|
strange feelings re Daisy posted:New York City released a PSA about what to do if the city is nuked lmao. My favorite part is "you've got this". My friends, if you are in NYC when a nuke lands, you absolutely do not "got this". gently caress
|
#
?
Jul 13, 2022 19:01
|
|
|
|
| # ? May 20, 2024 15:50 |
|
|
strange feelings re Daisy posted:"you've got this" Shades posted:New York, Max. That's the place to make it now. You're talking nine thousand tons of steel. Four thousand tons of aluminium. I mean, five to six million miles of copper wire. Kitchen appliances. Typewriters. Audio gear. Tons of auto parts. Works of art, hanging in the galleries. Just hanging there, waiting to be plucked. I mean, clothing. Toupees. Bridgework. False teeth. Prosthetic limbs. You name it. New York has got it all.
|
|
#
?
Jul 14, 2022 06:45
|
|
|
Make fun of him all you want but the city was never nuked, not even once, when Giuliani was in office.
|
|
#
?
Jul 14, 2022 07:32
|
|
|
Mantis42 posted:Make fun of him all you want but the city was never nuked, not even once, when Giuliani was in office. I think I would have irrevocably snapped if Andrew Giuliani had won the nomination and then the governor's seat
|
|
#
?
Jul 14, 2022 14:05
|
|
|
Frosted Flake posted:The linked article says the Navy was told the pipes were steel instead of PVC, which breaks down from contact with jet fuel, and the contractor apparently substituted it to cut costs. One would think defrauding the government and effectively sabotaging the military would have consequences, but I guess as long as the checks clear everything is fine.
|
|
#
?
Jul 14, 2022 16:29
|
|
|
skooma512 posted:One would think defrauding the government and effectively sabotaging the military would have consequences, but I guess as long as the checks clear everything is fine. Sure the consequence is you have to hire a bunch of Navy dudes for $$$$, the revolving door doesn’t come cheap
|
|
#
?
Jul 14, 2022 19:07
|
|
|
Trabisnikof posted:Sure the consequence is you have to hire a bunch of Navy dudes for $$$$, the revolving door doesn’t come cheap I’d think there will be a claim and then maybe subrogation.
|
|
#
?
Jul 14, 2022 19:37
|
|
|
Mango Press 🥭🗝 posted:
ngl i would be suffering from anxiety if i was in one of those swimming tanks and had to deal with some of those waves
|
|
#
?
Jul 15, 2022 16:59
|
|
|
Danann posted:(from t.me/mangopress/8300, via tgsa) A bunch of them swamped in Normandy.
|
|
#
?
Jul 15, 2022 17:03
|
|
|
they might as well be targets for emplaced atgms.
|
|
#
?
Jul 15, 2022 17:14
|
|
|
e: wrong war thread
tazjin has issued a correction as of 01:20 on Jul 16, 2022 |
|
#
?
Jul 16, 2022 01:12
|
|
|
is it currently technologically possible to build a fission bomb that would only blow up say a duplex
|
|
#
?
Jul 19, 2022 20:50
|
|
|
indigi posted:is it currently technologically possible to build a fission bomb that would only blow up say a duplex no that's a job for conventional explosives i mean, unless it was a really big duplex
|
|
#
?
Jul 19, 2022 20:52
|
|
|
Foo Diddley posted:no that's a job for conventional explosives I know you’d use conventional explosives, fortunately that wasn’t my question. I’m asking if it’s technologically possible
|
|
#
?
Jul 19, 2022 20:54
|
|
|
indigi posted:I know you’d use conventional explosives, fortunately that wasn’t my question. I’m asking if it’s technologically possible i'm saying it's not, even with the smallest fission bomb there'd be too much explosion
|
|
#
?
Jul 19, 2022 20:59
|
|
|
indigi posted:is it currently technologically possible to build a fission bomb that would only blow up say a duplex yes actually. there are suitcase nukes whose yield is only in the hundreds of tons of tnt
|
|
#
?
Jul 19, 2022 21:12
|
|
|
indigi posted:I know you’d use conventional explosives, fortunately that wasn’t my question. I’m asking if it’s technologically possible fissionable materials have a critical mass; that is, there is a theoretical minimum mass of material that needs to be present to make it go from sitting there menacingly to exploding, even if it is 100% purity in a perfect sphere for pu-239 (the material used in the W54 warhead on the davy crockett recoilless rifle and the us military 'atomic demolition charge' project) that's 10 kg. so no matter how you design it, it is going to involve a runaway fission reaction of 10 kg of material i'm not a nuclear physicist and can't do the math myself, but from my lay perspective the minimum possible explosion looks to be at leastwo oklahoma city bombings; somewhere in the 10s of tons of TNT order of magnitude
|
|
#
?
Jul 19, 2022 21:14
|
|
|
Stairmaster posted:yes actually. there are suitcase nukes whose yield is only in the hundreds of tons of tnt that'd probably wake the neighbors
|
|
#
?
Jul 19, 2022 21:15
|
|
|
other, more implausible, fission sources exist but even the most impossible-to-ever-make-a-critical-mass-at-100%-purity isotope of californium that has had the figures declassified is only 1/4 the critical mass, not the multiple orders of magnitude difference that would be necessary
|
|
#
?
Jul 19, 2022 21:17
|
|
|
cataclysm grenades took down whole skyscrapers and i don't think you'll get smaller than that
|
|
#
?
Jul 19, 2022 21:19
|
|
|
Stairmaster posted:yes actually. there are suitcase nukes whose yield is only in the hundreds of tons of tnt that's gonna blow up more than one duplex
|
|
#
?
Jul 19, 2022 21:24
|
|
|
you know the critical mass is dependent on local density, as in you take the fissionable material, and compress it enough to cause a runaway fission reaction. the mass of the bomb is variable, you can use less fission material if you put more explosive lenses on it.
|
|
#
?
Jul 19, 2022 21:34
|
|
|
lollontee posted:you know the critical mass is dependent on local density, as in you take the fissionable material, and compress it enough to cause a runaway fission reaction. the mass of the bomb is variable, you can use less fission material if you put more explosive lenses on it. so you use more/bigger explosive lenses you can make a smaller fission warhead, I don't know how to optimize that but I think maybe if you're going whole hog on conventional explosives like that you'll get to the point where the conventional explosives alone will damage more than a duplex before you even factor your micronuke detonation in
|
|
#
?
Jul 19, 2022 21:42
|
|
|
atelier morgan posted:fissionable materials have a critical mass; that is, there is a theoretical minimum mass of material that needs to be present to make it go from sitting there menacingly to exploding, even if it is 100% purity in a perfect sphere The W54 is supposedly configurable as low as 10 tons. And the British version contained a lot less than 10kg of material, probably through fancy design: quote:It has been alleged that the British "Wee Gwen" warhead was a copy of the W54.[4] Though never put into production, Wee Gwen was to contain 1.6 kilograms (3.5 lb) of plutonium and 2.42 kilograms (5.3 lb) uranium.
|
|
#
?
Jul 19, 2022 21:44
|
|
|
probably you can get some kind of mass savings that way? but literally everything about the assemblies used in nuclear devices is extremely classified so  you probably can't get multiple orders of magnitude out of it, like you would need to in order to scale it down far enough for this hypothetical. Trabisnikof posted:The W54 is supposedly configurable as low as 10 tons. And the British version contained a lot less than 10kg of material, probably through fancy design: that figure is why i said two oklahoma city bombings earlier, that was roughly 5 tons of tnt-equivalent atelier morgan has issued a correction as of 21:53 on Jul 19, 2022 |
|
#
?
Jul 19, 2022 21:51
|
|
|
Filthy Hans posted:so you use more/bigger explosive lenses you can make a smaller fission warhead, I don't know how to optimize that but I think maybe if you're going whole hog on conventional explosives like that you'll get to the point where the conventional explosives alone will damage more than a duplex before you even factor your micronuke detonation in the smaller the nuke, the bigger the lenses in relation have to be! but no, you will not reach such a point, for the same reason as an explosively formed penetrator is only damaging in the direction of the explosion you will hit a point of diminishing returns, but since nobody has really tried to minituarize nukes in the most efficient manner possible, we don't really know where that is!
|
|
#
?
Jul 19, 2022 21:56
|
|
|
it's only a matter of time before neutron bomb technology gets to the point where landlords get the ok to use them as a more efficient alternative to the standard eviction process
|
|
#
?
Jul 19, 2022 22:09
|
|
|
Filthy Hans posted:it's only a matter of time before neutron bomb technology gets to the point where landlords get the ok to use them as a more efficient alternative to the standard eviction process A classic idea https://www.youtube.com/watch?v=L8zhNb8ANe8
|
|
#
?
Jul 19, 2022 22:14
|
|
|
Filthy Hans posted:so you use more/bigger explosive lenses you can make a smaller fission warhead, I don't know how to optimize that but I think maybe if you're going whole hog on conventional explosives like that you'll get to the point where the conventional explosives alone will damage more than a duplex before you even factor your micronuke detonation in this sounds about right
|
|
#
?
Jul 19, 2022 22:20
|
|
|
atelier morgan posted:fissionable materials have a critical mass; that is, there is a theoretical minimum mass of material that needs to be present to make it go from sitting there menacingly to exploding, even if it is 100% purity in a perfect sphere You can design a nuclear weapon with considerably less than 10 kg of Pu-239. The 10kg figure is a very basic estimate: 1.) It is the "bare sphere" critical mass, meaning there is no neutron reflector around the fissile material: any neutrons which escape the assembly are lost. A neutron reflector can reduce the critical mass to less than half that of the bare sphere critical mass. 2.) It assumes density at standard atmospheric pressure. The entire point of an implosion assembly is to convert a subcritical mass into a critical one by virtue of compression. The critical mass (or any reactivity parameter) scales approximately as 1/C^2, where C is the density ratio (although, for reflected systems the scaling exponent is a bit lower than 2, since the reflector material is generally not compressed to the same ratio as the core). Practical compression systems, where the mass of high explosive is kept to within an order of magnitude or two of the fissile mass, can achieve density ratios of around 1.5-2.0 . The absolute limit for shock compression by high explosive is probably around ~2. So the amount of Pu-239 needed to make a bomb go bang is substantially less than 10 kg. It is relatively easy to design weapons with 4-5 kg (an often published figure for many American fission triggers). It should be quite possible to design a weapon with even 2 kg, if the implosion system is good and a suitable reflector is used. The absolute minimum amount of plutonium needed to make a bomb is probably between 1-2 kg. Tritium boosting would ensure that the efficiency of even such a small weapon could still be good. Such a minimum size fission stage may not be optimal for efficiently driving the 2nd stage of a thermonuclear weapon. The size of the required high explosive drivers and reflector may also increase total weight over a system using modestly more fissile mass. That may be why actual weapons seem to use larger than the minimum required fissile mass.
|
|
#
?
Jul 19, 2022 22:41
|
|
|
Filthy Hans posted:it's only a matter of time before neutron bomb technology gets to the point where landlords get the ok to use them as a more efficient alternative to the standard eviction process working on this atm
|
|
#
?
Jul 19, 2022 22:45
|
|
|
Morbus posted:Tritium boosting would ensure that the efficiency of even such a small weapon could still be good. Such a minimum size fission stage may not be optimal for efficiently driving the 2nd stage of a thermonuclear weapon. The size of the required high explosive drivers and reflector may also increase total weight over a system using modestly more fissile mass. That may be why actual weapons seem to use larger than the minimum required fissile mass. tritium boosting, as in a fusion second stage? dont those take up a huge amount of space tho?
|
|
#
?
Jul 19, 2022 22:49
|
|
|
Frosted Flake posted:A bunch of them swamped in Normandy. Wasn't that cause the Sherman DD had that big canvas skirt up around it so it would just catch and fill with sea water?
|
|
#
?
Jul 19, 2022 22:50
|
|
|
Also if I were in charge of Iran's nuclear weapons program, I would: 1.) Clandestinely develop a robust, tritium boosted implosion system designed for ~1.5-3.0 kg of reactor grade plutonium. "Weapons grade" plutonium isn't needed and doesn't significantly change the critical mass requirements, it's just that reactor grade plutonium has some heat dissipation, radiation, and background neutron issues. These are all irrelevant in a small, boosted weapon, though. This system could be tested without any fissile material to the point of being assured of its reliability. The needed amounts of reactor grade plutonium for several bombs could be recovered by small-scale and difficult to detect chemical reprocessing of small amount of reactor fuel over the course of a decade or so. 2.) Use the above in a conservatively designed 2-stage pseudo Teller-Ulam (really just "Ulam") design where on the order of 10 kg of moderately enriched uranium are compressed by the trigger in #1, possibly with tritium boosting in the secondary as well. The compression achieved by even a lovely radiation implosion device would be more than enough to fission the enriched (but not weapons grade) uranium, and such a two step weapon would be much easier to design than an actual thermonuclear bomb while easily achieving yields in the 20-100 kT range. All the major difficulties of a thermonuclear design (reaching the required pressures in the fussion fuel without excessive pre-heating, achieving ignition in the compressed secondary, optimal size and composition of the high-Z radiation tamper...) are eliminated and even the dumbest, ultra-conservative design will easily achieve sufficient compression to fission the enriched uranium. The above would be a very effective demonstrator weapon, could be practically deliverable, and could make use of small amounts of clandestinely produced reactor grade Pu and large amounts of enriched but not weapons grade uranium. It would also be a convenient test platform and starting point for a thermonuclear weapon. Anyway that's my ted talk
|
|
#
?
Jul 19, 2022 23:04
|
|
|
tritium boosting etc would make the boom more efficient not less, though useful if you're iran's nuclear program not so for trying to make a nuclear weapon with the yield of like, 1 kg of dynamite as was posited
|
|
#
?
Jul 19, 2022 23:07
|
|
|
lollontee posted:tritium boosting, as in a fusion second stage? dont those take up a huge amount of space tho? No you just put like 2 grams of tritium-deuterium gas right inside the fission core. As soon as your fission assembly begins to go critical (even at the poo poo-tier fizzle stage), it generates more than enough heat to cause a decent number of fusion reactions in the boost gas. This produces a large number of energetic neutrons, which "help along" the fission reactor much faster than would occur if it were limited to the neutrons produced only by its own fission. As the fissioning continues, more heat, more fusion, more neutrons, and so on. So a small amount of tritium (deuterium doesn't count since its so cheap) greatly increases the efficiency of the fission bomb, and also simplifies its design in many ways
|
|
#
?
Jul 19, 2022 23:08
|
|
|
atelier morgan posted:tritium boosting etc would make the boom more efficient not less, though oh whoops i thought we were just talking about minimizing fissile material not minimizing yield.
|
|
#
?
Jul 19, 2022 23:10
|
|
|
Morbus posted:No you just put like 2 grams of tritium-deuterium gas right inside the fission core. As soon as your fission assembly begins to go critical (even at the poo poo-tier fizzle stage), it generates more than enough heat to cause a decent number of fusion reactions in the boost gas. This produces a large number of energetic neutrons, which "help along" the fission reactor much faster than would occur if it were limited to the neutrons produced only by its own fission. As the fissioning continues, more heat, more fusion, more neutrons, and so on. So a small amount of tritium (deuterium doesn't count since its so cheap) greatly increases the efficiency of the fission bomb, and also simplifies its design in many ways just by virtue of adding lots of neutrons to the mix??? huh, alright, 1-proton, two-neutron, make interesting. how do you make that stable chemically tho? just react the fissile metal with tritium?
|
|
#
?
Jul 19, 2022 23:19
|
|
|
lollontee posted:just by virtue of adding lots of neutrons to the mix??? huh, alright, 1-proton, two-neutron, make interesting. how do you make that stable chemically tho? just react the fissile metal with tritium? I think the usual practice is to have a cavity in the core (making the fissile material a shell rather than a sphere is beneficial for compression anyway) and to inject tritium from a reservoir during arming, since otherwise hydrogen gas diffuses into and out of everything. You could use tritiated + deuterated lithium too, but tritium has a short enough half life that it needs to be periodically replaced anyway, and that's much easier if it's in an external reservoir.
|
|
#
?
Jul 19, 2022 23:32
|
|
|
|
| # ? May 20, 2024 15:50 |
|
|
Morbus posted:I think the usual practice is to have a cavity in the core (making the fissile material a shell rather than a sphere is beneficial for compression anyway) and to inject tritium from a reservoir during arming, since otherwise hydrogen gas diffuses into and out of everything. You could use tritiated + deuterated lithium too, but tritium has a short enough half life that it needs to be periodically replaced anyway, and that's much easier if it's in an external reservoir. hmm...... 
|
|
#
?
Jul 19, 2022 23:38
|
|