| ▲ | Supermancho a day ago |
| > One proposed version[^1] had the force of more than 600,000 Hiroshimas. Even so, Cold War analysts coolly judged that it could reduce a region the size of France to ashes. His weapon was a planet shaker. It could end civilization. Except...
[^1] https://archive.ph/Md1YG [^1]https://nuclearsecrecy.com/nukemap/ Were they just wrong by an order of magnitude or 2 because of previously unforseen limits, like air pressure? Or maybe 100MT is not the same as 600k Hiroshimas. Casually, the blast doesn't look like it's has a similar effect. |
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| ▲ | mikeyouse 18 hours ago | parent | next [-] |
| It’s a reference to this paragraph where they hypothesized about a 10,000MT bomb; > All of which is to say that the idea of making hydrogen bombs in the hundreds-of-megatons yield range was hardly unusual in the late 1950s. If anything, it was tame compared to the gigaton ambitions of one of the H-bomb’s inventors. It is hard to convey the damage of a gigaton bomb, because at such yields many traditional scaling laws do not work (the bomb blows a hole in the atmosphere, essentially). 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. Teller’s crazy ass wanted to build a 10,000MT bomb with a 1,000MT primary.. https://en.m.wikipedia.org/wiki/Sundial_(weapon) |
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| ▲ | mousethatroared 20 hours ago | parent | prev | next [-] |
| Big boom booms are easy. Nuclear bomb design research since the sixties is all about making them as clean and low yield as possible. These two goals are counters to each other, but once you've mastered it your nuclear arsenal becomes less of a garage queen and a lot more useful. |
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| ▲ | somenameforme 20 hours ago | parent | prev | next [-] |
| Your linked site for some reason doesn't include fallout by default, nor does it seem to factor casualties from it. Turn on fallout + surface burst, and a 100MT bomb's deadly fallout range goes from the center of France (where the label is on their map) to the center of Germany and I suspect that's an extreme underestimation, especially the conic they give. It's also possible that the NYTimes is conflating facts by accident. Your demo link only accounts for single big-blast effects but the way you optimize damage with nukes is lots of smaller bombs, often in a single bomb - MIRV is one name for this. The reason is pretty simple. We approximate the explosive range as a sphere and the volume of that sphere is proportional to the cube (^1/3) of the yield. So if you increase the yield by 10x you only increase the explosive radius by something like 2.15x. On the other hand, detonate 10 bombs side by side and you increase the radius by 10x. This not only maximizes damage, but also works to further nullify any sort of anti-missile defense. And 100MT would be well more than enough to obliterate France. You can also kind of intuit this by thinking about 100MT means. That's 100,000,000 TONS of TNT explosive capacity. That's about 1.5 tons of TNT for each and every person in France. That's just a stupidly massive absurd amount of destruction. |
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| ▲ | 05 18 hours ago | parent | next [-] | | > detonate 10 bombs side by side and you increase the radius by 10x By 10**.5~=3.2x | | |
| ▲ | lostlogin 16 hours ago | parent [-] | | It’s not very tidy phrasing, but I think the meaning is that 10 detonations next to each other (blast diameters touching) is 10x the diameter? | | |
| ▲ | somenameforme 15 hours ago | parent [-] | | He's right. You'd want to arrange them in a square for comparable coverage so it'd be sqrt(10) = ~3.2. It feels somehow nice and correct that an effort to reduce a 3d problem (basically a lot of our boom goes up or down, which is not necessary in most cases) to a 2d one changes it from a gain of x^(1/3) to x^(1/2). | | |
| ▲ | lostlogin 14 hours ago | parent [-] | | The OP presumably meant a line of blasts though? That would possibly be the least efficient orientation after blasting the same spot 10x. | | |
| ▲ | TheOtherHobbes 12 hours ago | parent [-] | | Depends on your goal, the nature of the target, and how much damage you want to do. At one extreme there are precision attacks in silos and airfields. At the other are genocide attacks where you want to kill as many people as possible and leave as much of the land uninhabitable for as long as possible. In the middle are precision strategic attacks, where you want to leave infrastructure and buildings so you have the option to invade and take over. |
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| ▲ | pfdietz 10 hours ago | parent | prev [-] | | The fallout from a bomb is going to depend on its design. In a typical thermonuclear bomb, most of the yield is still from fission, so there are lots of fission products. The purpose of the fusion is to generate neutrons to more thoroughly fission the fissionable material. However, it's possible to design thermonuclear bombs with greatly reduced fission fraction. The extreme example of that were the Ripple tests, which the US conducted shortly before atmospheric tests were banned. These involve a secondary without a fission "spark plug", where carefully tailored implosion cause the density/temperature at the core of the secondary to reach conditions for fusion ignition, in a way very similar to how inertial confinement fusion reactors are imagined to work. The most extreme of these has been reported to derive 99% of its yield from fusion reactions. If the neutrons from these are absorbed in something with low activation the fallout could be greatly reduced. |
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| ▲ | MathMonkeyMan 21 hours ago | parent | prev | next [-] |
| Wikipedia says that the bomb that destroyed Hiroshima had a yield of about 16 kilotons of TNT. 600k of those would be 16*600 megatons, or 9600 megatons. That's 96 times more than the original target yield of 100 megatons for Tsar Bomba. I don't know if that's possible, but it makes sense that it would "reduce a region the size of France to ashes." Maybe the design had a lot of stages. |
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| ▲ | cjbgkagh 21 hours ago | parent | next [-] | | IIRC there is no hard limit on the size of a hydrogen bomb. That said many small nukes operating as a cluster cover more area for the same material due to the inverse cubed law. | | |
| ▲ | dghlsakjg 20 hours ago | parent [-] | | AFAIK, you can just pack as much fuel as you want into the secondary to scale the size of a thermonuclear bomb. So yeah, there is no size limit. Interesting aside; the US had the dial-a-yield mechanism that allowed one bomb to deliver a selectable amount of energy, not sure what the mechanism for this was, however. As to your second sentence, pretty sure that’s what a MIRV is. | | |
| ▲ | chickenbig 17 hours ago | parent | next [-] | | > not sure what the mechanism for this was, however. Boosting (injection of deuterium/tritium into the centre of the pit) causes a large increase in yield because fusion generates lots of high energy neutrons that go on to fast fission your (still compressed) pit. According to one weapons designer, boosting is mainly responsible for the remarkable 100-fold increase in the efficiency of fission weapons since 1945.
https://en.wikipedia.org/wiki/Boosted_fission_weapon | |
| ▲ | dboreham 18 hours ago | parent | prev [-] | | Variable yield weapons presumably still exist. Particularly depth charges iirc. Usually the yield can be selected between two or more fixed levels rather than a continuously variable input. Often this is implemented with tricks such as disabling the secondary and/or disabling boosting in the primary. |
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| ▲ | 21 hours ago | parent | prev [-] | | [deleted] |
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| ▲ | benbayard 19 hours ago | parent | prev | next [-] |
| I think it's probably referring to this bomb: https://www.youtube.com/watch?v=E55uSCO5D2w I think the key is proposed weapon, instead of practical weapon. It's a fascinating video, you should check it out! |
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| ▲ | CamperBob2 20 hours ago | parent | prev [-] |
| Teller really, really wanted to build a gigaton bomb. That may have been what the author was thinking of. |
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| ▲ | wat10000 9 hours ago | parent [-] | | He also proposed a 10 gigaton bomb. It was referred to as a “backyard bomb.” Meaning that you didn’t have to figure out how to put it on a missile or bomber. You could just detonate it in your backyard and it would do the job of destroying the enemy (and everyone else). |
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