Hiroshima, Nagasaki & the First Atomic Bombs Hiroshima, Nagasaki & the First Atomic Bombs By Marc Lallanilla, Staff Writer | May 9, 2014 07:27pm ET MORE This photo of the mushroom cloud over Nagasaki was taken by Charles Levy from one of the B-29 Superfortresses used in the attack. Credit: U.S. National Archives By the summer of 1945, World War II had raged across several continents for six years, beginning when German forces invaded Poland in 1939. To a world grown weary of death and destruction, the surrender of Nazi Germany on May 8, 1945, was welcome news. Japan, however, vowed to fight to the very end. Their resolve was evident in the Battle of Okinawa: By the time it ended in June, Allied forces lost more than 14,000 soldiers and Japan's military suffered more than 77,000 deaths — plus the loss of an estimated 100,000 Japanese civilians. Against this backdrop, Allied forces drew up plans for Operation Downfall, a large-scale invasion of Japan.

But with Allied casualties from an invasion estimated to reach 1 million deaths — plus another 10 million Japanese casualties, including civilians — Allied planners searched for another way to end the war, which they found in the Manhattan Project. This is a mockup of "Little Boy," the atomic bomb that was dropped over Hiroshima, Japan, on Aug. 6, 1945. Credit: U.S. National Archives The Manhattan Project Concerned over reports that Nazi Germany was developing a new type of weapon using radioactive uranium, in 1939 U.S. government officials began to investigate the potential of uranium — particularly the uranium-235 isotope — for making a powerful bomb. Within a matter of months, a coalition of American, British and European scientists — many of whom were refugees from Germany, Italy and other fascist nations — began collaborating on a vast international project to develop a uranium-based bomb before any Axis powers beat them to it. Because one early component of the project was based in the U.S. Army's Manhattan District, the name Manhattan Project eventually stuck, though work was carried out in Los Alamos, New Mexico; Oak Ridge, Tennessee; Hanford, Washington; Chalk River, Ontario, and several other sites.

After several years of intensive research under strict secrecy, the Manhattan Project developed two different bombs that used two different nuclear materials: uranium-235 and plutonium-239. This is a mockup of "Fat Man," the atomic bomb that was dropped over Nagasaki, Japan, on Aug. 9, 1945. Credit: U.S. Department of Defense 'Little Boy' and 'Fat Man' About 140 pounds (64 kilograms) of highly enriched uranium-235 was used to create "Little Boy," a nuclear-fission bomb that worked by shooting a large, hollow cylinder of uranium over a smaller uranium insert. Far from little, the bomb weighed about 9,700 pounds (4,400 kg). "Fat Man" was even bigger — about 10,300 pounds (4,670 kg) — and used a core of plutonium-239 to create a nuclear chain reaction that would release the energy of about 21 kilotons of TNT dynamite.

[ Countdown: Top 10 Greatest Explosions Ever ] The complexity of the plutonium bomb caused some concern among project engineers, so a test of the bomb was scheduled for July 16, 1945. On that day, at Alamogordo, New Mexico, the first atomic bomb blast the world had ever witnessed occurred, ushering in the Atomic Age. One of the few buildings left standing in Hiroshima was the Genbaku Dome of the Hiroshima Chamber of Commerce, which stood very close to the epicenter of the atomic bomb blast on Aug. 6, 1945. Today it is preserved as a peace memorial and is a UNESCO world heritage site. Credit: Public domain. Hiroshima In 1945, Hiroshima, Japan, was a city of about 350,000 people that was largely untouched by the war. Situated on a coastal plain, the city was an important manufacturing and military center — at least 40,000 military personnel were stationed in Hiroshima during the summer of 1945. For these and other reasons, the city was selected as the first target of an atomic bomb attack. Early in the morning of Aug.

6, a B-29 airplane named Enola Gay (after the mother of its pilot, Colonel Paul Tibbets) took off from Tinian, an island roughly six hours from Hiroshima by air. Inside the Enola Gay's bomb bay was "Little Boy." At 8:15 a.m., the Enola Gay's bay doors opened and "Little Boy" was dropped over Hiroshima. The bomb exploded about 1,900 feet (580 meters) over the unsuspecting city. The enormous blast instantly destroyed most of the city and claimed some 45,000 lives; another 19,000 people are estimated to have died from radiation exposure or other direct effects within four months. "The mushroom [cloud] 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," said the Enola Gay's tail gunner, Staff Sgt. Robert Caron. "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." On the ground, however, the scene was more horrific than spectacular.

"In the following waves [after the initial blast] people’s bodies were terribly squeezed, then their internal organs ruptured," wrote a journalist with LIFE magazine . "Then the blast blew the broken bodies at 500 to 1,000 miles per hour through the flaming, rubble-filled air. Practically everybody within a radius of 6,500 feet was killed or seriously injured and all buildings crushed or disemboweled." These photos show Nagasaki before and after the atomic blast on Aug. 9, 1945. Credit: U.S. National Archives Nagasaki To the surprise of some Allied military commanders, the destruction of Hiroshima did not bring about a Japanese surrender. Of the cities remaining on the Allied force's list of potential targets, the ancient fortress city of Kokura was at the top of the list. Shortly before 4 a.m. on Aug. 9, a B-29 named Bockscar (a pun on the aircraft's captain, Frederick C. Bock) took off from Tinian, headed for the city of Kokura.

In the plane's bomb bay was the plutonium-fueled "Fat Man." Cloud cover and poor visibility over Kokura spared the city, so the crew of Bockscar headed toward Nagasaki. A large seaport, the city was home to several important manufacturers, including the Mitsubishi Steel and Arms Works, and enterprises devoted to shipbuilding, weapons development and other military industries. It, too, was obscured by clouds, but the crew was able to find a break in the cloud cover, and shortly after 11 a.m., "Fat Man" exploded over Nagasaki. The powerful blast destroyed much of the city, and at least 40,000 people were killed immediately. The hilly terrain of Nagasaki — and the fact that the bomb was dropped almost 2 miles (3.2 km) from its intended target — prevented greater destruction. Nonetheless, by the end of 1945, about 80,000 people died from the bomb over Nagasaki. About half of the city was reduced to rubble and ash by the blast and the subsequent fires. Effects of the blasts At noon on Aug.

15 — six days after Nagasaki was bombed — Japanese Emperor Hirohito announced an unconditional surrender, effectively ending World War II. Jubilant celebrations broke out across the globe, but there was little to celebrate in Japan. The exact number of deaths from the bombings of Hiroshima and Nagasaki will never be known, but at least 103,000 died from the immediate blast or the effects of radiation sickness, according to the World Nuclear Organization . There were also a high number of stillbirths and birth deformities reported among survivors of the bombings. However, no long-term genetic damage has been reported among the survivor's children, who are subject to ongoing screening. After the victors' initial celebrations quieted down, there was profound soul-searching by most of the people involved in the decision to use atomic weaponry. The devastation wrought by two just two bombs was unprecedented in human history, and the debate over the use of nuclear weapons remains relevant to this day. "Yesterday man unleashed the atom to destroy man, and another chapter in human history opened, a chapter in which the weird, the strange, the horrible becomes the trite and obvious," wrote a New York Times correspondent one day after the Hiroshima bombing.

Alarmed by the use of atomic weaponry, many of the scientists responsible for the Manhattan Project organized as the Federation of Atomic Scientists , an organization that continues to work against nuclear proliferation. Atom bomb successfully tested - Jul 16, 1945 - HISTORY.com Atom bomb successfully tested Publisher A+E Networks On this day in 1945, at 5:29:45 a.m., the Manhattan Project comes to an explosive end as the first atom bomb is successfully tested in Alamogordo, New Mexico. Plans for the creation of a uranium bomb by the Allies were established as early as 1939, when Italian emigre physicist Enrico Fermi met with U.S. Navy department officials at Columbia University to discuss the use of fissionable materials for military purposes. That same year, Albert Einstein wrote to President Franklin Roosevelt supporting the theory that an uncontrolled nuclear chain reaction had great potential as a basis for a weapon of mass destruction. In February 1940, the federal government granted a total of $6,000 for research.

But in early 1942, with the United States now at war with the Axis powers, and fear mounting that Germany was working on its own uranium bomb, the War Department took a more active interest, and limits on resources for the project were removed. Brigadier-General Leslie R. Groves, himself an engineer, was now in complete charge of a project to assemble the greatest minds in science and discover how to harness the power of the atom as a means of bringing the war to a decisive end. The Manhattan Project (so-called because of where the research began) would wind its way through many locations during the early period of theoretical exploration, most importantly, the University of Chicago, where Enrico Fermi successfully set off the first fission chain reaction. But the Project took final form in the desert of New Mexico, where, in 1943, Robert J. Oppenheimer began directing Project Y at a laboratory at Los Alamos, along with such minds as Hans Bethe, Edward Teller, and Fermi. Here theory and practice came together, as the problems of achieving critical mass-a nuclear explosion-and the construction of a deliverable bomb were worked out.

Finally, on the morning of July 16,in the New Mexico desert120 miles south of Santa Fe, the first atomic bomb was detonated. The scientists and a few dignitaries had removed themselves 10,000 yards away to observe as the first mushroom cloud of searing light stretched 40,000 feet into the air and generated the destructive power of 15,000 to 20,000 tons of TNT. The tower on which the bomb sat when detonated was vaporized. The question now became-on whom was the bomb to be dropped? Germany was the original target, but the Germans had already surrendered. The only belligerent remaining was Japan. A footnote: The original $6,000 budget for the Manhattan Project finally ballooned to a total cost of $2 billion. Related Videos The First Atomic Bomb Blast, 1945 The First Atomic Bomb Blast, 1945 Printer Friendly Version >>> The events that took place in a remote area of New Mexico during the predawn hours of July 16, 1945 forever changed the world.

In the early morning darkness the incredible destructive powers of the atom were first unleashed and what had been merely theoretical became reality. The blast, .034 seconds after detonation The test was the culmination of three years' planning and development within the super secret Manhattan Project headed by General Leslie R. Groves. Dr. J. Robert Oppenheimer directed the scientific team headquartered at Los Alamos, New Mexico. An isolated corner of the Alamogordo Bombing and Gunnery Range located 230 miles south of Los Alamos was selected for the test that was given the code-name "Trinity." Even before the bomb was tested, a second bomb was secretly dispatched to the Pacific for an attack on the Japanese city of Hiroshima. Preparations for the test included the building of a steel tower that would suspend the bomb one hundred feet above ground. Many were apprehensive - there were concerns that the blast might launch a cataclysmic reaction in the upper atmosphere leading to world destruction. Some feared the consequences of radio-active fallout on civilian populations surrounding the test site. Still others feared the test would be an outright dud. Observers were sent to surrounding towns to monitor the results of the blast and medical teams were kept on alert.

Finally, the rains that had delayed the test for almost two weeks subsided and in the darkness of that July morning history was made. "We were reaching into the unknown and we did not know what might come of it." Two days after the blast, General Groves, head of the Manhattan Project, sent a Top Secret memorandum to Secretary of War Stimson detailing the events of that morning. Groves included the description of General Thomas Farrell who was in an observation hut close to the blast along with a hand-full of scientists and other personnel. We join General Farrell's account a few hours before the explosion: ADVERTISMENT "The scene inside the shelter was dramatic beyond words. In and around the shelter were some twenty-odd people concerned with last minute arrangements prior to firing the shot. Included were: Dr. Oppenheimer, the Director who had borne the great scientific burden of developing the weapon from the raw materials made in Tennessee and Washington and a dozen of his key assistants - Dr. Kistiakowsky, who developed the highly special explosives; Dr. Bainbridge, who supervised all the detailed arrangements for the test; Dr. Hubbard, the weather expert, and several others.

Besides these, there were a handful of soldiers, two or three Army officers and one Naval officer. The shelter was cluttered with a great variety of instruments and radios. For some hectic two hours preceding the blast, General Groves stayed with the Director, walking with him and steadying his tense excitement. Every time the Director would be about to explode because of some untoward happening, General Groves would take him off and walk with him in the rain, counseling with him and reassuring him that everything would be all right. At twenty minutes before zero hour, General Groves left for his station at the base camp, first because it provided a better observation point and second, because of our rule that he and I must not be together in situations where there is an element of danger, which existed at both points. General Leslie R. Groves (left) and Dr. J. Robert Oppenhiemer Just after General Groves left, announcements began to be broadcast of the interval remaining before the blast. They were sent by radio to the other groups participating in and observing the test. As the time interval grew smaller and changed from minutes to seconds, the tension increased by leaps and bounds.

Everyone in that room knew the awful potentialities of the thing that they thought was about to happen. The scientists felt that their figuring must be right and that the bomb had to go off but there was in everyone's mind a strong measure of doubt. The feeling of many could be expressed by ''Lord, I believe; help Thou mine unbelief.' We were reaching into the unknown and we did not know what might come of it. It can be safely said that most of those present - Christian, Jew and Atheist - were praying and praying harder than they had ever prayed before. If the shot were successful, it was a justification of the several years of intensive effort of tens of thousands of people statesmen, scientists, engineers, manufacturers, soldiers, and many others in every walk of life. In that brief instant in the remote New Mexico desert the tremendous effort of the brains and brawn of all these people came suddenly and startlingly to the fullest fruition. Dr. Oppenheimer, on whom had rested a very heavy burden, grew tenser as the last seconds ticked off. He scarce breathed. He held on to a post to steady himself.

For the last few seconds, he stared directly ahead and then when the announcer shouted 'Now!' and there came this tremendous burst of light followed shortly thereafter by the deep growling roar of the explosion, his face relaxed into an expression of tremendous relief. Several of the observers standing back of the shelter to watch the lighting effects were knocked flat by the blast. The tension in the room let up and all started congratulating each other. Everyone sensed 'This is it!' No matter what might happen now all knew that the impossible scientific job had been done. Atomic fission would no longer be hidden in the cloisters of the theoretical The bomb is unloaded at the base of the tower. July 13, 1945 physicists' dreams. It was almost full grown at birth. It was a great new force to be used for good or for evil. There was a feeling in that shelter that those concerned with its nativity should dedicate their lives to the mission that it would always be used for good and never for evil. Dr. Kistiakowsky, the impulsive Russian, [actually an American and a Harvard professor] threw his arms around Dr. Oppenheimer and embraced him with shouts of glee. Others were equally enthusiastic.

All the pent-up emotions were released in those few minutes and all seemed to sense immediately that the explosion had far exceeded the most optimistic expectations and wildest hopes of the scientists. All seemed to feel that they had been present at the birth of a new age - The Age of Atomic Energy - and felt their profound responsibility to help in guiding into right channels the tremendous forces which had been unleashed for the first time in history. As to the present war, there was a feeling that no matter what else might happen, we now had the means to insure its speedy conclusion and save thousands of American lives." References: General Farrell's account appears in - Department of State, Foreign Relations for the United States Conference of Berlin (Potsdam) (1945); Lansing, Lamont, Day of Trinity (1965). How To Cite This Article: "The First Atomic Bomb Blast, 1945," EyeWitness to History, (2003). First Atomic Bomb Dropped on Japan; Missile Is Equal to 20,000 Tons of TNT; Truman Warns Foe of a 'Rain of Ruin' Read the full text of The Times article or other headlines from the day.

First Atomic Bomb Dropped on Japan; Missile Is Equal to 20,000 Tons of TNT; Truman Warns Foe of a 'Rain of Ruin' NEW AGE USHERED Day of Atomic Energy Hailed by President, Revealing Weapon HIROSHIMA IS TARGET 'Impenetrable' Cloud of Dust Hides City After Single Bomb Strikes By SIDNEY SHALETT Special to THE NEW YORK TIMES RELATED HEADLINES Report by Britain: 'By God's Mercy' We Beat Nazis to Bomb, Churchill Says: Roosevelt Aid Cited: Raiders Wrecked Norse Laboratory in Race for Key to Victory Steel Tower 'Vaporized' in Trial of Mighty Bomb: Scientists Awe-Struck as Blinding Flash Lighted New Mexico Desert and Great Cloud Bore 40,000 Feet Into Sky Trains Canceled in Stricken Area: Traffic Around Hiroshima Is Disrupted -- Japanese Still Sift Havoc by Split Atoms Atom Bombs Made in 3 Hidden 'Cities': Secrecy on Weapon So Great That Not Even Workers Knew of Their Product Reich Exile Emerges as Heroine in Denial to Nazis of Atom's Secret OTHER HEADLINES Hiram W.

Johnson, Republican Dean in the Senate, Dies: Isolationist Helped Prevent U.S. Entry Into League -- Opposed World Charter: California Ex-Governor Ran for Vice President With Theodore Roosevelt in '12 -- In Washington Since '17 Jet Plane Explosion Kills Major Bong, Top U.S. Ace: Flier Who Downed 40 Japanese Craft, Sent Home to Be 'Safe,' Was Flying New 'Shooting Star' as a Test Pilot Kyushu City Razed: Kenney's Planes Blast Tarumizu in Reord Blow From Okinawa, Rocket Site Is Seen, 125 B-29's Hit Japan's Toyokawa Naval Arsenal in Demolition Strike Morris Is Accused of 'Taking a Walk': Fusion Official 'Sad to Part Company' -- McGoldrick Sees Only Tammany Aided Chinese Win More of 'Invasion Coast': Smash Into Port 121 Miles Southwest of Canton -- Big Area Open for Landing Turks Talk War if Russia Presses; Prefer Vain Battle to Surrender Washington, Aug.

6 -- The White House and War Department announced today that an atomic bomb, possessing more power than 20,000 tons of TNT, a destructive force equal to the load of 2,000 B-29's and more than 2,000 times the blast power of what previously was the world's most devastating bomb, had been dropped on Japan. The announcement, first given to the world in utmost solemnity by President Truman, made it plain that one of the scientific landmarks of the century had been passed, and that the "age of atomic energy," which can be a tremendous force for the advancement of civilization as well as for destruction, was at hand. At 10:45 o'clock this morning, a statement by the President was issued at the White House that sixteen hours earlier- about the time that citizens on the Eastern seaboard were sitting down to their Sunday suppers- an American plane had dropped the single atomic bomb on the Japanese city of Hiroshima, an important army center. Japanese Solemnly Warned What happened at Hiroshima is not yet known.

The War Department said it "as yet was unable to make an accurate report" because "an impenetrable cloud of dust and smoke" masked the target area from reconnaissance planes. The Secretary of War will release the story "as soon as accurate details of the results of the bombing become available." But in a statement vividly describing the results of the first test of the atomic bomb in New Mexico, the War-Department told how an immense steel tower had been "vaporized" by the tremendous explosion, how a 40,000-foot cloud rushed into the sky, and two observers were knocked down at a point 10,000 yards away. And President Truman solemnly warned: "It was to spare the Japanese people from utter destruction that the ultimatum of July 26, was issued at Potsdam. Their leaders promptly rejected that ultimatum.

If they do not now accept our terms, they may expect a rain of ruin from the air the like of which has never been seen on this earth." Most Closely Guarded Secret The President referred to the joint statement issued by the heads of the American, British and Chinese Governments in which terms of surrender were outlined to the Japanese and warning given that rejection would mean complete destruction of Japan's power to make war. [The atomic bomb weighs about 400 pounds and is capable of utterly destroying a town, a representative of the British Ministry of Aircraft Production said in London, the United Press reported.] What is this terrible new weapon, which the War Department also calls the "Cosmic Bomb"? It is the harnessing of the energy of the atom, which is the basic power of the universe. As President Truman said, "The force from which the sun draws its power has been loosed against those who brought war to the Far East." "Atomic fission" - in other words, the scientists' long-held dream of splitting the atom- is the secret of the atomic bomb. Uranium, a rare, heavy metallic element, which is radioactive and akin to radium, is the source essential to its production. Secretary of War Henry L.

Stimson, in a statement closely following that of the President, promised that "steps have been taken, to assure us of adequate supplies of this mineral." The imagination-sweeping experiment in harnessing the power of the atom has been the most closely guarded secret of the war. America to date has spent nearly $2,000,000,000 in advancing its research. Since 1939, American, British and Canadian scientists have worked on it. The experiments have been conducted in the United States, both for reasons of achieving concentrated efficiency and for security; the consequences of having the material fall into the hands of the enemy, in case Great Britain should have been successfully invaded, were too awful for the Allies to risk. All along, it has been a race with the enemy. Ironically enough, Germany started the experiments, but we finished them. Germany made the mistake of expelling, because she was a "non-Aryan," a woman scientist who held one of the keys to the mystery, and she made her knowledge available to those who brought it to the United States.

Germany never quite mastered the riddle, and the United States, Secretary Stimson declared, is "convinced that Japan will not be in a position to use an atomic bomb in this war." A Sobering Awareness of Power Not the slightest spirit of braggadocio is discernible either in the wording of the official announcements or in the mien of the officials who gave out the news. There was an element of elation in the realization that we had perfected this devastating weapon for employment against an enemy who started the war and has told us she would rather be destroyed than surrender, but it was grim elation. There was sobering awareness of the tremendous responsibility involved. Secretary Stimson said that this new weapon "should prove a tremendous aid in the shortening of the war against Japan," and there were other responsible officials who privately thought that this was an extreme understatement, and that Japan might find herself unable to stay in the war under the coming rain of atom bombs. It was obvious that officials at the highest levels made the important decision to release news of the atomic bomb because of the psychological effect it may have in forcing Japan to surrender. However, there are some officials who feel privately it might have been well to keep this completely secret.

Their opinion can be summed up in the comment by one spokesman: "Why bother with psychological warfare against an enemy that laready is beaten and hasnt't sense enough to quit and save herself from utter doom?" The first news came from President Truman's office. Newsmen were summoned and the historic statement from the Chief Executive,who still is on the high seas, was given to them. "That bomb," Mr. Truman said, "had more power than 20,000 tons of TNT. It had more than 2,000 times the blast power of the British 'Grand Slam,' which is the largest bomb (22,000 pounds) ever yet used in the history of warfare." Explosive Charge Is Small No details were given on the plane that carried the bomb. Nor was it stated whether the bomb was large or small. The President, however, said the explosive charge was "exceedingly small." It is known that tremendous force is packed into tiny quantities of the element that constitutes these bombs. Scientists, looking to the peacetime uses of atomic power, envisage submarines, ocean liners and planes traveling around the world on a few pounds of the element.

Yet, for various reasons, the bomb used against Japan could have been extremely large. Hiroshima, first city on earth to be the target of the "Cosmic Bomb," is a city of 318,000, which is- or was- a major quartermaster depot and port of embarkation for the Japanese. In addition to large military supply depots, it manufactured ordinance, mainly large guns and tanks, and machine tools, and aircraft-ordinance parts. President Truman grimly told the Japanese that "the end is not yet." "In their present form these bombs are now in production," he said, "and even more powerful forms are in development." He sketched the story of how the late President Roosevelt and Prime Minister Churchill agreed that it was wise to concentrate research in America, and how great secret cities sprang up in this country, where, at one time, 125,000 men and women labored to harness the atom. Even today more than 65,000 workers are employed. "What has been done," he said, "is the greatest achievement of organized science in history.

"We are now prepared to obliterate more rapidly and completely every productive and enterprise the Japanese have above ground in any city. We shall destroy Japan's power to make war." The President emphasized that the atomic discoveries were so important, both for the war and for the peace, that he would recommend to Congress that it consider promptly establishing "an appropriate commission to control the production and use of atomic power within the United States." "I shall give further consideration and make further recommendations to the Congress as to how atomic power can become a powerful and forceful influence toward the maintenance of world peace," he said. Secretary Stimson called the atomic bomb "the culmination of years of herculean effort on the part of science and industry, working in cooperation with the military authorities." He promised that "improvements will be forthcoming shortly which will increase by several fold the present effectiveness." "But more important for the long-range implications of this new weapn," he said, "is the possiblity that another scale of magnitude will be developed after considerable research and development.

The scientists are confident that over a period of many years atomic bombs may well be developed which will be very much more powerful than the atomic bombs now at hand." Investigation Started in 1939 It was late in 1939 that President Roosevelt appointed a commission to investigate use of atomic energy for military purposes. Until then only small-scale researach with Navy funds had taken place. The program went into high gear. By the end of 1941 the project was put under direction of a group of eminent American scientists in the Office of Scientific Research and Development, under Dr. Vanever Bush, who reported directly to Mr. Roosevelt. The President also appointed a General Policy Group, consisting of former Vice President Henry A. Wallace, Secretary Stimson, Gen. George C. Marshall, Dr. James B. Conant, president of Harvard, and Dr. Bush. In June 1942, this group recommended vast expansion of the work transfer of the major part of the program to the War Department. Maj. Gen. Leslie R. Groves, a native of Albany, N.

Y., and a 48-year-old graduate of the 1918 class at West Point, was appointed by Mr. Stimson to take complete executive chargeof the program. General Groves, an engineer, holding the permanent Army rank of lieutenant colonel, received the highest praise from the War Department for the way he "fitted together the multifarious pieces of the vast, country-wide jigsaw," and, at the same time, organized the virtually air-tight security system that kept the project a secret. A military policy committee also was appointed, consisting of Dr. Bush, chairman; Dr. Conant, Lieut. Gen. Wilhelm D. Styer and Rear Admiral William R. Purnell. In December, 1942, the decision was made to proceed with construction of large-scale plants. Two are situated at the Clinton Engineer Works in Tennessee and a third at the Hanaford Engineer Works in the State of Washington. These plants were amazing phenomena in themselves. They grew into large, self-sustaining cities, employing thousands upon thousands of workers.

Yet, so close was the secrecy that not only were the citizens of the area kept in darkness about the nature of the project, but the workers themselves had only the sketchiest ideas- if any- as to what they were doing. This was accomplished Mr. Stimson said, by "compartmentalizing" the work so "that no one has been given more information than was absolutely necessary to his particular job." The Tennessee reservation consists of 59,000 acres, eighteen miles west of Knoxville, it is known as Oak Ridge and has become a modern small city of 78,000, fifth largest in Tennessee. In the State of Washington the Government has 430,000 acres in an isolated area, fifteen miles northwest of Pasco. The settlement there, which now has a population of 17,000, consisting of plant operators and their immediate families, is known as Richmond. A special laboratory also has been set up near Santa Fe, N. M., under direction of Dr. J. Robert Oppenheimer of the University of California, Dr. Oppenheimer also supervised the first test of the atomic bomb on July 16, 1945.

This took place in a remote section of the New Mexico desert lands, with a group of eminent scientists gathered, frankly fearful to witness the results of the invention, which might turn out to be either the salvation or the Frankenstein's monster of the world. Mr. Stimson also gave full credit to the many industrial corporations and educational institutions which worked witht he War Department in bringing this titanic undertaking to fruition. In August, 1943, a combined policy committee was appointed, consisting of Secretary Stimson, Drs. Bush and Conant for the United States; the late Field Marshall Sir John Dill (now replaced by Field Marshal Sir Henry Maitland Wilson) and Col. J. J. Llewellin (since replaced by Sir Ronald Campbell), for the United Kingdom, and C. D. Howe for Canada. "Atomic fission holds great promise for sweeping developements by which our civilization may be enriched when peace comes, but the overriding necessities of war have precluded the full exploration of peacetime applications of this new knowledge," Mr. Stimson said.

"However, it appears inevitable that many useful contributions to the well-being of mankind will ultimately flow from these discoveries when the world situation makes it posssible for science and industry to concentrate on these aspects." Although warning that many economic factors willhave to be considered "before we can say to wha t extent atomic energy will supplement coal; oil and water as fundamental sources of power," Mr. Stimson acknowledged that "we are at the threshold of a new industrial art which will take many years and much expenditures of money to develop." The Secretary of War disclosed that he had appointed an interim committee to study post-war control and development of atomic energy. Mr. Stimson is serving as chairman, and other members include James F. Byrnes, Secretary of State; Ralph A. Bard, former Under-Secretary of the Navy; William L. Clayton, Assistant Secreatry of State; Dr. Bush, Dr. Conant, Dr. Carl T. Compton, chief of the Office of Field Service in OSRD and president of Massachusetts Institute of Technology, and George L. Harrison, special consultant to the Secretary of War and president of the New York Life Insurance Company. Mr. Harrison is alternate chairman of the committee.

The committee also has the assistance of an advisory group of some of the country's leading physicists including Dr. Oppenheimer, Dr. E. O. Lawrence, Dr. A. H. Compton and Dr. Enrico Fermi. The War Department gave this supplementary background on the development of the atomic bomb. "The series of discoveries which led to developemnt of the atomic bomb started at the turn of the century when radioactivity became known to science. Prior to 1939 the scientific work in this field was world-wide, but more particularly so in the United States, the United Kingdom, Germany, France, Italy and Denmark. One of Denmark's great scientists, Dr. Neils Bohr, a Nobel Prize winner, was whisked from the grasp of the Nazis in his occupied homeland and later assisted in developing the atomic bomb. "It is known that Germany worked desperately to solve the problem of controlling atomic energy." A Science Odyssey: People and Discoveries: The first atomic bomb is detonated The first atomic bomb is detonated 1945 Photo: Atomic bomb test explosion in Alamagordo, New Mexico, July 16, 1945.

AP/Wide World Photos In 1932, James Chadwick discovered the neutron , a small atomic particle with mass but no charge. This turned out to be an extremely useful tool for bombarding atomic nuclei. Two years later, Enrico Fermi bombarded uranium with neutrons, hoping that it would cause the uranium to emit a beta particle and become a new, artificial element above uranium in the periodic table. It seemed he had done this and in the process showed that slow-moving neutrons were more effective than high-energy neutrons for the task. Fermi won the Nobel Prize for his work in 1938. He was a committed antifascist and when he and his wife left Italy for the Nobel ceremony, it was for good. They settled in the United States. Meanwhile, Fermi's work had produced some puzzling results and physicists Otto Hahn, Fritz Strassmann, and Lise Meitner took it up in Germany. They began to suspect that Fermi hadn't created a new element at all but might have actually split the uranium atom in two -- at that point a barely imaginable event.

Before they could confirm this, Meitner -- who was an Austrian of Jewish descent -- had to flee the country when Germany annexed Austria in 1938. With the help of Niels Bohr , she got a position in Stockholm. From there, Meitner and her nephew Otto Frisch proved that the uranium atom had been split. Hahn published the results in January 1939 and Meitner and Frisch published the explanation a month later, introducing the term "nuclear fission." Using Bohr's liquid drop model of the nucleus, they suggested that when split, both halves of the atom would have a positive charge and would repel each other with powerful force. The German government took little notice of the finding at first. But others felt the implications were immediately clear. Niels Bohr brought news of Meitner's discovery to the United States in 1939. Several scientists, realizing that fission could be used to build a devastating weapon, wrote to President Roosevelt to inform him. He immediately set up a committee to research the matter. (Back in Germany, Hahn refused to do weapons research. He had worked on chemicals used as weapons in World War I.

His advisers assured him it would bring a speedier end to the war, but he was horrified when he saw Russian soldiers who'd been gassed.) By the end of 1941, British studies had outlined the materials requirements for an atomic bomb and uranium research was going on at about 12 American universities. In 1942 Fermi's team at the University of Chicago created a sustained chain reaction of fission for the first time. Also during 1942, the Manhattan District of the Corps of Engineers was formed to construct three secret "cities" for major portions of atomic bomb development. At Oak Ridge, Tennessee, a nuclear reactor and plant for separating uranium 235 from natural uranium was built. In Hanford, Washington, three reactors were built to extract plutonium (another element with atoms that could be split) from a non-fissionable type of uranium. Finally a lab for the design and construction of the bomb was built at Los Alamos, New Mexico. The cost of these Manhattan Project installations was $2 billion. J.

Robert Oppenheimer was made director of the Los Alamos lab, and in 1943 he gathered about 200 of the best scientists in the field to live and work there. They designed two bombs, one using uranium (called "Little Boy") and one using plutonium ("Fat Man"). By early 1945, the plants at Oak Ridge and Hanford had produced enough raw material for testing. On July 13, 1945, at a site called Trinity 100 km northwest of Alamogordo, a plutonium bomb was assembled and brought to the top of a tower. The test was postponed by thunderstorms. On July 16, the bomb was detonated, producing an intense flash of light seen by observers in bunkers 10 km away and a fireball that expanded to 600 meters in two seconds. It grew to a height of more than 12 kilometers, boiling up in the shape of a mushroom. Forty seconds later, the blast of air from the bomb reached the observation bunkers, along with a long and deafening roar of sound.

The explosive power, equivalent to 18.6 kilotons of TNT, was almost four times larger than predicted. Some of the Los Alamos scientists had circulated a petition asking President Truman to give Japan a warning and a chance to surrender before using the bomb. Some signed, some didn't, but the project remained a secret until the end. Twenty-one days after the test, the B-29 bomber Enola Gay dropped the uranium bomb on Hiroshima, Japan. Three days later the plutonium bomb was used to bomb Nagasaki. The two bombs killed approximately 150,000 people when they fell. Earlier in the year, intense bombing of Tokyo with conventional bombs had killed about 100,000 people without causing Japan to surrender, but on August 15, 1945, Japan officially surrendered, bringing an end to World War II. After the war, hydrogen bombs and other nuclear weapons continued to be developed by the United States and its former ally the Soviet Union. The competition between the ideologically different nations led to an "arms race" that shaped the postwar decades both economically and philosophically. Nuclear fission was also put to civilian use in power generators in several countries.

They made cheap electricity and were a source of radioisotopes for other types of research, but came with their share of problems and dangers. Reactors are still in use, but in many places have fallen out of favor as an energy source. Copyright notice: The photo above is copyright protected and is the property of the Associated Press. Any use without prior written permission from AP/Wide World Photos is prohibited. Any violation will be subject to legal action. The first atomic bomb test is successfully exploded - Jul 16, 1945 - HISTORY.com The first atomic bomb test is successfully exploded Share this: The first atomic bomb test is successfully exploded Author The first atomic bomb test is successfully exploded URL Publisher A+E Networks On this day in 1945, at 5:29:45 a.m., the Manhattan Project comes to an explosive end as the first atom bomb is successfully tested in Alamogordo, New Mexico. Plans for the creation of a uranium bomb by the Allies were established as early as 1939, when Italian emigre physicist Enrico Fermi met with U.S. Navy department officials at Columbia University to discuss the use of fissionable materials for military purposes.

That same year, Albert Einstein wrote to President Franklin Roosevelt supporting the theory that an uncontrolled nuclear chain reaction had great potential as a basis for a weapon of mass destruction. In February 1940, the federal government granted a total of $6,000 for research. But in early 1942, with the United States now at war with the Axis powers, and fear mounting that Germany was working on its own uranium bomb, the War Department took a more active interest, and limits on resources for the project were removed. Brigadier-General Leslie R. Groves, himself an engineer, was now in complete charge of a project to assemble the greatest minds in science and discover how to harness the power of the atom as a means of bringing the war to a decisive end. The Manhattan Project (so-called because of where the research began) would wind its way through many locations during the early period of theoretical exploration, most importantly, the University of Chicago, where Enrico Fermi successfully set off the first fission chain reaction. But the Project took final form in the desert of New Mexico, where, in 1943, Robert J.

Oppenheimer began directing Project Y at a laboratory at Los Alamos, along with such minds as Hans Bethe, Edward Teller, and Fermi. Here theory and practice came together, as the problems of achieving critical mass—a nuclear explosion—and the construction of a deliverable bomb were worked out. Finally, on the morning of July 16,in the New Mexico desert120 miles south of Santa Fe, the first atomic bomb was detonated. The scientists and a few dignitaries had removed themselves 10,000 yards away to observe as the first mushroom cloud of searing light stretched 40,000 feet into the air and generated the destructive power of 15,000 to 20,000 tons of TNT. The tower on which the bomb sat when detonated was vaporized. The question now became—on whom was the bomb to be dropped? Germany was the original target, but the Germans had already surrendered. The only belligerent remaining was Japan. A footnote: The original $6,000 budget for the Manhattan Project finally ballooned to a total cost of $2 billion.

Related Videos International Day Against Nuclear Tests, 29 August International Day Against Nuclear Tests 29 August On-site inspection experts stand near the collapse crater of an underground nuclear explosion at the Nevada National Security Site, USA. Photo: The Official CTBTO Photostream Ending Nuclear Testing The history of nuclear testing began early on the morning of 16 July 1945 at a desert test site in Alamogordo, New Mexico when the United States exploded its first atomic bomb. Designated as the Trinity Site, this initial test was the culmination of years of scientific research under the banner of the so-called “ Manhattan Project ”. In the five decades between that fateful day in 1945 and the opening for signature of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in 1996, over 2,000 nuclear tests were carried out all over the world. The United States conducted 1,032 tests between 1945 and 1992. The Soviet Union carried out 715 tests between 1949 and 1990. The United Kingdom carried out 45 tests between 1952 and 1991.

France carried out 210 tests between 1960 and 1996. China carried out 45 tests between 1964 and 1996. In the five decades between 1945 and 1996, over 2,000 nuclear tests were carried out all over the world. After the CTBT was opened for signature in September 1996, about half a dozen nuclear tests have been conducted: India conducted two tests in 1998 (India had also conducted one so-called peaceful nuclear explosion in 1974.) Pakistan conducted two tests in 1998. The Democratic People’s Republic of Korea announced that it had conducted a nuclear test in 2006. Types of Nuclear Tests Nuclear explosions have been detonated in all environments: above ground, underground and underwater. Bombs have been detonated on top of towers, onboard barges, suspended from balloons, on the earth's surface, underwater to depths of 600m, underground to depths of more than 2,400m and in horizontal tunnels.

Test bombs have been dropped by aircraft and fired by rockets up to 200 miles into the atmosphere. Atmospheric testing Atmospheric testing refers to explosions which take place in or above the atmosphere. All told, of the over 2,000 nuclear explosions detonated worldwide between 16 July 1945 (United States) and 29 July 1996 (China), 25 % or over 500 bombs were exploded in the atmosphere: over 200 by the United States, over 200 by the Soviet Union, about 20 by Britain, about 50 by France and over 20 by China. Signing of the Partial Test Ban Treaty, 5 August 1963. Secretary of State Dean Rusk signing for the United States; Foreign Minister Andre Gromyko, signing for the Soviet Union; and Lord Hume signing for the United Kingdom. Photo: CTBTO International concern over radioactive fallout resulting from atmospheric tests escalated in the mid 1950s. In March 1954, the United States tested its hydrogen bomb Castle Bravo in the Pacific’s Marshall Islands.

The Bravo test created the worst radiological disaster in the United States’ testing history. By accident, local civilians on the Marshall Islands, US servicemen stationed on Rongerik atoll, and the Japanese fishing trawler Lucky Dragon, were contaminated with the fallout. Nuclear weapon tests have been carried out in all environments: above ground, underground and underwater. Atmospheric testing was banned by the 1963 Partial Test Ban Treaty. Negotiations had largely responded to the international community’s grave concern over the radioactive fallout resulting from atmospheric tests. The United States, the Soviet Union and the United Kingdom became Parties to the Treaty; France and China did not. France conducted its last atmospheric test in 1974, China in 1980. CTBTO's infrasound IMS stations are used to detect nuclear explosions by monitoring low-frequency sound waves in the atmosphere. CTBTO Radionuclide IMS stations are designed to detect radioactive particles emanating from an atmospheric test. Underwater testing Underwater testing refers to explosions which take place underwater or close to the surface of the water. Relatively few underwater tests have been conducted.

The first underwater nuclear test — Operation Crossroads — was conducted by the United States in 1946 at its Pacific Proving Grounds in the Marshall Islands with the purpose of evaluating the effects of nuclear weapons used against naval vessels. Later, in 1955, the United States’ Operation Wigwam conducted a single underwater nuclear test at a depth of 600 m to determine the vulnerability of submarines to nuclear explosions. Underwater nuclear explosions close to the surface can disperse large amounts of radioactive water and steam, contaminating nearby ships, structures and individuals. Underwater nuclear testing was banned by the 1963 Partial Test Ban Treaty. The CTBTO's hydroacoustic IMS stations are those best suited to detect nuclear explosions underwater. Of the over 2,000 nuclear explosions detonated worldwide between 1945 and 1996, 25% or over 500 bombs were exploded in the atmosphere. Underground testing Radionuclide station 56, Peleduy, Russian Federation. Photo: CTBTO Underground testing means that nuclear explosions are detonated at varying depths under the surface of the earth. These comprised the majority (i.e.

about 75%) of all nuclear explosions detonated during the Cold War (1945–1989); that is, over 800 of all tests conducted by the United States and nearly 500 of all tests conducted by the Soviet Union. When the explosion is fully contained, underground nuclear testing emits negligible fallout compared to atmospheric testing. However, if underground nuclear tests "vent" to the surface, they can produce considerable radioactive debris. Underground testing is usually evident through seismic activity related to the yield of the nuclear device. Underground nuclear testing was banned by the 1996 Comprehensive Nuclear-Test-Ban Treaty (CTBT) that bans all nuclear explosions on Earth. 75% of all nuclear test explosions during the cold war were conducted underground. The CTBTO’s seismic IMS stations are used to detect nuclear explosions underground. The seismic data is combined with radionuclide data. Only the radionuclide technology can determine if an explosion is nuclear in origin; its stations and laboratories around the world monitor the presence of particulates and/or noble gases in the atmosphere.

For more details see Nuclear Testing Tally : A numeric breakdown of the number of atmospheric and underground nuclear tests conducted by each testing country for each year from 1945–2006. Nuclear Testing 1945–2009 The beginning of the nuclear era The United States launched the Nuclear Age in the pre-dawn hours of 16 July 1945 when it detonated a 20-kiloton atomic bomb code-named ”Trinity“ at Alamogordo, New Mexico. Under the umbrella of the “Manhattan Project”, the test’s original purpose had been to confirm that an implosion-type nuclear weapon design was feasible. It also gave United States’ scientists and the military an idea of what the actual size and effects of such nuclear explosions would be before using them in combat. While the Alamogordo test demonstrated many of the explosion's effects, it failed to provide a meaningful comprehension of radioactive nuclear fallout, which was not well understood by project scientists until years later.

The United States dropped two atomic bombs on Japan towards the end of World War II: one an untested gun-type fission bomb called “Little Boy” on Hiroshima on 6 August 1945; another implosion-type bomb tested at Alamogordo for the first time a month earlier and called “Fat Man” on Nagasaki on 9 August. Together these two bombs killed some 220,000 Japanese citizens outright, with over 200,000 more dying subsequently from lethal radiation overdoses. From “hot war” to Cold War The first USSR nuclear test "Joe 1" at Semipalatinsk, Kazakhstan, 29 August 1949. Photo: CTBTO No sooner was World War II brought to a close in August 1945 than an all-out technical-industrial nuclear weapons race ensued between the two newly emerging superpowers, the United States and the Soviet Union. Between 1946 and 1949, the United States conducted an additional six tests. Then on 29 August 1949, the Soviet Union tested its first atomic bomb, “Joe 1”.

This test marked the beginning of the “Cold War” nuclear arms race between the two superpowers. With the Soviet Union's first atomic bomb test on 29 August 1949, the "cold war" nuclear arms race between the USSR and the United States was on. At the outset, neither the United States nor the Soviet Union had many nuclear weapons to spare so their nuclear testing was relatively limited. However, by the 1950s the United States had established a dedicated test site (Nevada Test Site) and was also using a site in the Marshall Islands (Pacific Proving Grounds) for extensive nuclear testing. The Soviet Union also began testing on a limited scale, primarily in Semipalatinsk in the Soviet Republic of Kazakhstan. Early tests were used primarily to ascertain the military effects of nuclear weapons and to test new weapon designs. Exacerbated tensions and an atmosphere of pervasive fear and suspicion catalyzed competition to build more powerful and sophisticated bombs. During the 1950s new hydrogen bomb designs were tested in the Pacific, as were new and improved fission weapon designs.

In 1954 India's Prime Minister Jawaharlal Nehru became the first statesmen to call for a "stand still" agreement on nuclear testing. The Castle Bravo test created the worst radiological disaster in the United States' testing history. Bikini Atoll, Marshall Islands, 1 March 1954. Photo: CTBTO The United Kingdom became the third country to test nuclear weapons on 3 October 1952. Initially, the United Kingdom tested mainly in Australia and later on in the United States. From 1958 onwards its programme was closely coordinated with that of the United States through the UK-US Mutual Defense Agreement. The first hydrogen bomb On 1 November 1952 the United States became the first country to test a hydrogen bomb. The Castle Bravo test on 1 March 1954 yielded 15 megatons and was the largest nuclear weapon ever detonated by the United States. By accident, the inhabited atolls of Rongelap, Rongerik and Utirik were contaminated with radioactive fallout, as was the Japanese fishing trawler Lucky Dragon. The controversy over radioactive fallout from testing activities caused great international concern.

India’s Prime Minister Jawaharlal Nehru was the first statesman to call for a “stand still” agreement on nuclear testing on 2 April, 1954. However, this did little to stop the extensive nuclear testing that characterized the following 35 years, not subsiding until the end of the Cold War in the late 1980s. From 1955 to 1989, the average number of nuclear tests conducted every year was 55. Nuclear testing peaked in the late 1950s and early 1960s. The year 1962 alone saw as many as 178 tests: 96 conducted by the United States and 79 by the Soviet Union. This was the year of the Cuban Missile Crisis when the Cold War threatened to become a nuclear war. The preceding year had seen the testing of the largest nuclear weapon ever exploded, the Soviet Union’s “Tsar Bomba” with an estimated yield of 50 megatons. It was tested at the Novaya Zemlya test site near the Arctic Circle.

France and China became nuclear weapon States in 1960 and 1964 respectively, with both nuclear programmes intended to provide credible nuclear deterrents. France initially tested in Algeria, and later on in the South Pacific. China conducted all its nuclear tests at Lop Nur in Xinjiang Province. The 1963 partial test ban treaty banned nuclear testing, including testing for peaceful purposes, in the atmosphere, underwater and in space... but not underground. The early 1960s also saw the introduction of the only testing limitation effort that had concrete effects on how testing was conducted during the Cold War. The 1963 Partial Test Ban Treaty banned nuclear testing for military and for peaceful purposes, in the atmosphere, underwater and in space. The Treaty was important from an environmental point of view, curbing the radioactive fallout closely associated with atmospheric tests, but did little to prevent overall nuclear testing, which largely moved underground.

Burgeoning nuclear arsenals The world’s nuclear arsenals ballooned throughout the Cold War, from slightly more than 3,000 weapons in 1955 to over 37,000 weapons by 1965 (United States 31,000 and the Soviet Union 6,000), to 47,000 by 1975 (United States 27,000 and Soviet Union 20,000), and over 60,000 in the late 1980s (United States 23,000 and the Soviet Union 39,000). According to the Nuclear Threat Initiative, Israel initiated a nuclear programme in the 1950s, and had completed the R&D phase of its nuclear weapon programme in 1966, although it has not, to public knowledge, tested such a weapon. Israel has adopted a so-called “nuclear ambiguity policy”, neither confirming nor denying its nuclear status. It is not a party to the 1968 Non-Proliferation Treaty, and it has signed but not ratified the CTBT.

Officially, India became the sixth nation to develop nuclear weapons, conducting a nuclear test, declared as a peaceful nuclear explosion, in May 1974. In 1982, one additional nation, South Africa, acquired nuclear weapons, according to the Monterey Institute’s Center on Non-Proliferation Studies. To public knowledge, South Africa did not conduct any nuclear tests. Less than ten years later, with the anticipated transition to a majority-elected government, South Africa dismantled all of its nuclear weapons, the only nation to date that voluntarily relinquished the nuclear arms under its complete control. The dismantling was completed in 1991. The same year, South Africa acceded to the 1968 Non-Proliferation Treaty as a non-nuclear weapon State. It voted overwhelmingly to end apartheid on 18 March 1992. Underground nuclear testing was banned by the 1996 Comprehensive Nuclear-Test-Ban Treaty, which bans all nuclear explosions on Earth. The world did not witness any significant decrease in nuclear testing activities and nuclear weapons acquisition among the nuclear weapon States until the early 1990s.

The total number of nuclear tests in the second half of the 1980s amounted to as many as 174. But warmer relations between the Soviet Union and the United States from the mid-1980s prepared the way, as did the fall of the Berlin Wall in 1989 and the 1991 dissolution of the Soviet Union, which was superseded by the Russian Federation. Belarus, Kazakhstan and Ukraine who, together with Russia, had hosted the Soviet nuclear arsenal, became non-nuclear weapon States under the Non-proliferation Treaty. The USSR's main test site, Semipalatinsk in Kazakhstan, was closed in 1991. Moratoria on nuclear testing In 1990, the Soviet Union proposed a moratorium on nuclear testing that was agreed to by the United Kingdom and the United States. This created an opportunity to move ahead for those advocates who, for decades, had promoted a comprehensive ban on all nuclear testing.

Some six nuclear tests were conducted between 1998 and 2009: two by India and two by Pakistan in 1998 and one by the Democratic People's Republic of Korea (DPRK) in 2006 and another one by the DPRK in 2009. The Soviet Union’s last nuclear test took place on 24 October 1990; the United Kingdom’s on 26 November 1991 and the United States’ on 23 September 1992. France and China conducted their last tests in January and July 1996 respectively, before signing the Comprehensive Nuclear-Test-Ban Treaty on the day it opened for signature, 24 September 1996, together with the other three nuclear weapon States and 66 other countries. (For the status of signature and ratification of the Treaty today, please click here ). France closed and dismantled all its nuclear test sites in the 1990s — the only nuclear weapon State to date that has done so.

Breaking the de facto moratorium About six nuclear tests were conducted between 1998 and 2009: two by India and two by Pakistan in 1998 and one by the Democratic People’s Republic of Korea (DPRK) in 2006 and another one by the DPRK in 2009, thus four times breaking the de facto moratorium that the CTBT had established. India conducted two underground nuclear tests, code-named “Shakti (Power) ‘98”, on 11 and 13 May 1998 at its Pokhran underground testing site. In contrast to India’s initial nuclear test in 1974, this time there were no claims that these were “peaceful tests”. On the contrary, government officials were quick to emphasize the military nature of the explosions. A scant two weeks later, Pakistan reacted, conducting two underground nuclear tests at its Ras Koh range. Both India and Pakistan immediately moved to announce unilateral moratoriums on nuclear testing and have conducted no nuclear tests since 1998. To read more about the 1998 tests conducted by India and Pakistan, see The Treaty: History .

The announced nuclear test by the DPRK on 9 October 2006 broke the eighth-year-long de facto moratorium and was against the letter and spirit of the Comprehensive Nuclear-Test-Ban Treaty. Again on 9 October 2006, the announced nuclear test by the DPRK broke that eight-year-long de facto moratorium. It was met with near unanimous global expressions of concern. The UN Security Council strongly condemned the act as a clear threat to international peace and security. The Chairman and the Executive Secretary of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), as well as States Signatories, expressed grave concern at the declared test and characterized the event as an action against the letter and the spirit of the CTBT. The DPRK tested a second time on 25 May 2009, an act that was once again met with worldwide condemnation. To read more about the announced nuclear test by the DPRK and the CTBTO findings in connection with this declared test, please click here: 2006 and 2009 .

See an approximate overview of all nuclear testing to date, as well as the CTBT status of the countries that have conducted nuclear tests. See also map . Comprehensive Nuclear-Test-Ban Treaty (CTBT) The Treaty Central to the issue of the Day against Nuclear Tests is the Comprehensive Nuclear Test Ban Treaty which bans nuclear testing everywhere on planet — surface, atmosphere, underwater and underground. The Treaty takes on significance as it also aimsto obstruct the development of nuclear weapons: both the initial development of nuclear weapons as well as their substantial improvement (H-bomb) necessitate real nuclear testing. The CTBT makes it almost impossible for countries that do not yet have nuclear weapons to develop them. And it makes it almost impossible for countries that have nuclear weapons to develop new or more advanced weapons. It also helps prevent damage caused by nuclear testing to humans and the environment. History Between 1945 and 1996, when the CTBT opened for signature, over 2000 nuclear tests were conducted: by the United States (1000+) Soviet Union (700+), France (200+), United Kingdom and China (45 each).

Three countries have broken the de-facto moratorium and tested nuclear weapons since 1996: India and Pakistan in 1998 and the Democratic People’s Republic of Korea (DPRK) in 2006. Many attempts were made during the Cold War to negotiate a comprehensive test ban, but it was only in the 1990s that the Treaty became a reality. The CTBT was negotiated in Geneva between 1994 and 1996. The Treaty has yet to enter into force All 44 States specifically listed in the Treaty — those with nuclear technology capabilities at the time of the final Treaty negotiations in 1996 — must sign and ratify before the CTBT can enter into force. Of these, nine are still missing: China, DPRK, Egypt, India, Indonesia, Iran, Israel, Pakistan and the USA. DPRK, India and Pakistan have yet to sign the CTBT. Otherwise, 182 countries have signed, of which 153 have ratified the Treaty (as of May 2010 including three of the nuclear weapon States: France, Russian Federation and the United Kingdom).

The Treaty Organization Since the Treaty is not yet in force, the Organization is called the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Organization, or CTBTO. It was founded in 1996, with approximately 260 staff from most of the CTBT’s 182 Member States. It is headed by the Executive Secretary, Tibor Tóth (Hungary). The CTBTO’s main tasks are the promotion of the Treaty and the build-up of the verification regime so that it is operational when the Treaty enters into force. The budget is around US$120,000,000 or €82,000,000. Verification regime It is a unique and comprehensive system. At the heart of the verification regime is the International Monitoring System (IMS), which consists of 337 facilities located all over the world that constantly monitor the planet for signs of nuclear explosions. Around 80% of these facilities are already sending data to the International Data Centre at the CTBTO headquarters in Vienna. The IMS uses the following four state-of-the-art technologies: Seismic: Fifty primary and 120 auxiliary seismic stations monitor shockwaves in the Earth.

The mandate of the CTBTO is to detect nuclear explosions such as those announced by the DPRK in 2006 and 2009. To do so, it needs to find the needle in the haystack: the vast majority of shockwaves — many thousands every year — are caused by earthquakes whereas others are man-made explosions such as mine explosions. Hydroacoustic: Eleven hydrophone stations “listen” for sound waves in the oceans. Sound waves from explosions can travel extremely far underwater. Infrasound:Sixty stations on the surface can detect ultra-low frequency sound waves (inaudible to the humanear) that are emitted by large explosions. Radionuclide: Eighty stations measure the atmosphere for radioactive particles, 40 of them also pick up noble gas. Only these measurements can give a clear indication as to whether an explosion detected by the other methods was actually nuclear or not. They are supported by 16 radionuclide laboratories.

On-site-Inspection If the data from the IMS stations indicate that a nuclear test has taken place, a Member State can request for an on-site-inspection to be carried out to collect evidence that will allow the final assessment to be made regarding whether a nuclear explosion — a Treaty violation — has actually taken place. This will only be possible after the CTBT has entered into force. A large on-site inspection exercise was carried out in September 2008 in Kazakhstan. Civil and scientific applications The IMS data are provided to the CTBT Member States. They are used also for applications other than test-ban verification, such as for tsunami-warning (by proving timely data), research on the Earth’s core, monitoring of earthquakes and volcanoes; research on the oceans, climate change research and many other applications.

Question: The first atomic bomb explosion was carried out in which US state?
Answer: New Mexico