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Thread: pressure detonated bomb

  1. #1 pressure detonated bomb 
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    since terroists only have acess to low grade nuclear material(such as cesium chloride),maybe i could post this, is it possible to have a mass of high grade nuclear material in sphere at subcrtical mass and drop it in marina trench, and could it explode?


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  3. #2  
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    It would neither explode nor implode if it is sub-critical.

    Nuclear bombs do not 'explode' they 'detonate' - you basically force two seperate lumps of fissile mateial together- Hey you know all this, BUT all a nuclear bomb actually does is radiate energy. There is no 'explosion' The energy released instantaneously super heats the surrounding atmosphere to millions of degrees [I don't know how many though], this then expands the atmosphere rapidly causing the increase in temperature to dissipate outwards as a pressure wave, after a while the air rapidly cools, contracts and then returns (so there is a double blast wave, out and back). A 'fireball' mostly consisting of people, animals, children, buildings chickens, newspapers and all the other city detritus then rises into the air at the point of detonation.

    THat's why zapping meteors or comets with Nukes is crap, there's no atmosphere to expand and cause the blast wave!, there would simply be a bright flash, and some vaporising of material close by.

    My understanding is they have to be 'fused' together in as short a time as possile so high explosives are used to force them together. Then there are Plutonium bombs. In the bottom of your trench I suspect that even if the two quantities combined were super-critical, all you would get is the classic 'meltdown' or china syndrome.


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  4. #3  
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    hehe
    i mean will the pressure be able to make the mass detonate?
    lets say have a mass @0.95 critical
    if u drop it.. and become crushed smaller and smaller,
    like fatman but uses water pressure instead of explosive pressure
    hmm
    what does china syndrome mean?
    anyway...
    how would the explosion explosion affect water beside making radioactive tsunamis(kinda cool)
    sorry for bad english
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  5. #4  
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    No. Dropping something or crushing it will not change it's mass. Rocks at the bottom of the ocean are not crushed. At 95% CM I should imagine it will generate a lot of heat though, even before you start. THink of Cherbobyl, where as it got towards super critical it just heated rapidly and caused an explosion. It would not make a tsunami unless it triggered a massive subterranean earthquake. China syndrome is a meltdown.
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    thnx for the clarification
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    Quote Originally Posted by billco
    No. Dropping something or crushing it will not change it's mass. Rocks at the bottom of the ocean are not crushed. At 95% CM I should imagine it will generate a lot of heat though, even before you start. THink of Cherbobyl, where as it got towards super critical it just heated rapidly and caused an explosion. It would not make a tsunami unless it triggered a massive subterranean earthquake. China syndrome is a meltdown.
    Why would this not work? assuming the pressure is sufficient the material would reach critical mass surely?

    Bear in mind critical mass is dependant on he shape of the material, andis probably calculated for a sphere or cube, wheras a rod or a foil could be many times bigger....
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    Critical mass yes, is calculated as a sphere as far as I know. Also if you have not got a critical mass then no 'boom' just a lot of heat and radiation you may like to know its called critical mass not critical density. I still say rock is in all normal senses incompressible, as is water (when devoid of gas). Anyway apart from 2 key ingredients anybody could knock up a nuclear weapon, You'll find everything at your local scrapyard except the enriched uranium, and the accelerant.
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    Quote Originally Posted by Megabrain
    I still say rock is in all normal senses incompressible, as is water (when devoid of gas).
    I have no idea what you mean by 'normal senses'. However, as someone whose income and lifestyle are intimately connected with the compressibility of rock I can assure you it is - in any normal scientific use of the term - compressible.
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    I think you are refering to pore compressibility, which does not of itself compress the rock, in the normal sense I am refering to dropping it overboard at sea, or with the tools you you might have available in your garage.

    UNless of course you are playing with words and any force exerted on the rock places it in a state of compression?
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  11. #10  
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    Quote Originally Posted by Megabrain
    I think you are refering to pore compressibility, which does not of itself compress the rock, in the normal sense I am refering to dropping it overboard at sea, or with the tools you you might have available in your garage.
    Unless of course you are playing with words and any force exerted on the rock places it in a state of compression?
    I don't think dropping rocks overboard, or playing with them in your garage is anything like the 'normal sense' for a rock. Rocks 'live' in the ground. Having recovered core from several thousand feet below surface level I can assure you the little bastards are compressed (and no, I am not just talking about the pore fluids).
    Do they compress as well as hydrogen? You know that is a silly question, but that almost seems what you mean by 'a normal sense'. Solids are compressible. Rock is compressible. Subsurface rock is compressed. You would be compressed if you had 5000psi applied to you. In that regard a rock is no different. (And I sure as heck can apply 5000psi to a rock in my garage using just the tools I have there.)
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    Could you gice me an example of how much you could reduce the volume of say, 1 cubic centimetre of flint by, and how much pressure would that take?
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  13. #12  
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    Now who is playing with words. The last time I looked flint was not a rock, but a mineral.
    Claystones, mudstones, marls, sandstones, siltstones, conglomerates, breccias, calcarenties, calcilutites, gypsums, anhydrites ect are all compressible. (As is flint. If it wasn't we couldn't fail it mechanically)
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  14. #13  
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    When you say rock is compressible, I think you are using one of those words whose general meaning is very different to the specific meaning it has in geology. All rocks so far as I know are made of minerals (excluding [maybe] some types such as anchracite?). Look at the thread, read the context in which uranium is being talked about and answer the question for the guy. My understanding is that pressure to rock causes it to either fracture,melt,deform or some combination of these and in no circumstances here on earth will it reduce in volume by more than an imperceptible amount for a finite time (such as 'bouncing' one rock off another. Of course this could all be bollocks but I reckon you are playing with the word compressible.
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    I do not see why the proposed method would not work, if a high enough pressure is reached. As said above, the result would not be an 'explosion' as such, however, many man-made nuclear weapons are desingned as implosion type bombs, and use this very method to detonate.

    The 'most favourable' reaction would be achieved if there was a cavity present within the sphere.

    I am unsure, however, as to whether or not the underwater pressure is enough to collapse the sphere at ANY depth.
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  16. #15  
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    Quote Originally Posted by billco
    It would neither explode nor implode if it is sub-critical.

    Nuclear bombs do not 'explode' they 'detonate' - you basically force two seperate lumps of fissile mateial together- Hey you know all this, BUT all a nuclear bomb actually does is radiate energy. There is no 'explosion' The energy released instantaneously super heats the surrounding atmosphere to millions of degrees [I don't know how many though], this then expands the atmosphere rapidly causing the increase in temperature to dissipate outwards as a pressure wave, after a while the air rapidly cools, contracts and then returns (so there is a double blast wave, out and back). A 'fireball' mostly consisting of people, animals, children, buildings chickens, newspapers and all the other city detritus then rises into the air at the point of detonation.

    THat's why zapping meteors or comets with Nukes is crap, there's no atmosphere to expand and cause the blast wave!, there would simply be a bright flash, and some vaporising of material close by.

    My understanding is they have to be 'fused' together in as short a time as possile so high explosives are used to force them together. Then there are Plutonium bombs. In the bottom of your trench I suspect that even if the two quantities combined were super-critical, all you would get is the classic 'meltdown' or china syndrome.
    You say that there is no explosion but thats what an explosion is is the rapid expansion of air due to a highly reactive exothermic reaction.
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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  17. #16  
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    I think what bilico is doing is attempting to differentiate between an explosion as a result of a chemical reaction and the after-effects of a nuclear reaction.
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