Atom Bomb

Atom Bomb

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Just before the First World War two German scientists, James Franck and Gustav Hertz carried out experiments where they bombarded mercury atoms with electrons and traced the energy changes that resulted from the collisions. Their experiments helped to substantiate the theory put forward by Nils Bohr that an atom can absorb internal energy only in precise and definite amounts.

In 1921 two Otto Hahn and Lise Meitner, discovered nuclear isomers. Over the next few years they devoted their time to researching the application of radioactive methods to chemical problems.

In the 1930s they became interested in the research being carried out by Enrico Fermi and Emilio Segre at the University of Rome. This included experiments where elements such as uranium were bombarded with neutrons. By 1935 the two men had discovered slow neutrons, which have properties important to the operation of nuclear reactors.

Otto Hahn and Lise Meitner were now joined by Fritz Strassmann and discovered that uranium nuclei split when bombarded with neutrons. In 1938 Meitner, like other Jews in Nazi Germany, was dismissed from her university post. She moved to Sweden and later that year she wrote a paper on nuclear fission with her nephew, Otto Frisch, where they argued that by splitting the atom it was possible to use a few pounds of uranium to create the explosive and destructive power of many thousands of pounds of dynamite.

In January, 1939 a Physics Conference took place in Washington in the United States. A great deal of discussion concerned the possibility of producing an atomic bomb. Some scientists argued that the technical problems involved in producing such a bomb were too difficult to overcome, but the one thing they were agreed upon was that if such a weapon was developed, it would give the country that possessed it the power to blackmail the rest of the world. Several scientists at the conference took the view that it was vitally important that all information on atomic power should be readily available to all nations to stop this happening.

On 2nd August, 1939, three Jewish scientists who had fled to the United States from Europe, Albert Einstein, Leo Szilard and Eugene Wigner, wrote a joint letter to President Franklin D. Roosevelt, about the developments that had been taking place in nuclear physics. They warned Roosevelt that scientists in Germany were working on the possibility of using uranium to produce nuclear weapons.

Roosevelt responded by setting up a scientific advisory committee to investigate the matter. He also had talks with the British government about ways of sabotaging the German efforts to produce nuclear weapons.

In May, 1940, Germany invaded Denmark, the home of Niels Bohr, the world's leading expert on atomic research. It was feared that he would be forced to work for Nazi Germany. With the help of the British Secret Service he escaped to Sweden before being moving to the United States.

In 1942 the Manhattan Engineer Project was set up in the United States under the command of Brigadier General Leslie Groves. Scientists recruited to produce an atom bomb included Robert Oppenheimer (USA), David Bohm (USA), Leo Szilard (Hungary), Eugene Wigner (Hungary), Rudolf Peierls (Germany), Otto Frisch (Germany), Felix Bloch (Switzerland), Niels Bohr (Denmark), James Franck (Germany), James Chadwick (Britain), Emilio Segre (Italy), Enrico Fermi (Italy), Klaus Fuchs (Germany) and Edward Teller (Hungary).

Winston Churchill and Franklin D. Roosevelt were deeply concerned about the possibility that Germany would produce the atom bomb before the allies. At a conference held in Quebec in August, 1943, it was decided to try and disrupt the German nuclear programme.

In February 1943, SOE saboteurs successfully planted a bomb in the Rjukan nitrates factory in Norway. As soon as it was rebuilt it was destroyed by 150 US bombers in November, 1943. Two months later the Norwegian resistance managed to sink a German boat carrying vital supplies for its nuclear programme.

Meanwhile the scientists working on the Manhattan Project were developing atom bombs using uranium and plutonium. The first three completed bombs were successfully tested at Alamogordo, New Mexico on 16th July, 1945.

By the time the atom bomb was ready to be used Germany had surrendered. Leo Szilard and James Franck circulated a petition among the scientists opposing the use of the bomb on moral grounds. However, the advice was ignored by Harry S. Truman, the USA's new president, and he decided to use the bomb on Japan.

On 6th August 1945, a B29 bomber dropped an atom bomb on Hiroshima. It has been estimated that over the years around 200,000 people have died as a result of this bomb being dropped. Japan did not surrender immediately and a second bomb was dropped on Nagasaki three days later. On 10th August the Japanese surrendered. The Second World War was over.

From chemical evidence, Hahn and Strassmann conclude that radioactive barium nuclei (atom number Z = 56) are produced when uranium (Z = 92) is bombarded by neutrons. it has been pointed out that this might be explained as a result of a "fission" of the uranium nucleus, similar to the division of a droplet into two. The energy liberated in such processes was estimated to be about 200 Mev, both from mass defect considerations and from the repulsion of the two nuclei resulting from the "fission" process.

If this picture is correct, one would expect fast-moving nuclei of atomic number 40 to 50 and atomic weight 100 to 150, and up to 100 Mev energy, to emerge from a layer of uranium bombarded with neutrons. In spite of their high energy, these nuclei should have a range in air of a few millimeters only, on account of their high effective charge (estimated to be about 20), which implies very dense ionization. Each such particle should produce a total of about 3 million ion pairs.

By means of a uranium-lined ionization chamber, connected to a linear amplifier, I have succeeded in demonstrating the occurrence of such bursts of ionization. The amplifier was connected to a thyratron which was biased so as to count only pulses corresponding to at least 5 x 105 ion pairs. About 15 particles per minute were recorded when 300 milligram of radium, mixed with beryllium, was placed one centimeter from the uranium lining. No pulses at all were recorded during repeated check runs of several hours total duration when either the neutron source or the uranium lining was removed. With the neutron source at a distance of four centimeters from the uranium lining, surrounding the source with paraffin wax enhanced the effect by a factor of two.

It was checked that the number of pulses depended linearly on the strength of the neutron source; this was done in order to exclude the possibility that the pulses are produced by accidental summation of smaller pulses. When the amplifier was connected to an oscillograph, the large pulses could be seen very distinctly on the background of much smaller pulses due to the alpha particles of uranium.

By varying the bias of the thyratron, the maximum size of pulses was found to correspond to at least 2 million ion pairs, or an energy loss of 70 Mev of the particle within the chamber. Since the longest path of a particle in the chamber was 3 centimeters, and the chamber was filled with hydrogen at atmospheric pressure, the particles must ionize so heavily that they can make 2 million ion pairs on a path equivalent to 0.8 cm of air or less. From this it can be estimated that the ionizing particles must have an atomic weight of at least about seventy, assuming a reasonable connection between atomic weight and effective charge. This seems to be conclusive physical evidence for the breaking up of uranium nuclei into parts of comparable size, as indicated by the experiments of Hahn and Strassmann.

Experiments with thorium instead of uranium gave quite similar results, except that surrounding the neutron source with paraffin did not enhance, but slightly diminished the effect. This gives evidence in favor of the suggestion that also in the case of thorium some, if not all of the activities produced by neutron bombardment, should be ascribed to light elements. it should be remembered that no enhancement by paraffin has been found for the activities produced in thorium, except for one which is isotopic with thorium and is almost certainly produced by simple capture of the neutron.

Meitner has suggested another interesting experiment. If a metal plate is placed close to a uranium layer bombarded with neutrons, one would expect an active deposit of the light atoms emitted in the "fission" of the uranium to form on the plate. We hope to carry out such experiments, using the powerful source of neutrons which our high-tension apparatus will soon be able to provide.

Roosevelt: "Could Bohr be whisked out from under Nazi noses and brought to the Manhattan Project?"

Stephenson: "It will have to be a British mission. Niels Bohr is a stubborn pacifist. He does not believe his work in Copenhagen will benefit the Germany military caste. Nor is he likely to join an American enterprise which has as its sole objective the construction of a bomb. But he is in constant touch with old colleagues in England whose integrity he respects."

A weapon of an unparalleled power is being created which will completely change all future conditions of warfare. Unless some agreement about the control of the use of the new active materials can be obtained in due time, any temporary advantage, however great, may be outweighed by a perpetual menace to human security. An initiative, aiming at forestalling a fateful competition, should serve to uproot any cause of distrust between the powers of whose harmonious collaboration the fate of coming generations will depend.

You may be quite sure that any power that gets hold of the secret will try to make the article and that this touches the existence of human society. The matter is out of all relation to anything else that exists in the world, and I could not think of participating in any disclosure to third or fourth parties at the present time. I do not believe there is anyone in the world who can possibly have reached the position now occupied by us and the United States.

I voiced to him my grave misgivings, first on the basis of my belief that Japan was already defeated and that dropping the bomb was completely unnecessary, and secondly because I thought that our country should avoid shocking world opinion by the use of a weapon whose employment was, I thought, no longer mandatory as a measure to save American lives. It was my belief that Japan was, at that very moment, seeking some way to surrender with a minimum loss of "face".

Once it had been tested, President Truman faced the decision as to whether to use it. He did not like the idea, but was persuaded that it would shorten the war against Japan and save American lives. It is my opinion that the use of this barbarous weapon at Hiroshima and Nagasaki was of no material assistance in our war against Japan. The Japanese were already defeated and ready to surrender because of the effective sea blockade and the successful bombing with conventional weapons.

It was my reaction that the scientists and others wanted to make this test because of the vast sums that had been spent on the project. Truman knew that, and so did the other people involved. However, the Chief Executive made a decision to use the bomb on two cities in Japan. We had only produced

two bombs at that time. We did not know which cities would be the targets, but the President specified that the bombs should be used against military facilities.

The lethal possibilities of atomic warfare in the future are frightening. My own feeling was that, in being the first to use it, we had adopted an ethical standard common to the barbarians of the Dark Ages. I was not taught to make war in that fashion, and wars cannot be won by destroying women and children. We were the first to have this weapon in our possession, and the first to use it. There is a practical certainty that potential enemies will develop it in the future and that atomic bombs will some time be used against us.

We spent a lot of time and risked a lot of lives to do so. Of my little group of eight, two were killed. We were using high explosives and radioactive material in large quantities for the first time. There was a series of events that rocked us. We were working hard, day and night, to do something that had never been done before. It might not work at all. I remember working late one night with my friend Louis Slotin. He was killed by a radiation accident. We shared the job. It could

have been I. But it was he, who was there that day.

James Franck, a truly wonderful man, produced the Franck Report: Don't drop the bomb on a city. Drop it as a demonstration and offer a warning. This was about a month before Hiroshima. The movement against the bomb was beginning among the physicists, but with little hope. It was strong at Chicago, but it didn't affect Los Alamos.

We heard the news of Hiroshima from the airplane itself, a coded message. When they returned, we didn't see them. The generals had them. But then the people came back with photographs. I remember looking at them with awe and terror. We knew a terrible thing had been unleashed. The men had a great party that night to celebrate, but we didn't go. Almost no physicists went to it. We obviously killed a hundred thousand people and that was nothing to have a party about. The reality confronts you with things you could never anticipate.

Before I went to Wendover, an English physicist. Bill Penney, held a seminar five days after the test at Los Alamos. He applied his calculations. He predicted that this would reduce a city of three or four hundred thousand people to nothing but a sink for disaster relief, bandages, and hospitals. He made it absolutely clear in numbers. It was reality. We knew it, but we didn't see it. As soon as the bombs were dropped, the scientists, with few exceptions, felt the time had come to end all wars.

The chief lesson I have learned in a long life is that the only way you can make a man trustworthy is to trust him; and the surest way to make him untrustworthy is to distrust him. If the atomic bomb were merely another, though more devastating, military weapon to be assimilated into our pattern of international relations, it would be one thing. We would then follow the old custom of secrecy and nationalistic military superiority relying on international caution to prescribe the future use of the weapon as we did with gas. But I think the bomb instead constitutes merely a first step in a new control by man over the forces of nature too revolutionary and dangerous to fit into old concepts. My idea of an approach to the Soviets would be a direct proposal after discussion with the British that we would be prepared in effect to enter an agreement with the Russians, the general purpose of which would be to control and limit the use of the atomic bomb as an instrument of war.

Dr. Sasaki and his colleagues at the Red Cross Hospital watched the unprecedented disease unfold and at last evolved a theory about its nature. It had, they decided, three stages. The first stage had been all over before the doctors even knew they were dealing with a new sickness; it was the direct reaction to the bombardment of the body, at the moment when the bomb went off, by neutrons, beta particles, and gamma rays. The apparently uninjured people who had died so mysteriously in the first few hours or days had succumbed in this first stage. It killed ninety-five per cent of the people within a half-mile of the center, and many thousands who were farther away. The doctors realized in retrospect that even though most of these dead had also suffered from burns and blast effects, they had absorbed enough radiation to kill them. The rays simply destroyed body cells– caused their nuclei to degenerate and broke their walls. Many people who did not die right away came down with nausea, headache, diarrhea, malaise, and fever, which lasted several days. Doctors could not be certain whether some of these symptoms were the result of radiation or nervous shock. The second stage set in ten or fifteen days after the bombing. Its first symptom was falling hair. Diarrhea and fever, which in some cases went as high as 106, came next. Twenty-five to thirty days after the explosion, blood disorders appeared: gums bled, the white-blood-cell count dropped sharply, and petechiae [eruptions] appeared on the skin and mucous membranes. The drop in the number of white blood corpuscles reduced the patient's capacity to resist infection, so open wounds were unusually slow in healing and many of the sick developed sore throats and mouths. The two key symptoms, on which the doctors came to base their prognosis, were fever and the lowered white-corpuscle count. If fever remained steady and high, the patient's chances for survival were poor. The white count almost always dropped below four thousand; a patient whose count fell below one thousand had little hope of living. Toward the end of the second stage, if the patient survived, anemia, or a drop in the red blood count, also set in. The third stage was the reaction that came when the body struggled to compensate for its ills–when, for instance, the white count not only returned to normal but increased to much higher than normal levels. In this stage, many patients died of complications, such as infections in the chest cavity. Most burns healed with deep layers of pink, rubbery scar tissue, known as keloid tumors. The duration of the disease varied, depending on the patient's constitution and the amount of radiation he had received. Some victims recovered in a week; with others the disease dragged on for months.

As the symptoms revealed themselves, it became clear that many of them resembled the effects of overdoses of X-ray, and the doctors based their therapy on that likeness. They gave victims liver extract, blood transfusions, and vitamins, especially Bl. The shortage of supplies and instruments hampered them. Allied doctors who came in after the surrender found plasma and penicillin very effective. Since the blood disorders were, in the long run, the predominant factor in the disease, some of the Japanese doctors evolved a theory as to the seat of the delayed sickness. They thought that perhaps gamma rays, entering the body at the time of the explosion, made the phosphorus in the victims' bones radioactive, and that they in turn emitted beta particles, which, though they could not penetrate far through flesh, could enter the bone marrow, where blood is manufactured, and gradually tear it down. Whatever its source, the disease had some baffling quirks. Not all the patients exhibited all the main symptoms. People who suffered flash burns were protected, to a considerable extent, from radiation sickness. Those who had lain quietly for days or even hours after the bombing were much less liable to get sick than those who had been active. Gray hair seldom fell out. And, as if nature were protecting man against his own ingenuity, the reproductive processes were affected for a time; men became sterile, women had miscarriages, menstruation stopped.

The bomb that hurried Russia into Far Eastern war a week ahead of schedule and drove Japan to surrender has accomplished the specific job for which it was created. From the point of view of military strategy, $2,000,000,000 (the cost of the bomb and the cost of nine days of war) was never better spent. The suffering, the wholesale slaughter it entailed, have been outweighed by its spectacular success; Allied leaders can rightly claim that the loss of life on both sides would have been many times greater if the atomic bomb had not been used and Japan had gone on fighting. There is no answer to this argument. The danger is that it will encourage those in power to assume that, once accepted as valid, the argument can be applied equally well in the future. If that assumption should be permitted, the chance of saving civilization - perhaps the world itself - from destruction is a remote one.

You have asked for the comment, in writing, of each cabinet officer on the proposal submitted by Secretary Stimson for the free and continuous exchange of scientific information (not industrial blueprints and engineering "know-how") concerning atomic energy between all of the United Nations. I agreed with Henry Stimson.

At the present time, with the publication of the Smyth report and other published information, there are no substantial scientific secrets that would serve as obstacles to the production of atomic bombs by other nations. Of this I am assured by the most competent scientists who know the facts. We have not only already made public much of the scientific information about the atomic bomb, but above all with the authorization of the War Department we have indicated the road others must travel in order to reach the results we have obtained.

With respect to future scientific developments I am confident that both the United States and the world will gain by the free interchange of scientific information. In fact, there is danger that in attempting to maintain secrecy about these scientific developments we will, in the long run, as a prominent scientist recently put it, be indulging "in the erroneous hope of being safe behind a scientific Maginot Line."

The nature of science and the present state of knowledge in other countries are such that there is no possible way of preventing other nations from repeating what we have done or surpassing it within five or six years. If the United States, England, and Canada act the part of the dog in the manger on this matter, the other nations will come to hate and fear all Anglo-Saxons without our having gained anything thereby. The world will be divided into two camps with the non- Anglo-Saxon world eventually superior in population, resources, and scientific knowledge.

We have no reason to fear loss of our present leadership through the free interchange of scientific information. On the other hand, we have every reason to avoid a shortsighted and unsound attitude which will invoke the hostility of the rest of the world.

In my opinion, the quicker we share our scientific knowledge the greater will be the chance that we can achieve genuine and durable world cooperation. Such action would be interpreted as a generous gesture on our part and lay the foundation for sound international agreements that would assure the control and development of atomic energy for peaceful use rather than destruction.

Soviet atomic bomb project

The Soviet atomic bomb project [1] (Russian: Советский проект атомной бомбы, Sovetskiy proyekt atomnoy bomby) was the classified research and development program that was authorized by Joseph Stalin in the Soviet Union to develop nuclear weapons during World War II. [2] [3]

Although the Soviet scientific community discussed the possibility of an atomic bomb throughout the 1930s, [4] [5] going as far as making a concrete proposal to develop such a weapon in 1940, [6] [7] [8] the full-scale program was not initiated until World War II.

Because of the conspicuous silence of the scientific publications on the subject of nuclear fission by German, American, and British scientists, Russian physicist Georgy Flyorov suspected that the Allied powers had secretly been developing a "superweapon" [3] since 1939. Flyorov wrote a letter to Stalin urging him to start this program in 1942. [9] : 78–79 Initial efforts were slowed due to the German invasion of the Soviet Union and remained largely composed of the intelligence knowledge gained from the Soviet spy rings working in the U.S. Manhattan Project. [2]

After Stalin learned of the atomic bombings of Hiroshima and Nagasaki, the program was pursued aggressively and accelerated through effective intelligence gathering about the German nuclear weapon project and the American Manhattan Project. [10] The Soviet efforts also rounded up captured German scientists to join their program, and relied on knowledge passed by spies to Soviet intelligence agencies. [11] : 242–243

On 29 August 1949, the Soviet Union secretly conducted its first successful weapon test (First Lightning, based on the American "Fat Man" design) at the Semipalatinsk Test Site in Kazakhstan. [2]

Was there a Third A-Bomb? A Fourth? A Fifth?

High School textbooks teach that the atom bombs dropped on Hiroshima and Nagasaki were flown to Japan by B-29 Superfortresses based on Tinian in the Mariana Islands. They do not recognize that the bombs were actually assembled on Tinian under combat conditions, not at the Los Alamos Laboratory in New Mexico.

On January 19, 1945, Dr. J. Robert Oppenheimer, Director of the Los Alamos Laboratory, advised Maj. Gen. Leslie Groves, Commanding General, Manhattan Project, &ldquoAug. 1 for L.B [Little Boy] and 1- F. M. [Fat Man] Sept. for 2 or 3 F.M. October for 3 F. M&hellip.&rdquo In early February, General Groves sent Commander Fred Ashworth, USN, to the Marianas to pick a site for the assembly and delivery of the bombs. He chose Tinian because it was 100 miles closer to Japan than Guam, and Saipan was overcrowded with the 73 rd Bombardment Wing flying missions to Japan. Tinian became &ldquoPapacy.&rdquo

Groves then sent his colleague, Colonel Elmer E. Kirkpatrick, Jr., Army Corps of Engineers, to Tinian to oversee the construction of the necessary Manhattan Project facilities an ordnance area with technical labs for subassemblies, three bomb assembly buildings, and two bomb loading pits, without telling anyone in the Marianas, except Nimitz. Why three assembly buildings?

Meanwhile, Captain William Stirling &ldquoDeke&rdquo Parsons, USN, an ordnance specialist, assumed the position of Deputy Director of the Los Alamos Laboratory. His job was to design a bombing mechanism from all the gadgets the scientists had created, one that could be dropped from an airplane. Having created a proximity fuse for Navy 5&rdquo anti-aircraft guns and tested it in combat in the Southwest Pacific Area, he knew what had to be done to move the Project to the front successfully. Besides planning the deployment, he also oversaw the manufacture of bomb parts at various factories across America and coordinated shipments to a packaging warehouse in San Francisco.

Commander Ashworth and four men from the Project Alberta assembly teams arrived on Tinian on June 27 th and began organizing those bomb parts that had already arrived at the 1 st Ordnance technical area. There were enough to make fifty bombs, some of which would be used to make final test drops just off Tinian&rsquos northwest coast. Why fifty?

Three atom bomb assembly buildings had been completed. Little Boy test bombs and the active bomb would be assembled in building number one. Fat Man would be assembled in number three, the furthest north.

After Little Boy was dropped on August 6 th , the assembly building was cleaned and restructured to handle the far different Fat Man bombs. After Fat Man was dropped on August 9, work immediately began on another. On the 12 th , Truman decided no more bombs would be dropped without his signed order. General Carl Spaatz, now stationed at Guam recommended the next bomb be dropped in the burnt our section of Tokyo, so that Hirohito and his military clique could watch the show from the Palace. At that time, the plutonium core for the second Fat Man&mdashthe third bomb&mdashwas being loaded into a vehicle for the ride to Tinian, but never left Los Alamos.

Fortunately, Hirohito took command and ordered acceptance of the Potsdam Ultimatum, unconditional surrender, with the retention of Japan&rsquos traditional imperial system, kokutai.

Had Japan not surrendered, would there have been a third bomb, a fourth, a fifth, as many as necessary? No one will ever know.

Why the Atom Bomb Was One of the Greatest Weapons in U.S. History

As a weapon of war in World War II, the A-bomb was of greater shock than practical value.

Here’s What You Need to Remember: The secret of American victory in World War II was quantity and quality. Copious amounts of weapons and equipment that not only overwhelmed and outmatched the Axis arsenal, but helped enable Lend-Lease allies like Britain and Russia to do the same.

Not that every U.S. weapon was great. The ubiquitous M-4 Sherman tank was plentiful but mediocre. Early U.S. fighters like the P-40 and P-39 were nothing to brag about (except in the hands of the Flying Tigers), while U.S. submarine torpedoes had a bad habit of not exploding until late 1943.

But utilizing its massive industrial and technological base, America was able to produce some excellent weapons, including:

Proximity Fuzes:

Shell fuzes aren't usually thought of as weapons. But Japanese pilots and German infantrymen learned otherwise.

The issue was that in an era when most anti-aircraft guns lacked radar or sophisticated fire control computers, their chances of hitting a target were not great. So complex were the calculations required to compute where to intersect the path of shell and airplane two to five miles high that tens of thousands of rounds had to be fired on average to score a hit.

The problem became really acute when American warships encountered Japanese kamikazes destroying an aircraft hell-bent on crashing into your ship meant the suicide planes had to be shot down quickly.

Then someone had the bright idea of putting a tiny radar in the nose of each anti-aircraft shell. Instead of having to strike the aircraft to be effective, the shell could be set to explode once the onboard radar sensed the target was close enough, spraying a cloud of fragments that covered a wider area. The VT (variable time) fuze helped the U.S. Navy survive the kamikaze threat.

It also helped the hard-pressed U.S. Army at the Battle of the Bulge. Artillery shells are more effective if they detonate as airbursts above the ground, rather than bury themselves in the earth. Instead of spraying airplanes, clouds of shrapnel sprayed German infantry.

At the start of World War II, armies used bolt-action rifles that in some cases dated back to the nineteenth century.

Enter the M-1 Garand, a semi-automatic rifle that could pump out bullets with a far-higher rate of fire. The M-1 enabled U.S. infantry to generate remarkable rates of fire by the standards of the early 1940s.

That was fortunate because American infantry was otherwise weakly armed, with no squad-level machine gun to match the deadly German MG-42. Meanwhile, the Germans and Soviets, who had far more practical experience at ground warfare, ultimately opted to arm their troops with submachine guns that lacked range but could spew lots of bullets. But the M-1 was a solid, reliable weapon that gave American riflemen a fighting chance against their enemies.

Essex-class carrier:

The Pacific War was ultimately a war of carriers—those floating, mobile airfields that banished battleships from preying on vulnerable troops and supply convoys. The backbone of the late-war U.S. carrier fleet was the Essex-class flattop. Carrying about a hundred fighter, dive-bombers and torpedo-bombers, and equipped with sophisticated radar and fighter direction facilities, these carriers devastated the Imperial Japanese Navy in battles such as the Philippine Sea and Leyte Gulf.

The ultimate compliment to the Essex carriers was how long they lasted after the war. Ships such as USS Essex, Ticonderoga and Hancock continued to launch combat missions over Korea and Vietnam.

Gato-class subs:

U.S. Navy carriers and battleships got the glory for defeating Japan, but 55 percent of Japanese naval tonnage sunk was by U.S. submarines. By 1945, American subs had largely cut Japan's maritime lifeline to raw materials and food imports.

The efficient engine of this destruction was the Gato-class sub, the backbone of the U.S. underwater fleet. There is much discussion about how it stacked against World War II's other underwater killer, the German U-boat. The comparison is somewhat academic Japanese anti-submarine capabilities were so primitive that American subs never faced anything like the sophistication and intensity of those Allied defenses that killed more than 60 percent of U-boat crews. Nonetheless, the Gato-class has to rank as one of the most deadly naval weapons of all time.

The Atomic Bomb:

Including the A-bomb on a list that otherwise features conventional weapons seems out of place. That the atomic bomb was a weapon, there is no doubt. But it was a weapon of a different magnitude, a device that could pulverize an entire city more thoroughly than a raid by a thousand regular bombers. It also epitomized the ability of the United States to harness scientific and industrial resources on a single project, to a degree that no other nation could match.

As a weapon of war in World War II, the A-bomb was of greater shock than practical value. They were too complex to mass-produce in the late 1940s, and by 1945, American and British bombers had pretty much devastated every German and Japanese city worth bombing.

Nonetheless, in an era when radar and jet aircraft were considered the zenith of military technology, along came a weapon that could kill 60,000 people in a split-second. What more need be said?


On August 6, 1945, the United States dropped an atomic bomb on the city of Hiroshima. The bomb was known as "Little Boy", a uranium gun-type bomb that exploded with about thirteen kilotons of force. At the time of the bombing, Hiroshima was home to 280,000-290,000 civilians as well as 43,000 soldiers. Between 90,000 and 166,000 people are believed to have died from the bomb in the four-month period following the explosion. The U.S. Department of Energy has estimated that after five years there were perhaps 200,000 or more fatalities as a result of the bombing, while the city of Hiroshima has estimated that 237,000 people were killed directly or indirectly by the bomb's effects, including burns, radiation sickness, and cancer.

The bombing of Hiroshima, codenamed Operation Centerboard I, was approved by Curtis LeMay on August 4, 1945. The B-29 plane that carried Little Boy from Tinian Island in the western Pacific to Hiroshima was known as the Enola Gay, after pilot Paul Tibbets' mother. Along with Tibbets, copilot Robert Lewis, bombardier Tom Ferebee, navigator Theodore Van Kirk, and tail gunner Robert Caron were among the others on board the Enola Gay. Below are their eyewitness accounts of the first atomic bomb dropped on Japan.

Pilot Paul Tibbets: "We turned back to look at Hiroshima. The city was hidden by that awful cloud. boiling up, mushrooming, terrible and incredibly tall. No one spoke for a moment then everyone was talking. I remember (copilot Robert) Lewis pounding my shoulder, saying 'Look at that! Look at that! Look at that!' (Bombardier) Tom Ferebee wondered about whether radioactivity would make us all sterile. Lewis said he could taste atomic fission. He said it tasted like lead."

Navigator Theodore Van Kirk recalls the shockwaves from the explosion: "(It was) very much as if you've ever sat on an ash can and had somebody hit it with a baseball bat. The plane bounced, it jumped and there was a noise like a piece of sheet metal snapping. Those of us who had flown quite a bit over Europe thought that it was anti-aircraft fire that had exploded very close to the plane." On viewing the atomic fireball: "I don't believe anyone ever expected to look at a sight quite like that. Where we had seen a clear city two minutes before, we could now no longer see the city. We could see smoke and fires creeping up the sides of the mountains."

Tail gunner Robert Caron: "The mushroom itself was a spectacular sight, a bubbling mass of purple-gray smoke and you could see it had a red core in it and everything was burning inside. As we got farther away, we could see the base of the mushroom and below we could see what looked like a few-hundred-foot layer of debris and smoke and what have you. I saw fires springing up in different places, like flames shooting up on a bed of coals."

Six miles below the crew of the Enola Gay, the people of Hiroshima were waking up and preparing for their daily routines. It was 8:16 A.M. Up to that point, the city had been largely spared by the rain of conventional air bombing that had ravaged many other Japanese cities. Rumors abounded as to why this was so, from the fact that many Hiroshima residents had emigrated to the U.S. to the supposed presence of President Truman's mother in the area. Still, many citizens, including schoolchildren, were recruited to prepare for future bombings by tearing down houses to create fire lanes, and it was at this task that many were laboring or preparing to labor on the morning of August 6. Just an hour before, air raid sirens had sounded as a single B-29, the weather plane for the Little Boy mission, approached Hiroshima. A radio broadcast announced the sighting of the Enola Gay soon after 8 A.M.

The city of Hiroshima was annihilated by the explosion. 70,000 of 76,000 buildings were damaged or destroyed, and 48,000 of those were entirely razed. Survivors recalled the indescribable and incredible experience of seeing that the city had ceased to exist.

A college history professor: "I climbed Hikiyama Hill and looked down. I saw that Hiroshima had disappeared. I was shocked by the sight. What I felt then and still feel now I just can't explain with words. Of course I saw many dreadful scenes after that—but that experience, looking down and finding nothing left of Hiroshima—was so shocking that I simply can't express what I felt. Hiroshima didn't exist—that was mainly what I saw—Hiroshima just didn't exist."

Medical doctor Michihiko Hachiya: "Nothing remained except a few buildings of reinforced concrete. For acres and acres the city was like a desert except for scattered piles of brick and roof tile. I had to revise my meaning of the word destruction or choose some other word to describe what I saw. Devastation may be a better word, but really, I know of no word or words to describe the view."

Writer Yoko Ota: "I reached a bridge and saw that the Hiroshima Castle had been completely leveled to the ground, and my heart shook like a great wave. the grief of stepping over the corpses of history pressed upon my heart."

Those who were close to the epicenter of the explosion were simply vaporized by the intensity of the heat. One man left only a dark shadow on the steps of a bank as he sat. The mother of Miyoko Osugi, a 13-year-old schoolgirl working on the fire lanes, never found her body, but she did find her geta sandal. The area covered by Miyoko's foot remained light, while the rest of it was darkened by the blast.

Many others in Hiroshima, farther from the Little Boy epicenter, survived the initial explosion but were severely wounded, including injuries from and burns across much of their body. Among these people, panic and chaos were rampant as they struggled to find food and water, medical assistance, friends and relatives and to flee the firestorms that engulfed many residential areas.

Having no point of reference for the bomb's absolute devastation, some survivors believed themselves to have been transported to a hellish version of the afterlife. The worlds of the living and the dead seemed to converge.

A Protestant minister: "The feeling I had was that everyone was dead. The whole city was destroyed. I thought this was the end of Hiroshima—of Japan—of humankind. This was God's judgment on man."

A six-year-old boy: "Near the bridge there were a whole lot of dead people. Sometimes there were ones who came to us asking for a drink of water. They were bleeding from their faces and from their mouths and they had glass sticking in their bodies. And the bridge itself was burning furiously. The details and the scenes were just like Hell."

A sociologist: "My immediate thought was that this was like the hell I had always read about. I had never seen anything which resembled it before, but I thought that should there be a hell, this was it—the Buddhist hell, where we were thought that people who could not attain salvation always went. And I imagined that all of these people I was seeing were in the hell I had read about."

A boy in fifth grade: "I had the feeling that all the human beings on the face of the earth had been killed off, and only the five of us (his family) were left behind in an uncanny world of the dead."

A grocer: "The appearance of people was. well, they all had skin blackened by burns. They had no hair because their hair was burned, and at a glance you couldn't tell whether you were looking at them from in front or in back. Many of them died along the road—I can still picture them in my mind—like walking ghosts. They didn't look like people of this world."

Many people traveled to central places such as hospitals, parks, and riverbeds in an attempt to find relief from their pain and misery. However, these locations soon became scenes of agony and despair as many injured and dying people arrived and were unable to receive proper care.

A sixth-grade girl: "Bloated corpses were drifting in those seven formerly beautiful rivers smashing cruelly into bits the childish pleasure of the little girl, the peculiar odor of burning human flesh rose everywhere in the Delta City, which had changed to a waste of scorched earth."

A fourteen-year-old boy: "Night came and I could hear many voices crying and groaning with pain and begging for water. Someone cried, 'Damn it! War tortures so many people who are innocent!' Another said, 'I hurt! Give me water!' This person was so burned that we couldn't tell if it was a man or a woman. The sky was red with flames. It was burning as if scorching heaven."

For more testimonials from survivors, visit Voices from Japan.

The Atomic Bomb: Hiroshima and Nagasaki

On August 6, 1945, after 44 months of increasingly brutal fighting in the Pacific, an American B-29 bomber loaded with a devastating new weapon appeared in the sky over Hiroshima, Japan. Minutes later, that new weapon—a bomb that released its enormous destructive energy by splitting uranium atoms to create a chain reaction—detonated in the sky, killing some 70,000 Japanese civilians instantly and leveling the city. Three days later, the U.S. dropped a second atomic bomb over the city of Nagasaki, with similarly devastating results. The following week, Japan’s emperor addressed his country over the radio to announce the decision to surrender. World War II had finally come to its dramatic conclusion. The decision to employ atomic weapons against Japan remains a controversial chapter in American history. Even before the new President Harry S. Truman finalized his decision to use the bombs, members of the President’s inner circle grappled with the specifics of the decision to drop the new weapon. Their concerns revolved around a cluster of related issues: whether the use of the technology was necessary to defeat an already crippled Japan whether a similar outcome could be effected without using the bomb against civilian targets whether the detonation of a second bomb days after the first, before Japan had time to formulate its response, was justified and what effect the demonstration of the bomb’s devastating power would have on postwar diplomacy, particularly on America’s uneasy wartime alliance with the Soviet Union.

The ongoing struggle to present the history of the atomic bombings in a balanced and accurate manner is an interesting story in its own right, and one that has occasionally generated an enormous amount of controversy. In 1995, anticipating the 50th anniversary of the end of World War II, the Smithsonian’s National Air and Space Museum planned a display around the fuselage of the Enola Gay, the aircraft that dropped the first bomb, for its museum on the National Mall. That exhibit would place the invention of atomic weapons and the decision to use them against civilian targets in the context of World War II and the Cold War, provoking broader questions about the morality of strategic bombing and nuclear arms in general.

The design for the exhibit quickly triggered an avalanche of controversy. Critics charged that it offered a too-sympathetic portrayal of the Japanese enemy, and that its focus on the children and elderly victims of the bombings at Hiroshima and Nagasaki encouraged visitors to question the necessity and morality of the weapons. As originally written, those critics alleged, the exhibit forwarded an anti-American interpretation of events surrounding the bombs’ use. That such a message was to appear in a national museum amplified the frustrations of critics (especially veterans’ groups), who believed that the exhibit should not lead museumgoers to question the decision to drop the bomb or to portray the Pacific war in morally neutral terms. In place of the original exhibit, veterans’ organizations offered a replacement exhibit with a very different message. Their proposed exhibit portrayed the development of the atomic weapons as a triumph of American technical ingenuity, and the use of both bombs as an act that saved lives—the lives of American soldiers who would otherwise have had to invade the Japanese home islands, and the lives of thousands of Japanese who would, it was assumed, have fought and died with fanatic determination opposing such an invasion. The revised exhibit removed the questioning tone of the original, replacing it with more certainty: the use of the bombs, it argued, was both necessary and justified.

The historians who produced the original exhibit stood accused of historical revisionism by their critics, of needlessly complicating patriotic consensus with moral concerns. The fallout from the controversy led to loud, public debate in the halls of Congress and, ultimately, to the resignation of several leaders at the museum. When the controversy died down, the Smithsonian elected not to stage any exhibit of the aircraft fuselage. Years later, the plane went on display at the Smithsonian’s Udvar-Hazy Center outside Washington, DC, where it resides now, accompanied by a brief placard detailing its technical specifications.

Because the use of the atomic weapons evokes such passionate responses from Americans—from those who believe that the use of the bombs was wholly justified to those who believe that their use was criminal, and the many people who fall somewhere in between—it is a particularly difficult topic for textbooks to discuss. In order to avoid a potentially treacherous debate, textbooks have often adopted a set of compromises that describe the end of the war but avoid or omit some of the most difficult parts of the conversation. A 1947 history textbook, produced just two years after the bombings did just this, sidestepping the controversy by presenting the story at a distance and refraining from interpretation or discussion of civilian casualties: “The United States unveiled its newest weapon, demonstrating twice—first at Hiroshima and then at Nagasaki—that a good-sized city could almost be erased from the map in one blinding flash. Confronted by this combination of forces, Japan surrendered August 14.”

Later textbooks made other compromises. The 2005 textbook A History of the United States adopts a familiar tone, arguing that President Truman based his decision to drop the bomb mainly on a complex calculus of the cost in human lives if the war were to continue: “Should the United States use the atomic bomb? No one knew how long Japan would hold out.” That uncertainty forced American planners to assume the worst: “If the war dragged on and Americans had to invade Japan, it might cost a million lives. The atomic bomb, President Truman knew, might kill many thousands of innocent Japanese. But life for life, the odds were that it would cost less.” A 2006 textbook, The Americans, suggests that the decision to drop the bomb occurred largely outside moral concerns: “Should the Allies use the bomb to bring an end to the war? Truman did not hesitate. On July 25, 1945, he ordered the military to make final plans for dropping two atomic bombs on Japan.” The paragraph on the decision concludes with a compelling quote from the President himself: “Let there be no mistake about it. I regarded the bomb as a military weapon and never had any doubt it should be used.” Other recent textbooks have labored to present this often-contentious topic in a more nuanced manner. The 2007 textbook American Anthem describes the decision-making process as an involved one, observing “Truman formed a group to advise him about using the bomb. This group debated where the bomb should be used and whether the Japanese should be warned. After carefully considering all the options, Truman decided to drop the bomb on a Japanese city. There would be no warning." The carefully written passage does not suggest that the question of whether to use the bomb against civilian targets was part of the debate it describes the inquiry as focused on where to drop the bomb and whether a warning would precede its use. More recent textbooks often offer viewpoints from other perspectives—including Japanese civilians, who suffered the legacy of atomic fallout for decades after the original explosion—from a morally neutral stance, inviting (or directly asking) readers to make their own judgments. Besides offering a description of Truman’s decision-making process, the American Anthem textbook includes a passage of equivalent length that describes the destruction on the ground, anchored by a quote from a survivor of the Hiroshima bomb. It also features a “Counterpoints” section that contrasts a quote from Secretary of War Henry Stimson supporting the bomb’s use with one from Leo Szilard, an atomic physicist, characterizing the use of the bombs against Japan as “one of the greatest blunders of history.”

A discussion that focuses primarily on the need to employ the bomb in order to save lives—the lives of Japanese civilians as well as those of American soldiers—is incomplete. In fact, as the documentary record shows, there was a good deal of debate over the use of the weapons during the summer of 1945, much of which focused on more complex issues than the lives that would be saved or lost in ending the war.

When nuclear radiation was harmless-Not!!

Most people will have heard of the “Manhattan Project” it was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada.

Despite the data gathered from the Hiroshima and Nagasaki bombing, the nuclear testing were still conducted in an extremely reckless manner far in to the 1950s and 1960s.

The picture on the top shows five air force officers standing directly below ground zero for an atmospheric nuclear test. 18,500 feet above their heads, a two-kiloton atomic bomb is about to go off.

Their goal is to prove that these nuclear tests are safe. When an NPR reporter tried to look into these men’s fate, the photographer told them, “Quite a few have died from cancer. No doubt it was related to the testing.”

A pig is placed into an aluminum barrel before a nuclear test.
This pig, and others like it, were placed in barrels in various places around ground zero for various nuclear tests so that researchers could study the effects of radiation on living things.

Just after a nuclear bomb was detonated, two soldiers use their hands to frame the mushroom cloud for the camera.

Nye County, Nevada. May 1, 1952.

An “atomic pin-up girl” at a Las Vegas party dances for the camera while a nuclear bomb explodes behind her.

Military men watch as the mushroom cloud from a nuclear blast drifts up overhead.

Nye County, Nevada. April 22, 1952

The U.S. Army 11th Airborne Division sit and watch the mushroom cloud rise.

Yucca Flats, Nevada. November 1, 1951.

From a parking lot in Nevada, miles away from the test site, a mushroom cloud is still visible. Radioactive particles can be seen drifting through the air, toward the neighboring towns.

Frenchman Flat, Nevada. June 24, 1957.

After the first nuclear test in Bikini Atoll, a man is put through a medical examination to see how being exposed to radiation has affected him.

Bikini Atoll, Marshall Islands.

A mushroom cloud erupts over Bikini Atoll during a nuclear test. July 25, 1946.

The people of Bikini Atoll are relocated to the nearby island of Rognerik Atoll so that the U.S. Government can continue nuclear testing.

Bikini Atoll, Marshall Islands. March 7, 1946.

A crowd, mostly news correspondents, lines up to hop on the bus so they can watch an “Open Shot” nuclear test.

“Open Shot” tests were open to the public. Reporters and dignitaries were invited to come out to the Nevada desert and watch a nuclear bomb explode.

Las Vegas, Nevada. March 16, 1953.

“Explosives,” reads a warning sign, one of the only lines of defense keeping civilians from wandering onto the site of an underground nuclear test.

Lamar County, Mississippi. September 1964.

Photographers set up their camera to film the first ever nuclear test to appear on national television.

Nye County, Nevada. April 1952.

An audience at an “Open Shot” nuclear test gaze up in excitement to watch a nuclear bomb explode.

Nye County, Nevada. April 6, 1955

Marines participating in a nuclear test run their morning exercises around the Nevada Proving Grounds.

Nye County, Nevada. June 22, 1957.

A Goodyear Blimp, flying five miles away from ground zero, crashes into the ground, torn down by the heat of the blast.

Nye County, Nevada. August 7, 1957.

The USS Independence after being stationed too close to a nuclear test.

Navy officers are on the ship, trying to study its remains and salvage what’s left of it.

Bikini Atoll, Marshall Islands. July 23, 1946.

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Little Boy: The First Atomic Bomb

Two American atomic bombs ended World War II in August 1945, and the devastation will be forever remembered. In an instant when the first bomb was dropped, tens of thousands of residents of Hiroshima, Japan were killed by “Little Boy,” the code name for the first atomic bomb used in warfare in world history.

The Project

Scientists developed the technology for the atomic weapon during the highly classified project code-named “The Manhattan Project.” U.S. Army Col. Leslie R. Groves oversaw the military’s participation, while civilian scientist Robert Oppenheimer was in charge of the team designing the core details of Little Boy. Facilities for the research were set up in Manhattan, Washington State, Tennessee, and New Mexico. Scientists on the project drew from the earlier work done by physicists Enrico Fermi and Leo Szilard, both of whom received funding from the U.S. Government in the late 1930s to study enriched uranium in nuclear chain reactions. The enriched uranium-235 was the critical element in creating an explosive fission reaction in nuclear bombs.

The Manhattan Project team agreed on two distinct designs for the atomic bombs. In Little Boy, the first atomic weapon, the fission reaction occurred when two masses of uranium collided together using a gun-type device to form a critical mass that initiated the reaction. In effect, one slug of uranium hit another after firing through a smooth-bore gun barrel. The target was in the shape of a solid spike measuring seven inches long and four inches in diameter. The cylinder fit precisely over the spike as the two collided together creating the highly explosive fission reaction. While the theory of the gun firing concept was not fully tested until the actual bomb dropped on Hiroshima, scientists conducted successful lab tests on a smaller scale that gave them confidence the method would be successful.

The final construction of Little Boy occurred in stages. Various components of the bomb were transported by train from Los Alamos, New Mexico, to San Francisco, California. There, the heavy cruiser USS Indianapolis shipped the collection of parts to Tinian Island in the Pacific Ocean south of Japan, where it arrived on July 26. In order to prevent a catastrophic accident, the target piece of enriched uranium flew separately aboard three C-54 Skymaster transport planes to Tinian Island, where it also arrived on July 26. Upon final assembly, Little Boy weighed 9,700 pounds and measured 10 feet in length and 28 inches in diameter.

Once on Tinian, the officer in charge of Little Boy’s assembly, U.S. Navy Capt. William S. Parsons, decided to forestall the final segment of assembly until the very last moment. He did this in order to prevent a catastrophic accidental detonation caused by an electrical short or crash.

The Mission

In the early morning hours of August 6, 1945, a B-29 bomber named Enola Gay took off from Tinian and proceeded north by northwest toward Japan. The bomber’s primary target was the city of Hiroshima, located on the deltas of southwestern Honshu Island facing the Inland Sea. Hiroshima had a civilian population of almost 300,000 and was a critical military center that included 43,000 soldiers.

The aircraft, piloted by the commander of the 509th Composite Group, Col. Paul Tibbets, flew at low altitude on automatic pilot before climbing to 31,000 feet as it closed in on the target area. At approximately 8:15 a.m. Hiroshima time, the Enola Gay released “Little Boy” over the city. Forty-three seconds later, a massive explosion lit the morning sky as the bomb detonated 1,900 feet above the city, directly over a parade field where soldiers of the Japanese Second Army were doing calisthenics.

Even though the Enola Gay had already flown 11 and a half miles away from the target after dropping its payload, it was rocked by the blast. After the initial shock wave hit the plane, the crew looked back at Hiroshima, and Tibbets recalled that “The city was hidden by that awful cloud . . . boiling up, mushrooming, terrible and incredibly tall.” [1] The force of the explosion was later estimated at 15 kilotons (the equivalent of 15,000 tons of TNT).

Many Americans viewed the bombing as a necessary means toward an end to the conflict with Japan. When Dr. J. Robert Oppenheimer was briefed on the bombing, he expressed guarded satisfaction. He, more than any other, understood the power of the weapon he helped produce and the destruction that was unleashed on humanity.

We will never definitively know how many died as a result of the bombing of Hiroshima. Some 70,000 people are estimated to have perished as a result of the initial blast, heat, and radiation effects. This included about 20 American airmen who were held as prisoners in the city. By the end of 1945, because of the continuing effects of radioactive fallout and other after effects, including radiation poisoning, the Hiroshima death toll was likely over 100,000. The five-year death total may have even exceeded 200,000, as cancer and other long-term effects are considered.

Read the blog post Harry Truman and the Bomb and the notes of Captain Robert Lewis, co-pilot of the Enola Gay, to learn more about the first atomic aomb.

Primary Sources

“Japanese doctors said that those who had been killed by the blast itself died instantly. But presently, according to these doctors, those who had suffered only small burns found their appetite failing, their hair falling out, their gums bleeding. They developed temperatures of 104, vomited blood, and died. It was discovered that they had lost 86 percent of their white blood corpuscles. Last week the Japanese announced that the count of Hiroshima’s dead had risen to 125,000.” — From the article “What Ended the War,” LIFE magazine, 9/17/1945

This article published in LIFE magazine was the first eye-witness account of the bombing that the American public was exposed to. The graphic description could only instill fear in the American public. This account made the public fully aware of the power and consequences of nuclear weaponry, and they became afraid about the future use of nuclear weaponry. This account could only cover the short-term effects of the atomic bomb and nuclear fallout, so the immediate fear quickly vanished and became passionate nationalism. However, once the long-term impact of dropping the atomic bomb over Japan became evident, ethical debates concerning the atomic bomb became prevalent in American politics and lay-person conversations. The public began to question governmental motives and science as a whole. Controversy swirled, and continues to swirl, around whether or not detonating the atomic bomb was a necessity in ending the war, or if it was simply a display of scientific power to set the United States apart from its enemies as a superior nation. Ultimately, first-hand accounts, such as this one, brought fear and distrust into the public sphere. This distrust and fear set the stage for cultural shifts, especially with the approach of the Cold War and scientific advancements concerning nuclear fallout.

Fallout Informational Documentary – 1955

This documentary aired in 1955, in the midst of the Cold War, as a precautionary informational video informing the general public on how to stay safe and avoid the harmful effects of nuclear fallout. As described in the video, fallout was not localized to the test site in which the nuclear weapon had been detonated, so anyone within a few hundred miles radius of the test site had to be careful to avoid nuclear fallout. Some of the safety steps explained include listening to the local radio for any updates on nearby nuclear fallout, avoiding windows and doors, using sandbags to prevent fallout from entering windows and small openings, and stocking up on supplies such as food and water in the event that nuclear fallout prevents leaving the home for extended periods of time. However, as the Cold War progressed, fears about nuclear fallout and radiation were not limited to only nuclear weapons testing as the public concern of a nuclear war grew as well. This documentary is an attempt to calm and inform the American public through small safety steps. However, nuclear fallout cannot be avoided simply by following the steps outlined in this documentary, but it gave the public a sense of control over a dangerous and scary situation. It also failed to acknowledge the true dangers that nuclear fallout can cause to people and the environment. Essentially, this documentary is nothing more than an attempt to use media to calm the fears of the American public as the Cold War waged on and the threat of nuclear war was deeply present in American culture.

Newspaper Article – 1995

As stated, this newspaper article concerns a man protesting at the Trinity Site in New Mexico where the first atomic bomb to be created was tested. A significant part of this event is that the man protesting was from Harrisburg, Pennsylvania, where one of the worst nuclear power plant meltdowns in the United States had ever occurred. The man is enraged by his personal experience with the harmful effects of nuclear radiation, and he most likely disagrees with the military action taken in Japan using nuclear weaponry. Culturally, this article exemplifies how different the American public’s perspective concerning nuclear fallout has come to be. Immediately following the bombing of Hiroshima and Nagasaki, Americans were afraid of nuclear power and how it could potentially harm them, especially as the Cold War progressed following World War II. However, the negative impacts of nuclear fallout had been discovered through various methods of scientific research over time, and the American public became frustrated with both their lack of control over nuclear weapons testing, and the carelessness with which the testing was done. This article shows the public’s sentiments concerning nuclear weapon use by the United States from both past and present, and the cultural shift that came along with this changing perspective.

Genes, Development, and Cancer – Edward B. Lewis, 2004

Edward B. Lewis was an American geneticist that had performed Nobel Prize winning studies on Drosophila, which founded the field of developmental genetics. During the 1950s and 1960s, he performed studies concerning the effects of nuclear radiation and nuclear fallout by examining the medical records of the survivors in Nagasaki and Hiroshima, and discovered that “health risks from radiation had been underestimated.” In a specific study done in prompted by atomic tests done in Nevada in 1958, Lewis discovered that the thyroids of young children and infants was susceptible to radioiodine released during these nuclear tests. Studies in the late 1950s showed that the milk of cows that had fed on the nuclear fallout contaminated grass near the test site in Nevada contained concentrated amounts of radioiodine. Therefore, when a young child or infant had been fed the contaminated milk, the thyroid of these individuals absorbed the beta radiation from radioiodine. A subsequent study showed a significant increase in thyroid cancer among individuals who were infants or young children during the atomic bomb testing done in 1958 in Nevada. Similarly, in 1963 Lewis performed a radiologist study which found that low doses of ionizing radiation, the type of radiation found in nuclear fallout, can induce leukemia in exposed individuals. The publication of these studies stoked the public’s aversion to nuclear weapons testing and development within the United States. The American public felt that the government was careless in testing these weapons within the country, where fallout could be carried for thousands of miles by jet streams, and effectively pollute the nation. The health hazards involved in nuclear detonation also resulted in a greater public fear of nuclear war during the Cold War, which resulted in a lifestyle driven by fear and distrust.

The invention of the nuclear bomb

The Trinity Test fireball, the first nuclear bomb, 16 milliseconds after ignition.

Leo Szilard was waiting to cross the road near Russell Square in London when the idea came to him. It was 12 September 1933. A little under 12 years later, the US dropped an atom bomb on Hiroshima, killing an estimated 135,000 people.

The path from Szilard’s idea to its deadly realisation is one of the most remarkable chapters in the history of science and technology. It features an extraordinary cast of characters, many of them refugees from Fascism who were morally opposed to the bomb but driven by the dreadful prospect of Nazi Germany getting there first.

Szilard himself was a Hungarian-born Jew who had fled Germany for the UK two months after Adolf Hitler became chancellor. He arrived in a country that was then at the forefront of nuclear physics. James Chadwick had just discovered the neutron and Cambridge physicists soon “split the atom”. They broke a lithium nucleus in two by bombarding it with protons, verifying Albert Einstein’s insight that mass and energy were one and the same, as expressed by the equation E = mc2.

Szilard’s eureka moment was based on this groundbreaking experiment. He reasoned that if you could find an atom that was split by neutrons and in the process emitted two or more neutrons, then a mass of this element would emit vast amounts of energy in a self-sustaining chain reaction.


Szilard pursued the idea with little success. It wasn’t until 1938 that the breakthrough came – ironically in the Nazi capital Berlin, where German physicists Otto Hahn and Fritz Strassman bombarded uranium atoms with neutrons. When they analysed the debris they were stunned to find traces of the much lighter element barium.

As luck would have it, Hahn and Strassman were opponents of the regime. Hahn wrote to the Austrian chemist Lise Meitner, who had worked with him in Berlin until she fled to Sweden after the Nazis occupied Vienna in 1938. Meitner wrote back explaining that the uranium nucleus was splitting into two roughly equal parts. She called the process “fission”.

The next piece of the puzzle came when Italian physicist Enrico Fermi, who had fled Fascism and was working at Columbia University in New York, discovered that uranium fission released the secondary neutrons that were needed to make the chain reaction happen. Szilard soon joined Fermi in New York.

Together they calculated that a kilogram of uranium would generate about as much energy as 20,000 tonnes of TNT. Szilard already saw the prospect of nuclear war. “There was very little doubt in my mind that the world was headed for grief,” he later recalled.

Others did have doubts, however. In 1939 the Danish physicist Niels Bohr – who was actively helping German scientists escape via Copenhagen – poured cold water on the idea. He pointed out that uranium-238, the isotope which makes up 99.3 per cent of natural uranium, would not emit secondary neutrons. Only a very rare isotope of uranium, uranium-235, would split in this way.

However, Szilard remained convinced that the chain reaction was possible, and feared that the Nazis knew it too. He consulted fellow Hungarian émigrés Eugene Wigner and Edward Teller. They agreed that Einstein would be the best person to alert President Roosevelt to the danger. Einstein’s famous letter was sent soon after the outbreak of war in Europe, but had little impact.

Things changed dramatically in 1940, when news filtered through that two German physicists working in the UK had proved Bohr wrong. Rudolf Peierls and Otto Frisch had worked out how to produce uranium-235 in large quantities, how it could be used to produce a bomb, and what the appalling consequences of dropping it would be. Peierls and Frisch – who Bohr had helped escape – were also horrified at the prospect of a Nazi bomb, and in March they wrote to the British government urging prompt action. Their “Memorandum on the Properties of a Radioactive ‘Super-Bomb‘” was more successful than Einstein’s letter to Roosevelt. It led to the initiation of the British bomb project, codenamed Tube Alloys.

The letter also galvanised the US into action. In April 1940 the government appointed the veteran physicist Arthur Compton to head a nuclear weapons programme, which eventually became the Manhattan Project. One of his first moves was to bring together various chain reaction research groups under one roof in Chicago. That summer the team began a series of experiments to make the chain reaction happen.

The bombing of Pearl Harbor in December 1941 added further impetus. A year later the Manhattan Project team was ready to attempt a chain reaction in a pile of uranium and graphite they had assembled in a squash court underneath a stand of the University of Chicago’s football field. On Wednesday, 2 December 1942, they did it.

Celebrations were muted. Once the reaction was confirmed, Szilard shook hands with Fermi and said: “This will go down as a black day in the history of mankind.”

Over the next four years the US, UK and Canada poured vast resources into the Manhattan Project. Tube Alloys continued for a while but was eventually absorbed into the US project. The Nazis initiated a nuclear weapons programme but made little progress.

On 16 July 1945 the US detonated the world’s first nuclear bomb in the New Mexico desert. The test was final, terrible proof that nuclear energy could be weaponised, and prompted Robert Oppenheimer to recall a passage from the Hindu scripture, Bhagavad Gita: “I am become death, the destroyer of worlds.”

The attacks on Japan started a worldwide arms race. Following 1945, the US developed massively destructive hydrogen bombs, which exploited nuclear fusion rather than fission. The Soviets developed and tested their own bomb in 1949. The world’s nuclear arsenal now stands at about 27,000 bombs.

Watch the video: Ποιος ήταν ο λόγος που εξαφανίστηκαν οι Δεινόσαυροι