann Did at Los Alamos - https://news.ycombinator.com/item?id=28673376 https://news.ycombinator.com/item?id=28673376 - Sept 2021 (152 comments)

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nmwnmw 3y ago

Highly recommend The Man from the Future: The Visionary Life of John von Neumann by Ananyo Bhattacharya. Talks about this time plus many of his other contributions to e.g. game theory.

stevenwoo 3y ago
I read that and really wanted more details on the science stuff so I guess it's a good intro to get one started investigating, and the part where the author introduces the woman who was the love of his life (up to that point) and then they were married was unintentionally hilarious because she was not mentioned up to that point in the book despite knowing each other since childhood and prior pages had stories about him carousing at university, IIRC.
serjester 3y ago
Personally I found this underwhelming- the book read like a long CV. I wish it talked more about him as a person. But to each their own.

surprisetalk 3y ago

If you’re looking for a dramatic, fictionalized biography of Von Neumann and surrounding characters, I highly recommend The MANIAC: https://bookshop.org/p/books/the-maniac-benjamin-labatut/19622872 https://bookshop.org/p/books/the-maniac-benjamin-labatut/196...

jonplackett 3y ago

I’m curious, since I never studied maths past A level. Is there a difference to the way it’s taught now compared to whenever von Neumann was studying. What I mean is, the way I was taught maths and science in general was with a feeling of “look we basically know everything just learn this and you’ll be fine”. Rather than that there are MASSIVE open questions and things we don’t understand at all. Please learn maths and physics and fix them, will you? I’m basically curious how a fairly young person gets into their head a thought like “Hey, why don’t I just revolutionise a few things? That seems totally reasonable for me to do that.”

tekla 3y ago
Some people just seem to be born with the gift and are simply better. I recommend reading about Srinivasa Ramanujan https://en.wikipedia.org/wiki/Srinivasa_Ramanujan https://en.wikipedia.org/wiki/Srinivasa_Ramanujan
- jonplackett 3y ago
  This is fascinating. Thanks for sharing.
- hakdbha 3y ago
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- mycologos 3y ago
  Ramanujan is an interesting comparison. He was an outstanding mathematician, but it feels like his prowess came from a deep love of math and concomitant time spent on it. There's an anecdote somewhere about child Ramanujan working his way through thousands of elementary lemmas for fun, and I wonder if this gave him the almost occult intuitive ability reported by his collaborators. The stories about him have a tone of awe, but not fear. In some contrast, von Neumann seems to have been able to take his enormous fluid intelligence and speed and apply it to pretty much whatever problem he decided, and he did it across many areas, including non-scientific ones. The stories about him are tinged with a little unease, and it's a little harder to see the human underneath his achievements.

randcraw 3y ago

BTW, the author of this piece is an amazing writer. The rest of his blog and the blog roll at 3quarksdaily are worth a closer look.

RcouF1uZ4gsC 3y ago

von Neumann was the genius's genius. Even the people a at Los Alamos had a suspicion that von Neumann operated on a different level from themselves. From wikipedia: Nobel Laureate Hans Bethe said "I have sometimes wondered whether a brain like von Neumann's does not indicate a species superior to that of man".[29] Edward Teller observed "von Neumann would carry on a conversation with my 3-year-old son, and the two of them would talk as equals, and I sometimes wondered if he used the same principle when he talked to the rest of us."

TMWNN 3y ago
Unsurprisingly, von Neumann was one of The Martians. <https://en.wikipedia.org/wiki/The_Martians_(scientists) https://en.wikipedia.org/wiki/The_Martians_(scientists)>
zero_k 3y ago
I am 100% with you. I have infinite admiration for von Neumann's talents. He was the genius of the geniuses. I wish I could have a 10 minute chat with him. He'd blow my mind, I'm sure. I'd love to explain some of the research issues I'm working on to him, I have a feeling he'd nail them to the ground. His resume is absolutely insane. The dude invented merge sort and it's an effin' side-note to his work. Like, WAT. His achievements could fill the resume of 50 Nobel Laureate scientists. Plus apparently he had a CHARACTER, like a real one. Would have loved to shoot the sh&t with him.
- satori99 3y ago
  There were others in his league who have been mostly lost in history. When von Neumann first published a description of a stored-program binary computing machine in 1945, he cited only one paper -- which was co-authored by Walter Pitts; https://nautil.us/the-man-who-tried-to-redeem-the-world-with-logic-235253/ https://nautil.us/the-man-who-tried-to-redeem-the-world-with...
  - cmehdy 3y ago
    Thank you for sharing this, beautiful and tragic as it is.

AlbertCory 3y ago

> “Using a term like nonlinear science is like referring to the bulk of zoology as the study of non-elephant animals.” Gotta remember that one. Even though it wasn't JvN.

pfdietz 3y ago
The JvN quote I remember is from Ulam. In this story, Ulam and vN are at seminar, watching a presentation where the speaker has put up a cloud of data points on a slide and has, with great hope, stated they fall on a line. JvN leans over to Ulam and whispers, "well, at least they lie on a plane."

tyre 3y ago

Minor side point, did anyone else find it odd that the author almost exclusively referred to the subject as "Johnny"?

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mycologos 3y ago
IIRC that's the name that friends and colleagues used to refer to him. It pops up in a lot of their quotes.
- mkl 3y ago
  Many of the quotes are from https://web.archive.org/web/20200626032839/https://www.youtube.com/watch?v=Y2jiQXI6nrE&feature=youtu.be https://web.archive.org/web/20200626032839/https://www.youtu..., where they do say Johnny a lot.

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unsigner 3y ago

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awestroke 3y ago
I would not want to live in a world where nobody opposes the US
skrebbel 3y ago
I’ll never understand this sentiment. You’re actually for killing all the Russians? Everything the Nazis did pales in comparison, how can anyone be this evil? I don’t understand it about von Neumann and I don’t understand it about comments like these.
- unsigner 3y ago
  Not all Russians, no. I think the suffering during the Cold War, and the current war in Europe (which has so far only reached Georgia. Moldova, and Ukraine, with a satellite conflict simmering in Bosnia) is due to only one of the evils being defeated in WWII, and the other left to grow and pretend to be an esteemed citizen of the world.)
archagon 3y ago
You're OK with tens of millions murdered civilians? Shame on you.
- unsigner 3y ago
  I’m not okay with the German and Japanese civilian casualties during WWII either, but I think the world is better off with Hitler defeated. Similarly, I think we would be in a better place if Stalin was defeated, and Russia rebuilt in a western image like Germany and Japan were.

hilux 3y ago

Interesting: Oswald Veblen, the recipient of the von Neumann letter, was the nephew of Thorstein Veblen, who gave a name to "conspicuous consumption," among other things.

mkl 3y ago

The YouTube video linked in reference 11 has been taken down, but I found it on the Internet Archive: https://web.archive.org/web/20200626032839/https://www.youtube.com/watch?v=Y2jiQXI6nrE&feature=youtu.be https://web.archive.org/web/20200626032839/https://www.youtu... I've just watched it, and it was very interesting (though a low quality copy). From 1966, it has many people who knew him talking about him.

justanotherjoe 3y ago

What a wonderfully written article. Anyone knows why exactly it's such an easy read? I wish I can write this well and this clearly

Mikhail_K 3y ago

I have searched the article (and another one that the author linked) for the clarity regarding what, specifically, were the original contributions of von Neumann to the computer science. The best I could gather was that he was a "generalist" and that he popularized the principles developed during the work on ENIAC and EDVAC wider, than the engineers who designed those machines intended (to their displeasure). The specifics of computer architecture do not seem to be his idea. I welcome corrections to the impression that I've formed. Program stored in the same memory as data, particularly, strikes me as mixed blessing, given that it has proved over the years to be a never-drying wellspring of security vulnerabilities.

OskarS 3y ago
It may seem like a mixed blessing now, but without von Neumann architectures computers would not be what they are now. It's an ingenious, and non-obvious idea, that there should be no essential distinction between "program" and "data" (indeed, Turing machines are based on this idea as well). von Neumann was enormously important in early Computer Science, his contributions cannot be understated. Indeed, Knuth credits him with the one of the most fundamental concepts in all of programming, subroutines (Turing had similar ideas in England around the same time). For more specific examples, von Neumann also came up with the concept of the PRNG, and the first practical algorithm (the "middle square" method). PRNGs are not obvious: before von Neumann, people had only tried generating random numbers using a table or primitive hardware RNGs. He was the one who came up with the idea to generate random numbers using arithmetic methods already present in computers. He also came up with the worlds first practical computer algorithm for sorting, merge sort. There's a huge number of other examples, early CS is riddled with ideas that can from von Neumann.
- Mikhail_K 3y ago
  > without von Neumann architectures computers would not be what they are now. He did not develop that architecture. It is not his idea. The article is pretty clear on that. The subroutines were not original, as Turing also came up with them.

Oarch 3y ago

What a wonderful read. Makes me slightly bothered he didn't get so much as a cameo in the Oppenheimer film. The book the author referenced, Turing's Cathedral, is a great read for anyone who enjoyed this and wants to know more.