The+Making+of+the+Atomic+Bomb+Review

__The Making of the Atomic Bomb__ – Richard Rhodes (C. 1986)

Richard Rhodes’s __The Making of the Atomic Bomb__ is a long and detailed work outlining the major breakthroughs in understanding radioactivity and the manipulation of such radioactive isotopes in the efforts of creating massive amount of energy and devastating weaponry. In a few decades the world’s scientific community went from near ignorance of to the understanding and manipulation of radioactive elements for whatever purposes they or their respective countries deemed necessary. In order to manipulate radioactive elements to be used in a new super weapon, they of course had to be understood. It is not until 1939 that Leo Szilard, who at that time had been living in America for a few years, proved that uranium could indeed cause a chain reaction, and was at the same time and with the help of many other Americans in the know, trying to keep it a secret so that the Germans did not find out ( pp. 292-296).

Thus, most of the beginning of the book deals with the incremental advances made by physicists from around the world in the understanding of radioactive elements. A lot of the attention focuses on two men in particular, Ernest Rutherford and Niels Bohr. One of the first big discoveries was made by Ernest Rutherford and Otto Hahn in 1905, that radiothorium, radium and actinium all emitted the same alpha particles. This was later built upon and Rutherford received the 1908 Nobel Prize for his paper stating that all radioactive isotopes released the same charged helium alpha particles. He had demystified the transmutations that radioactive elements seem to go through as they decay (p. 45).

Following up with more experimentation regarding alpha particles, Rutherford and Hans Geiger needed a device which could count individual particles, and they did just that. They created a device that produced audible indications when alpha particles passed through a counting chamber, what we know today as the Geiger counter (p. 47). Rutherford, Geiger and Ernest Marsden began experimenting with the tendencies of alpha particles to penetrate certain objects while being deflected off others (all witnessed by projecting their images onto special screens). As a result of these experiments, they witnessed individual alpha particles colliding, which Rutherford took to mean that atoms have solid nuclei at the center. He published his findings to the public on March 7, 1911 (pp. 45-50). At the time, the structure of the atom was still a mystery. The theorized models of the atom were few and far between and differed greatly between each theory.

One theory belonged to a Japanese physicist, Hantaro Nagaoka, who in 1903 postulated that the atom could best be described with a “Saturnian” model, flat rings of electrons around a positively charged nucleus (p. 50). Rutherford knew this theory could not be true because, while Saturn’s rings were held in place by gravity, positive and negative charges repel. Yet it made no sense: atoms were the most stable thing in the universe but there //had// to be a positive nucleus and the negative electrons were arranged in //some// way which allowed the atom to be stable and strong. Rutherford needed help to properly theorize the true model of the atom (p. 52).

Luckily, working for Rutherford seemed like a dream job to many aspiring scientists. Niels Bohr, who had been working at Oxford’s Cavendish Laboratory under J.J. Thomson, was thoroughly //bored//. With permission he moved to Manchester to work under Rutherford in the spring of 1912 (p. 64).

Bohr was clearly the man Rutherford needed, for Bohr made many discoveries on his own while working under Rutherford. Bohr developed the use of radioactive tracers over several years (used today in medicinal practice and biological research, p. 67), published the radioactive displacement law: that alpha particle emitting elements shift two elements to the left on the periodic table when they decay and 1 place to the right if they emit beta particles (p. 68), won the 1922 Nobel Prize for a paper he published on the model of the atom.

Bohr and Rutherford both knew that classical mechanics could not be applied to understand the atom. Max Planck introduced quantum theory to apply it to thermodynamics, Einstein used it to further understand the forms light takes, and Bohr realized he must apply it to understand the atom. All of these discoveries on the road to manipulating the atom to make atomic bombs is well summarized by Bohr when he tells his colleagues that “’It is wrong to think that the task of physics is to find out how nature //is//’ – which is the territory classical physics had claimed for itself. ‘Physics concerns what we can //say// about nature’ (p. 77).”

Robert Oppenheimer graduated from Harvard and wanted to work at Cambridge under Rutherford, who had taken over in lieu of the elder J.J. Thomson, but wasn’t accepted because Rutherford disliked Oppenheimer’s supervisor, Percy Bridman (p. 123). J.J. Thomson, who perhaps had an eye for talent, was able to “smuggle” Oppenheimer in as a lab worker, from which point he could work his way up. The problem, however, was that Oppenheimer was //terrible// at experimentation and lab work. With no success in the labs and frustration abound, Oppenheimer knew he had to move on. Inspired by Bohr to become a theoretical physicist, he moved to Gottingen, Germany to work. Quantum theory was a popular post-WWI topic and so he collaborated with Bohr on a paper on the quantum theory of molecules. Aside from this major accomplishment, he also published 16 papers of his own between 1926 and ’29 (p. 127). He then moved back to the United States and took up jobs at both the California Institute of Technology at Pasadena and University of California Berkley.

Once again, by 1939 it was common knowledge among the leading American physicists (American used loosely, of course, because with the invasion of Poland in 1939 and tension having been built up in the years before that between the Nazi party and the rest of Europe, many scientists fled to the United States) that chain reactions are possible in uranium 235. They were still unsure of the percentages, but Szilard and others discovered that it was likely over at least over 50% likely. The scientists debated what to do with this information. Most agreed it must be kept a secret so that Nazis would not find out, others foresaw its use in power production and weapons, due to the potential chain reactions and the ensuing massive releases of energy, and others, namely Bohr, doubted entirely that much progress would be in any way with uranium, simply because the 235 isotope was scarce and hard to separate from U238.

It was too late, however. The Germans had easy access to general works regarding radioactive elements and fission. It was just a matter of time before they made their own speculations just as the American scientists had done. It wasn’t long before Paul Harteck, a physicist in Hamburg, thought to apply fission to weapons technology and reported his idea to a Wehrmacht ordnance officer and nuclear physicist through the following message: We take the liberty of calling to your attention the newest development in nuclear physics, which, in our opinion, will probably make it possible to produce an explosive many orders of magnitude more powerful than the conventional ones… That country which first makes use of it has an unsurpassable advantage over the others. (p. 296)

Meanwhile, the new American physicists, also known as the Hungarian conspiracy: Leo Szilard, Edward Teller and Eugene Wigner, along with Albert Einstein, decided it was time to make known the potential advantages and dangers of the new discoveries. With the help of Alexander Sachs, an economist and friend of the president, the physicists wrote a letter and had it delivered to President Roosevelt. Sachs presented the letter to the President as soon as a meeting could be arranged with the busy leader. Roosevelt understands their meaning right away – if a super weapon can be made from fissionable uranium, then they would have to do it before the Nazis could (pp. 308-314).

Ironically, at the same time the Hungarian conspiracy was trying to get a hold of the President, he was thoroughly busy with an anti-bombing campaign. Americans were appalled by the bombing of civilian targets that was taking place in Europe. Shanghai, Barcelona and Warsaw were all too much to take. The entire nation together made movements to stop these actions and invited Great Britain to join, who did, as well as Germany ( who were in the process of still bombing Warsaw to soften It up before the invasion of Poland) (p. 310). In hindsight we can see this is extremely ironic, as only a few years later Americans would aid in the devastating British led firebombing of Hamburg and Dresden and we would, of course, use the atomic bomb on Japan twice.

A subsequent meeting between Roosevelt, the physicists and top military leaders won the physicists a bit of funding to run some experiments and investigate whether an atomic weapon would truly be plausible. Alfred Nier, a physicist at University of Minnesota was already taking the next steps when, in October of 1939 he separated U235 from U238 with a mass spectroscope and began studying which is better for slow neutron fission, which will sustain a chain reaction (p. 317).

Thus many other scientists began pursuing the same answers. Which type of fission of U235 would sustain a chain reaction and give them the energy release they wanted? Slow neutron fission of U238 was deemed impossible, fast fission of it impractical. Slow fission of 235 might be used for power production, but it would not suffice to create a weapon. Otto Frisch and Rudolf Peierls realized that fast neutron fission of U235 would be the only solution, and that a new method could be used to isolate 235: gaseous diffusion of the two isotopes by the use of Clusius tubes. After some number crunching, they realized a small facility packed with these Clusius tube stations could isolate enough U235 for a bomb (p. 323).

Unfortunately, the Germans also came to the same conclusions. They began the construction of Clusius tube facilities and were trying to secure heavy water as a medium from a chemical plant in Vemork in occupied Norway (pp. 326-327). The French, Russians and Japanese also suspected what was going on and began their own work on fission (p. 327). G.P. Thomson formed a committee about the possibility of atomic weapons for Britain. All the members were skeptics, just like Bohr, but they were suddenly made believers with the Frisch-Peierls findings (p. 330).

Alas, Roosevelt’s campaign did not last long. While most bombing targeted airstrips and other military targets, civilians were frequently accidentally caught in the crossfire. With the bombing of Warsaw, however, and both sides outraged at other instances of civilians getting hit, they began intentionally targeting civilians and thus Great Britain and Germany both withdrew from the bombing pact.

In this transition period, an American liaison to the British government, James Bryant Conant, offers an interesting viewpoint after he began helping the British develop gas to fight back against the Germans after the devastation of Ypres: I did not see in 1917, and do not see in 968, why tearing a man’s guts out by a high-explosive shell is to be preferred to maiming him by attacking his lungs or skin. All war is immoral. Logically, the 100 percent pacifist has the only impregnable position. Once that is abandoned, as it is when a nation becomes a belligerent, one can talk sensibly only in terms of the violation of agreements about the way war is conducted, or the consequences of a certain tactic or weapon.” (p. 358) This standpoint is indeed logical, and is similar to the later idea that the atomic bomb does with one piece of ordnance what would normally take thousands of bombers and hundreds of thousands of pounds of ordnance to do.

Heisenberg took up the lead in the German atomic research. Speaking to military leaders, he proposed the practicality and usefulness of nuclear power and weaponry in a February 1942 meeting. He also brings up plutonium, a by-product of a uranium reactor, which can also be used to make powerful bombs. Research for bombs was stopped later in 1942, however, because it was obvious it would likely not be done by the end of the war and there were no cyclotrons in Germany, thus multiplying the difficulties. The military leaders and Hitler agreed that if it could not be finished in time, it would not be a worthwhile pursuit. Many of them also doubted the ability of such a small amount of substance to release such a massive amount of energy. Thus, nuclear fission was pursued only in the interests of energy production. The Americans, however, did not know this and were still racing to get started on their bomb, fearing Germany could very well be in progress with the construction of their own (pp. 403-405). So, American physicists began collaborating, even though there was no official program set up yet. The University of Chicago was happy to host them and offer them their facilities, as they were eager to help in any way they could with the war effort. Oppenheimer communicates frequently with Wigner’s theoretical team here and also begins recruiting some of his own favorites to his own team at Berkley, championing primarily Hans Bethe and Edward Teller, among others (p. 416).

The U.S. government decided to take an official hand in the production of the bomb. Colonel Leslie R. Groves was promoted to General and appointed to oversee the operation (p. 425). The increase in funding and official cooperation from the government was a big plus for the physicists. Enrico Fermi and his team had also just finished their “pile” experiment (early version of a reactor) on December 2nd, 1942, after coming up with the idea one year before and spending months preparing it (p. 440). Groves and Oppenheimer first meet in October 1942 when the General visits Berkley. Oppenheimer immediately expresses the need for a central laboratory for the project to be carried out in and Groves agrees. After much hesitation due to his having dated one and then married another woman, both of whom were known to have been communists at one time, the military higher-ups OK’ed Oppenheimer as the Manhattan Project leader (pp. 448-449). The military and Groves begin searching for a suitable location and eventually find a mesa near Jemez Springs, New Mexico (pp. 455-456).

As scientists from all over the U.S. gathered at the new and still under construction Los Alamos lab, they immediately begin theorizing. Many had varying ideas on how to design the bomb. They wanted the maximum energy possible. Even if their design failed, the bomb itself would not be a complete dud; it would still explode, so there was no fear of the enemy recovering the designs, however, the process of obtaining the U235 and making the bomb would take so long they wanted to be sure there would be no mistake. The problem was, at this early stage, there was no chance for experimentation, and it would all rely on theory (pp. 462-265). After much debate as to the core design, a Caltech physicist and Oppenheimer recruit, Seth Neddermeyer combines the best of all the ideas put forth and suggests an implosion method to trigger the chain reaction. There were many problems with the original “gun” design to trigger the chain reaction, but it was championed by the leading elder physicists like Oppenheimer, Bethe, and Fermi, and thus Neddermeyer’s theory was mostly left alone, with only he and a few others doing scale implosion experiments with conventional ordnance and iron pipes (p. 467).

On May 10, 1943 a review committee gives the official “OK” for Los Alamos, outlining their priorities as 1) Work on the fission bomb 2) Work on a thermonuclear bomb 3) Find methods to purify plutonium (by-product of uranium fission would later be recycled for use in plutonium bombs)

Before this official nod from the government, the scientists were really only discussing the ordnance aspect of the weapon, which none of them knew much of anything about. When they realized things like this, they imported more people. Thus, there were always new employees, continuous construction, scarce water and intermittent electricity in the quickly erected near shantytown. By the summer of 1943, however, Los Alamos was fully operational and experiments were being run (p. 476).

Groves tells the physicists, who are arguing over which methods are best, that they don’t have time to decide. If one method of doing things will definitely work, but another method is more promising, they’re authorized and encouraged to just try everything and maintain them simultaneously. They were in race to make a bomb, and any method that could work should be tried. Thus construction began on new uranium separation facilities to try all three methods in a town called Oakridge in Tennessee, under the guise “Clinton Engineering Works (pp. 486-487). One of the more promising methods was electromagnetic separation. It required the construction of expensive electromagnetic “racetracks” to separate U235 but it had a good output projection. The bad news was they could only work in pairs: a primary Alpha track and a secondary Beta track to refine the separated 235. Many tracks would have to be built to achieve reasonable production rates, and the fact that they had to be built in pairs didn’t help cut costs. Ultimately the silver plates used along the tracks corroded too much and the powerful pumps used to create vacuums in the track were constantly leaking. Suddenly whole tracks began to fail and had to be disassembled and sent away to be repaired, effectively crossing electromagnetic separation off the list (pp. 489-493). So a new facility sprung up, the Hanford Engineering Works along the Columba River starting in early 1943 and was slated to be a plutonium method facility.

Before the bomb was even underway, the physicists were thinking of potential weapons they could make in the time being. When Fermi discovered new isotopes in his reactor experiments like strontium 90, which was highly poisonous and was deposited in human bone in place of calcium, thus made irremovable, the dark Oppenheimer suggested it be used to poison German food, with the result of killing hundreds of thousands. Quoting Rhodes: “There is no better evidence anywhere in the record if the increasing bloody-mindedness of the Second World War than that Robert Oppenheimer, a man who professed at various times in life to be dedicated to Ahimsa (‘The Sanscrit words that means doing no harm or hurt’ he explains) could write with enthusiasm of preparations for the mass poisoning of as many as five hundred thousand human beings (p. 511).” (pp. 510-511).

The war would indeed have to come to a bloody end. In an official press conference where Roosevelt and Churchill were discussing the eventual terms of surrender, Roosevelt accidentally said they would accept nothing short of unconditional surrender from Italy, Japan and Germany. Churchill agreed, even though before the official meeting they decided to leave unconditional surrender out. And so unconditional surrender became part of the Allied policy, something that would only occur after much more bloodshed (p. 521).

After having fled Denmark when the Nazis reoccupied it and spent some time with his son in England, Bohr was shipped off to Los Alamos, where he was welcomed with open arms. Bohr had revealed to Groves one of Heisenberg’s designs for a nuclear reactor. Still paranoid about the German bomb potential, they worried over whether this might be used as a weapon. After some consideration, Bethe and Teller concluded that a reactor does not contain as much energy as its equivalent mass in TNT. In fact, they should have been reassured that they were well ahead of the Germans on any bomb they might have had, considering how different and inefficient their reactor design was (p. 524).

After much debate as to what to do with much of the new atomic research breakthroughs (i.e. to tell the Soviets or not to tell the Soviets), the American projects went underway. Many new plutonium reactors went online, now the primary reliance for U235 separation due to the crippled electromagnetic “racetracks” and the slower gaseous diffusions proved less useful.

In 1945 the Los Alamos scientists still only had the two crude ideas for design of the bomb: “gun” and implosion. James Bryant Conant sought to make improvements in these areas. He estimated the gun design to be the most powerful, but didn’t entirely rule out the implosion method either. He proposed that the smaller implosion design could be used for more surgical strikes while the more massively powerful gun design bomb would be used for the original devastating area effect. Either way, with reactors pumping out U235, they had to get to work on the bomb designs so they could be ready to pack it with the necessary materials when they were all accounted for (p. 561). As if the projected damage which would be caused by the fission gun design weren’t enough, the top physicists at Los Alamos were also investigating the possibility of a thermonuclear weapon as well. Although it was more theoretically confined to paper than even the fission bomb was at the time, they realized if they added heavy hydrogen to the equation, they could make an even stronger bomb, a true super weapon, with a potential projected explosion equivalent to one million tons of TNT and affect 3,000 square miles (p. 563).

In March 1944 Oppenheimer and other Project overseers planned for the first full scale test of the implosion design bomb, which Oppenheimer later codenamed Trinity. The problem with getting the implosion design right was explosions happen in a fraction of a second. They literally had to study the way the shockwaves traveled and deformed the shell and interior of the bomb in order to anticipate whether or not it could truly cause the chain reaction correctly. In order to do this, they devised a blast-house with X-ray equipment and high speed cameras looking in to monitor the explosions (pp. 571-573). While Groves pushed for the real bombs to get underway, rather than dummy test bombs for the flight crews to practice with, The U.S. and Britain began letting loose with conventional bombs. The U.S. was regularly bombing Japanese cities (though leaving “virgin” targets for atomic bombs) and the British massacred Dresden with incendiary bombs.

President Roosevelt died on April 12th. Many of the Los Alamos staff were worried as to whether the Manhattan Project would continue. Oppenheimer kept a cool head and calmed everyone. While Truman was being sworn in as President, Otto Frisch delivered to Oppenheimer his report on the critical mass of the first bomb – Little Boy, which would need multiple critical masses. While it made things a little more complicated, they had a definitive idea of what they had to do, and with the reactors at Hanford and Clinton running 24/7, they were sure to have the necessary U235 in no-time (p. 613-614).

Not even Truman knew about the atomic bomb. Within a day of being sworn in he was informed of the Manhattan Project’s true details, piece by piece. At first he was only told generalizations about the creation of an extremely powerful weapon and that its completion would likely force the Axis powers to surrender on the terms of the U.S. He was intrigued and as more information was fed to him he supported the Project (pp. 617-619).

The American Air Force kept a list of cities to be kept intact, in prep for testing a powerful new weapon. The reserved cities were Tokyo Bay (for Tokyo itself had been firebombed fairly thoroughly, Yokohama, Nagoya, Osaka, Kobe, Hiroshima, Kokura, Fukuoka, Nagasaki and Sasebo (p. 628).

With the death toll in Europe rising, no true end in sight pending the completion of the atomic bombs and the Pacific theater to deal with afterwards, the Americans began to accept that fact that they would indeed likely be forced to use the bomb not as a tool to pressure surrender, but as the weapon it was built to be. With a list of Japanese cities on reserve, Oppenheimer began a Target Committee, the agenda of which included such decisions to be made and effects to be considered as height of the detonation, weather considerations, psychological effects, military targets, radiological effects, practice bombing and bomb tests among other things (pp. 630-631).

The Trinity test site was chosen in March 1944 and the tower was constructed by 1945. It was just a matter of time before the bomb was finished and tested. There was enough plutonium to be formed into the core of the bomb, but there was a little more waiting to be done for the other components to be finished and assembled. The first atomic bomb, of the same plutonium core and design as the Fat Man to be dropped on Nagasaki, was detonated on July 16th 1945, just seconds before 5:30am (pp. 652-672).

With a successful bomb test complete, Los Alamos was eager to complete Little Boy and Fat Man. Little Boy was completed on July 31st, 1945, with only a few pieces left removed as a precaution until it was ready to be used. The bombing of Hiroshima was delayed a few days by weather and so the bombers practiced at sea. Once the weather cleared up, the mission was confirmed to take place on August 6th. Flying at 31,000 feet the Enola Gay dropped the bomb upon Hiroshima, exploding at 8:16 a.m. local time, 45 seconds after being released from the bomb bay (pp. 699-712). The Fat Man bomb was detonated over Nagasaki 3 days later at 11:02 a.m. local time. Despite the horror stories of the survivors of Hiroshima, the military leaders of Japan still did not wish to surrender. Emperor Hirohito sent surrender terms of his own to the United States through Switzerland. He would surrender if and only if he remained Emperor and no change to the nation’s government was made. Many of the President’s cabinet went into the ensuing meeting expecting him to accept, but it seems Truman was not about to forget Roosevelt’s and Churchill’s demands for unconditional surrender (p. 742).

Hints of surrender reached American military bases on August 14th confirmed when Emperor Hirohito broadcast the surrender of Japan to his nation the next day, spoke to his own people who had never heard his voice before (p. 745).

So the Allies got their unconditional surrender. They fought to secure the world from the tyranny of Nazis controlling all of Europe. They characterized their enemies as monsters and huns yet our own nation raced to complete a new weapon which took the lives of over 200,000 innocent people in the span of three days, killed more over the next few years, maimed the survivors and adversely affected generations of human beings. We did so in the interests of self-preservation – a conventional war with Japan would have been drawn out and likely would have ended in our defeat, for they had as many millions of people and would fight to the last man, woman and child.

“’To avert a vast, indefinite butchery,’ Winston Churchill summarizes in his history of the Second World War, ‘to bring the war to an end, to give peace to the world, to lay healing hands upon its tortured peoples by a manifestation of overwhelming power at the cost of a few explosions, seemed, after all our toils and powers, a miracle of deliverance’” (p. 697).