What is it that the author thinks is particularly unusual about this image? Pretty much every schematic of a Teller-Ulam type weapon -- a schematic which you will find in every introductory Nuclear Physics textbook -- shows a large cylinder with a spherical fission device at the top and a cylindrical fusion device at the bottom, plus some FOGBANK-type material of unconfirmed purpose. This image looks exactly like those schematics except that someone has imagined some little channels which look like they're intended to move energy from the primary to the secondary. Without detailed simulation and testing, a prospective weapons designer has no way of knowing whether those channels are representative of a real weapon, or just a superficially plausible hallucination.
Overall this looks like someone asked a physics undergraduate to spend an hour imagining roughly how the well-known schematic might be fitted inside a real warhead case. It probably is exactly that. I can't imagine that showing it to the North Koreans advanced their nuclear programme by any more than fifteen minutes.
> What is it that the author thinks is particularly unusual about this image?
In two decades of crawling through most of the declassified public nuclear material from the US nuclear weapons program, some exposure to classified material, and numerous hours of interviews with working and retired nuclear scientists he believes it's the single most detailed schematic of an actual specific type of warhead he's seen so far.
As he's blogging about this it's almost certain he has had real current working nuclear weapons experts from his contact list read the advances and not disagree.
Correct or not, it's not a casual random thought from someone with no exposure to such diagrams.
OK, but my question remains: what is it that the author thinks is particularly unusual about this image?
I'm not a nuclear scientist, but I did study nuclear physics to master's level. To my eye, there's nothing at all interesting about this image. It looks like informed speculation. Without any confirmation that this is a real weapons design (and I see no reason at all to believe it is) then it tells us absolutely nothing which hasn't been in the public domains for decades.
> As he's blogging about this it's almost certain he has had real current working nuclear weapons experts from his contact list read the advances and not disagree.
That seems extremely unlikely to me. People who have held the appropriate clearance to verify whether this is or is not representative of a real weapon, do not tend to casually liaise with someone who has spent their career attempting to prise open that veil of secrecy. In fact, their own careers and liberty depend on not making such personal connections.
> what is it that the author thinks is particularly unusual about this image?
The level of detail, particularly the articulation of components/subsystems (primary, secondary, radiation case, interstage medium, tamper, fusion fuel, and a "sparkplug"). All according to the article. Per author, DoE has very strict guidelines on the depiction of nukes, and this image appears to violate those guidelines. The official depictions are often just simple shapes, like "two circles in a box," that do not convey any meaningful information about weapon design.
I am speculating here, but it seems like DoE must believe that anything beyond simple shapes may provide bad actors (i.e. anyone but US Govt and allies) clues as to how to build a thermo-nuke.
> I am speculating here, but it seems like DoE must believe that anything beyond simple shapes may provide bad actors (i.e. anyone but US Govt and allies) clues as to how to build a thermo-nuke.
It's a bit like the Egg of Columbus. Doing it the first time needs a team of visionary geniuses, but once the trick is known to work then even us pedestrians could manage it given enough time and resources.
the problem is usually getting the fissile material.
as far as non-state actors go though, other types of WMD are probably more attainable. Aum Shinrikyo is probably the most infamous example where a cult manufactured multiple chemical weapons. https://en.wikipedia.org/wiki/Aum_Shinrikyo#Tokyo_subway_sar...
Yes and no. For terrorism purposes, the primary (more or less the same as a "Hiroshima"-level "A"-bomb) would surely more than suffice.
I'm sort of struggling to think why anyone other than a nation state (looking to prove itself worthy of a seat at various tables) would want to possess more bang than that.
Granted there are a few nations at or close to A-bomb tech whom we would definitely not want having its bigger brother. Iran and NK especially.
I feel like the Nth Country Experiment kind of invalidates the idea that it makes sense to worry so much about hiding all of this, though? That 3 fresh physics PhDs were able to design a working bomb in as many years without having subject matter expertise to me shows that shows that the sort of adversary that has the resources to build such a project will have access to the resources to design it, too.
Conclusion: that's a diagram of the obvious approach to building a thermonuclear device, which happens to be completely wrong for classified reasons, and if you pursue this design you're going to waste a decade before you figure out why.
More likely is that the obvious approach is also totally the right approach and anyone with the relevant education could easily come up with it themselves, but the US government still censors it out of security theatre.
The blog goes into detail about how releasing any wrong information or misinformation about a secret, still defines the bounds and brackets the real information, and allows eliminating possible options (as no agency would reveal the truth.)
If that was the case, an actor could go "this is obviously not the way to build this, lets move on" so in a way, you have sped up the development.
Just like saying, "We have 100,000 nukes" (a lie), everyone knows its a lie, which means we DO NOT have 100,000 nukes, as we wouldn't reveal the truth.
Enough of these little "misinformations" get released, the closer to the truth someone can get.
Or, there are 5 people doing this type of research across the world, 3 of them barely taking calls on iOS and the rest just finally managed to migrate from IRIX to Cygwin last year, and they are to take all necessary actions for operational security and talent acquisition.
I don't work in or around this field and never have. You have as much knowledge about it as I do. That was just my interpretation of the situation, based on watching too many movies.
The author should look into https://www.castelion.com/ a company started by SpaceX employees and with deep connections to Elon's Starlink and Strategic Defense Initiative.
As nmadden noted there's a lot of detail in the article .
> That seems extremely unlikely to me.
None the less his nuclearsecrecy blog has been about for many many years and he's had a great deal of contact with people who have walked up to the line. It's not that uncommon for historians to have neither confirm nor deny but we can understand various silences relations with experts - even the OG Manhatten Project had embedded historians and archivists who toed the line on handling and preserving materials and held long meetings on what to release | not release and when.
There are even a few DoE employed HN users here who know their areas of expertise and comment right up to the point where they shut up (an often shut down | change accounts) - they don't say what they shouldn't but they have chatted until they don't anymore .. which is interesting in itself.
There's a lot of detail about why the author thinks it is notable that Sandia released this image. There's very little about what it is in this image itself that the author finds interesting, save for some comment about a dip which could be intended to focus neutron flux from the primary to the secondary. I feel that's the kind of thing an appropriate undergraduate would imagine in a short amount of time.
I think you’re just looking for the surprise factor in the wrong place. The notability is all about Sandia’s public release criteria, which are pretty much orthogonal to whether or not the information is publicly known. I don’t think the author finds any particular detail interesting or new in and of itself, they even compare to other public illustrations that have the kind of detail you are talking about.
The author is a historian whose main published work is the book Restricted Data: The History of Nuclear Secrecy in the United States. He isn't very interested in the information itself; he's interested in where it comes from and in the process that led to its release. It's notable not because it contains interesting information, it's notable because it seems like it might represent a radical break with established patterns in US government procedures with regards to restricted data (which is a special and very weird kind of classification that only applies to nuclear secrets).
In other words: the author is interested in the institutions and policies that manage nuclear secrets, not so much in the secrets themselves.
In a different post[0] regarding a fumbled redaction that released similar information about what a warhead looks like, he had this to say:
> It’s also just not clear that these kinds of [declassification] mistakes “matter,” in the sense of actually increasing the danger in the world, or to the United States. I’ve never come across a case where some kind of slip-up like this actually helped an aspiring nuclear weapons state, or helped our already-advanced adversaries. That’s just not how it works: there’s a lot more work that has to be done to make a working nuke than you can get out of a slip-up like this, and when it comes to getting secret information, the Russians and Chinese have already shown that even the “best” systems can be penetrated by various kinds of espionage. It’s not that secrets aren’t important — they can be — but they aren’t usually what makes the real-world differences, in the end. And these kinds of slip-ups are, perhaps fortunately, not releasing “secrets” that seem to matter that much.
> If anything, that’s the real critique of it: not that these mistakes happen. Mistakes will always happen in any sufficiently large system like this. It’s that there isn’t any evidence these mistakes have caused real harm. And if that’s the case… what’s the point of all of this secrecy, then?
> The most likely danger from this kind of screw up is not that enemy powers will learn new ways to make H-bombs. Rather, it’s that Congressmen looking to score political points can point to this sort of thing as an evidence of lax security. The consequences of such accusations can be much more damaging and long-lasting, creating a conservatism towards secrecy that restricts access to knowledge that might actually be important or useful to know.
> There are even a few DoE employed HN users here who know their areas of expertise and comment right up to the point where they shut up (an often shut down | change accounts)
It seems like one could pretty easily build a database and track online commenters that are government affiliated. I've seen several on reddit from various three letter agencies (see r/TSA, r/1811, r/securityclearance, r/cbpoapplicant/). They usually try to self-limit what they share, but inevitably say things that aren't approved to be public.
If you gathered a database of posts across these forums, it would be easier to reconstruct info across different sources. Regularly scraping the site and flagging whatever gets deleted by the mods to read is also a good strategy, as they do often remove posts for being too sensitive.
You could also identify patterns of content they engaged with that resulted in information disclosure. For example, there used to be a CBP officer on Reddit that had offered on at least one occasion to look up someone's PASSID in their internal systems because their GE application had gotten stuck in processing. Someone could make a similar post to solicit them to "help" them with a similar situation as a means of info gathering.
As you said, what they don't share is often informative as well. For example, someone asked that account what it meant when the officer said they "had three BTPs" and sent them to secondary; his response was that it was too sensitive to disclose. I can't find the term in any public docs, so the existence of this procedure itself is info that could be valuable to a threat actor. They could also just try posting about the same thing until someone different reveals slightly more info.
These internal acronyms can also be used as a shibboleth when posting to subconsciously make people more comfortable sharing info in response. If the term is internal, and you ask a question to a "fellow employee" online, they may disclose things that they think you already know. You can find a lot of info about the systems they use in public PIA/SORN notices. Unclassified codenames can also be used as a Google search tactic to uncover content posted by insiders and filtering out news articles and other public results.
Even detailed descriptions of agency procedures by the public is valuable, if summarized and put into a database. Inevitably, things are overheard or observed each time one interacts with security forces. Everything from their facial expression, how much they are typing, etc. can reveal how you are perceived. On Chinese social media, for example, there is a lot of discussion of US immigration procedures and which ports/offices are perceived as most strict. One could run statistics based on others posts about visa and entry denials to identify weaknesses and reconstruct non-public procedures.
For example, this thread discusses a TSA procedure I saw myself: https://old.reddit.com/r/tsa/comments/14l1ca1/what_is_the_bo.... One respondent says it is sensitive, and another tries to deflect the question by saying it is to "weight down light things" while also admitting it "distinguishes the bag for the X-ray operator."
It's pretty obvious that the "paper weight" (the code name which someone helpfully shared) contains the image of a prohibited item (or a known pattern) to test that the X-ray operator is paying attention; the tray was sent to secondary but not actually searched beyond removing the object.
This comment (https://www.reddit.com/r/tsa/comments/1clxfn8/comment/l2wox2...) indirectly confirms that TSA does collaborate with law enforcement to help forfeit cash which was the subject of a recent lawsuit by the Institute for Justice, by saying "there was no need to notify anyone because they traveling domestically," implying that they do notify LE if international.
Does the TSA officially work with local law enforcement? I am not sure about their policy, but many TSA staff want local law enforcement jobs. As such, TSA staff will do whatever they preceive as favor to local law enforcement to gain "preceived" advantage from local law enforcement in future hiring "you scratch my back, I will get yours" type situation and mentality. Problematically, the favor depends on the customs and courtesies of the location. Overall, this leads to what a previous poster described as a "win" for point counting congresspeople while leaving society less safe and vulnerable to self interest of a TSA staffer for personal gain.
I read it as being related to the "line in the sand" idiom. There exists some set of rules, the "line". Exactly what is and isn't allowed under those rules is a bit arbitrary, like the exact location where you would draw a line in the sand with your finger. What matters is that the line has been drawn, and everybody knows that the line may not be crossed.
Under that metaphor, a person may stay very far from the line, to avoid accidentally stepping over it, or they may walk right up to the line. Metaphorically, the former would be a person who refuses to answer any questions about nuclear secrets, regardless of whether the question can be legally answered. The latter would be a person who knows exactly what can be legally answered, and will give as full of an answer as is allowed. They know where the line in the sand is, and have walked up to the line.
It means going to the limit of what is allowed, the line represents some limit/law/threshold that cannot be crossed. In this case the veil of secrecy that separates what is/is not public about nuclear weapons.
Normally you would stay well away from said "line". Occasionally though someone may "walk" right up to the "line" but no further.
You can take it to mean that someone knows something secret but is carefully only talking about what isn't secret. The risk is that they might inadvertently reveal some information of what is beyond the line.
To "cross the line" means that you went too far, in this context meaning that someone revealed secrets or otherwise talked about things that they shouldn't reveal. So to walk up to the line means that the person was willing to talk about the topic or share their knowledge, but did so without "crossing the line."
It’s related to the term crossed the line, which I believe originated with Cesar crossing the rubicon. Crossing the line means breaking some rule or taboo in a way that has significant or permanent consequences. Walking up to the line is getting close without crossing.
ChatGPT's really good for that kind of a thing, but in this case it's a saying popularized by a Johnny Cash song about staying loyal and committed to his wife while being on the road and facing temptation.
> OK, but my question remains: what is it that the author thinks is particularly unusual about this image?
This is explained in the blog post: Publications generally avoid going anywhere near that level of detail, even if not representing actual/accurate data (to avoid the appearance of leaking anything sensitive even if it actually isn't - as the post explains).
I'm not contemptuous or mocking, and I'm sorry it came across that way. I am annoyed at having my time wasted by what I feel is a clickbait article.
Given the article title, the accusation of straw-manning is really unfair. Your comment would also have been better without the jab; if you're familiar with the field then we both know why I left science for software, and it isn't because of a lack of jobs.
Gently: The snark you’re getting is undeserved, but you are doing the “but why male models?” thing. You gotta make a left turn here :)
Let’s reset: Hey, did Sandia use a thermonuclear secondary in a product logo? Did they actually? Despite all the reasons they wouldn’t? If they did, why? Was it a mistake or on purpose? Neither one quite makes sense.
Those are interesting questions! But there’s no alleged secrets leak, and there’s nothing else that’s interesting about that specific picture. You could say it’s implied somehow, but in that case you really got got by anti-clickbait. “Did Sandia use a thermonuclear secondary in a product logo?” is the whole riddle, and the answer is the whole blog post.
Well, I think the (wouldn't really call it snark, more accurate dissection) is deserved, and instructive! But otherwise I think you're right. They are interesting questions, and gnarfgabrl (or whatever) seemed obtusely resistant, to the point of needlessly quarrelsome for quarrels sake, of appreciating that genuine interestingness.
To base an adjudication of the accusation of straw manning on an article title is proving my point so thanks. Hahaha! :)
Your "apology" would be better (and real) without the mislaying of responsibility: you cannot be sorry for "how it came across" (ie, other people's reactions, not your responsibility). You can only be sorry, if you think you have something to be sorry for, for what you did. Otherwise it seems like a fake apology where you pretend the blame is other people's reactions, rather than how you acted. Hahaha! :) Get it? Yeah, anyway. :)
I just felt you were being deliberately provocative based off an incomplete understanding/reading of the article, for attention (mocking genuine outrage). Which is basically live straw manning HN for selfish reasons, so I attacked with insight. Was i wrong?
He says it a few paragraphs in:
“To give a sense of how strange this is, here is the only “officially sanctioned” way to represent a multistage thermonuclear weapon, according to US Department of Energy guidance since the 1990s:
Figure 13.9, “Unclassified Illustration of a Staged Weapon
(Source: TCG-NAS-2, March 1997),” from the Nuclear Matters Handbook 2020 (Revised), published by Deputy Assistant Secretary of Defense for Nuclear Matters.
Two circles in a box, maybe inside of a reentry vehicle. That’s it. Nothing that gives any actual sense of size, location, materials, physicality.”
If the story here is that the US DoE is now implicitly confirming common public-domain knowledge that can be found immediately on Wikipedia then sure, that's a story of minor interest. That story is nothing like the title of the blog, though!
One thing to keep in mind is that the author’s interest lies in the nature of nuclear secrecy, and not necessarily the secrets themselves. It’s a subtle distinction but I think explains why the author finds the fact that this type of diagram was officially released by a national lab interesting, even if the information has previously made its way to the public domain in other unofficial ways.
speculation can be found on Wikipedia, perhaps accurate speculation, perhaps not.
DoE contractors leaking details that confirm that speculation would indeed be a big deal, and might well save adversaries some real time and mistakes they’d otherwise make.
Unless he is actually employed in the classification process inside these agencies, he does not know everything that is officially sanctioned. It’s all guesswork, from the outside.
The unusual thing, as stated repeatedly throughout the article, is that this is published by people who are under one of the strictest censorship systems in the world, a system that explicitly exist to prevent the publication exactly this sort of thing.
Yes. And as you'll know, since we both read the article, the author mentions what I believe to be the correct conclusion:
> The “obvious” answer, if my above assertions are true, is that it must not actually represent a thermonuclear secondary. [...] It could be some kind of pre-approved “unclassified shape” which is used for diagnostics and model verification, for example. There are other examples of this kind of thing that the labs have used over time. That is entirely a possibility.
However, he then goes on to immediately reject this "obvious" answer, because he thinks the well-known schematics of fission-fusion bombs give the appearance of a classified shape, and because he feels it is "provocative" for a government weapons lab to show a mock up of a well-known schematic in one of their publications. Those positions seem very weak to me.
He later finds basically the same object with the caption "The multiple components of a nuclear weapon body are highlighted in this intentionally simplified mesh" from another publication of Sandia, making that theory kind of unlikely
I don't understand that conclusion. That sentence, in my mind, makes that conclusion more likely. They say it is an intentionally simplified mesh. Which to me means it is not the real deal. So why does this sentence makes you think the theory is unlikely? (Or what is the specific part of the theory you think it makes it unlikely?) Genuinely curious.
I took the quote [1] to basically mean "we might think this is a nuclear warhead, but in fact it is not, rather it is some kind of random test object used to demonstrate the software". Obscure part of a washing mashine, random geometric shape, etc.
[1] "The “obvious” answer, if my above assertions are true, is that it must not actually represent a thermonuclear secondary. [...] It could be some kind of pre-approved “unclassified shape” which is used for diagnostics and model verification, for example."
> Obscure part of a washing mashine, random geometric shape, etc.
Oh i see what you mean. I took the theory to be that it is looking like a nuclear warhead but it doesn't have the right dimensions, or even the right arrangement of the components. Kind of like the difference between the real blueprints of a submarine (very much classified) or the drawing evoking the same feel but drawn by someone who has never seen the inside of a submarine nor does really know any details (not classified).
The key issue making the publication remarkable is that the shown geometry is quite plausible as an internal structure of a two stage weapon, but is being disclosed through a censorship regime that typically thinks the precise length of the enclosing cone is classified.
So a even a diagram that is abstracted and slightly fudged would be a huge departure from what the censors usually think is ok, which is weird!
Photos of even a hint of the inside are rare enough that he has another article show (in effect) a hint of an imprint from an old photocopying mistake.
I also doubt it's useful, but Ted Taylor could supposedly walk around a room full of nukes and guess based on the shape of the casing what was unique about a design
I feel like the most novel aspect of this image is an implication of the shape of the reflective casing at the far rear of the device--it seems to suggest a parabolic "shaped charge" sort of focusing element that likely helps to boost the neutron flux and initiate the "spark plug" from the rear at the same time as from the front.
Hmm. I've read every book on the subject and I have a feeling I've heard this arrangement already somewhere (shape of the mirrors used to direct the radiation pressure, not neutron flux).
Find the paragraph that says "so this is awfully strange" and start there. It's a detailed analysis of the graphic in question, and what's "unusual" about it is that this graphic, with the detail identified by the author, has been published at all.
The next paragraph details what the author would have expected to be published by comparison.
And then figure 13.9 is what the DoD expects to see published at all.
> What is it that the author thinks is particularly unusual about this image?
Read the article and look at the "officially sanctioned" diagram. This looks like the tl;dr of what he things about this:
> Anyway, I’m just surprised the DOE would release any image that gave really any implied graphical structure of a thermonuclear secondary, even if it is clearly schematic and meant to be only somewhat representative. It’s more than they usually allow!
> ...but we’re given a rare glimpse inside of modern thermonuclear warheads. Now, there isn’t a whole lot of information that one can make out from these images. The main bit of “data” are the roughly “peanut-shaped” warheads, which goes along with what has been discussed in the open literature for decades about how these sorts of highly-efficient warheads are designed. But the Department of Energy doesn’t like to confirm such accounts, and certainly has never before let us glimpse anything quite as provocative about these warheads. The traditional bomb silhouettes for these warheads are just the dunce-cap re-entry vehicles, not the warheads inside of them.
Low radiation steel is less needed because new steel is lower radiation. The atmospheric radiation level has dropped and steel making uses oxygen instead of air.
Presumably there are uses that need old steel but they are probably smaller amounts.
> Low radiation steel is less needed because new steel is lower radiation. The atmospheric radiation level has dropped and steel making uses oxygen instead of air.
> Presumably there are uses that need old steel but they are probably smaller amounts.
This comment seems out of place? It would have made sense as a reply to a different comment thread in a different article a couple weeks ago: https://news.ycombinator.com/item?id=41323780 but I don't get how/why it ended up here. No one was talking about steel at all, as far as I can see?
edit: oh, there's another article today where folks are talking about low-background steel. I assume this comment was just supposed to go there. https://news.ycombinator.com/item?id=41436009
Not that the image itself is particularly useful or descriptive (it's not), but because the review office is rather quite conservative when deciding what to release, and anything suggestive of a real device is usually right out. In this case, the initial approval was probably an anomaly. I suspect that the reviewers looked at it that day and thought "eh, this is so far from reality that it's just not a big deal", and let it go. Any other day or set of reviewers and it probably would have been kicked back. It would be interesting to know the story around that approval, and what the fallout was, if any.
Any further use isn't very surprising. Once it is approved and in the wild, re-using it is not really a problem (especially if being run through the same office for approval again).
Even so, it would be very unusual if I understand the author correctly:
> ... at least historically, the Atomic Energy Commission and its successor organizations have frowned on disinformation and misinformation for other very practical reasons. If you release a lie, you run the risk of someone noticing it is a lie, which can draw more attention to the reality. And even misinformation/inaccuracy can put “brackets” around the possibilities of truth. The goal of these organizations is to leave a total blank in the areas that they don’t want people to know about, and misinformation/disinformation/inaccuracy is something other than a total blank.
In other words, the author expected to see a previously familiar schematic or nothing. This is clearly not nothing, and also not a familiar schematic, hence the surprise.
plus the us disinvolvment has driven incentives to get nukes through the roof.ukraine support is a scary casus belli if you are the neighbor of a landenpire.
Now imagine broke Pakistan auctioning off nukes to american allies in eastern europe or chinese neighbors. the maga movement has a price tag and thats that for this world order.
The article is not about warhead technology, it is actually about the internal culture of how the military and nuclear-adjacent agencies classify and communicate about nuclear technology.
But here’s the thing: that internal culture is just as opaque to outsiders as the technology itself! No outsider actually knows how the internal folks think, feel, and decide about little graphics or schematics or whatever. They’ve just inferred some heuristics from incomplete data.
And this is basically just saying “this little graphic seems to violate my heuristics.” Which makes for interesting reading, but there is no real actual objectively verifiable content in this article.
Betteridge’s Law tells us the answer to the headline question is always “no.” And in this case I think common sense agrees: Sandia Lab probably did not give the entire thermonuclear ballgame away with a logo graphic.
Please provide even one link to an image or book or anything that proves what you're saying is true. The fact that this is the top comment is troubling, since your question is answered throughout the article. The thing you're claiming (basically that imagery like this can be found all over the place) is so easy to prove, one wonders why you haven't done it here or in any of your other comments.
My question isn't answered in the article, as I repeatedly explain elsewhere in this thread.
As you only require one reference, I will present K.S. Krane, Introductory Nuclear Physics, section 14.5 "Thermonuclear Weapons." The relevant schematic is numbered 14.19. I chose this because it's a textbook that I remember using myself; I'm not sure what is usually used these days.
Yes, that's the schematic. To me the two look essentially identical save for topology and some imagined details.
I don't believe either of them are actually representative of a function warhead; see for instance https://images.app.goo.gl/aEBGKmAb8NsoAWe87, which suggests that in a real design the primary and secondary are inverted compared to the image shown in the blog post.
No. That is not a nuke. It is a mass simulator, specifically the electronic model of a mass simulator for a warhead. The various colors represent density of material. This would be used during aerodynamic simulations. That is why it is behind the graph about processors. This also explains the simple geometry as keeping things simple reduces the number of calculations.
(Note that nuke warheads fall nose-first, the opposite of space capsules. So the dense material is packed in the nose, with the lighter stuff at the back.)
The nearby disk looks like a represention of airflow around a falling warhead. They, like apollo, likely had an offset center of gravity that allowed them to stear by rotation, creating the asymetrical airflow shown on the disk. Falling in a spiral also probably frustrates interception. So that whole corner of the image is advertising Sandia's ability to do aerodynamic simulations.
You have a technical expertise just close enough to, but firewalled from the actual doe nk physics, where maybe the same image couldn't be released by anyone with doe clearance.
But the guy a few buildings over just doing 'hypothetical' center of gravity modeling? Doesn't necessarily have to live by the exact same rules or go through the same release/declass process as someone with actual weapons schematics.
It leaves a lot still unanswered- but explains away some of the seemingly self- contradictory Sandia policy discussed in the article.
In industrial speak: inside-the-fence vs outside-the-fence regulatory framework, or something similar.
Sometimes the guy outside the fence 'gets away with things' because those things are OK to do outside the fence.
The people doing the bomb, the physics package, would be very much removed from the weapon delivery people designing the actual warhead. The warhead people probably see no more detail than the mass numbers for the bomb. The warhead is essentially a very fast gliding aircraft with a literal kill switch.
Reminds me of another design secret that leaked out because someone published a paper titled something like "X-ray crystallography of Lithium Deuteride under high pressure."
People very quickly figured out that this was the source of the D-T fuel in fusion part of the bomb instead of cryogenic D-T liquid. Lithium Deuteride is nasty stuff, but it's a storable solid. When bombarded with neutrons from the fission primary, the Lithium splits and forms tritium, which then combines with the deuterium that was the other half of the crystal.
The reason the usage was obvious (from the title alone!) is that very few chemists would care about any property of Lithium Hydride, which is dangerous to handle and has few practical uses. Lithium Deuteride is unheard of in analytical chemistry, and its crystallography under high pressure is totally uninteresting to anyone... except physicists working on atomic weapons.
I've done branding and identity design in the past, and got university training to do it. I've also worked as a developer and contributed a ton to FOSS projects. That an engineering organization thinks this is a product logo is entirely unsurprising. I'll bet their interfaces are really something.
The most frustrating thing about being a designer in those environments is the dunning-krueger cockiness many technical people have in their understanding of design, which they usually believe is purely an aesthetic consideration.*
It's not even like a junior developer trying to 'correct' a senior developer about coding practices in a dev meeting— the better analog is a designer that watched a half hour Coding for Designers talk at a conference trying to correct a senior developer about coding practices in a stand-up, because they'd never have been invited to the dev meeting to begin with. If there were only designers in that meeting— and they likely find the other designer more credible because they jibe with their perspective, don't realize how important the developers input is, and might have watched that same conference talk— that could damage a project. In my experience, designers are way more likely to be solo in meetings with developers and the echo chamber of developer 'expertise' on design drowns out actual professional design expertise. In most FOSS projects, is bleaker than that because designers don't even bother trying.
* though completely out-of-context "rules" born from Tufte quotes aren't uncommon. In art school, we were told that we need to understand the rules in order to know when to break them. Imagine someone who'd never driven before that memorized a few pages of the driving manual calling you an unqualified driver because your actions didn't comply with the letter of one page they memorized even if it was qualified by another, or required for safety.
I've never understood this use of the phrase 'senior developer' like it's evidence of being masterful at coding. In my experience half the juniors and half the seniors were good and the other half were bad. Tenure gets you a bit of perspective but it didn't turn bad programmers into good ones...
I don't think it's meaningless even if it's not completely codified. I use the term senior as a way to distinguish someone that's competent enough and knowledgeable enough about the environment to direct technical initiatives like architectural decisions that will be acted upon by other developers, and be a consistent go-to resource for others for questions either about the environment or coding. When I you l was a chef, it was a little more cut-and-dried because the organization required more of a hierarchy, but there was still the same dichotomy. Lots of young talent could mop the floor with the older cooks — but it was a combination of knowing the environment— eg cuisine, equipment, processes, etc— and knowing how to cook. It wasn't at all unheard of to have a young cook make sous chef over older cooks, effectively becoming the senior, even if they were still asking the older cooks questions about how specific things get done around there.
I agree that it _should_ imply expertise, but it doesn't in practice. It bugs me because start using it as a status thing: "how to think like a senior developer", "listen to me because I'm a senior deveveloper". The title hasn't earned its credentials and it keeps getting used to fake credentials. Instead we should talk about good developers vs. bad ones.
Heck, I know someone who got the title of "senior" on their first job out of a bootcamp. They were credible in the sense that they had worked at other companies before and had a grown-up and dependable demeanor. But they weren't someone I would want to take coding advice from.
I've been lucky in that anywhere I've worked, titles like that came with additional technical responsibilities and were awarded by technical managers who actually had a stake in whether or not people were qualified for them. The youngest company I've worked for started in the early 90s, though, so I've weirdly avoided a lot of the practices born from startup culture over the past couple of decades, and haven't had the chance to get burned by (many of) them. Sort of parallel to your criticism is the "what do I call myself on LinkedIn before I've had any actual job titles" thing, which I really don't care about. I've had a bunch of job titles over the years and I've gotten 'less' descriptive in my 'business card' level title for those sorts of uses— I think it's all up to whoever is doing the hiring to cut through the chaffe, and anything on LinkedIn should be considered marketing fluff anyway. Maybe it's different with ATS job applications and HR people?
It really is, it’s just much more graphically detailed than the usual product logo, probably because it was designed by nuclear weapon designers and not by professional graphic designers.
I've worked on (unrelated to nuclear stuff) computer simulation projects for the Navy where they had standard, notional models of the battleship which had the same sort of general properties you'd expect a battleship to have, but wasn't based on the design of any real battleship, so they could share them with researchers to develop their codes on without having to worry about revealing classified details.
Wonder if this isn't something similar, if the DoE has some sort of "standardized notional warhead" design they can use to give to outside researchers without having to give every post-doc and grad-student a security clearance.
The author addresses this in the addendum after the article. Something like that already exists, and it isn't this.
> MACE (Modal Analysis Correlation Exercise) assembly, and was created by the UK Atomic Weapons Research Establishment in the 1990s to serve as a sort of a Utah Teapot of weapons structural modeling: a benign shape that could be used to test aspects of the code that would nonetheless tell you if the code would work for real weapons assemblies.
Do you actually mean battleship, or frigate, corvette, aircraft carrier, etc? Battleships in the sense of the Iowa class and similar haven't been a thing in the US Navy for a very long time, unless you were working on blast damage/effect simulations in the 1980s when Reagan reactivated them for a short time.
> This is the kind of thing that I think people assume the government labs might do, but in my experience, is pretty unusual and pretty unlikely. In general, you have to remember that the national laboratories are pretty, well, boring, when it comes to classified information. They want to be boring in this respect. They are not doing cloak-and-dagger stuff on the regular. They’re scientists and engineers for the most part. These are not James Bond-wannabes.
The Sandia folks may be extra special, it is a pretty famous place. But engineers are people first of course, so lots of variation. And also, some are super serious of course, but there are hacker tendencies, playful tendencies. I bet if some intelligence agency folks wanted to, they could find some engineers out there who’d be receptive to this sort of thing.
If it is a fake, known-stupid design, including it would be a funny prank that wastes the time of people that might want to nuke us, right?
I visited Los Alamos earlier this year and talked to a retired materials scientist at the visitor center. He said that we have lots of books about the science and scientists that worked on the bomb during WWII, but very little mention of the engineering or engineers - and that's largely because it's extremely classified. The scientists can talk about most of their work because it's too broad to give any real aid to the enemy, but the engineers can't because they could REALLY speed up someone else's weapons program.
Somebody (probably a programmer or engineer) took the time to create all of that rad 3D word art, multicolored pie-chart, and the mountain logo, it's not hard to imagine they'd also throw in an eye-catching fake nuclear warhead for fun.
I bet it's an inside joke, like Lenna.jpeg. Some outdated / test / dead-end, or otherwise harmless project put there as a wink to everyone involved in the industry. Maybe it's something an intern ruined on his first day and made entire lab work on for three weeks without realizing?
I see a few commenters think the big chart/diagram in the first picture is the one being discussed. It is not, it's the rightmost slice ("Salinas") of that infographic which shows something like a warhead. It's shown blown up (pun intended) in the second picture of the article.
Basically 0 CAD models you see with color coding and a mesh are actually accurate.
In order to mesh the geometry for finite element analysis, the geometry virtually always needs to be defeatured.
So the cross sectional CAD model here is a nice curiosity but basically useless for any reverse engineering purposes which is the key reason this stuff is kept secret.
In Germany we say "The DIN knows non color". DIN is our standardization organization and informally also how their documents are called.
I did finite element model preparation for a living many year ago and it did not only involve heavy defeaturing but interestingly also remeshing with quads.
Renderers love triangles, FE solvers love boring quads.
> Renderers love triangles, FE solvers love boring quads.
Btw even in Blender (which is pure visual rendering) people prefer quads. The common wisdom is that you should keep your topology quads with nice rectangle-ish aspect ratios if you can at all. It is not that triangles don't work, but they have a tendency to do visually unpleasant silly things when animated or sculpted or subdivided.
The "quads only" rationalizations come off as quite cargo-culty.
Sure, edge rings won't have dead ends, and that's useful when adding edge loops to increase detail, but doesn't necessarily mean the topology is of high quality. Using only quads some cursed helix type topology can be constructed.
First thing subdivision will do on non-quads is ortho(1) operator, so a nice averaged vertex in the middle will be added. High side count cylinders will have weird saddles around caps, but that's due to subdivision being wrong tool for the task.
Quads can be abused to look bad too. If a mesh looks bad, it's a bad mesh. If animated mesh looks bad, it's bad rigging and skinning. Knowing "this one industry secret" won't fix those.
Most 3D meshes will have a combination of hexahedral and tetrahedral elements anyway so the surface will be a combination of trangular and quadrilateral elements. Accuracy and convergence wise, it doesn't matter as much as polynomial order/time step size/element size.
yeah there are several adaptive meshing techniques that use a mixture nowadays, imagine a bar with a hole bored through it, you might use quad meshes for the majority of the bar and then switch to tetrahedral meshes close to the bore hole to better model the curved geometry of the hole, and increase the node density in high stress concentration regions for a more accurate simulation.
Sandia FEM is using the different blocks (colors) to represent different materials. This is pretty common in a multi physics finite element program.
This story is probably nothing interesting because this went through all the public use approvals needed for public presentations and being available on osti.gov.
It is probably just a toy test problem used on a capabilities logo for Sierra. Maybe it comes from some sort of integration test that is easier to run than the actual problem.
I would bet a few dollars that no Facility Security Officer (the name for people who manage security programs for defense contractor, despite sounding like a Sunday name for ‘guards’) in the entire NNSA complex has ever read Arms and Influence. That’s not quite their demographic profile.
That was my first thought too. If you screw up once, and then redact it in the future it's screaming "Hey everybody look here, there's classified information"
Some people are confused why this could be a big deal. An analogy: on GitHub, if you echo a GitHub access token in an action’s log, it will be automatically censored. This post would be like noticing that someone’s action step is just named ghp_1ae27h… and that the name isn’t censored, and speculating on what that says about the token-censorship algorithm
Key point: if you try it yourself, it will be in clear-text for you (you already know your password, so there's no issue), but everyone else will only see "***".
This thing could be a test object that doesn't work as an actual nuclear warhead but is similar enough to validate the discussed software: real-world crash tests match software simulations, and being accurate at simulating the dummy is a guarantee of being accurate at simulating classified weapon designs.
> Someone reminded me of something I had seen years ago: the British nuclear program at Aldermaston, when it has published on its own computer modeling in the past, used a sort of “bomb mockup” that looks far more deliberately “fake” than this Sandia one. I offer this up as what I would think is a more “safe” approach than something that looks, even superficially, like a “real” secondary design:
> This is called the MACE (Modal Analysis Correlation Exercise) assembly, and was created by the UK Atomic Weapons Research Establishment in the 1990s to serve as a sort of a Utah Teapot of weapons structural modeling: a benign shape that could be used to test aspects of the code that would nonetheless tell you if the code would work for real weapons assemblies.
The author doesn't convincingly rule out the possibility that this is what it is. The other possible answers seem less plausible than it being a fake shape for software testing that happens to look fancier than past test shapes.
The author wasn't trying to be convincing. "I’m just surprised the DOE would release any image that gave really any implied graphical structure of a thermonuclear secondary, even if it is clearly schematic and meant to be only somewhat representative. It’s more than they usually allow!"
My reply was to point out that the author discussed issues related to HelloNurse's suggestion.
The tone of this kind of article has to be nice and diplomatic, and mistakes need to remain hypothetical and attributed to the largest possible organizational unit (DARPA having surprising policies, not the mechanical finite element simulation software team spreading data they consider harmless).
The second object that appears near the end of the article looks like a simplified version of the first with more basic shapes, as if someone was asked by someone else to draw a less suggestive replacement of the original (possibly with the sole purpose of appearing in slides); in a natural design process the cruder design would have appeared first.
Heh. Ask my mother about the time that Sandia dropped an atomic bomb casing in the streets of Albuquerque.
IIRC the story, this was still during WWII. They were testing the flight characteristics of the bomb casing. It did not contain a core. But it was still extremely classified. They had the test casing in the back of a truck, taking it from Sandia to Kirtland AFB. The truck got in an accident, the tailgate fell open, and the bomb casing fell out and went rolling around in the street.
Let's assume the schematic depicts a genuine weapon, and that this was a massive redaction screw-up.
I think the author is omitting the most likely explanation for why it wasn't redacted in future publications.
It took from 2007 to 2024 for someone (him) to publicly notice this.
If your job was to censor documents coming out of Sandia National Laboratories, and you screwed up this massively, what's your incentive to call attention to your screw-up?
Better to just coast along, by the time you retire or move on to another job your ass is off the firing line.
Ditto (but less so) if this was your co-worker or team mate, after all North Korea, Iran etc. already have access to the published document.
What could anyone in your organization possibly gain from the ensuing shitstorm of admitting something like that?
Has this person worked, well, pretty much anywhere, where people have a stronger incentive to cover their own ass and keep out of trouble than not?
Or, that internal report and subsequent shitstorm did happen, but what do you do at that point? Make a big public fuss about it, and confirm to state actors that you accidentally published a genuine weapons design?
No, you just keep cropping that picture a bit more, eventually phase it out, and hope it's forgotten. Maybe they'll just think it's a detailed mockup of a test article. If it wasn't for that meddling blogger...
Edit: Also, I bet there's nobody involved in the day-to-day of redacting documents that's aware of what an actual weapons design looks like. That probably happens at another level of redaction.
So once something like this slips by it's just glazed over as "ah, that's a bit detailed? But I guess it was approved already, as it's already published? Moving on.".
Whereas a censor would have to know what an actual thermonuclear device looks like to think "Holy crap! Who the hell approved this?!". And even then they and the organization still need the incentive to raise a fuss about it.
My experience working for huge orgs where success and failure is many nodes removed from individual actions makes me vote for this as the most likely scenario.
It took until 2024 for the author to see the image, he noticed the screw up within moments of looking at it. Betting that no one is going to look at a logo before you change jobs is a pretty big gamble.
Updating a logo (especially a bad logo) after a couple of years is not exactly a newsworthy event. If you replaced any other part I would not assume it was to correct an accidental disclosure of classified information.
Isn't one of best ways to verify this is to computationally "detonate" a similar model? If it's real, it should compress nuclear part, if it's not, it behaves like a HEAT warhead or whatever it is based on, or is that not the case?
There is the fission stage and the fusion stage. The fission stage in this image is not well represented. It is generally known how to make a fission stage similar to the “Fat Man” device but the “Fat Man” device is larger than the whole warhead with both a fission and fusion stage that fits on a Minuteman 3.
The fission stage in that warhead has numerous refinements that help miniaturize it, for instance the implosion is probably not spherical so it can fit in the pointy end of the warhead. A really refined modern weapon is packed with details like that.
The secondary isn't well represented either: that radiation case isn't focusing any X-Rays and the stairstep in the tamper would tear it in two when ablation started. Plus, as you note, the primary is impossibly screwed up as well, with what looks like a single point of initiation and zero details on the boosting. It doesn't just look simplified, it looks like every part has been corrupted with a feature that makes it impossible to mistake for real while being slightly less crude than the "Mastercard" or British designs.
Besides, real engineering doesn't just need a schematics, it needs details, and some of the missing ones are notorious (FOGBANK) and inherently difficult to figure out with any confidence in the absence of weapons tests (or even more expensive giant buildings crammed to the gills with lasers).
So yeah, not very useful to an aspiring designer. I understand the author's surprise but I suspect they really did just become a few notches less crazy about the redundant protection on information that has been public for 30 years.
Also the mental models of proliferation are warped by secrecy. For instance, Iraqis got caught building Calutrons when the official line was to watch out for plutonium reprocessing and centrifuges... Despite the fact that the enriched uranium used for the first nuclear weapon used in war was produced with a Calutron!
Anyone responsible who thinks about this stuff, even if they don't have a security clearance, will look into the question of what the ethics are and what the legal consequences of secrecy laws are if you talk about certain things you think about. I had dinner with a nuclear scientist at a conference, for instance, who told me that he hadn't told anyone else about his concern that Np237 was the material that terrorists would most want to steal from a commercial reprocessing facility (if they knew what we knew) and I told him it was no problem because people from Los Alamos had published a paper with specifics on that a few years earlier.
They would be in possession of an image. It is hard to understand what the author is hand-wringing about. It is not that nobody knows how these weapons are supposed to work. The real barrier is that to obtain the materials necessary you need a big-ish industrial base and if you do that that leaves signatures the relevant agencies can detect.
It is not even clear if when he speaks about "safe" is he talking about being safe from nuclear proliferation, or safe from clueless bureaucrats causing you legal trouble.
The author is a historian who has published a book that is specifically about the history of nuclear secrecy in the United States. Not about the history of nuclear tech or nuclear weapons, about the history of restricted data, the special classification grade for the information. How the classification works and what is considered safe to release and what isn't is in itself one of his main research interests.
My impression from his book is that his position on nuclear secrecy is that a lot of it is pointless or outright contra-productive, but that isn't really the point of the blog post. The point of the blog post is that if something has changed about what information is considered safe to release, that is interesting to him. He is more interested in the humans and institutions than in the technology, I'd say.
> It is hard to understand what the author is hand-wringing about.
The issue seems to be “Organisations party to classified information have to keep it secret regardless of whether it’s in the public domain”.
As an academic historian the author is intrigued by the diagram - was it a mistake or was it authorised as a declassified representation? Either way, the consequences would be of interest.
> It is not that nobody knows how these weapons are supposed to work.
Optimally small, lightweight, robust, safe, reliable - all sorts of engineering short-cuts or novel techniques … you don’t want to give way accidental insights about the “hows” an enemy hasn’t thought of.
The "large industrial base" is required primarily to highly enrich uranium (or plutonium).
A modern fusion bomb requires much less of that than the initial fission bombs.
So I don't know how much a state actor could infer from an image like that, if we assume it's a schematic of an actual bomb.
But it's just not true that someone in possession of detailed plans for how to construct a bomb isn't put into a much better position. They'll need a much smaller amount of fissionable material than they otherwise would with a cruder design.
Probably the guy who produced that part of the graphic was not told what a thermonuclear warhead actually looks like, because he didn't need to know, so he just whipped up his own idea of it from speculative public images. Knowing that the graphic came from somebody who didn't actually know anything, the censors didn't see the need to worry about it.
> Knowing that the graphic came from somebody who didn't actually know anything, the censors didn't see the need to worry about it.
That is not how nuclear secrets work. The US Department of Energy holds that restricted data (a special kind of classification that only applies to nuclear secrets) is "born secret". That means, even if you come up with a concept for a nuclear weapon completely independently without ever talking to anyone, it is considered classified information that you are not allowed to redistribute. This doctrine is highly controversial and the one time it has been tried in court the verdict was inconclusive, but to this day it is how the DoE interprets the Atomic Energy Act of 1954.
In general this is very precarious to attempt to enforce, of course. If the DoE sues someone because they published their nuclear weapon designs, that'd be seen as a tacit admission that the design could potentially work. Nevertheless they actually did do this at one point (United States v. Progressive, Inc., 1979).
One thing he doesn't consider: Perhaps if they do not call it a nuclear warhead, or place it in the context of a larger drawing that tells you it's a warhead, having a sort of blobby, colorful model shape is considered plausibly nonsensical enough that it doesn't matter to the censors.
Powerpoint slides are such a hilarious opsec risk.
When @Snowden blew the whistle on the NSA spying operation, all he did was download everybody's powerpoint presentations and send them to @andygreenwald.
That would have made a good Silicon Valley plot: they discover they accidentally put a trade secret in their logo, and have to jump through hoops to collect, hide, and delete the bad version without making competitors curious about their effort.
For anyone interested in the basics of nuclear weapons, I highly recommend the "Nuclear 101: How Nuclear Bombs Work" lectures by Matthew Bunn, a man heavily involved in nuclear arms control.
His lectures are always highly entertaining, a real pleasure to watch.
This is a clip from his lecture explaining the basics of thermonuclear warheads:
Given the nature of nuclear weapons work, isn't anything presented by someone basically speculation? If he actually had the information he wouldn't be able to talk about it. He seems to have been involved at the government level in the storage and handling of weapons, not production of them.
Fun idea, there basically are no nuclear secrets. If you look long enough you can pretty much learn everything except some in the weeds details of the most modern nuclear warheads. My basic premise is all our “enemies” have this info by now and the complexity is actually in building them, not how they work or how to build them.
As search engines continue their trend of considering your search term just a suggestion, I can't pull it up, but there's also a case where a high school physics class decided to try to design one and also came adequately close.
The hard thing that is actually the stopper is the enrichment of the relevant materials. The other hard part is getting the best possible yield; there's huge variances in what you get from the same amount of fuel depending on how well you can put it together before it blows itself apart, but that's not a stopper for a terrorist group. Getting to Hiroshima levels is apparently not that difficult, as evidence by the fact it was done so many decades ago.
Delivery is another major challenge, but I'll consider that separate from the task of creating one at all.
This is concept is a neat one that I think differentiates the real world from many fantasy worlds. In the latter, many of the core problems are built around somebody having "forbidden" or "dark" knowledge, or the heroes needing to find just the right rare answer to some kind of fundamental problem that somebody wrote down but that was suppressed. Think Horcruxes in Harry Potter sort of a deal.
In the real world, we have classification, but by-and-large those are about very specific elements of very specific things (i.e. the exact shape/location of that secondary, not that the secondary exists or that Sandia does modeling of that sort of thing). No one's really the gatekeeper of knowledge of things like nuclear engineering or biological gain-of-function. There's not really a litmus test for someone to attend to a microbiology graduate program or take a chemistry class that would enable them to develop synthetic drugs.
Same thing with martial arts; no one's hiding some secret martial technique. A BJJ purple belt will, in a fistfight, toy with just about anyone else on the planet not trained in jiujitsu like they're a toddler. And you can just, like, walk into many strip malls across the North America, pay your $200/mo, and a few years later of consistently showing up, you're there. No secret death touch or spiritual clarity needed.
Funny example. I am a BJJ purple belt. I love BJJ analogies. It is analogous to the mental work in tech. There is just hard, physical work, repetition, analysis, and more work. It’s very rewarding. Just like tech problem solving. That’s the secret to most things. Hard, sometimes wearying, sometimes joyful, work.
I think secrets are largely against the ideals of the enlightenment. There are certain temporal operational concerns. Democracy dies the death of a thousand cuts when unelected bureaucrats classify the most mundane things by default “just in case”. 9/11 happened because of these silos. Our foreign adversaries often know more about what we are up to than US citizens, etc.
Using publicly available knowledge won't get you a working nuke, even if you have the necessary fissile material. A lot of finicky details have to be just right in order to get a nuclear explosion instead of a fizzle. C.f. https://en.wikipedia.org/wiki/Fogbank
More often than not, comparatively simple chemical reactions are hard to reproduce reliably just by reading the research papers.
I have watched a lot of Nile Red and agree with this. The actual things that happen that kick off the nuclear reaction are kind of crazy and I can see how it would be very difficult. However, you know it is possible and the shape and structure of it. Any nation state has the resources to do it and it would not take them very long because the physics are all sorted. I actually kind of doubt America could even just produce another nuclear weapon on demand because we have lost a lot of the how-to institutional knowledge.
I think enough is known now to really narrow down the problem to something a nation state can do.
There was once an article in a pop sci magazine 25 odd years ago about how to build a nuke in a house; basically a pipe / barrel from the attic to the basement, a concave bit of plutonium or the right kind of uranium in the basement encased in a good carrier like concrete, and a convex matching part at the top of the barrel. Explosives behind the top one, launch the one towards the other, ????, nuke. In theory.
That said, if it was that easy, I'm sure we would've had terrorist attacks with nukes already. Or if terrorism was that big an issue. I don't know if it hasn't happened yet because technology and three-lettered agencies are doing their job right though.
Casting, machining or welding plutonium into the right shapes and purities without killing your self, or some of the other exotic metals, without killing your self or making your neighbours sick in a sub 1-3 week horizon is incredibly challenging. The exact geometries you need to achieve aren’t easily available either neither is measuring is you achieved them without again killing your self.
Getting a dirty fizzle is a lot easier which is why people are afraid of dirty weapons by terrorists.
Getting the right type of plutonium in sufficient quantity is an order of magnitude harder than either of them - there is essentially no naturally occurring plutonium, it only comes as a side effect of neutron bombardment of specific isotopes of Uranium, which are already hard to seperate, and only under specific conditions are the right types of plutonium isotopes to be useful produced. And even then, it’s non trivial to seperate them.
The whole thing is a giant, high profile, and dirty mess.
Making the entire thing efficient enough to actually be delivered to a target is also another matter. This requires precise calculation of the geometries and very precise grades of plutonium, barrel pipe, and explosives. How do you even keep the gun type shapes from deforming in the barrel?
[Cut to me in 1999 driving my old station wagon down to the local hardware store to pick up a few kilos of highly purified enriched uranium and some C4]
>> ,I'm sure we would've had terrorist attacks with nukes already. Or if terrorism was that big an issue
There are two problems with that statement. Let’s examine them
Firstly, does majority of terrorists want to nuke NewYork? If you gave 9/11 bombers a 5 megaton warhead, would they use it? You have to remember that many of them imagine they have a just cause.
Second, imagine you are could make a nuke at home and were completely immoral, who would you sell it to?
There are many evil governments and organisations that could pay more and be better clients than terrorists.
The hardest part of building nukes is acquiring weapon-grade enriched uranium, because it's controlled as hell and you will get bombed if you try to make your own.
If you spend hundreds of millions of dollars on enriched uranium, paying salaries for team of engineers is the easy part.
North Korea, Pakistan, India, South Africa & likely Israel didn't get bombed due to their enrichment programs.
There is a rumor that the USSR flirted with the idea of a pre-emptive strike on Mainland China to decapitate their nuclear program after the Sino-Soviet split. This did not happen obviously.
Iran didn't get bombed, although that may just be because other forms of sabotage were available.
Syria & Iraq on the other hand, yeah those got bombed. But it's not 100% a guarantee.
The fact nukes are hard to make aren't because of lack of knowledge, everyone knows how to make nuclear weapons - the issue is materials. Control of them is closely guarded and you tend to get disappeared or bombed if you make them yourself.
> I happened to look at a slide deck from Sandia National Laboratories from 2007 that someone had posted on Reddit late last night (you know, as one does, instead of sleeping), and one particular slide jumped out at me:
The author is making fun of themselves for being up late reading this deck instead of sleeping. They’re not making fun of the person who posted the slide deck.
It's not a diagram or mock-up, it's a direct representation of the real thing for computer simulations, similar to CAD. The dimensions and shape of the components are accurate. And the author is calling it a logo because the picture is used to represent and advertise the software.
The author of the post claims that the warhead-like design "is literally the logo for this particular software framework." I can't verify this claim, but other Sandia frameworks (e.g. Sierra) use similar, equally overdesigned logos, so it's plausible.
And why wouldn't they? As wikipedia states, SNL's mission includes "roughly 70 areas of activity, including nuclear deterrence, arms control, nonproliferation, hazardous waste disposal, and climate change."
Overall this looks like someone asked a physics undergraduate to spend an hour imagining roughly how the well-known schematic might be fitted inside a real warhead case. It probably is exactly that. I can't imagine that showing it to the North Koreans advanced their nuclear programme by any more than fifteen minutes.
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