[HN Gopher] The untold story of the world's biggest nuclear bomb ___________________________________________________________________ The untold story of the world's biggest nuclear bomb Author : Amorymeltzer Score : 97 points Date : 2021-10-29 12:13 UTC (10 hours ago) (HTM) web link (thebulletin.org) (TXT) w3m dump (thebulletin.org) | gjkood wrote: | "Now I am become Death, the destroyer of worlds" - J. Robert | Oppenheimer's thoughts on witnessing the first atomic bomb test. | A quote from the Bhagavad-Gita. | | That bomb was finally measured to be 'only' 20 kilotons. [1] | | God I hope one of these is never dropped in anger. | | 1. https://www.osti.gov/opennet/manhattan-project- | history/Event... | cuspycode wrote: | That's what he thought, and afterwards said he thought, and | it's a great quote. What he actually said at the time according | to his brother Frank Oppenheimer was "It worked!"[0] | | [0] https://en.wikiquote.org/wiki/Robert_Oppenheimer | kragen wrote: | Two were: one on Hiroshima, one on Nagasaki. | Someone wrote: | I think it's ambiguous grammatically, but I read "one of th | _e_ se" as one of the much bigger ones discussed in the | article. "One of th _o_ se" for me would have been a | reference to the previous sent me, i.e. to a | Hiroshima/Nagasaki sized one. | throwawaysea wrote: | Can you really say those were dropped in anger? From what | I've read they were dropped to avoid the cost to American | lives a ground invasion would bring. Several warnings were | given to Japanese leadership to avoid a bad outcome, which | were not heeded. The first bomb itself did not result in a | surrender either. To me the motivation was less about anger | and more about practicality. | AnimalMuppet wrote: | "In anger" in these contexts usually means "trying to kill | people", as opposed to "in testing or training". It does | not mean that the people who did so were angry at the time. | vpribish wrote: | it's like an idiom, man. | robin_reala wrote: | Would have been easy to drop one on, say, Tokyo bay if you | wanted intimidation. But the US also wanted reliable data | on the effects to buildings and people. | MomoXenosaga wrote: | Were the atomic bombs really all that different from the | systematic fire bombing of Japanese cities? | | I think what got Japan to surrender was a certain common | sense in the emperor and some of the elite that a final | last stand wouldn't do them much good. Especially not | with the Soviets joining in. | retrac wrote: | It's a fixed expression meaning "with intent to harm". | https://en.wiktionary.org/wiki/fire_in_anger | jvolkman wrote: | The size comparisons in the left margin are a great touch. Tsar | Bomba just keeps going. | skyechurch wrote: | >A 100-megaton bomb releases 10 times more energy than a | 10-megaton bomb, but it does not do 10 times more damage. This is | because the blast effects of explosions scale as a cubic root, | not linearly. So a 10-megaton bomb detonated at an optimal | altitude might do medium damage to a distance of 9.4 miles (15 | kilometers) from ground zero, but a 100-megaton bomb "only" does | the same amount of damage to 20.3 miles (33 kilometers). In other | words, a 100-megaton explosion is only a little more than twice | as damaging as a 10-megaton bomb. | | Area scales as square of radius, so (assuming the radius | calculations are right, the ratios are approx cube root of 10 | which is napkin-level correct) more than 4x as much area is | effected (incinerated). | | Doesn't change much about the political/historical issues, but | you would fail high school math for this. | yunohn wrote: | > Area scales as square of radius (...) | | Yes, but they're referring to volume - which does scale as a | "cube". Bombs detonate in 3D, not 2D - moreso when | aerial/aquatic. | | > but you would fail high school math for this | | This seems quite vitriolic and uncalled for. | skyechurch wrote: | But they are referring to a radius of a surface area on the | Earth being destroyed, which goes as radius^2 (or ~volume^2/3 | if you detonate in optimally). | | >This seems quite vitriolic and uncalled for. | | I apologize if this sounded too harsh, but "The Bulletin of | Atomic Scientists" should not make basic errors like this. It | was a very interesting historical article, but when you miss | stuff like this, which is simple to catch, I wonder about the | journalistic fact checking, which is considerably harder. | CapitalistCartr wrote: | It's not a mistake at all. They understand nuclear yields | fine. The exact effects are complicated by wave reflectiins | off Earth, changes in the atmosphere at different | altitudes, etc. but basic cube law is a decent | approximation. The bomb fills a volume of space, the cube | of the increase of the radius of damage. The radius of | damage is a linear measurement. | skyechurch wrote: | It is a mistake. The bomb does not damage a radius, it | damages an area which is quantified by a radius squared. | Again, this is high school geometry, not controversial, | and maybe there are factors not explained which make this | correct in a sense (maybe "damage" is a term of art which | varies by the square root of area destroyed? Seems | unintuitive, but I'm not an expert in atom bombs or much | of anything.) | | It's a silly error which in no way undercuts anything in | the article afaict, but it annoys because it is very | simple and obviously true by unit analysis. I make silly | errors too, as we all do, present company excepted. But | it does undercut my confidence in the more far difficult | journalistic work being done, which I cannot interrogate | with my limited mathematical skills and pretty much have | to take on faith. To me it speaks to the question of | whether I "learned something" or "read some words". | | This is a very boring digression and I take full | responsibility for making a ticky-tacky point, which I | have now I believe fully explained and contextualized. | CJefferson wrote: | I bomb exploded near the surface of the earth will, in | effect, explode as a hemisphere, which is why there is a | cube root. If you could somehow make the force spread | only over the surface of the earth it would be radius | squared, but that isn't what happens -- most of it goes | into the air. | | You could think about what would happen in space (a | spherical explosion), then consider what would happen as | it got closer to the earth. | skyechurch wrote: | >In evaluating the destructive power of a weapons system, | it is customary to use the concept of equivalent megatons | (EMT). Equivalent megatonnage is defined as the actual | megatonnage raised to the two-thirds power: | | >EMT = Y[^]2/3 where Y is in megatons. | | >This relation arises from the fact that the destructive | power of a bomb does not vary linearly with the yield. | The volume the weapon's energy spreads into varies as the | cube of the distance, but the destroyed area varies at | the square of the distance. | | Src: | https://www.atomicarchive.com/science/effects/energy.html | | It's just geometry, or dimensionality, you cannot | directly compare 1D and 2D quantities. Type mismatches | are often bad in programming, but always fatal in | physics. | pdkl95 wrote: | [the 8km wide fireball created by the Tsar Bomba] | https://web.archive.org/web/20081117095628im_/http://www.ato... | | Depictions of the Tsar Bomba usually focus on the huge mushroom | cloud, which is _awesome_ (in the original "causing awe or | terror" meaning of the word). However, I think the geometric | simplicity of the fireball is even more effective at _inspiring | awe_. | | For a brief moment, the sky was filled with the light of a | _human-made star_. | philipkglass wrote: | There was plenty of technical headroom left for making more | fearsome weapons in the early 1960s. Fortunately, the pace of | innovation plummeted after atmospheric testing ended, and none of | the later nuclear weapons states have surpassed the high water | mark set by Cold War era superpower rivalry. Chuck Hansen's book | _The Swords of Armageddon_ is a fascinating account of the vast | hidden empire of the post war Atomic Energy Commission, and how | it developed atomic weapons _so far_ beyond the early atomic | bombs used on Japan. And then again optimized thermonuclear | weapons so far past the early hydrogen bombs. | KennyBlanken wrote: | It's worth noting, in case anyone thinks that we somehow slowed | down testing with the atmospheric test ban...that we went on to | conduct 1,352 nuclear weapon detonations. That's roughly 3/4 of | all nuclear testing. It really is mind-boggling that we set off | so many. | [deleted] | Synaesthesia wrote: | But really, how much more do you want? The US upped the ante | several times, developing all kinds of more advanced super | weapons, as well as modes of delivery, the first long range | bombers, the Hydrogen bomb, ICBM's, MIRV, the Neutron bomb ... | I mean, as you say it was FAR beyond the early atomic weapons. | And they're continuing with development, in secret of course | ... | MomoXenosaga wrote: | Americans keep developing their missile shield so China and | Russia need to keep developing ways to outsmart it. It will | never end. | vkou wrote: | A missile shield that actually works will actually | precipitate a nuclear conflict, because it means an end to | MAD. If you know that your adversary will become | invulnerable to your counter-strike in three months, the | optimal game-theory solution is to strike him _today_. | | Optimistically, military planners are aware of this, and | are just doing pork barrel spending. | | Pessimistically, military planners don't care about this, | and are actively working on 'winning' a nuclear war. | Enginerrrd wrote: | This doesn't really follow IMO and is a result of deep | oversimplifications. | | Even if you make those simplifications though: If your | choices are pre-emptive strike where MAD applies now | (near-total destruction) vs. live to 3 months from now, | where you have a post-MAD world where one adversary | dominates, the post-MAD dominant adversary no longer has | the incentive to pre-emptively strike since they aren't | worried about a pre-emptive strike from their adversaries | since they'd have an effective missile defense system. | joconde wrote: | > If you know that your adversary will become | invulnerable to your counter-strike in three months, the | optimal game-theory solution is to strike him today. | | Striking today means MAD happens and your country gets | wasted. That only makes sense if the shield-building | adversary is some sort of psychopath who wants to see you | dead. | | The 3 big nuclear powers don't seem to be that stupid. | Maybe the calculus would be different with Israel vs Iran | or India vs Pakistan, where the conflict has religious | aspects. | gjkood wrote: | Just searched for Hansen's book on Amazon. The only one | available was 'U.S. Nuclear Weapons the Secret History'. Steep | price, $159 for a used copy. | philipkglass wrote: | _The Swords of Armageddon_ was only ever available digitally | (first on CD-ROM, then as download). Hansen 's widow used to | sell it after his death but she is no longer responding to | sales requests. Or at least mine was ignored early this year. | You can find it on Library Genesis. | | _U.S. Nuclear Weapons: The Secret History_ is sadly missing | from LibGen, but it appears to be available as a digital | checkout from the Internet Archive. It 's a good companion | book to _Swords_ because it went through a professional | editing-publishing cycle. _Swords_ is a lot longer and rawer, | with a higher ratio of text to illustrations. | LorenPechtel wrote: | They quit making bigger booms because there was no need for | them. Two factors are at work: | | 1) Square-cube law. You do more damage with a collection of | smaller warheads than with one big one with the same total | yield. | | 2) The Earth isn't flat. Once a boom gets big enough the area | of damage doesn't go up much as the shockwave ends up | separating from the ground and the atmosphere above the bomb | just ends up blasted off. Note that this does *not* limit the | usefulness of big bombs detonated high up for thermal and EMP | effects. Very big booms in low orbit could be very nasty with | total surprise. | perl4ever wrote: | >They quit making bigger booms because there was no need for | them | | Obviously there's no need for them on Earth or anywhere | nearby. | | But it might become useful to scale nuclear explosions to an | arbitrary extent if/when something large on a collision | course with Earth is discovered. | Arainach wrote: | Less than you'd think. At the scale of object which poses a | serious collision risk to Earth, nuclear weapons could (at | best) break up the object, but would have no realistic | chance of significantly reducing the mass/momentum of the | object. Unless you can break it up into dust (which at that | scale you can't), most of it is still going to land on | Earth and do just as much damage. | hwbehrens wrote: | Actually, one recent work on n-body gravitational methods | found that "nuclear explosives remain an indispensable | element of the planetary defense portfolio." [0] | | In particular, although these dispersion methods (as you | pointed out) don't typically reduce the impact energy to | zero, they offer a roughly 2 order-of-magnitude decrease | in impact energy while requiring only month-scale | warning. | | In contrast, diversion techniques which _can_ reduce the | impact energy to 0 (e.g. by shifting the impactor to | 'miss' our planet) can require decade-scale to accomplish | their goal. | | [0]: https://www.sciencedirect.com/science/article/pii/S0 | 09457652... | GoodbyeMrChips wrote: | > And then again optimized thermonuclear weapons | | Here in Blighty, during the early cold war we built fall-out | shelters and equipped a civilian force with "Green Goddess" | fire engines to enable them to extinguish fires from nuclear | flash. | | Yet this all stopped after development and adoption of the | Hydrogen Bomb..... because unlike nuclear weapons (kT yield), | trying to defend against thermonuclear weapons (MT yield) is | pointless. This was a very real and honest defence policy. | | https://en.wikipedia.org/wiki/Green_Goddess | | [In the UK, some younger people may recognise the Green Goddess | Fire engine because they were seen during fireman strikes]. | [deleted] | bronlund wrote: | It may be untold to you, but here in Norway, it lighted up the | sky pretty good :D | trhway wrote: | The Tsar Bomba idea is revived in the Poseidon nuclear very large | torpedo which is estimated to have up to 100Mt yield and intended | to hit large oceanside cities. Interesting that back then Saharov | proposed such weapon and was shamed and shut down by the USSR | Navy along the lines that "Navy fights enemy forces and is | against such a clear attack on civilians". 50+ years later here | we're - the Poseidons are put in service. It goes slow and deep - | about 30 knots cruise at 1000m depth, beyond detection - and it | would take it days to reach the enemy shores from several | thousands miles distance, yet the idea here is that it will still | come and assure the destruction, pretty much Kubrik style ( or | that StarTrek episode where they were trying to stop the large | autonomous space torpedo which was on its way to the target). | | https://en.wikipedia.org/wiki/Status-6_Oceanic_Multipurpose_... | nielsbot wrote: | I know this is OT, BUT | | This site's cookie warning says: Please indicate your consent to | our tracking tools and the sharing of this information by | selecting "I Consent" or by _continuing to browse this website._ | | The "continuing to browse this website" seems shady. Can someone | explain how this is even supposed to work? Is there a timer that | expires? If I scroll at all am I opted in? | | Also, is this even legal in jurisdictions that require a cookie | opt-out? I thought I read some language about required a positive | user interaction to accept tracking. | inetknght wrote: | > _The "continuing to browse this website" seems shady_ | | 1. open browser | | 2. navigate to website | | 3. website installs cookies | | 4. you must have already consented! | bobthepanda wrote: | A fair amount of websites block EU IPs to avoid complying with | GDPR. | ranger_danger wrote: | Why would they have to comply anyway if they have no presence | in the EU? | camhenlin wrote: | EU citizen might register in which case they could be | forced to comply or suffer fines | ranger_danger wrote: | Fines enforced by who? They are not EU citizens or | corporations. | monsieurbanana wrote: | I don't remember I've ever had that, although I've moved out | or Europe a year ago. | TheOtherHobbes wrote: | It's a small number. But it does happen. | | You don't want the interest of 445 million people, most of | whom will consent to tracking? OK with me. | dandotway wrote: | However, a study from 1963 suggested that, if detonated 28 miles | (45 kilometers) above the surface of the Earth, a 10,000-megaton | weapon could set fires over an area 500 miles (800 kilometers) | in diameter. Which is to say, an area about the size of France. | | If thousands of such _gigaton_ bombs were developed then MAD | (Mutually Assured Destruction) would be more taxpayer efficient | because we could simply stop funding expensive rocket and | submarine weapons delivery systems, as they would only add an | unnecessarily complicated step to the process. Just detonate your | gigaton arsenal on your own nation 's soil. When an animal is in | great pain and cannot be saved, we usually consider the most | compassionate course of action to euthanize. So in the event of | MAD, just instantly vaporize your own population to spare them a | few months of clinging to life with radiation sickness, | starvation, cannibalism, and the lawless raping and murdering of | the earth's final warlords. The multiple gigaton bombs detonated | on your own soil will ensure the agonizing death of all your | enemies that don't similarly self-euthanize. | philipkglass wrote: | I presume that this is facetious, but it's not too far off the | mark. See this other great Nuclear Secrecy blog post, "In | Search of a Bigger Boom": | | http://blog.nuclearsecrecy.com/2012/09/12/in-search-of-a-big... | | _The scientist Edward Teller, according to one account, kept a | blackboard in his office at Los Alamos during World War II with | a list of hypothetical nuclear weapons on it. The last item on | his list was the largest one he could imagine. The method of | "delivery" -- weapon-designer jargon for how you get your bomb | from here to there, the target -- was listed as "Backyard." As | the scientist who related this anecdote explained, "since that | particular design would probably kill everyone on Earth, there | was no use carting it anywhere."_ | dandotway wrote: | I guess "truth is stranger than fiction." ;-) Blog comment | from the link you posted: | | _The 10GT weapon really would have been BACKYARD. At 6MT | /tonne (the upper bound for thermonuclear weapons) it would | have weighed 1667 tonnes._ | camhenlin wrote: | Similar idea to the doomsday device described in Dr. | Strangelove! | 542354234235 wrote: | Hydrogen bombs are endlessly fascinating and horrifying. The | physics and engineering that goes into them is amazing, | especially when it boils down to triggering alternating dominos | of progressively larger fission and fusion reactions. | pinewurst wrote: | There's a referenced article in there on the US RIPPLE concept | for large, efficient weapons that's well worth tracking down. | AnimalMuppet wrote: | https://direct.mit.edu/jcws/article-abstract/23/2/133/101892... | | You need an MIT account, though. Would anyone with one care to | summarize? | perihelions wrote: | Archive.org has it, | | https://scholar.google.com/scholar?q=J+Grams+-+Journal+of+Co. | .. | AnimalMuppet wrote: | Following the _second_ search item found eventually got me | to https://muse.jhu.edu/article/794729 | | This seems to be the actual article. | Amorymeltzer wrote: | This is by Alex Wellerstein, who is unparalleled when it comes to | writing about nuclear weapon history. His occasional blog | http://blog.nuclearsecrecy.com/ is an excellent read. | nielsbot wrote: | So crazy and dangerous. | | For some reason makes me think of the Demon Core accident(s), | from the early days of bomb development: | | https://en.wikipedia.org/wiki/Demon_core | jcims wrote: | I read this every time I see a link to it. Slotin's exposure | incident really resonates with me for some reason, it plays | in my head like a movie and I'm Slotin. I can just imagine | ears ringing and a metallic taste in my mouth as my brain | slowly comes to grips with the fact that I'm a dead man | walking. (For some reason i have a stuffy nose too) | | The other thing I come away from this thinking is that our | bodies are way better at dealing with damage from radiation | than we give them credit for. | olau wrote: | I'm left wondering if women would make for statistically | better bomb putter-togetherers. If the account on Wikipedia | is to be believed, it sounds like a true Darwin award with | only a screwdriver separating him from certain death. | dang wrote: | There's a related blog post: | http://blog.nuclearsecrecy.com/2021/10/29/the-possibility-of... | | (via https://news.ycombinator.com/item?id=29039900, but there's | no real thread there) | throwawaysea wrote: | Here is the footage of the Tsar Bomba detonation that was | declassified a year ago: https://youtu.be/YtCTzbh4mNQ ___________________________________________________________________ (page generated 2021-10-29 23:00 UTC)