Dark Sun: The Making Of The Hydrogen Bomb

by Richard Rhodes

Here, for the first time, in a brilliant, panoramic portrait by the Pulitzer Prize-winning author of The Making of the Atomic Bomb, is the definitive, often shocking story of the politics and the science behind the development of the hydrogen bomb and the birth of the Cold War.Based on secret files in the United States and the former Soviet Union, this monumental work of history discloses how and why the United States decided to create the bomb that would dominate world politics for more than forty years.

Genres: History, Science, Nonfiction, Physics, War, Politics, Military Fiction

1252 pages, Kindle Edition

First published January 1, 1995

About the author

Richard Lee Rhodes is an American journalist, historian, and author of both fiction and non-fiction (which he prefers to call "verity"), including the Pulitzer Prize-winning The Making of the Atomic Bomb (1986), and most recently, Arsenals of Folly: The Making of the Nuclear Arms Race (2007). He has been awarded grants from the Ford Foundation, the Guggenheim Foundation, the MacArthur Foundation and the Alfred P. Sloan Foundation among others.

He is an affiliate of the Center for International Security and Cooperation at Stanford University. He also frequently gives lectures and talks on a broad range of subjects to various audiences, including testifying before the U.S. Senate on nuclear energy.

Reviews

[Matt · Rating 4 out of 5]

“If the Soviet Union had been the United States’s Second World War ally, it was also the only possible enemy to survive the general destruction with sufficient military power to challenge American hegemony. Its army occupied the eastern half of Europe. The United States believed it had a trump card in the atomic bomb, but even that advantage was a wasting asset. On [September 19, 1945]…physicist Klaus Fuchs, a member of the British mission at Los Alamos, was finishing up delivering information about the atomic bomb by hand to Harry Gold…who was a courier for Soviet intelligence. Fuchs had been passing information on the atomic-bomb project to Soviet agents since 1941. In June he had delivered to Gold a complete description of the Fat Man plutonium implosion bomb…In October 1945, with Fuchs’s information…the head of Soviet foreign intelligence in Moscow was able to send to the commissar for state security…a detailed plan of the plutonium implosion bomb for Soviet scientists to duplicate. The war was over. The atomic arms race had begun…”
- Richard Rhodes, Dark Sun: The Making of the Hydrogen Bomb

Following up a classic is hard. In The Making of the Atomic Bomb, Richard Rhodes delivered a masterpiece, elegantly combining science writing, biographical portraiture, and good old fashioned storytelling into a poignant and compelling tale of men and women who set out to end a war by making a weapon so terrible that war would be unthinkable.

Dark Sun is a direct sequel to The Making of the Atomic Bomb, and one cannot fault Rhodes for attempting to recreate his greatest success. In focusing on the hydrogen bomb, he once again has a fascinating cast of characters – many of them scientists – struggling with the conflict between what can be discovered, and what should.

Being an extremely talented author-historian, with a keen grasp on how to make advanced physics understandable to a layperson, Dark Sun is a very good book. However, it does not have the clean narrative arc that history provided for the saga of the atomic bomb. As a result, Rhodes often seems to be wandering around, trying to figure out what he’s really trying to say.

***

Dark Sun feels like several books stitched together. All of them are good in and of themselves, but the transitions are not entirely seamless, and this doesn’t quite cohere as a whole.

The first third of the book is a mirror-twin of The Making of the Atomic Bomb, except that it focuses on the Soviet side of the story, as they attempt to make their own super-weapon. This involves a great deal of time spent unraveling the knotted-together threads of the Soviet Union’s espionage activities within the United States, while both sides were fighting Nazi Germany.

The middle third of Dark Sun covers the scientific debate over whether or not the hydrogen bomb was feasible, and the political/moral debate over whether it should be pursued. This involves the splintering of the brain trust that had worked together at Los Alamos during the Second World War. This schism centered on former Manhattan Project Director J. Robert Oppenheimer, who came out against the hydrogen bomb, and Hungarian physicist Edward Teller, who advocated so fiercely for the potentialities of megaton destruction that he formed the model of Stanley Kubrick’s Dr. Strangelove.

The final third describes the creation of the H-bomb itself, set against the backdrop of worsening geopolitical tensions, including growing atomic stockpiles in the U.S. and U.S.S.R., the Korean War, and the “Red Scare” in America, which saw Oppenheimer stripped of his security clearance.

The upshot of this structure is that the hydrogen bomb itself is never front-and-center. Rather, this often feels like a general history of the Cold War from 1945 to 1962, with an emphasis on the development of nuclear deployment strategies and deterrence.

***

Obviously, history does not conform itself to dramatic imperatives. While the creation of the atomic bomb has a beginning, middle, and end, the birth of the hydrogen bomb is not so straightforward. As a result – and as noted above – Dark Sun can feel diffuse at times. Sometimes it’s all about spies; sometimes its about weighing the different design types for an H-bomb; and sometimes it’s about smart people wrestling with profound ethical questions.

Still, it’s worth noting that each of these individual parts are well-done. Rhodes is a very good writer, able to deliver a powerful scene, illuminating sketches of the people involved, and clear descriptions of byzantine processes. For example, he does a wonderful job putting into words an event that mostly defies description: the explosion of an H-bomb.

Once the explosion broke through the casing, it expanded in seconds to a blinding white fireball more than three miles across…and rose over the horizon like a dark sun; the crews of the task force, thirty miles away, felt a swell of heat as if someone had opened a hot oven, heat that persisted long enough to seem menacing. ‘You would swear that the whole world was on fire,’ one sailor wrote home who turned around like Lot’s wife to look. For a moment, the fireball seemed to hover; then it began to rise… Momentarily the huge Mike fireball created every element that the universe had ever assembled and bred artificial elements as well…Swirling and boiling, glowing purplish with gamma-ionized light, the expanding fireball began to rise, becoming a burning mushroom cloud balanced on a wide, dirty stem with a curtain of water around its base that slowly fell back into the sea…

All of this is undergirded by really deep research. Even though Dark Sun was published all the way back in 1995 – the same year the Project Venona decrypts were declassified – this still holds up remarkably well. Part of the reason is that Rhodes talked to a lot of the players, including Teller, J. Carson Mark, and Luis Alvarez. Rhodes’s immersion in this topic means that his judgments – on such things as the value of Soviet espionage to their own atomic weapons program – carries a great deal of weight.

***

Thermonuclear weapons are orders of magnitude more destructive than atomic weapons. Theoretically, there is no limit to how destructive an H-bomb can be. Edward Teller – who can seem a borderline psychopath at times – often mused upon this, and came up with a bomb he called the “Backyard,” because it could blow up the earth from wherever it sat. The hydrogen bomb gave humans the chance to truly destroy life on earth, as though we needed more help in our self-destructive tendencies.

Despite this, Dark Sun does not feel as vital as The Making of the Atomic Bomb. I think this is because of the H-bomb’s inevitability. Once the splitting of atoms had been perfected, it was only a matter of time before sometime decided to fuse them together.

***

The fact that Dark Sun is not as good as its Pulitzer Prize-winning forebear does not mean it lacks for an important lesson about the arc of progress. We humans are curious, clever, often smart, and are always looking for the next advancement. But we are also small-minded, cruel, occasionally dumb, and tend to weaponize all of our inventions. As a species, we are always plunging forward heedlessly. While Rhodes is concerned with growing stockpiles of redundantly destructive warheads, the warnings apply just as much to potentially catastrophic technologies such as artificial intelligence. The end – it seems – will not come with a bang or a whimper, but with a great idea.

[George Kaslov · Rating 5 out of 5]

This book is no Making of the Atomic Bomb, but it is still an excellent account of the history of the H-Bomb. It continues exactly where the Making of the Atomic Bomb ended and it proceeds to tell the history of not the H-bomb but the start of the Cold War. With Russian espionage, first Soviet atomic bomb, Berlin air lift and the Korean war the Cold War started and just like with the Atomic Bomb previously, fear and uncertainty gave the true reasons to make the H-Bomb, for it's history is unavoidably linked with these events.


... Otherwise it would have been a very short book.

[James Murphy · Rating 4 out of 5]

Years ago I'd read and enjoyed Rhodes's earlier The Making of the Atomic Bomb. Because that was a history of atomic research, the Manhattan Project, and the resulting bombings of Hiroshima and Nagasaki, I'd expected Dark Sun to be a history in a similar style. It's partly that; the record of how thermonuclear theory was developed into a weapon is only a piece of the huge story he tells. Dark Sun, continuing the history of nuclear arms begun with The Making of the Atomic Bomb, includes 2 important facets of the nuclear arms story: espionage and Soviet nuclear arms research. Large portions of the book are devoted to detailing how the Soviet Union obtained atomic weapons technology from persons within the Manhattan Project and how they'd begun their own development by the end of the war. The story of how they acquired that knowledge as well as the stories of the individuals responsible for the espionage makes for fascinating reading. Also a necessary part of the history is the evolution of Soviet nuclear weapons and testing. There are many surfaces to these complicated events, but Rhodes's grasp of them seems sure, from the political maneuverings of high-powered intellectuals within the scientific community to a history of the Cold War and the arms race to well-honed portraits of the major players involved at all levels. Because the chapters dealing with nuclear theory, bomb design, and fission were over my head, I was grateful they aren't the bulk of the book; I struggled with understanding in ways I didn't remember from my reading The Making of the Atomic Bomb. The most fascinating chapters of the book--the accounts of espionage and the Soviet research and development--aren't technical at all, and they make for gripping reading. For me, Rhodes covers the Cold War and arms race and the many tensions and scares resulting from them too briefly. But, as I say, it's a huge book as it is. I was surprised by many things: at how extensive Soviet atomic research was before the end of the war, for instance, and at how single-mindedly Curtis LeMay and the men around him tried to effect a preemptive war with the Soviets, and at how destructive thermonuclear weapons themselves are. I thought I knew, but I didn't. Good book.

[Sean Wilson · Rating 5 out of 5]

Dark Sun is a monumental piece of history writing. Richard Rhodes' dense and gripping look into the world of the hydrogen bomb is probably one of the most definitive books on nuclear history, Cold War politics and a disturbing insight into nuclear science. Above all that, it is a fascinating study of human nature under this scientific breakthrough and political paranoia. It's truly disturbing that man has created a weapon that harnesses the power of the Sun.

[Ben · Rating 5 out of 5]

- I've never read a passage so erotic that subtly turns in gross horror. (The incredible depth and detail of the ignition of the Mike thermonuclear device and all of the physics involved in it's operation as it expands outwards and turns into a wave of destruction.)

- WTF moment 1: Curtis LeMay casually flying spy planes over Russia with possible hopes that he could start WWIII. He'd spent years getting the U.S. bombing force into a potent force, and seemed extremely into not letting the force go to waste. He seems correct that in 1952 or 1954 if he wanted to wipe out Russia and their ability to retaliate, he could, and that if the choice was between mutually destruction later, or Russia destruction now, he was correct. But also, we're alive now so that choice wasn't necessary? He also had comments about how the u.s. military strength at the time was way more than the rest of the world and how the U.S. could have flexed it's military to gain power. It seems like military people really seem to think about death differently than most civilians and I'd like to understand that better. In General leMay's mind 80Million Russian deaths is fine, as it would increase the U.S. power relative to the rest of the world. The deaths don't really count as part of his calculus. In most people's mind, 80 million deaths and the destruction of Russian culture really outweigh U.S. becoming relatively more powerful.

WTF moment 2: A bunch of people had some last minute wtf-are-we-doing-let's-stop-this thoughts before the first H-bomb test. They were thinking if there is anytime to negotiate a no-bomb-testing-treaty, now was the time to do it, before anyone exploded any H-bombs. The bomb testing was 2 days before the presidential election, and the people sent this guy down to the Marshall Islands to convince the bomb people to have some 'technical difficulties' and delay the explosion a few days just in case the next president had a different opinion than Truman. So the guy goes down there talks to a bunch of people and then they say whatever, you're call dude. But then the guy doesn't want Truman to be mad at him, or something, so he says go ahead and explode it as normal. Wtf dude, history is counting on you!

WTF moment 3: There really were thousands of Russian spies all over the U.S. in the 40s. I'm interested in whether the Red Scare was a bit more based in truth than I thought? Also though, something that came up several times in the book is if you are a weird / socially difficult person, than others will use politics to remove you from power, citing your opposing views, lack of management skills, past connections to political groups, etc. Some of the spies and many people with soviet sympathies had no idea what was actually going on in the country, but were more passing along information because they hoped it would be helpful to this idealistic movement.

The first computer program run on an electronic computer --- ENIAC --- was a monte carlo simulation of a thermonuclear explosion, as von Neuman was trying to figure out the feasibility of the weapon.

WTF moment 4: The United States bombing of North Korea had about 1.5-2 million casualties, about the same number as all of the Japanese casualties in WW2. They destroyed 10-100% of the largest 20 cities or so, looks like maybe 60% on average. Basically all urban areas were bombed. In general I feel like I have more empathy for those guys in Idaho that live in bunkers in the middle of nowhere.

psuedo WTF moment 5: An unarmed atom bomb exploded on the runway about 30 miles from San Francisco when it was taking off to go to Korea. (There was an accident and the plane crashed on takeoff) At first I thought this was a big deal, but then I realized that an unarmed A-bomb is mostly just a bunch of normal explosive without the plutonium core to arm it. It did throw normal U-238 around the runway, which just seems like a regular, normal level of military fuckup. Now I hope that planes don't crash when they fly armed bombs.

I don't think these are necessarily the moments that are going to stay with me, but I sort of have to process them before I can start thinking about what the arms race was doing and why it occurred, and the similarities between Los Alamos and other technology organizations.

Not as good of a book as the making of the atomic bomb, but I still learned a bunch and it gave me lots of feels on several topics so 5*.

[Richard · Rating 4 out of 5]

Richard Rhodes described the beginnings of the atomic age in his "The Making of the Atomic Bomb." The scientific-military Manhattan Project was born of the necessity to beat the Nazis into production of atomic bombs and ended with their use by the United States against Japan. "Dark Sun" tells the history of nuclear bomb development since that time. It contains a wealth of scientific descriptions, such as a discussion of the physics of thermonuclear (TN) devices and their construction (e.g., Teller's "Alarm Clock design compared with Sakharov's "Layer Cake" hydrogen bomb), but the lay reader will find the book easily understandable and informative. This book is in a way more interesting to read than Rhodes' earlier book, containing a detailed description of the spying which produced the Soviet atomic bomb.

"Dark Sun" starts before the chronological ending of Rhodes' "The Making of the Atomic Bomb." The United States was sending thousands of tons of material to Russia during World War II in order to help its wartime ally fight Germany. The Roosevelt government had actually granted Lend-Lease to Russia after Hitler had invaded that country, and before the United States entered the war. Lend-Lease (the shipment of war material without prior payment by the receiving nation, with promise to pay somewhere in the post-war future) had been devised by Franklin Roosevelt as a means of helping Great Britain to survive after the war started in 1939.

The interesting thing about this arrangement was that the Soviets were using this conduit of weapons and materials as a means of carrying out an espionage program in the United States. I had not realized until I read this book how much the Russians were taking advantage of this situation. Huge quantities of industrial information and even strategic metals passed under the lax noses of U.S. customs and went to Russia during the war.

This espionage system became the vehicle for Soviet spies and secret agents to make contact with scientists working on atomic bomb development in the United States and England, most notably at the Los Alamos atomic laboratory in New Mexico. Joseph Stalin had ordered the start of atomic bomb development in his country in early 1943. Physicist Igor Kurchatov was placed in charge of the scientific program, which was patterned after the American program since it was able to use tested and tried methods stolen from Los Alamos. The secret materials were obtained in the United States through agents of the intelligence apparatus established by Lavrenti Beria, the head of Stalin's Secret Police. There were several Los Alamos workers selling secrets to the Soviets, but chief among them was Klaus Fuchs, a German emigre scientist working for the British at Los Alamos. Fuchs had knowledge of all atomic development secret processes and sent everything he knew to Beria's operatives. Machinest David Greenglass, Ethel Rosenberg's brother, passed along drawings of implosion bomb designs through operatives working with his brother-in-law, Julius Rosenberg. Harry Gold was part of the Greenglass/Rosenberg connection; Ethel's actual involvement or lack of it still remains hotly contested among historians and surviving family members. Others who engaged in spy activity for the Soviets included Steve Nelson, Haakon Chevalier, Israel Halperin, Morton Sobell and Alan Nunn May.

The Soviets were receiving so much good atomic intelligence that Beria and Kurchatov suspected American intelligence was deliberately trying to redirect them with bogus information. They confirmed the veracity of the information by checking the data from one source against another, but the pressure of having a good part of World War II being fought on their soil kept Russia from going full steam with their bomb program until after the war. The United States government was stunned to discover that the Russians detonated their first bomb, a copy of the U.S. Trinity bomb (the first atomic bomb ever detonated, in July 1945), on August 29, 1949; earlier estimates were that Russia would need upwards of twenty years to develop an atomic bomb.

Rhodes paints a picture of this immediate post-World War II period as a time when history could have taken different directions and ended up with different outcomes; he makes it clear that the way things actually happened, involving decades of nuclear arms race, were not the optimum result. The post-war years saw the United States building up a stockpile of atomic bombs that it initially felt it had a monopoly on; President Harry Truman acted in accordance with a policy of "containment" that attempted to check the perceived expansionism and paranoia being displayed by the Soviet Union. Winston Churchill's "Iron Curtain" speech of 1946 confirmed that our old wartime ally was now our rival. Things became more strained among the former war allies when the Truman Doctrine announced the future Cold War doctrine of the need to support free people resisting subjegation, clearly aimed at Soviet expansionist activities. Russia answered this in less than a year with the Soviet occupation of Prague on February second, 1948; the end of US-USSR collaboration, including the end of any chance for nuclear disarmament negotiations can be dated from this point. The first Cold War confrontation occurred shortly thereafter, with the Russian blockade of Berlin in June 1948, which was combatted and finally defeated in May 1949 by the allies' Berlin Airlift.

Rhodes seems to argue that the fear and paranoia over the beginning of the Cold War caused the scales of military policy to tip in favor of the war hawks who brought on the greatest arms race in history. Rhodes is completely aware that deteriorating relations among the former World War II allies were a fact of life and would cause considerable post-war problems. He also is not a Luddite. His view, which seems to be alligned with Robert Oppenheimer's view of the development of nuclear weapons, is that the building of the atomic bomb by the United States was a necessary and spectacular scientific/military achievement. (Reviewer's note: Oppenheimer pointedly did not join some of his former Los Alamos colleagues who, postwar, expressed guilt about their involvement in the development of nuclear weapons). This philosophy does not, however, embrace the arguments made by atomic scientists like Ernest Laurence, Luis Alvarez and Edward Teller that the United States should have gone into a crash program to develop thermonuclear bombs (from Rhodes' "Arsenals of Folly, The Making of the Nuclear Arms Race, Vintage, 2007, p. 70: Bombs made by fusing hydrogen to helium, releasing enough nuclear energy to dwarf fission weapons, i.e., with fireballs measured in miles rather than feet, and their yields measured in megatons, or millions of tons of TNT equivalent explosive power, instead of in kilotons, or thousands of tons of equivalent TNT). More pertinent, the policies which called for the eventual building of literally thousands of nuclear and TN bombs are questioned.

Historically, that argument is over. Harry Truman gave the green light to proceed with TN development in January, 1950. This was the same month that Fuchs was convicted of espionage. Julius and Ethel Rosenberg and others were also arrested for espionage; the Rosenberg's were later convicted and sentenced to death. Numerous international developments helped to support Teller's H-Bomb rationale at this time, including the Russian and Communist China-supported invasion of South Korea in June 1950. Senator Joe McCarthy was capitalizing on the public anxieties arising over these troubling examples of threats to the American way of life by ratcheting up the Red Fever with his ever-growing lists of (never disclosed) supposed federal government employees who were working for the Soviet Union.

Rhodes' main point is that nothing good came from the transition of Los Alamos National Laboratory into a post-war perpetual builder of WMD for the arms race. He asserts, along with Oppenheimer, that the United States could have been amply served by a military which relied on a mix of conventional weapons and smaller, tactical battlefield nuclear weapons (Reviewer's note: So-called "Theater" weapons with more limited explosive power than TN weapons, intended for use primarily against military instead of civilian targets). Having thousands of nuclear weapons available, at an eventual total cost to the United States alone of four trillion dollars, only caused the possibility of world destruction while contributing nothing to our ability to enhance the outcome of the wars we have fought since World War II.

For the record, the United States detonated its first Hydrogen Bomb in the South Pacific on November 1, 1952. The Soviets exploded their first Hydrogen Bomb in November, 1955. Their bomb was developed by physicist, and future peace activist Andrei Sakharov. Rhodes does not discuss how the Russians obtained the information to build their bomb. I checked this on the internet and apparently no definitive records from the old Soviet Union in this regard have been made available to researchers of this subject. There is speculation that Soviet scientific analysis of fallout from U.S. testing at Bikini Atoll in 1954 provided key information; another possibility is that Sakharov solved this puzzle through his own knowledge of physics.

[Peter Tillman]

Added this to the long-term TBR list. I liked his first Making of the A-bomb a lot.

I came across this quote from the book:
"The discovery in 1938 of how to release nuclear energy introduced a singularity into the human world — a deep new reality, a region where the old rules of war no longer applied. The region of nuclear singularity enlarged across the decades, sweeping war away at its shock front until today it excludes all but civil wars and limited conventional wars …

Science has revealed at least world war to be historical, not universal, a manifestation of destructive technologies of limited scale. In the long history of human slaughter, that is no small achievement."

The context being the surprising peace-keeping power of nuclear weapons: no nuclear-armed state has attacked a nuclear-armed adversary. So far, anyway.

That would be the book I would like to read. Which, of course, is a hypothetical. Hard to prove a negative! Still, suggestions welcome!

[Dan · Rating 5 out of 5]

An excellent follow up to Rhodes' Pulitzer winning 'Making of the Atomic Bomb'. This one is about the history and development of the Super Bomb. This tome contains a great deal of espionage and less physics than the first one but it is still quite dense and took me some time to read it.

5 stars. Highly recommended.

[Hirondelle (not getting notifications)]

I loved The Making of the Atomic Bomb. Considering this, though if I do it will not be anytime soon. And I just might not, I am not sure I am up to more Szilard, Oppenheimer and Teller...

[Michael Burnam-Fink · Rating 3 out of 5]

The hydrogen bomb is the natural sequel to the atomic bomb, but Dark Sun is a shadow of its predecessor, and Rhodes can't find a single narrative thread in this trudge of a history.

The individual pieces are there, the transformation of the American atomic complex from a handful of scattered parts in the late 1940s to an instrument capable of killing a nation in 1955 is a fascinating story of bureaucratic transformation. The Teller-Ulam device is a masterpiece of precision engineering, directed towards evil ends. And there are personalities aplenty, from Teller to Oppenheimer to Curtis LeMay. The Russian atomic bomb effort was guided by plans stolen from Los Alamos by Klaus Fuchs, and the Rosenbergs paid with their lives for their minor part as couriers. Yet, I had no real sense of the people, or the uncertain time of the age. I love this stuff, and this book was a struggle to get through.

[Jonathan Mannhart · Rating 5 out of 5]

What I don't like about this book is that they built a bigger bomb.

But this is not the author’s fault, so I can't really blame him. Great historic record. Five stars.

[Ben · Rating 3 out of 5]

While parts of this were very interesting, it was overall much weaker than the first book. I think what I liked most about the first book was Rhodes's description of the science and engineering that went into building the atomic bomb. There is some of that here, but significantly less. There is much more about Soviet spying---material which is somewhat dated and, to me, pedestrian. Rhodes also tries to quickly go over the history of US policy on nuclear weapons, but it is too brief and has been covered better elsewhere.

> A nuclear reactor generates far more neutrons than a cyclotron. That higher neutron flux had transmuted more of the uranium in the reactor to Pu240. The spontaneous fission rate of reactor-produced Pu239, with its greater admixture of Pu240, turned out to be five times greater than that of cyclotron-produced plutonium, unacceptably high for gun assembly. Even at the highest attainable muzzle velocities, a plutonium bullet would melt before it had time to mate with a target assembly. By July 1944, when Fuchs talked to Chadwick, Los Alamos had decided that the plutonium gun would have to be scrapped.

> If the information that plutonium bred in a natural-uranium reactor could be a shortcut to the bomb was the first Anglo-American breakthrough that the Soviet espionage network delivered to Soviet scientists, the information that implosion was superior to gun assembly was the second. But whether this information came from Alan Nunn May or from some other source, as yet unknown, the declassified Soviet record does not reveal. It almost certainly did not come from Klaus Fuchs

> Serber remembers, "on Edward Teller's blackboard at Los Alamos I once saw a list of weapons—ideas for weapons—with their abilities and properties displayed. For the last one on the list, the largest, the method of delivery was listed as ‘Backyard.' Since that particular design would probably kill everyone on earth, there was no use carting it elsewhere."

> the British were preparing secretly to build their own atomic bomb, and what Fuchs knew was valuable to them. He thus became a vector for nuclear proliferation to England as well as the Soviet Union. "He is the only physicist I know who truly changed history," Hans Bethe comments

> The three production reactors at Hanford had sickened with what came to be called "Wigner's disease" (after the Hungarian-born theoretical physicist Eugene Wigner, who designed the reactors and predicted the effect): graphite bombarded intensely with neutrons stored the acquired energy by rearranging its crystal lattices, which caused it to swell and occlude the reactor fuel-element channels

> Arkadi Admovich Brish, personally repaired it. Brish, twenty-nine in 1946, "blond, with gray eyes nearly the color of steel" in Zukerman's recollection, later the director of a leading institute, was a man so vigorous that the Sarovians cooked up a unit of productive activity—the Brish—in his honor and measured their own contributions comparatively in milli- and micro-Brishes.

> Theoretically, lithium in a bomb would pick up neutrons from D + D reactions or from fission and make tritium in situ; the T would then react with D, releasing energy and making more neutrons, which would repeat the cycle. The advantage of using lithium in a thermonuclear device would be at least twofold: it would generate tritium at hand, reducing or eliminating the need for incorporating expensive reactor-bred tritium into the design; and it was a solid at room temperature and did not require maintaining within a bomb at several hundred degrees below zero (with all the elaborate bottling and insulating that would entail) as liquid deuterium did. But lithium deuteride had the serious disadvantage that its Z was three times that of deuterium; it radiated at nine times the rate of the hydrogen isotopes and therefore appeared to be far more difficult to ignite

> San Francisco was another favorite target; SAC once faux-bombed it more than six hundred times in one month

> Mao at that time was planning an invasion of Taiwan, for which he had a promise of Soviet support. (Truman had announced on January 5 that the US would not intervene in Taiwan, a point Mao had taken to heart.) If Mao expressed fear that the US would defend South Korea, he would have to admit the possibility that the US would also defend Taiwan, in which case the Soviets would certainly back away from their promise. Rather than take that risk, Mao tepidly endorsed Kim's adventure. … Dogged by delays, Mao was forced to put his Taiwan invasion on hold—permanently, as it turned out. If there had not been a Korean war in the summer of 1950 there might well have been a Chinese war between the United States and the People's Republic of China.

> Chemical explosives were inadequate on two grounds: they blew material into the thermonuclear fuel that would probably quench the thermonuclear burn entirely, and they could not generate sufficient compression to make a useful difference in the thermonuclear reaction rates. Ulam's "iterative scheme," says Mark, "changed all that."

> How original were Ulam's and Teller's ideas? Who should receive more credit for the breakthrough? Opinion among knowledgeable participants and observers ranges far and wide. Bethe assessed the Teller-Ulam invention of staging and compression most generously … What Ulam did was not a thermonuclear device. It was a general idea. What Teller did was convert that into something which was a sketch of a Super that would work. Teller sketched out a super bomb. Ulam simply presented a fairly general idea in dealing with that topic. I think Teller has slighted Ulam, but I think also Teller does deserve fifty-one percent of the credit. Ulam discounted the originality of the invention late in life, but by then Teller had worked for years to deny his colleague's contribution … It's true that Ulam thought that you could use … hydrodynamic shock. That's certainly there too. It doesn't move as rapidly as radiation does. It's harder to control and direct. So if you were trying to exercise Ulam's idea of using hydrodynamic shock you'd find, by God, radiation gets there first. Teller then is supposed to have proposed that it would be better to use radiation than to rely on [material shock]. Well, he was right, it was simpler, but you couldn't have avoided it. Had you sat down to design the thing, asking, now, what's the material shock doing, where is it, how fast does it move? You'd say, dear God, the radiation is going faster, it's there, so let's concentrate on that. So it was hardly an important circumstance that Teller thought of radiation whereas Ulam thought of … material [shock].

> Teller added a crucial additional stage to the Teller-Ulam configuration: a second fission component positioned within the thermonuclear second stage to increase the efficiency of thermonuclear burning. … Teller realized that a subcritical stick of U235 or plutonium, positioned where the sparkplug would form at the center axis of the deuterium cylinder, would be compressed to supercriticality by the leading edge of the imploding shock wave. This second fission explosion would then push outward against the implosion that was pushing inward; with careful design, the main implosion and the sparkplug explosion might be made to come to equilibrium, stabilizing in a hot, highly compressed critical layer that would advance outward through the deuterium fuel mass and burn it much more efficiently and completely than could an unboosted sparkplug alone. Teller called this design "an equilibrium thermonuclear gadget" in a report he signed on April 4, 1951; he claimed it in the report's subtitle as "a new thermonuclear device."

> the Teller-Ulam invention—staging, implosive fuel compression before ignition and a fission-boosted sparkplug—as its ingenious principal mechanism.

> The disadvantage of pure deuterium was that it would have to be maintained below its boiling point of 23.5 degrees Kelvin 2 to remain liquid; that meant the test device would have to incorporate sophisticated insulation and a cryogenic cooling system. … Holloway's team soon settled on liquid deuterium despite its engineering challenges, Carson Mark reports, primarily because it would give the cleanest physics

> More than 75 percent of Mike's yield, about eight megatons, came from the fission of the big U238 pusher around the secondary; in that sense it was less a thermonuclear than a big, dirty fission bomb. Fission-fusion-fission, the staging arrangement came to be called. If Los Alamos had devised a way to burn unlimited quantities of thermonuclear fuel, it had also devised a way to burn unlimited quantities of cheap ordinary uranium.

> The hydrogen bomb … would be a most important event in worldwide policy. And that scoundrel Beria allowed himself to make this decision outside of the Central Committee. Evidently Beria had been confident enough of his ascent to power to assume that he would command sole authority by the time the thermonuclear design was ready to be tested, in August 1953.

> It was expected to yield about five megatons, but the group at Los Alamos that had measured lithium fusion cross sections had used a technique that missed an important fusion reaction in lithium7, the other 60 percent of the Shrimp lithium fuel component. "They really didn't know," Harold Agnew explains, "that with lithium7 there was an n, 2n reaction [i.e., one neutron entering a lithium nucleus knocked two neutrons out]. They missed it entirely. That's why Shrimp went like gangbusters." Bravo exploded with a yield of fifteen megatons, the largest-yield thermonuclear device the US ever tested

> You know, he [Oppenheimer] is one of the most amazing men that the country has ever produced in his ability to influence people. It is just astounding the influence that he has upon a group. It is an amazing thing. His domination of the General Advisory Committee was so complete that he always carried the majority with him, and I don't think any views came out of that Committee that weren't essentially his views. … Many of our boys [at Berkeley] came back from [wartime Los Alamos] pacifists. I judged that was due very largely to his influence

> Oak Ridge and Hanford doubled in size. Two vast gaseous-diffusion plants came on line, drawing more power than the Tennessee Valley Authority and Hoover, Grand Coulee and Bonneville dams could have delivered in concert; by 1957, the AEC consumed 6.7 percent of total US electrical power. … Building the new production complexes required more than 11 percent of annual US nickel production, 34 percent of stainless steel, 33 percent of hydrofluoric acid. From $1.4 billion in 1947, AEC capital investment increased to almost $9 billion by 1955, exceeding the capital investment of General Motors, Bethlehem and US Steel, Alcoa, DuPont and Goodyear combined

> SAC had reconnaissance aircraft flying secret missions over the Soviet Union twenty-four hours a day, he explained. "If I see that the Russians are amassing their planes for an attack, I'm going to knock the shit out of them before they take off the ground." Sprague was shocked. "But General," he countered, "that's not national policy." Sprague remembered LeMay responding, "I don't care. It's my policy. That's what I'm going to do." Wiesner says LeMay responded, "It's my job to make it possible for the President to change his policy"—a less insubordinate answer, but only barely

> More dangerous by far than all these incidents was Curtis LeMay's overconfident and belligerent advice to President Kennedy, whom he believed to be a coward. Knowing that the US and the USSR were approaching mutual deterrence and that SAC was therefore a wasting asset, LeMay pushed Kennedy to up the ante, bomb Cuba and take out the missile sites. … When the President questioned what the response of the Russians might be, General LeMay assured him that there would be no reaction. President Kennedy was skeptical. … contrary to CIA estimates, the Soviet forces in Cuba during the missile crisis possessed twenty nuclear warheads for medium-range R-12 ballistic missiles that could be targeted on US cities as far north as Washington, DC, as well as nine tactical nuclear missiles which the Soviet field commanders in Cuba were delegated authority to use—the only time such authority was ever delegated by the Soviet leadership.

> it was Edward Teller, not Robert Oppenheimer, who had delayed the development of the hydrogen bomb. He did so by defining that device from the beginning as a mechanism for achieving megaton-range yields. His characteristic grandiosity blinded him to the more modest possibilities of his Alarm Clock, which was inherently physically feasible and practical at high-kiloton yields

[Ian Mewhinney · Rating 4 out of 5]

This was an outstanding historical nonfiction book as expected. Amazing narration from Grover Gardner on the audiobook, I found a tape rip. A lengthy read at 29 hours on the audiobook, but it has good pace and structure in the book. Not as heavy on the dry physics as the "Making Of The Atomic Bomb" by Rhodes. This was a lot more political than the first book. The whole first part covers a refresh of the original fission designs, but also focuses on the USSR espionage with the Rosenbergs and David Greenglass who were spies. It also includes the shift in ethical view changes of the physicists who were on the Manhattan Project, who were still consulting while going back to their PhD teachings. The second part continues into development of the theories for 2 stage thermonuclear designs and the struggle of deciding where to focus their production of materials like deuterium for fusion, and compares the nuclear arms race of the cold war very well. It goes into great detail of 2 of the US tests: Ivy Mike and Castle Bravo. 2 different designs, and also the most well known/documented in media. Surprised he didn't touch on Tsar Bomba near the end. Also had a full account of the trial of J Robert Oppenheimer and the stupidity of McCarthyism. He was basically set up, he was accused of trying to delay the US from winning the arms race, even though he just had a change of heart after seeing the power of the WWII bomb yields. Maybe I need to find a Soviet nuclear history book sometime to get a better picture of the other side. 4.25/5

[James Veliky · Rating 5 out of 5]

I pulled this book off the shelf after twenty- eight years. I bought it in 1995 at Walden Books(remember them). I was motivated to read it after seeing the Christopher Nolan film -“Oppenheimer”. This dense work took me six months to read- it almost killed me. Great book about the making of the hydrogen bomb from both sides of the Cold War. A lot of great understanding of history here- a lot of it that I lived through as a boy( the Cuban Missed Crisis).
If the names of the Russian and Hungarian physicists and generals weren’t so long this book would be about fifty pages shorter(smile).
Thank you Richard Rhodes. You are great.

[Kris · Rating 5 out of 5]

A story of science, politics and espionage. The major players are drawn in almost novel level detail. It’s a bit too thorough to be a constant page turner, but as a work of history it is informative and entertaining.

[Volo Bonetskyy · Rating 5 out of 5]

Mix of history after WWII, cold war and nuclear physics of the hydrogen bomb (like the first atomic bombs weren't enough). Many crazy stories about politicians, scientists and army.
"Now I am become Death, the destroyer of worlds.", as Oppenheimer quoted Bhagavad Gita.

[W K · Rating 5 out of 5]

Excellent read...can be too detailed at times, but well written history of a complex subject.

[Andrew Sternisha · Rating 3 out of 5]

Does a nice job showing the conflict between civilian leaders and military leaders, Lemay in particular, on nuclear policy in the US.

[Mac · Rating 3 out of 5]

Borrow.

Authoritative, scientifically literate, and tracks the key figures and their personalities well. The first two hundred pages, however, feel almost like they belong in another book as they focus almost entirely on Soviet espionage. The source material is impressive but it nonetheless feels out of place at the depth it's shared.

[Matt Gallant · Rating 5 out of 5]

solid country gold yet again

[Pablo Bilbao · Rating 5 out of 5]

Thanks, Diogo, for such a great book.

A fantastic and detailed account of the development of the hydrogen bomb and the arms race during the Cold War. It's packed with espionage, twists, and a significant amount of well-explained physics.

Characters like Teller, Neumann, Fuchs, Szilard, and Rabi, with their quotes, bring the situations vividly to life.

[U · Rating 4 out of 5]

Overall, the book is an excellent overview of Russian espionage in the scientific community and describes the history and making of the hydrogen bomb. I’ve gotten to know many individuals throughout the book, including the two most in intriguing folks (in my opinion): Klaus Fuchs and Robert Oppenheimer. I enjoyed reading their testimonies and seeing Oppie’s involvement in the physics community at Los Alamos. The book’s other ‘plot’ is this race between the USSR and America. Again, intriguing to see the views of so many scientists, but sometimes saddening to see politics get in the way of other innovations. The discussions about Bikini, Joe bombs (with Stalin and Sakharov’s views), giddy Russian spies turned sentenced individuals, the end result of not having to go through with full blown WW3 nuclear warfare while still being vigilant and ahead of the Soviets in some way (in particular, someone believed Cuban missile crisis was a loss for the US, that we didn’t act upon the destruction correctly, baffled me. As stated, lives were lost and it would have only been worse if we didn’t do what we had), beginnings at Los Alamos and Uranium research, and the firing of the Mike all made this an entertaining and informative read. You’ll see the realities of nuclear development and raw emotions of physicists and politicians alike. It’s long, did get a bit repetitive, and jumped around from Soviet to US views but I actually quite liked that.

[Daniel · Rating 5 out of 5]

Not nearly as much scientific meat on this bone as in Rhodes' previous book, all-time classic The Making of the Atomic Bomb. But there is a substantial amount of espionage and historical context to keep your interest, should that be your thing. I did spend a lot of time asking perplexity questions, though, to fill in a lot of the science dots, so I still feel like it was an extremely productive learning experience, even if some of it was outside the book proper.

[Angelo · Rating 5 out of 5]

Uma extensa pesquisa produziu um mapa completo não só da criação das bombas de hidrogênio, mas também da geopolítica do pós guerra, com o surgimento da guerra fria e da corrida nuclear, com as consequências conhecidas , como a queda da URSS e o abandono de políticas sociais nos EUA.

[Alan Gerling · Rating 4 out of 5]

After recently reading Hiroshima Nagasaki, I found myself curious about how the hydrogen bomb was developed and tested. Amazon recommended that I read Dark Sun. I started the book in the background (theology and some other reading took priority) several months ago and have been chewing on it ever since. Spoiler, this book is not short! I read almost everything electronically, but if you were to pick up the paperback, it's 700+ pages long.

I've been chewing on it for a while. However, you'll notice that I am writing a review, so the book never ended up in my "abandoned" pile. My continuing curiosity always caused me to pick it back up and read another chapter. The latter chapters do pick up (I kind of got the impression that Rhodes was running out of space). The earlier chapters are really devoted to understanding the science and people essential to the atomic program in the US and USSR.

Rhodes writing style is all over the place. He seems to be unable to resist following a tangent or packing in every bit of his research. The hydrogen bomb isn't really discussed until the final third of the book. Rhodes also clearly has a fascination with the espionage, spending significant time discussing the various Soviet espionage efforts, the FBI investigation of those efforts, and the trials resulting from those investigations. He honestly could have written a completely separate book, as I failed to see how much of this espionage narrative supported the main subject of the book, the design of the hydrogen bomb. 

Also, a large part of this book is trying to understand the deterrence and arms race between the US and the USSR. He brings this all to bear in the Epilogue, showing the futility of the nuclear arms race, which cost the US 4 trillion dollars, and was a large factor in the financial breakdown of the USSR. I found this quote from Solly Zuckerman to be particularly relevant to today's news cycle:

"In light of the certain prospect of retaliation, there has been literally no chance at all that any sane political authority, in either the United States or the Soviet Union, would consciously choose to start a nuclear war. This proposition is true for the past, the present and the foreseeable future.... In the real world of real political leaders . . . a decision that would bring even one hydrogen bomb on one city of one's own country would be recognized in advance as a catastrophic blunder; ten bombs on ten cities would be a disaster beyond history, and a hundred bombs on a hundred cities are unthinkable."

I don't know about you, but the words, "sane political authority" send shivers up my spine. I'm not sure with North Korea, we're dealing with a "sane" leader. He does build a convincing case though, particularly following the Cuban missile crisis, that the arms race and nuclear build-up was not only counter-productive but really in many ways defied any logic. 

Looking at the book as a whole, I would recommend it, particularly for someone who is a history buff. I suggest that perhaps you pretend the title of the book is something like, Dark Sun: A History of the Nuclear Arms Race of the 20th Century. If you pretend thusly, the book would be quite excellent and on target!

[William Hamman · Rating 4 out of 5]

It is best for me to regard "Dark Sun" as a direct sequel to "The Making of the Atomic Bomb", because that's exactly what it is. "Dark Sun" presumes that you're read the other book, so it doesn't recapitulate much of the physics or history of the atomic bomb. It only has one reasonably technical section at all, a lucid and clear description of X-ray ablation and pusher recoil as it pertained to the Ivy Mike weapon.

The rest of it is largely concerned with Soviet espionage, the history of some aspects of the Soviet bomb program, and a lot of political wrangling that led to, in the end, the adoption of MAD as national policy and the to my mind unfortunate decision to turn on Oppenheimer. (I don't really mean to editorialize in a review, but MAN did I ever get sick of Edward Teller and his cohorts after a while.) Given that much of the Soviet bomb program is probably still classified by the Russians, and that we'll probably never know what information the FBI gathered illegally about the Rosenbergs and Oppenheimer, this is probably about as close to the truth as I'll ever read.

Perhaps the most ominous part of the book, for me, was finding out just how much LeMay and Power (as commanders of SAC) really wanted a nuclear war with the Soviets, to the point of being willing to provoke the Soviets on their own hook to push Truman or Eisenhower into a war they didn't want. At times it all seems like ideas that were dropped from the script from "Dr. Strangelove" and you think (or perhaps merely hope) that it couldn't possibly have really been that way, but the book is so authoritative that it's hard to maintain disbelief.

Having read two hefty, authoritative, and comprehensive books on atomic and thermonuclear weapons in a row, I think I'm going to look for something lighter in my next book - "Hello Kitty", possibly.

[Greg Brown · Rating 4 out of 5]

Rhodes' book on the history of the atomic bomb was a masterpiece; this, on the buildup to the hydrogen bomb, is merely excellent.

The first book has the benefit of a strong through-line and a nice dramatic arc as splitting the atom went from imaginable to possible to inevitable. Reality was more messy for the topics covered here, with Rhodes having to backtrack somewhat to cover Soviet spying on the Manhattan Project that accelerated and enabled their own atomic bomb breakthrough. The American side was somewhat stalled after World War II, only kicked back into action by Soviet progress and the building Cold War tensions and even then plagued by dead ends.

Rhodes does a great job with what he's given, and the benefit of writing this one after the end of the Cold War when Soviet archives and testimony became more widely available. The scientific explanations are as clear and fascinating as ever, and the characters vividly rendered enough that I even grew to hate Strauss and Teller by the very end. And as usual, some of the anecdotes are breathtaking. Highly recommended after you've read Rhodes' first entry in the series, and I'm excited to read his two follow-ups: TWILIGHT OF THE BOMBS and ARSENALS OF FOLLY.

[Brian · Rating 4 out of 5]

Richard Rhodes follow up to The Making of the Atomic Bomb provides a detailed history from the Manhattan Project to the development of the H-Bomb (Super) by both the Americans and the Russians. The book starts out with about 80 pages of summary on the Manhattan Project focusing mostly on the Soviet espionage as it relates to the Soviets development of the A Bomb and the push then by the Americans to invest in the development of the Super. From a detailed account of the spying done by the Rosenberg’s spy ring and Klaus Fuchs to the drama of Edward Teller and Robert Oppenheimer over the moral development of the H-Bomb you will find it all in this account. The discussions that were held by the sciences over building a bomb that could end all life on earth (never pursued) to the final tests that vaporized an island in the south pacific and once again infected a group of Japanese with radiation are all covered. Russia is not left out and the efforts of Beria and eventually Khrushchev’s diplomacy are well covered. In short like his first book this is a thorough account of the development of the Hydrogen Bomb on both sides of the Cold War.

[Todd Stockslager · Rating 4 out of 5]

Rhode's history of thermonuclear weaponry is well written, but the subject seems oddly dated, as if the "Cold War" and the terrors of atomic attack were something from centuries ago, not from my lifetime. The fear, dread, paranoia, and hysteria were very real and very recent, and it is only surely by the restraining hand of God in human history that it continues. Or, as Rhodes concludes, the greatest and only effective deterrent against nuclear war was "personal dread."

This abject and groveling fear in its own way changed history, shaping national policy during the Berlin crisis, the Cuban Missile crisis, in Southeast Asia, and 100 other small places. It made otherwise rational leaders envision and propose a plan to hide nuclear-tipped missiles in train cars and shuttle them continuously around the US--a plan that was proposed in my adult life time (late 70s and early 80s), and seemed positively Gothic (seemingly impossible, yet substantially real) in its horrific nature when I confronted it 20 years later in the display of one of the railroad cars and disarmed missiles in the museum at Wright-Patterson Air Force Base. "Personal dread" indeed

[Mike · Rating 4 out of 5]

Dark Sun is about much more than the bomb itself. It's really a history of the era -- the actions of the US and Soviet weapon builders, the spies who traded US secrets to the Soviets (during and after WWII), the ever-increasing requirements by US military planners for more bombs with ever-increasing power, and the main incidents of the cold war from the end of World War II until 1955, with a brief final flare-up during the Cuban missile crisis (the closest that either side ever came to launching a nuclear attack).

If you're interested in reading this, presumably you've already read Richard Rhodes's classic book The Making of the Atomic Bomb. It's a masterpiece--it presents multiple threads of activity coherently and does a singularly good job of explaining the physics, and the struggle of the physicists, as they race to build the first atomic bomb.

When this book starts, it initially feels like the unused leftover notes from his first book, as it details the espionage efforts of the Soviets and Soviet agents to steal the plans and the methods for producing the appropriate atomic materials and building an atomic bomb. Since this espionage started during the Manhattan project, it's necessary to step again through various aspects of the Manhattan Project and the various projects around it creating and supplying raw materials. This is the first of many points that this book, though theoretically self-contained, should be read as a sequel to The Making of the Atomic Bomb. Go and read that now, before attempting this.

Those espionage efforts -- of Klaus Fuchs, of Harry Gold, of Julius & Ethel Rosenberg, etc. -- are laid out in excruciating detail. The book jacket implies that the extent of their espionage would be new information to the general reader, and perhaps at the time it was written Rhodes did need to back up narrative with so much detail, but now it just seems excessive.

Equally detailed is how the Soviets use the results of their espionage to build their first breeder reactor and their first bomb. This is more harrowing, since the specter of Laventy Beria hangs over the heads of all the physicists attempting to build the bomb -- if it didn't work they were likely to all be shot.

With the Soviet testing of their first atomic weapon, this really kicks off the story of the hydrogen bomb. In response to the test, the US builds more atomic weapons and in tandem the Air Force's assessments for the number of bombs needed to attack and destroy the Soviet Union goes up. The first confrontations of the cold war -- the Berlin Blockade and the Korean War -- up the ante on what US military planners feel is needed. And SAC, as managed by General Curtis Lemay, begins 24-hour flights to allow the US to respond to a Soviet attack at a moment's notice.

As the cold war gets more active, we have the scariest points in the book, that highlight the insanity that was the arms race. The US military digests whether conducting a first strike is actually a rational policy. Lemay and others make plans for carrying out a nuclear attack on their own without a presidential order, if Washington DC were to be destroyed, though the chances of an accident happening seem monstrous. The ever-increasing requests for more and more power to dominate the Soviet Union and obliterate it in one shot. (Never mind the world-wide effects of such an attack.)

The paranoia was real and pervasive, and no politician dare say let's hold back and not just keep building more bombs. Indeed, presidential campaigns used a purported gap between us and the Soviet Union to score political points. And though some physicists and other leaders will caution that the US doesn't really need the hydrogen bomb, these concerns get overwhelmed and in the case of Robert Oppenheimer his career gets destroyed, by those who want to keep building.

As expected, the chief 'villain' of these efforts is Edward Teller--but this book expands on his passion for building ever bigger bombs by also detailing his inability to effectively manage projects that were intended to turn theory into reality. Thus, after the basic theoretical design for the bomb is created, he peevishly steps off the stage to let others do the difficult engineering. But yet, even though he could never have managed the building of a hydrogen bomb, he is known as the 'father of the hydrogen bomb' in the same way that Oppenheimer was the 'father of the atomic bomb'.

Ultimately, there are really just 2 chapters that detail the actual details of the making of the hydrogen bomb, and it's here that Rhodes shines. This new type of bomb was inherently more complicated than the original atomic bomb, in that it is a multi-stage weapon, not just a single implosion. Just as in his first book, Rhodes makes all the details here flow cogently but never simplistically, so that with the aid of some very useful diagrams, one really understands the principles behind the hydrogen bomb. Because this book has a more discursive format and covers much more than just the bomb building itself, this book has much less of these moments than his earlier book did. But thankfully, we do still get them -- it's when he's describing the technical hurdles, the solutions to the engineering problems, and the physics behind the bomb that his prose flows with a understandable and inevitable style. This ability to convey all this information as clearly and naturally as he does provides the main pleasure of Dark Sun.