The Atom Bomb: A Brief History


The Atom Bomb: A Brief History

A memory trip including dates and statistics, stating the facts, dates and events that took place during the starting phase of the Nuclear Weapons Project.

On August 2nd 1939, just before the beginning of World War II, Albert Einstein wrote to then President Franklin D. Roosevelt. Einstein and several other scientists told Roosevelt of efforts in Nazi Germany to purify U-235 with which might in turn be used to build an atomic bomb. It was shortly thereafter that the United States Government began the serious undertaking known only then as the Manhattan Project. Simply put, the Manhattan Project was committed to expedient research and production that would produce a viable atomic bomb.

The most complicated issue to be addressed was the production of ample amounts of `enriched' uranium to sustain a chain reaction. At the time, Uranium-235 was very hard to extract. In fact, the ratio of conversion from Uranium ore to Uranium metal is 500:1. An additional drawback is that the 1 part of Uranium that is finally refined from the ore consists of over 99% Uranium-238, which is practically useless for an atomic bomb. To make it even more difficult, U-235 and U-238 are precisely similar in their chemical makeup. This proved to be as much of a challenge as separating a solution of sucrose from a solution of glucose. No ordinary chemical extraction could separate the two isotopes. Only mechanical methods could effectively separate U-235 from U-238. Several scientists at Columbia University managed to solve this dilemma.

A massive enrichment laboratory/plant was constructed at Oak Ridge, Tennessee. H.C. Urey, along with his associates and colleagues at Columbia University, devised a system that worked on the principle of gaseous diffusion. Following this process, Ernest O. Lawrence (inventor of the Cyclotron) at the University of California in Berkeley implemented a process involving magnetic separation of the two isotopes.

Following the first two processes, a gas centrifuge was used to further separate the lighter U-235 from the heavier non-fissionable U-238 by their mass. Once all of these procedures had been completed, all that was needed to be done was to put to test the entire concept behind atomic fission.

Over the course of six years, ranging from 1939 to 1945, more than 2 billion dollars were spent on the Manhattan Project. The formulas for refining Uranium and putting together a working bomb were created and seen to their logical ends by some of the greatest minds of our time. Among these people who unleashed the power of the atomic bomb was J. Robert Oppenheimer.

Oppenheimer was the major force behind the Manhattan Project. He literally ran the show and saw to it that all great minds working on this project made their brainstorms work. He was amongst those who oversaw the entire project from its conception to its completion.

Finally the day came when all at Los Alamos would find out whether or not The Gadget (code-named during its development) was either going to be the colossal dud of the century or perhaps end the war. It all came down to a fateful morning of midsummer, 1945.

At 5:29:45 (Mountain War Time) on July 16th, 1945, in a white blaze that stretched from the basin of the Jemez Mountains in northern New Mexico to the still-dark skies, The Gadget ushered in the Atomic Age. The light of the explosion then turned orange as the atomic fireball began shooting upwards at 360 feet per second, reddening and pulsing as it cooled. The characteristic mushroom cloud of radioactive vapor materialized at 30,000 feet. Beneath the cloud, all that remained of the soil at the blast site were fragments of jade green radioactive glass...all of this caused by the heat of the reaction.

The brilliant light from the detonation pierced the early morning skies with such intensity that residents from a faraway neighboring community would swear that the sun came up twice that day. Even more astonishing is that a blind girl saw the flash 120 miles away.

Upon witnessing the explosion, reactions among the people who created it were mixed. Isidor Rabi felt that the equilibrium in nature had been upset -- as if humankind had become a threat to the world it inhabited. J. Robert Oppenheimer, though ecstatic about the success of the project, quoted a remembered fragment from Bhagavad Gita. "I am become Death," he said, "the destroyer of worlds." Ken Bainbridge, the test director, told Oppenheimer, "Now we're all sons of bitches."

Several participants, shortly after viewing the results, signed petitions against losing the monster they had created, but their protests fell on deaf ears. As it later turned out, the Jornada del Muerto of New Mexico was not the last site on planet Earth to experience an atomic explosion.

As many know, atomic bombs have been used only twice in warfare. The first and foremost blast site of the atomic bomb is Hiroshima. A Uranium bomb (which weighed in at over 4 & 1/2 tons) nicknamed "Little Boy" was dropped on Hiroshima August 6th, 1945. The Aioi Bridge, one of 81 bridges connecting the seven-branched delta of the Ota River, was the aiming point of the bomb. Ground Zero was set at 1,980 feet. At 0815 hours, the bomb was dropped from the Enola Gay. It missed by only 800 feet. At 0816 hours, in the flash of an instant, 66,000 people were killed and 69,000 people were injured by a 10 kiloton atomic explosion.

The point of total vaporization from the blast measured one half of a mile in diameter. Total destruction ranged at one mile in diameter. Severe blast damage carried as far as two miles in diameter. At two and a half miles, everything flammable in the area burned. The remaining area of the blast zone was riddled with serious blazes that stretched out to the final edge at a little over three miles in diameter.

On August 9th 1945, Nagasaki fell to the same treatment as Hiroshima. Only this time, a Plutonium bomb nicknamed "Fat Man" was dropped on the city. Even though the "Fat Man" missed by over a mile and a half, it still leveled nearly half the city. Nagasaki's population dropped in one split-second from 422,000 to 383,000. 39,000 were killed, over 25,000 were injured. That blast was less than 10 kilotons as well. Estimates from physicists who have studied each atomic explosion state that the bombs that were used, had utilized only 1/10th of 1 percent of their respective explosive capabilities.

While the mere explosion from an atomic bomb is deadly enough, its destructive ability doesn't stop there. Atomic fallout creates another hazard as well. The rain that follows any atomic detonation is laden with radioactive particles. Many survivors of the Hiroshima and Nagasaki blasts succumbed to radiation poisoning due to this occurrence.

The atomic detonation also has the hidden lethal surprise of affecting the future generations of those who live through it. Leukemia is among the greatest of afflictions that are passed on to the offspring of survivors.

While the main purpose behind the atomic bomb is obvious, there are many by-products that have been brought into consideration in the use of all weapons atomic. With one small atomic bomb, a massive area's communications, travel and machinery will grind to a dead halt due to the EMP (Electro- Magnetic Pulse) that is radiated from a high-altitude atomic detonation. These high-level detonations are hardly lethal, yet they deliver a serious enough EMP to scramble any and all things electronic ranging from copper wires all the way up to a computer's CPU within a 50-mile radius.

Conclusively, at one time, during the early days of The Atomic Age, it was a popular notion that one day atomic bombs would be used in mining operations and perhaps aid in the construction of another Panama Canal. Needless to say, it never came about. Instead, the military applications of atomic destruction increased. Atomic tests off the Bikini Atoll and several other sites were common until the Nuclear Test Ban Treaty was introduced. This treaty hopefully will be respected by all nations equally. 

The Decision to Use the Bomb

The modern nuclear arsenals and the struggle to control nuclear weaponry have brought new significance and controversy to the American use of the atomic bomb in World War II. This reading selection describes the circumstances surrounding the decision to use the atomic bomb. There is considerable debate among historians about the necessity of using the bomb to force Japan's surrender; there is perhaps even greater controversy concerning the moral principle involved in subjecting the two Japanese cities of Hiroshima and Nagasaki to this weapon. This latter point is raised, but not answered, at the end of the essay.

World War II was the second world-wide war in less than a generation's time. The World War I had erased any romantic illusions about the nature of modern war; World War II saw the complete mobilization of entire populations and economies in the waging of the war. It was fought with grim determination on every side. In such conditions, each side carried out acts of great brutality in the frustration and necessity of achieving victory.

For the first time outside a civil war, fighting spread beyond the armies to whole populations: Hitler used aerial bombing to try to break the spirit of the British; the Japanese used aerial bombing and soldiers against the Chinese civilian population; both Japan and Germany used their military forces to subdue resistance in occupied nations; and the allied forces used bombing to carry the war beyond the battle front and break the opposition of enemy populations. By the end of the war, technology had advanced to the point where such bombings were terrible: the allied bombing of Dresden killed tens of thousands of people, and the American firebombing of Tôkyô in March 1945 probably killed more than 100,000 people.

During this period, wartime technology raced ahead, as each side attempted to be the first to develop the techniques and equipment that would enable it to win. Many nations sought to decipher the secrets of atomic energy, but the United States was the first to develop the ultimate weapon, the atomic bomb.

Prelude to the Bomb: On April 1, 1945, the Allies invaded the southern Japanese island of Okinawa, and their victory there after bitter and bloody fighting with heavy losses on both sides proved that Japan could not win the war. It also proved, however, that invasion of the Japanese homeland would cause massive casualties on both sides. As American ground forces swept Okinawa clean of Japanese troops, the local civilians were caught in the middle. Subjected to gun fire, bombing, and infantry combat by the American advance, they were prevented from surrendering by the Japanese troops. Okinawa only served to confirm everyone's idea of how the final battle for the main islands of Japan would be fought.

The surrender of Okinawa caused the Japanese cabinet to collapse and a new, pro-peace prime minister and foreign minister pressed the army to allow negotiations. The Japanese military, however, trapped in its own mystique of rigid determination and self-sacrifice in the name of the nation and emperor, insisted on strict terms.

Just at this point, the atomic bomb became a reality. The first successful test of the atomic weapon was held on July l6, 1945. The United States now had the choice of using it to try to end the war in another way. All other forms of attack, from the grim battle for Okinawa to the terrible fire bombing of Japan's cities, had failed to deter the leaders in Tôkyô. Perhaps the atomic bomb would resolve the crisis without a need for invasion. President Truman, who had already left for Potsdam to meet with Churchill and Stalin, left instructions that the bomb was not to be used against Japan until after the Allies had agreed on and issued a declaration.

The Potsdam Declaration of July 26, issued by the Allied powers and calling for "unconditional surrender," was not acceptable to the Japanese military, despite the declaration's threat that failure to surrender would be met by "complete destruction" of the military and the "utter devastation of the Japanese home land." Following ten days of Japanese silence, the atomic bomb was dropped on August 6, 1945, on the city of Hiroshima.

The Impact on Japan: It was reported the next day to the Japanese Army General Staff that "the whole city of Hiroshima was destroyed instantly by a single bomb." On August 8 the army was further rocked by the news that the Russians, who had remained neutral to Japan throughout the war, had attacked Japanese forces on the Asian mainland. But despite the prime minister's insistence that Japan must accept surrender, the army insisted on total, last-ditch resistance. The news, midway through this conference, that the city of Nagasaki had also been destroyed by another atomic bomb, did not sway them from their determination.

Finally, the Japanese prime minister and his allies agreed that the only course was to have the emperor break the deadlock by expressing his view. The emperor's statement that Japan's suffering was unbearable to him and that he wished for surrender broke the military's opposition and began the process of ending the war in the Pacific.

Assessing the Decision: Was it necessary to use the atomic bomb to force Japan to surrender? This is a subject of heated debate among historians. Some point to the existence of a pro-peace faction in Japan, resisting the army and growing in strength. This faction had already tried to express Japan's interest in peace through the Russians, whom they believed were still neutral. In fact, the Russians had secretly agreed at the Yalta Conference in February 1945 to attack the Japanese.

Moreover, Japanese offensive capabilities were exhausted. The navy and air force were almost totally destroyed by the summer of 1945, and the Japanese islands were completely cut off from the rest of the world. The Russian attack of August 8 on Manchuria met little or no resistance.

Discussion Questions

1. How did the battle over the island of Okinawa influence the decision to use the atomic bomb?

2. How would you rank, from most important to least important, the several factors or considerations involved in the U.S. decision to drop the atomic bomb? Explain.

3. Today, the Japanese often say they have a "nuclear allergy," and the government accordingly has proclaimed "three nuclear principles," that it will not own or manufacture nuclear weapons and will not allow them to be brought into Japan.




Introduction

In August 1945 American aircraft dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki, killing over 100,000 people and injuring many more. Japan soon sued for peace and World War II ended. Ever since President Harry S. Truman made the fateful decision to unleash atomic weapons on Japan, contemporaries and historians have debated the morality, necessity, and consequences of the choice.

Truman said he authorized the use of the atomic bombs on populated areas because that was the only way to shorten the war and save American lives. Until the 1960s most historians accepted that conclusion. But recent scholarship, although not denying the argument that American lives would have been spared, has suggested that other considerations also influenced American leaders: relations with Soviet Russia, emotional revenge, momentum, and perhaps racism. Scholars today are also debating why several alternatives to military use of the bomb were not tried.

In early May 1945, Secretary of War Henry L. Stimson appointed an Interim Committee, with himself as chairman, to advise on atomic energy and the uranium bombs the Manhattan Engineering District project was about to produce. In the committee's meeting of May 31, 1945, the decision was made to keep the bomb project a secret from the Russians and to use the atomic bomb against Japan. On June 11, 1945, a group of atomic scientists in Chicago, headed by Jerome Franck, futilely petitioned Stimson for a non-combat demonstration of the bomb in order to improve the chances for postwar international control of atomic weapons. The recommendations of the Interim Committee and the Franck Committee are reprinted here.




Report of the Interim Committee on Military Use of the Atomic Bomb, May 1945 (1)

Secretary Stimson explained that the Interim Committee had been appointed by him, with the approval of the President, to make recommendations on temporary war-time controls, public announcement, legislation and post-war organization. . . . He expressed the hope that the [four] scientists would feel completely free to express their views on any phase of the subject.

The Secretary explained that General Marshall shared responsibility with him for making recommendations to the President on this project with particular reference to its military aspects; therefore, it was considered highly desirable that General Marshall be present at this meeting to secure at first hand the views of the scientists.

The Secretary expressed the view, a view shared by General Marshall, that this project should not be considered simply in terms of military weapons, but as a new relationship of man to the universe. This discovery might be compared to the discoveries of the Copernican theory and of the laws of gravity, but far more important than these in its effect on the lives of men. While the advances in the field to date had been fostered by the needs of war, it was important to realize that the implications of the project went far beyond the needs of the present war. It must be controlled if possible to make it an assurance of future peace rather than a menace to civilization.

The Secretary suggested that he hoped to have the following questions discussed during the course of the meeting:
  1. Future military weapons
  2. Future international competition
  3. Future research
  4. Future controls
  5. Future developments, particularly non-military.
At this point General Marshall discussed at some length the story of charges and counter-charges that have been typical of our relations with the Russians, pointing out that most of these allegations have proven unfounded. The seemingly uncooperative attitude of Russia in military matters stemmed from the necessity of maintaining security. He said that he had accepted this reason for their attitude in his dealings with the Russians and had acted accordingly. As to the post-war situation and in matters other than purely military, he felt that he was in no position to express a view. With regard to this field he was inclined to favor the building up of a combination among like minded powers, thereby forcing Russia to fall in line by the very force of this coalition. General Marshall was certain that we need have no fear that the Russians, if they had knowledge of our project, would disclose this information to the Japanese. He raised the question whether it might be desirable to invite two prominent Russian scientists to witness the test.

Mr. Byrnes expressed a fear that if information were given to the Russians, even in general terms, Stalin would ask to be brought into the partnership. He felt this to be particularly likely in view of our commitments and pledges of cooperation with the British. In this connection Dr. Bush pointed out that even the British do not have any of our blue prints on plants. Mr. Byrnes expressed the view, which was generally agreed to by all present, that the most desirable program would be to push ahead as fast as possible in production and research to make certain that we stay ahead and at the same time make every effort to better our political relations with Russia.

It was pointed out that one atomic bomb on an arsenal would not be much different from the effect caused by any Air Corps strike of present dimensions. However, Dr. Oppenheimer stated that the visual effect of an atomic bombing would be tremendous. It would be accompanied by a brilliant luminescence which would rise to a height of 10,000 to 20,000 feet. The neutron effect of the explosion would be dangerous to life for a radius of at least two-thirds of a mile.

After much discussion concerning various types of targets and the effects to be produced, the Secretary expressed the conclusion, on which there was general agreement, that we could not give the Japanese any warning; that we could not concentrate on a civilian area; but that we should seek to make a profound psychological impression on as many of the inhabitants as possible. At the suggestion of Dr. Conant the Secretary agreed that the most desirable target would be a vital war plant employing a large number of workers and closely surrounded by workers' houses.

There was some discussion of the desirability of attempting several strikes at the same time. Dr. Oppenheimer's judgment was that several strikes would be feasible. General Groves, however, expressed doubt about this proposal and pointed out the following objections: (1) We would lose the advantage of gaining additional knowledge concerning the weapon at each successive bombing; (2) such a program would require a rush job on the part of those assembling the bombs and might, therefore, be ineffective; (3) the effect would not be sufficiently distinct from our regular Air Force bombing program.




Report of the Franck Committee on the Social and Political Implications of a Demonstration of the Atomic Bomb (For a Non-Combat Demonstration), June, 1945 

The way in which the nuclear weapons, now secretly developed in this country, will first be revealed to the world appears of great, perhaps fateful importance.

One possible way--which may particularly appeal to those who consider the nuclear bombs primarily as a secret weapon developed to help win the present war--is to use it without warning on an appropriately selected object in Japan. It is doubtful whether the first available bombs, of comparatively low efficiency and small size, will be sufficient to break the will or ability of Japan to resist, especially given the fact that the major cities like Tôkyô, Nagoya, Osaka and Kôbe already will largely be reduced to ashes by the slower process of ordinary aerial bombing. Certain and perhaps important tactical results undoubtedly can be achieved, but we nevertheless think that the question of the use of the very first available atomic bombs in the Japanese war should be weighed very carefully, not only by military authority, but by the highest political leadership of this country. If we consider international agreement on total prevention of nuclear warfare as the paramount objective and believe that it can be achieved, this kind of introduction of atomic weapons to the world may easily destroy all our chances of success. Russia, and even allied countries which bear less mistrust of our ways and intentions, as well as neutral countries, will be deeply shocked. It will be very difficult to persuade the world that a nation which was capable of secretly preparing and suddenly releasing a weapon, as indiscriminate as the rocket bomb and a thousand times more destructive, is to be trusted in its proclaimed desire of having such weapons abolished by international agreement. We have large accumulations of poison gas, but do not use them, and recent polls have shown that public opinion in this country would disapprove of such a use even if it would accelerate the winning of the Far Eastern war. It is true, that some irrational element in mass psychology makes gas poisoning more revolting than blasting by explosives, even though gas warfare is in no way more "inhuman" than the war of bombs and bullets. Nevertheless, it is not at all certain that the American public opinion, if it could be enlightened as to the effect of atomic explosives, would support the first introduction by our own country of such an indiscriminate method of wholesale destruction of civilian life.

Thus, from the "optimistic" point of view--looking forward to an international agreement on prevention of nuclear warfare--the military advantages and the saving of American lives, achieved by the sudden use of atomic bombs against Japan, may be outweighed by the ensuing loss of confidence and wave of horror and repulsion, sweeping over the rest of the world, and perhaps dividing even the public opinion at home.

From this point of view a demonstration of the new weapon may best be made before the eyes of representatives of all United Nations, on the desert or a barren island. The best possible atmosphere for the achievement of an international agreement could be achieved if America would be able to say to the world, "You see what weapon we had but did not use. We are ready to renounce its use in the future and to join other nations in working out adequate supervision of the use of this nuclear weapon."

This may sound fantastic, but then in nuclear weapons we have something entirely new in the order of magnitude of destructive power, and if we want to capitalize fully on the advantage which its possession gives us, we must use new and imaginative methods. After such a demonstration the weapon could be used against Japan if a sanction of the United Nations (and of the public opinion at home) could be obtained, perhaps after a preliminary ultimatum to Japan to surrender or at least to evacuate a certain region as an alternative to the total destruction of this target.

It must be stressed that if one takes a pessimistic point of view and discounts the possibilities of an effective international control of nuclear weapons, then the advisability of an early use of nuclear bombs against Japan becomes even more doubtful--quite independently of any humanitarian considerations. If no international agreement is concluded immediately after the first demonstration, this will mean a flying start of an unlimited armaments race. If this race is inevitable, we have all reason to delay its beginning as long as possible in order to increase our head start still further. . . . The benefit to the nation, and the saving of American lives in the future, achieved by renouncing an early demonstration of nuclear bombs and letting the other nations come into the race only reluctantly, on the basis of guess work and without definite knowledge that the "thing does work," may far outweigh the advantages to be gained by the immediate use of the first and comparatively inefficient bombs in the war against Japan. At the least, pros and cons of this use must be carefully weighed by the supreme political and military leader ship of the country, and the decision should not be left to considerations, merely, of military tactics.

One may point out that scientists themselves have initiated the development of this "secret weapon" and it is therefore strange that they should be reluctant to try it out on the enemy as soon as it is available. The answer to this question was given above--the compelling reason for creating this weapon with such speed was our fear that Germany had the technical skill necessary to develop such a weapon without any moral restraints regarding its use.

Another argument which could be quoted in favor of using atomic bombs as soon as they are available is that so much taxpayers money has been invested in those projects that the Congress and the American public will require a return for their money. The above-mentioned attitude of the American public opinion in the question of the use of poison gas against Japan shows that one can expect, it to understand that a weapon can sometimes be made ready only for use in extreme emergency; and as soon as the potentialities of nuclear weapons will be revealed to the American people, one can be certain that it will support all attempts to make the use of such weapons impossible.

(1) and (2) From Major Problems in American Foreign Policy by Thomas G. Paterson. Copyright c 1978 by D.C. Heath and Company. Reprinted by permission of the publisher.


The Potsdam Declaration, July 26, 1945 

Proclamation Defining the Terms for the Japanese Surrender July 26, 1945

(1) WE--THE PRESIDENT of the United States, the President of the National Government of the Republic of China, and the Prime Minister of Great Britain, representing the hundreds of millions of our countrymen, have conferred and agree that Japan shall be given an opportunity to end this war.

(2) The prodigious land, sea and air forces of the United States, the British Empire and of China, many times reinforced by their armies and air fleets from the west, are poised to strike the final blows upon Japan. This military power is sustained and inspired by the determination of all the Allied Nations to prosecute the war against Japan until she ceases to resist.

(3) The result of the futile and senseless German resistance to the might of the aroused free peoples of the world stands forth in awful clarity as an example to the people of Japan. The might that now converges on Japan is immeasurably greater than that which, when applied to the resisting Nazis, necessarily laid waste to the lands, the industry, and the method of life of the whole German people. The full application of our military power backed by our resolve, will mean the inevitable and complete destruction of the Japanese armed forces and just as inevitably the utter devastation of the Japanese homeland.

(4) The time has come for Japan to decide whether she will continue to be controlled by those self-willed militaristic advisers whose unintelligent calculations have brought the Empire of Japan to the threshold of annihilation, or whether she will follow the path of reason.

(5) Following are our terms. We will not deviate from them. There are no alternatives. We shall brook no delay.

(6) There must be eliminated for all time the authority and influence of those who have deceived and misled the people of Japan into embarking on world conquest, for we insist that a new order of peace, security and justice will be impossible until irresponsible militarism is driven from the world.

(7) Until such a new order is established and until there is convincing proof that Japan's war-making power is destroyed, points in Japanese territory to be designated by the Allies shall be occupied to secure the achievement of the basic objectives we are here setting forth.

(8) The terms of the Cairo Declaration shall be carried out and Japanese sovereignty shall be limited to the islands of Honshû, Hokkaidô, Kyûshû, Shikoku and such minor islands as we determine.

(9) The Japanese military forces, after being completely disarmed, shall be permitted to return to their homes with the opportunity to lead peaceful and productive lives.

(10) We do not intend that the Japanese shall be enslaved as a race or destroyed as a nation, but stern justice shall be meted out to all war criminals, including those who have visited cruelties upon our prisoners. The Japanese Government shall remove all obstacles to the revival and strengthening of democratic tendencies among the Japanese people. Freedom of speech, of religion, and of thought, as well as respect for the fundamental human rights shall be established.

(11) Japan shall be permitted to maintain such industries as will sustain her economy and permit the exaction of just reparations in kind, but not those which would enable her to rearm for war. To this end, access to, as distinguished from control of, raw materials shall be permitted. Eventual participation in world trade relations shall be permitted.

(12) The occupying forces of the Allies shall be withdrawn from Japan as soon as these objectives have been accomplished and there has been established in accordance with the freely expressed will of the Japanese people a peacefully inclined and responsible government.

(13) We call upon the government of Japan to proclaim now the unconditional surrender of all Japanese armed forces, and to provide proper and adequate assurances of their good faith in such action. The alternative for Japan is prompt and utter destruction.

(3) This and other documents such as the Japanese surrender offer and the Imperial rescripts can be found in the appendices of Robert J. C. Buton Japan's Decision to Surrender (Stanford, California: Stanford University Press, 1954.)