Cleaning thermonuclear fire

exactly what would it not take to turn the world into one big fusion reaction, wiping it clean of life and making it a barren rock? Asking for a pal.

Graphic from the 1946 film, “One World Or None,” produced by the nationwide Committee on Atomic Suggestions, advocating for the importance of the international control of atomic power.

One might wonder whether that kind of question provided it self while I became reading the news headlines nowadays, plus one will be totally proper. However the explanation individuals typically ask this real question is in mention of the the story that researchers at Los Alamos thought there is a non-zero chance your Trinity test might ignite the environment throughout the very first wartime test.

The essential concept is a simple one: in the event that you heat up really light atoms (like hydrogen) to very high conditions, they’ll battle around like mad, therefore the chances that they’ll collide into both and undergo nuclear fusion become a great deal greater. If that occurs, they’ll release more energy. Imagine if the very first rush of an atomic bomb started fusion reactions floating around around it, say between your atoms of air or nitrogen, and people fusion responses generated enough power to start out more responses, and so forth, over the whole environment?

It’s difficult to say exactly how seriously it was taken. Its clear that at one point, Arthur Compton concerned about it, and that likewise, a few boffins developed persuasive thinking on effect that this couldn’t take place. James Conant, upon experiencing the searing temperature of the Trinity test, briefly reflected that possibly this rumored thing had, certainly, visited pass:

Then arrived a burst of white light that seemed to fill the sky and appeared to last for seconds. I’d expected a relatively fast and bright flash. The enormity associated with light and its own length quite stunned me personally. My instantaneous reaction was that something choose to go wrong which the thermal nuclear [sic] transformational of the atmosphere, as soon as talked about as possibility and jokingly referred to a few momemts early in the day, had actually taken place.

Which does at the very least tell us that some of those at the test remained joking about this, even around the previous couple of moments. Fermi reportedly took wagers on whether or not the bomb would destroy simply New Mexico or in fact the entire world, nonetheless it had been comprehended as being a laugh.1

The introduction associated with Konopinski, Marvin, and Teller paper of 1946. Filed under: “SCIENCE!“

Into the fall of 1946, Emil Konopinski, Cloyd Marvin, and Edward Teller (whom else?) composed up a paper describing why no detonation in the world ended up being likely to start an uncontrolled fusion response within the environment. It is really not clear to me whether this is often the logic they utilized prior towards the Trinity detonation, but it is most likely of the comparable character to it.2 In a nutshell, there clearly was only 1 fusion reaction in line with the constituents of the air which had any probability anyway (the nitrogen-nitrogen effect), and the scientists were able to show it was not to more likely to take place or spread. No matter if one makes assumptions your response had been much simpler to start than anyone thought it was probably be, it absolutely wasn’t likely to be suffered. The reaction would cool (through a selection of real mechanisms) faster than it might distribute.

That is all a typical section of Manhattan Project lore. But I suspect many who possess read with this prior to never have really see the Konopinski-Marvin-Teller paper to its end, in which they end for a less sure-of-themselves note:

There continues to be the remote possibility that several other less easy mode of burning may keep itself inside atmosphere.

Even if the effect is stopped within sphere of the few hundred meters radius, the resultant earth-shock while the radioactive contamination of the environment might become catastrophic for a world-wide scale.

One may conclude that the arguments of the paper allow it to be unreasonable to expect your N+N effect could propagate. An limitless propagation is even less likely. But the complexity associated with the argument and also the lack of satisfactory experimental foundations makes further work with the subject extremely desirable.

That’s not quite as protected as you might want, considering these boffins were in reality focusing on developing weapons plenty of that time period stronger than the Trinity unit.3

The relevant part of the Manhattan District History (cited below) interestingly links the study to the “Super” hydrogen bomb with the research into perhaps the atmosphere might be incinerated, which makes feeling, though it would be interesting to understand just how closely connected these questions in which.

There is an interesting section in the recently-declassified Manhattan District History‘s that covers the ignition for the environment issue. They repeat fundamentally the Konopinski-Marvin-Teller outcomes, and then conclude:

The impossibility of igniting the atmosphere was therefore guaranteed by science and good sense. The essential factors in these calculations, the Coulomb forces associated with nucleus, are one of the better comprehended phenomena of modern physics. The philosophic likelihood of destroying the planet earth, from the theoretical convertibility of mass into power, continues to be. The thermonuclear response, that is in order to now understood where such a catastrophe could take place, is evidently eliminated. The typical stability of matter in the observable universe contends against it. Further familiarity with the character regarding the great stellar explosions, novae and supernovae, will put light on these questions. Into the almost complete lack of genuine knowledge, it’s generally speaking believed your tremendous energy of those explosions is of gravitational rather than nuclear origin.4

Which again is at the same time reassuring and perhaps not reassuring. The footing which this knowledge was based ended up being… very good? But like good researchers these were happy, about in secret reports, to acknowledge there might actually be methods the earth become damaged through nuclear evaluating that they hadn’t considered. Intellectually honest, but in addition terrifying.

The ever relevant XKCD.

This dilemma arrived up once more prior to the process Crossroads nuclear tests in early 1946, that was to include a minumum of one underwater shot. None other than Nobel Prize-winning physicist Percy Bridgman stressed that detonating an atomic bomb under water might ignite a fusion effect into the water. Bridgman admitted their own ignorance into nuclear physics (his specialization had been high-pressure physics), but warned that:

Even the most readily useful human intellect has not imagination enough to envisage exactly what might take place once we push far into new territory. … To an outsider the tactics regarding the argument which will justify operating perhaps the slightest danger of that colossal catastrophe seems extremely weak.5

Bridgman’s worries weren’t actually your globe could be destroyed. He worried more that if the researchers showed up become cavalier about these specific things, therefore ended up being later on made public that their argument the safety associated with tests was according to flimsy evidence, that it would lead to a strong public backlash: “There might be a response against technology generally speaking which would end up in suppression of all clinical freedom while the destruction of technology itself.” Bridgman’s views were strong enough that they were forwarded to General Groves, but it isn’t clear whether or not they led to any significant modifications (though I wonder when they were the impetus for the write-up of this Konopinski-Marvin-Teller paper; the timing type of calculates, but we don’t understand).

There wasn’t lots of evidence this issue concerned the researchers an excessive amount of moving forward. They had other things on the head, like building thermonuclear weapons, and it quickly became clear that beginning a big fusion reaction by having a fission bomb is hard. Which can be, in its very own means, an answer to the initial concern: if starting a runaway fusion response on purpose is hard, and needs really particular forms of arrangements and factors to have working also on a (relatively) little scale, then beginning one in the entire atmosphere, will probably be impossible.

Operation Fishbowl, Shot Checkmate (1962) — the lowest yield weapon, but something about its perfect symmetry together with path regarding the rocket that put it into the air invokes the notion of a planet turning out to be a celebrity for me. Supply: Los Alamos Nationwide Laboratory.

Great — cross that one from the directory of possibilities. But it wouldn’t really be technology unless they also, in the course of time, re-framed issue: exactly what conditions could be needed whenever we were to turn the complete earth into a thermonuclear bomb? In 1975, a radiation physicist on University of Chicago, H.C. Dudley, published an article inside Bulletin of Atomic Scientists caution of the “ultimate catastrophe” of setting the environment burning. This received a few rebuttals and a lot of scorn, including one in pages associated with Bulletin by Hans Bethe, who’d formerly addressed this concern into the Bulletin in 1946. Interestingly, though, Dudley’s primary desire — that some body re-run these calculations on a modern computer simulation — did seem to generate research along these lines within Lawrence Livermore National Laboratory.6

In 1979, Livermore experts Thomas A. Weaver and Lowell Wood (the latter appropriately a well-known Edward Teller protege) published a paper on “Necessary conditions for the initiation and propagation of nuclear-detonation waves in airplane atmospheres,” which is a jargony way to ask issue into the name with this post. Here’s the abstract:

The basic conditions the initiation of a nuclear-detonation wave in an environment having airplane symmetry (age.g., a thin, layered fluid envelope for a earth or star) are developed. Two classes of these a detonation are identified: those where heat regarding the plasma resembles that the electromagnetic radiation permeating it, and the ones where the temperature associated with plasma is significantly greater. Necessary conditions are developed for the propagation of such detonation waves for an arbitrarily good distance. The contribution of fusion chain reactions to these processes is assessed. Through these factors, it’s shown that neither the environment nor oceans of this Earth may be designed to go through propagating nuclear detonation under any circumstances.7

Now if you simply browse the abstract, you might think it absolutely was merely another version (with fancier calculations) of this Konopinski-Marvin-Teller paper. And so they do rule out conclusively that N+N reactions would ever be energetic sufficient become self-propagating. But it is a lot more! Because unlike Konopinski-Marvin-Teller, it in fact centers around those “necessary conditions”: just what will have to be different, if you did want to have a self-propagating response?

The solution they found: if the Earth’s oceans had twenty times more deuterium than they actually contain, they could be ignited by a 20 million megaton bomb (which will be to say, a bomb utilizing the yield equivalent to 200 teratons of TNT, or perhaps a bomb 2 million times more powerful than the Tsar Bomba’s complete yield). If we assumed that this type of tool had even a fantastically efficient yield-to-weight ratio like 50 kt/kg, that’s still a tool that will weigh around a billion metric tons. To put that into viewpoint, that’s about ten times more mass than all the concrete of Three Gorges Dam.8

So there you have it — it can be done! You simply have to completely change the composition of the oceans and require a nuclear tool numerous instructions of magnitude more powerful than the gigaton bombs dreamed of by Edward Teller, then, perhaps, you’ll display the cleansing thermonuclear fire experience.

Which will be to express, this won’t be exactly how the planet dies. But don’t worry, there are plenty other plausible alternatives for human self-extinction around. They simply probably won’t be as quick.


I will be undergoing completing my book manuscript, that will be the actual work of the summer, therefore most other writing, including blog posting, is going for a back chair for a few months while We concentrate on that. The irreverent name of this post is obtained from a recurring theme into the Twitter feed of anthropology grad student Martin “Lick the Bomb” Pfeiffer, whose work you should have a look at when you yourself haven’t currently.

(The Impossibility of) Lighting Atmospheric Fire,” does a very good task of reviewing a few of the wartime conversations and clinical problems.

  • Emil Konopinski, Cloyd Marvin, and Edward Teller, “Ignition for the Atmosphere with Nuclear Bombs,” (14 August 1946), LA-602, Los Alamos National Laboratory. Konopinski and Teller additionally apparently composed an unpublished report about them in 1943. I have only seen mention of the it, as report LA-001 (suspiciously like the LA-1 that is the Los Alamos Primer), but have not seen it.
  • Teller, in October 1945, wrote the following to Enrico Fermi about the chance for a “Super” detonating the environment, as part of that which was basically a “Frequently expected Questions” in regards to the H-bomb: “Careful considerations and calculations have shown that there’s not the remotest likelihood of such an occasion [ignition associated with the atmosphere]. The concentration of energy encountered in super bomb just isn’t higher than that the atomic bomb. In my experience the risks were greater once the first atomic bomb had been tested, because our conclusions had been based in those days on longer extrapolations from understood facts. The chance associated with the super bomb doesn’t lie in physical nature however in human being behavior.” What I find most fascinating concerning this is his comment about Trinity, though Teller’s rhetorical point is an apparent one (overstate the Trinity uncertainty after the fact to be able to emphasize their certainty currently). Edward Teller to Enrico Fermi (31 October 1945), Harrison-Bundy data associated with the Development for the Atomic Bomb, 1942-1946, microfilm publication M1108 (Washington, D.C.: nationwide Archives and reports Administration, 1980), Roll 6, Target 5, Folder 76, “Interim Committee — Scientific Panel.”
  • Manhattan District History, Book 8, amount 2 (“Los Alamos – Technical”), paragraph 1.50.
  • Percy W. Bridgman to Hans Bethe, forwarded by Norris Bradbury to Leslie Groves via TWX (13 March 1946), copy in Nuclear Testing Archive, Las vegas, nevada, NV, document NV0128609.
  • H.C. Dudley, “The Ultimate Catastrophe,” Bulletin associated with Atomic researchers (November 1975), 21; Hans Bethe, “Can Air or liquid Be Exploded?,” Bulletin of the Atomic experts 1, no. 7 (15 March 1946), 2; Hans Bethe, “Ultimate Disaster?,” Bulletin of the Atomic researchers 32, no. 6 (1976), 36-37; Frank von Hippel, “Taxes Credulity (Letter towards the Editor),” Bulletin of Atomic boffins (January 1946), 2.
  • Thomas A. Weaver and Lowell Wood, “Necessary conditions for the initiation and propagation of nuclear-detonation waves in plane atmospheres,” Physical Review A 20, no. 1 (1 July 1979), 316-328. DOI: https://doi.org/10.1103/PhysRevA.20.316.
  • Specifically, they conclude it might take a 2 x 107 Mt power release, which they call “fantastic,” to ignite an ocean of 1:300 (instead of the actual 1:6,000) concentration of deuterium. Being an apart, but the collision event that created the Chicxulub Crater (and killed the dinosaurs, etc.) is believed to own released around 5 x 1023 J, which means about 120 million megatons of TNT. So’s not a totally unreasonable energy release for the earth to encounter during the period of its presence — simply not from nuclear weapons.
  • Silhouettes of the bomb

    You might think of the explosive part of a nuclear weapon as the “weapon” or “bomb,” but in the technical literature it has its own kind of amusingly euphemistic name: the “physics package.” This is the part of the bomb where the “physics” happens — which is to say, where the atoms undergo fission and/or fusion and release energy measured in the tons of TNT equivalent.

    Drawing a line between that part of the weapon and the rest of it is, of course, a little arbitrary. External fuzes and bomb fins are not usually considered part of the physics package (the fuzes are part of the “arming, fuzing, and firing” system, in today’s parlance), but they’re of course crucial to the operation of the weapon. We don’t usually consider the warhead and the rocket propellant to be exactly the same thing, but they both have to work if the weapon is going to work. I suspect there are many situations where the line between the “physics package” and the rest of the weapon is a little blurry. But, in general, the distinction seems to be useful for the weapons designers, because it lets them compartmentalize out concerns or responsibilities with regards to use and upkeep.

    Physics package silhouettes of some of the early nuclear weapon variants. The Little Boy (Mk-1) and Fat Man (Mk-3) are based on the work of John Coster-Mullen. All silhouette portraits are by me — some are a little impressionistic. None are to any kind of consistent scale.

    The shape of nuclear weapons was from the beginning one of the most secret aspects about them. The casing shapes of the Little Boy and Fat Man bombs were not declassified until 1960. This was only partially because of concerns about actual weapons secrets — by the 1950s, the fact that Little Boy was a gun-type weapon and Fat Man was an implosion weapon, and their rough sizes and weights, were well-known. They appear to have been kept secret for so long in part because the US didn’t want to draw too much attention to the bombing of the cities, in part because we didn’t want to annoy or alienate the Japanese.

    But these shapes can be quite suggestive. The shapes and sizes put limits on what might be going on inside the weapon, and how it might be arranged. If one could have seen, in the 1940s, the casings of Fat Man and Little Boy, one could pretty easily conjecture about their function. Little Boy definitely has the appearance of a gun-type weapon (long and relatively thin), whereas Fat Man clearly has something else going on with it. If all you knew was that one bomb was much larger and physically rounder than the other, you could probably, if you were a clever weapons scientist, deduce that implosion was probably going on. Especially if you were able to see under the ballistic casing itself, with all of those conspicuously-placed wires.

    In recent years we have become rather accustomed to seeing pictures of retired weapons systems and their physics packages. Most of them are quite boring, a variation on a few themes. You have the long-barrels that look like gun-type designs. You have the spheres or spheres-with-flat ends that look like improved implosion weapons. And you then have the bullet-shaped sphere-attached-to-a-cylinder that seems indicative of the Teller-Ulam design for thermonuclear weapons.

    Silhouettes of compact thermonuclear warheads. Are the round ends fission components, or spherical fusion components? Things the nuke-nerds ponder.

    There are a few strange things in this category, that suggest other designs. (And, of course, we don’t have to rely on just shapes here — we have other documentation that tells us about how these might work.) There is a whole class of tactical fission weapons that seem shaped like narrow cylinders, but aren’t gun-type weapons. These are assumed to be some form of “linear implosion,” which somewhat bridges the gap between implosion and gun-type designs.

    All of this came to mind recently for two reasons. One was the North Korean photos that went around a few weeks ago of Kim Jong-un and what appears to be some kind of component to a ballistic case for a miniaturized nuclear warhead. I don’t think the photos tell us very much, even if we assume they are not completely faked (and with North Korea, you never know). If the weapon casing is legit, it looks like a fairly compact implosion weapon without a secondary stage (this doesn’t mean it can’t have some thermonuclear component, but it puts limits on how energetic it can probably be). Which is kind of interesting in and of itself, especially since it’s not every day that you get to see even putative physics packages of new nuclear nations.

    Stockpile milestones chart from Pantex's website. Lots of interesting little shapes.

    Stockpile milestones chart from Pantex’s website. Lots of interesting little shapes.

    The other reason it came to mind is a chart I ran across on Pantex’s website. Pantex was more or less a nuclear-weapons assembly factory during the Cold War, and is now a disassembly factory. The chart is a variation on one that has been used within the weapons labs for a few years now, my friend and fellow-nuclear-wonk Stephen Schwartz pointed out on Twitter, and shows the basic outlines of various nuclear weapons systems through the years. (Here is a more up-to-date one from the a 2015 NNSA presentation, but the image has more compression and is thus a bit harder to see.)

    For gravity bombs, they tend to show the shape of the ballistic cases. For missile warheads, and more exotic weapons (like the “Special Atomic Demolition Munitions,” basically nuclear land mines — is the “Special” designation really necessary?), they often show the physics package. And some of these physics packages are pretty weird-looking.

    Some of the weirder and more suggestive shapes in the chart. The W30 is a nuclear land mine; the W52 is a compact thermonuclear warhead; the W54 is the warhead for the Davy Crockett system, and the W66 is low-yield thermonuclear weapon used on the Sprint missile system.

    A few that jump out as especially odd:

    • PowerPoint Presentation

      Is the fill error meaningful, or just a mistake? Can one read too much into a few blurred pixels?

      In the Pantex version (but not the others), the W59 is particular in that it has an incorrectly-filled circle at the bottom of it. I wonder if this is an artifact of the vectorization process that went into making these graphics, and a little more indication of the positioning of things than was intended.

    • The W52 has a strange appearance. It’s not clear to me what’s going on there.
    • The silhouette of the W30 is a curious one (“worst Tetris piece ever” quipped someone on Twitter), though it is of an “Atomic Demolition Munition” and likely just shows some of the peripheral equipment to the warhead.
    • The extreme distance between the spherical end (primary?) and the cylindrical end (secondary?) of the W-50 is pretty interesting.
    • The W66 warhead is really strange — a sphere with two cylinders coming out of it. Could it be a “double-gun,” a gun-type weapon that decreases the distance necessary to travel by launching two projectiles at once? Probably not, given that it was supposed to have been thermonuclear, but it was an unusual warhead (very low-yield thermonuclear) so who knows what the geometry is.

    There are also a number of warheads whose physics packages have never been shown, so far as I know. The W76, W87, and W88, for example, are primarily shown as re-entry vehicles (the “dunce caps of the nuclear age” as I seem to recall reading somewhere). The W76 has two interesting representations floating around, one that gives no real feedback on the size/shape of the physics package but gives an indication of its top and bottom extremities relative to other hardware in the warhead, another that portrays a very thin physics package that I doubt is actually representational (because if they had a lot of extra space, I think they’d have used it).1

    Some of the more simple shapes — triangles, rectangles, and squares, oh my!

    Some of the more simple shapes — triangles, rectangles, and squares, oh my!

    What I find interesting about these secret shapes is that on the one hand, it’s somewhat easy to understand, I suppose, the reluctance to declassify them. What’s the overriding public interest for knowing what shape a warhead is? It’s a hard argument to make. It isn’t going to change how to vote or how we fund weapons or anything else. And one can see the reasons for keeping them classified — the shapes can be revealing, and these warheads likely use many little tricks that allow them to put that much bang into so compact a package.

    On the other hand, there is something to the idea, I think, that it’s hard to take something seriously if you can’t see it. Does keeping even the shape of the bomb out of public domain impact participatory democracy in ever so small a way? Does it make people less likely to treat these weapons as real objects in the world, instead of as metaphors for the end of the world? Well, I don’t know. It does make these warheads seem a bit more out of reach than the others. Is that a compelling reason to declassify their shapes? Probably not.

    As someone on the “wrong side” of the security fence, I do feel compelled to search for these unknown shapes — a defiant compulsion to see what I am not supposed to see, perhaps, in an act of petty rebellion. I suspect they look pretty boring — how different in appearance from, say, the W80 can they be? — but the act of denial makes them inherently interesting.

    Notes
    1. One amusing thing is that several sites seem to have posted pictures of the arming, fuzing, and firing systems of these warheads under the confusion that these were the warheads. They are clearly not — they are not only too small in their proportions, but they match up exactly to declassified photos of the AF&F systems (they are fuzes/radars, not physics packages).