[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
        
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       (page generated 2021-10-29 23:00 UTC)