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Richard Garwin’s role in designing the hydrogen bomb was obscured

nytimes.com

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Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#11

Post by dghlsakjg »

cjbgkagh wrote: post #10
MathMonkeyMan wrote: post #8

Earlier quoted context omitted.

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.

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.

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.

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#12

Post by CamperBob2 »

Supermancho wrote: post #4

> 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 pressu…

Teller really, really wanted to build a gigaton bomb. That may have been what the author was thinking of.

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#13

Post by mousethatroared »

Supermancho wrote: post #4

> 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 pressu…

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.

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#14

Post by somenameforme »

Supermancho wrote: post #4

> 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 pressu…

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.

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#15

Post by benbayard »

Supermancho wrote: post #4

> 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 pressu…

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!

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#16

Post by dboreham »

dghlsakjg wrote: post #11
cjbgkagh wrote: post #10

Earlier quoted context omitted.

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.

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.

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.

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#17

Post by adastra22 »

perihelions wrote: post #7
jasonhong wrote: post #6

Incidentally, IEEE Spectrum published a fascinating interview with Dr. Garwin just a few months ago. https://spectrum.ieee.org/richard-garwin > At IBM, where he worked from 1952 to 1993, Garwin was a key contributor or a facilitator on some of the most important products and breakthroughs of his era, including magnetic resonance imaging, touchscreen monitors, laser printers, and the Cooley-Tukey fast Fourier transfor…

> "and the Cooley-Tukey fast Fourier transform algorithm" Supposedly, at Garwin's scheming, one of the creators wasn't aware the immediate application of the algorithms they were optimizing was nuclear weapons, > "Tukey reportedly came up with the idea during a meeting of President Kennedy's Science Advisory Committee discussing ways to detect nuclear-weapon tests in the Soviet Union by employing seismometers located…

That application was for detecting nuclear bombs, not making them. That’s a big difference.

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#18

Post by 05 »

somenameforme wrote: post #14
Supermancho wrote: post #4

> 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 pressu…

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 a…

> detonate 10 bombs side by side and you increase the radius by 10x

By 10**.5~=3.2x

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#19

Post by mikeyouse »

Supermancho wrote: post #4

> 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 pressu…

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)

Re: Richard Garwin’s role in designing the hydrogen bomb was obscured

#20

Post by opello »

adastra22 wrote: post #17
perihelions wrote: post #7

Earlier quoted context omitted.

> "and the Cooley-Tukey fast Fourier transform algorithm" Supposedly, at Garwin's scheming, one of the creators wasn't aware the immediate application of the algorithms they were optimizing was nuclear weapons, > "Tukey reportedly came up with the idea during a meeting of President Kennedy's Science Advisory Committee discussing ways to detect nuclear-weapon tests in the Soviet Union by employing seismometers located…

That application was for detecting nuclear bombs, not making them. That’s a big difference.

I expect at the time the distinction was irrelevant.

I also don't think it's necessary to be critical about the wording above. Perhaps "was related to nuclear weapons" reads better? But it's not exactly ambiguous, especially after reading the quoted passage.

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