Little Boy and Fat Man | Atomic Heritage Foundation Atomic Heritage Foundation Little Boy and Fat Man Little Boy and Fat Man History Page Type: Bombings of Hiroshima and Nagasaki An explosive nuclear chain reaction occurs when a sufficient quantity of nuclear fuel, such as uranium or plutonium, is brought together to form a critical mass. This is the minimum amount of fissionable material needed to start a chain reaction. The chain reaction starts when neutrons strike the heavy uranium or plutonium nucleus which splits releasing a tremendous amount of energy along with two or more neutrons which, in turn split more nuclei, and so on. For more information, see The Science Behind the Atom Bomb . Little Boy In this gun-type device, the critical mass is achieved when a uranium projectile which is sub-critical is fired through a gun barrel at a uranium target which is also sub-critical. The resulting uranium mass comprised of both projectile and target becomes critical and the chain reaction begins. Dropped on the Japanese city of Hiroshima on August 6, 1945 , it was the first nuclear weapon used in a war. Weight: 9,700 lbs Approx.

1.38% of the uranium fuel actually fissioned Explosive force: 15,000 tons of TNT equivalent Use: Dropped on Japanese city of Hiroshima ; August 6, 1945 Delivery: B-29 Enola Gay piloted by Col. Paul Tibbets Fat Man "Fat Man" was the second plutonium , implosion-type bomb. The first was the "Gadget" detonated at the Trinity site on July 16, 1945. In the implosion-type device, a core of sub-critical plutonium is surrounded by several thousand pounds of high-explosive designed in such a way that the explosive force of the HE is directed inwards thereby crushing the plutonium core into a super-critical state. Dropped on the Japanese city of Nagasaki on August 9, 1945 , it was the second nuclear weapon used in a war. Weight: 10,800 lbs The Designs of 'Fat Man' and 'Little Boy' The Designs of Fat Man and Little Boy Marc Stockbauer War & Peace: The Atomic Age: War, Peace, Power?

Fat Man and Little Boy, are the nicknames given to the first and only two Atomic bombs ever used in combat. Little boy was dropped on Hiroshima, Japan on August 6, 1945. Fat Man was detonated three days later over the city of Nagasaki. These two weapons were pivotal in saving the lives of thousands of Americans, and bringing the Second World War to a victorious end. The designs of these weapon systems were experimental, and technologically amazing. It was these first two designs which paved the way for future scientist to build weapons that yielded 200 to 300 times the destructive force of these two pioneers. The design of the Fat man device was basically the same as an experimental test version named Gadget. A test of the implosion bomb was considered essential due to the newness of the explosive wave shaping technology, and the complexity of the system. The first Soviet atomic bomb, code named RDS-1, is identical to the design of Gadget. This is because detailed descriptions of the design were given to Soviet intelligence by spies who worked for the United States at Los Alamos. The basic structure of the Fat Man was based on a series of 6 concentric nested spheres.

The outermost was the explosive lens system, followed by the absorber shell, the Uranium reflector shell, the plutonium pit, and lastly the innermost shell, the neutron initiator. The shell system basically worked as an implosion device. The outer shell was made of high-powered explosive that, when detonated, compressed the inner spheres and charged the uranium. The design was suggested by Robert Christy in order to minimize asymmetry and instability problems during implosion. The innermost shell, the plutonium pit, contained 6.2 kg of plutonium alloy contained in a 9.0 cm shell. It was solid except for an approximately 2.5 cm cavity in the center where the neutron initiator was placed. The pit was formed in two hemispheres. Since plutonium is a chemically very reactive metal, as well as a significant health hazard, each half-sphere was electroplated with nickel to avoid deteriorating reactions. The pit had a 2.5 cm hole capped with a plutonium plug to allow the insertion of the initiator after assembly. The neutron initiator used was called the "Urchin" or "screwball" design.

It was a sphere consisting of a hollow beryllium shell, with a solid beryllium pellet inside. The whole initiator weighed about 7 grams. The outer shell was 2 cm wide and 6 mm thick while the solid inner pellet was 8 mm wide. 15 parallel wedge-shaped grooves, each 2 mm deep, were cut into the inner surface of the shell. Like the pit, the shell was formed in two halves. The Urchin was activated by the arrival of the implosion shock wave caused by the outer lens shell. When the shock wave reached the beryllium walls of the cavity, they vaporized and formed a separate shock wave that struck the initiator. This collapsed the wedge shaped grooves in the outer initiator shell and created turbulence that rapidly mixed the plutonium and beryllium of the inner and outer spheres together. The alpha particles emitted by the new isotope then struck beryllium atoms, periodically knocking loose neutrons, perhaps one every 5-10 nanoseconds. It was these neutrons which progressed to the uranium tamper surrounding the pit, and provided the backbone for the explosion.

The pit was surrounded by a natural uranium tamper weighing 120 kg, with a diameter of 23 cm. The tamper formed a 7 cm thick layer around the pit. About 20% of the bomb yield was from fast fission of this layer. The pit and the tamper together comprised an essential component of the bomb. The nuclear implosion was so powerful that it compressed the pit and inner assemblies to 2.5 times their original density. Surrounding the tamper was an 11.5 cm thick aluminum sphere also weighing 120 kg. The primary purpose of this sphere, called the "pusher" or "absorber shell", was to reduce the effect of the Taylor wave. The Taylor wave is the rapid drop in pressure that occurs behind a shock wave. In other words, the scientists wanted as much pressure behind the shock wave as possible in order to increase the destructive power. By reducing the Taylor wave, the pressure of the transmitted shock wave increases, enhancing the pressure reached at the center of core, and thereby increasing the size of the explosion. The outermost shell was the high explosive lens system.

This made a layer some 47 cm thick weighing at least 2500 kg. This assembly consisted of 32 explosive lenses; 20 of them hexagonal, and 12 pentagonal. The lenses fitted together in the same pattern as a soccer ball, forming a complete spherical explosive assembly that was 140 cm wide. Each lens had three pieces: two made of high velocity explosive, and one of low velocity explosive. The outermost piece of high velocity explosive had a conical cavity in its inner surface into which fitted an appropriately shaped piece of slow explosive. The purpose of these paired pieces was to form a lens that shaped a convex, expanding shock wave into a convex converging one. The lenses were made by precision casting, so meltable explosives were utilized. The lens system had to be made to very precise tolerances. The composition and densities of the explosives had to be accurately controlled and extremely uniform. The pieces had to fit together with an accuracy of less than 1 mm to prevent irregularities in the shock wave which could alter the fission of the uranium. Accurate alignment of the lens surfaces was even more important than a close fit.

A great deal of tissue paper and scotch tape was also used to make everything fit snugly together. Each of the components of the bomb, from the lenses to the pit itself, were made as accurately as possible to insure accurate implosion and the highest densities possible in order to have efficient fission of the uranium. To achieve the most precise detonation synchronization possible in the outer lens system, conventional detonators consisting of an electrically heated wire, and a sequence of primary and secondary explosives were not used. Instead newly invented exploding wire detonators were used. This detonator consists of a thin wire that is explosively vaporized by a surge of current generated by a powerful capacitor. The shock wave of the exploding wire initiates the secondary explosive of the lenses. The discharge of the capacitor, and the generation of initiating shock waves by the exploding wires can be synchronized to +/- 10 nanoseconds. A disadvantage of this system is that large batteries, a high voltage power supply, and a very powerful capacitor bank (the one used weighed 400 lbs.) was needed to explode all 32 detonators simultaneously. The whole explosive assembly was held together by a shell made of a strong aluminum alloy called dural (or duraluminum).

A number of other shell designs had been tried and discarded. This shell design, designated model 1561, was made of an equatorial band bolted together from 5 segments of machined dural castings, with domed caps bolted to the top and bottom to make a complete sphere. The final bomb design allowed "trap door" assembly. The entire bomb could be assembled ahead of time, except for the pit/initiator. To complete the bomb, one of the domed caps was removed, along with one of the explosive lenses. The initiator was inserted between the plutonium hemispheres, and the assembled pit was inserted in a 40 kg uranium cylinder that slid into the tamper to make the complete core. The explosive lens was replaced, its detonator wires attached, and the cap bolted back into place. Safety was a serious problem for Fat Man, though in a comparison of worst case accidents, not as serious a problem as it was for Little Boy. Any accidental detonation of the high explosive lenses (in a fire or plane crash for example) would be certain to collapse the uranium core to its supercritical state.

The expected yield from the explosion would be on the order of tens of tons, roughly a factor of ten higher than the energy of the high explosive lens itself, but much less than the potential of the bomb. This meant that even if the plane crashed, the bomb would not detonate to full yield. In order to explode to full kilotonage the explosive wires had to be detonated. For transportation feasibility, as well as safety reasons, Fat man and other implosion bombs were not transported in assembled form but were put together shortly before use. Due to the complexity of the weapon, this was a process that took at least 2 days. Weapons of this design could only be left in the assembled state for a few days due to deterioration of the explosive wire detonation batteries. Fat Man was the more powerful of the two bombs. But this power came at a much greater cost, and a much more fragile design. Little Boy was much more conservative, and technologically easier to complete. The cost of this simplicity was power. "Little Boy" is the nick name given to the atomic bomb dropped on Hiroshima on August 6, 1945.

Little Boy was dropped from the Enola Gay, one of the B-29 bombers that flew over Hiroshima on that day. The design of Little Boy was completely different from Gadget/Fat Man. It was completed in February with only the field preparations necessary. All of the uranium used in Little Boy had gone through its final stages of enrichment in the Calutron electromagnetic isotope separators in Oak Ridge, Tennessee. The pit contained 64.1 kg of highly enriched uranium. By the time Little Boy was assembled, 50 kg of uranium was available at Oak Ridge, and an additional 14 kg of was on hand. All of it was used in the bomb. The Uranium used in Little Boy, however, was less pure than that used in Gadget/Fat Man, and consequentially added to the less efficient bomb. The Uranium of Little boy was divided into two pieces: the bullet and the target. The "bullet" was a cylindrical stack of six Uranium rings about 10 cm wide and 16 cm backed by a tungsten carbide disk and a steel backplate. All of this was contained within a 1/16 inch thick steel can to make a complete projectile.

The "target" was a hollow cylinder 16 cm long and wide, weighing 38.4 kg. The target was fabricated as two separate rings that were inserted in the bomb separately. Both the bullet and the target were sheathed in boron in order to absorb neutrons and reduce the chance of a criticality accident. The bomb was detonated by firing the bullet into the target via a high powered aircraft gun. The gun was a 3" diameter, six feet long anti-aircraft barrel that had been bored out to 4" to accommodate the bullet. It weighed about 450 kg, and used Cordite, a conventional artillery smokeless powder, as propellant. To reduce the possibility of the bullet being driven into the target by a plane crash, the fit of the barrel was intentionally made very tight. The bullet had to be rammed into the breech to assemble the weapon, and about 70,000 lb were required to drive it forward. Even with this precaution, a plane crash which caused the weapon to strike a hard surface could conceivably produce the 500 Gs of acceleration required to fire the bullet, and implode the weapon. Little Boy was a terribly unsafe weapon design.

Once the gun was loaded with the cordite propellant, anything that ignited it would cause a full yield explosion of the bomb. For this reason, the propellant was not loaded into the weapon on the ground. Instead, one of the bombers placed the cordite in the gun after take-off in case a crash or fire occurred. The complete weapon was 126 inches long, 28 inches in diameter and weighed 8900 lb. Both Fat man and Little boy were air burst bombs. This meant than an altimeter in the bomb acted as a trigger for the implosion systems. No other weapon like little boy has ever been detonated. Only five other Little Boy units were built, but none of these entered the US arsenal. The design was to unstable to pursue and, even though cost effective, did not produce the desired destructive force. The designs of Fat Man and Little Boy were radically different. The differing designs represented the economic, conservative approach, as well as the complicated, costly method. It was shown by these two bombs that the destructive power of nuclear fission could be harnessed in many ways, and that the possibilities for improvement and increased power were inevitable.

It was from these basic designs that scientists advanced to develop the modern nuclear arsenal that, if ever utilized, would make its predecessors seem like firecrackers. Fat Man and Little Boy - America in WWII magazine Fat Man and Little Boy Sixty years ago, a pair of atomic bombs scorched Hiroshima and Nagasaki. Today, people who helped build them and people who felt their deadly power still grapple with the bombs’ grim realities. By Terry W. Burger Seventeen-year-old Sumiko Koide was carrying her baby sister in the alley next to her parents’ house on August 6, 1945, when the world changed forever. At 8:15 a.m., the bomb nicknamed Little Boy exploded just less than 2,000 feet above the city. There was a silent flash, then chaos. The Koide family lived about 20 minutes by car from downtown Hiroshima. Destruction was everywhere. "My father had a greenhouse. All the glass was shattered. Much of it blew into the house," Koide says over the telephone from her home in Rawlings, West Virginia. Now 77, she lives as Sue Walker with her husband, Glenn Walker.

At one point after the blast, she recounts, a roof tile broke loose and hit her on the head, but neither she nor her sister was seriously injured. The bombing and its immediate aftermath stamped Walker’s memory with indelible images of horror. "I saw so many dead people," she says, "so many walking with the skin dropping off of their faces and hands, so many with their faces terribly bloated. " The Little Boy explosion was equal to about 18,000 tons of TNT. Nearly 70,000 men, women, and children flashed out of existence, and nearly 70,000 others were injured. Radiation killed many more over the next half-dozen years. The total death toll in Hiroshima was estimated at 140,000. Three days after the bombing that Walker witnessed, another bomb, nicknamed Fat Man, was exploded over Nagasaki. Though it missed its target by more than a mile, the bomb managed to destroy half the city. Nearly 40,000 died instantly, and more than 25,000 were injured.

By the end of the year, radiation poisoning had pushed the death toll up to 70,000. Many of Hiroshima’s children were out of the city when the bomb struck, on trips sponsored by their schools. They were spared, but many lost their families. Walker met Glenn while she was working in an orphanage for children whose parents were killed in the bombing. He was one of a group of GIs who brought food and candy for the kids. Glenn and she began to date and eventually married, neither of which won unanimous approval from the Koide family. But hostility eventually waned. "After a while, they held no grudges," Glenn says. "At the beginning, one of her uncles would not talk to me. That went on for several years. His brother was killed by the bomb. His daughter was missing for a while, and when she was found, she was terribly burned and later died." Asked whether the bombings could be justified, whether they shortened the war or saved lives in the long run, Walker replies, "I don’t know. I guess there would have been more people die in an invasion, but not all in one place.

It is hard to say that it should have been bombed." After a moment’s continued reflection, she adds, "We would not have given up, I think, if not for the bombing." She explains that each home had bamboo spears standing inside its front door in case of American invasion. Everyone, children included, had strict instructions from the government not to surrender if Americans came. "We were each to kill one and then ourselves." In fact, historians say, some of Japan’s leaders had wanted to end the war in the spring of 1945, but military leaders trained to preserve pride and honor at all costs held out. US leaders believed that Japan’s eventual surrender was inevitable, but that the number of lives lost would have been huge. Delanson Crist–son of Ray Crist, who worked on the Manhattan Project to develop the atom bomb–says that was a chief concern of the project’s scientists. "One of the reasons for dropping the bomb on Japan was the saving of so many lives, Japanese and Americans," he says. " After Germany surrendered, the allies were ready to go after the Japanese in their homeland. They were expecting hundreds and hundreds of thousands of deaths.

It’s a kind of terrible math: hundreds of thousands of casualties, versus many more hundreds of thousands of casualties. The bomb was dropped and that stopped everything. The Japanese ended up in peace negotiations." In late July, nearly three months after the German surrender in Europe, Radio Tokyo announced that Japan would continue to fight. Within nine days, the Enola Gay bore Little Boy to the dawning of a new age and a new hell–and the end of the war. Not all the scientists who helped figure out how to crack the atom to its heart and release the power that ultimately flattened Hiroshima were comfortable with the practical application of their work. Some had suggested that, if Japanese officials were given a demonstration of the bomb, they might be persuaded to surrender. J. Robert Oppenheimer, who headed the Manhattan Project, did not believe a mere demonstration would do the job. He concluded, "We see no acceptable alternative to direct military use." Oppenheimer was hardly enthusiastic about using the bomb, however.

At the first-ever atomic bomb test, in the American desert in July 1945, he reflected grimly, "I have become Death; the destroyer of worlds." In the years after the war, his vocal concerns over the dangers of nuclear weapons would prompt critics to accuse him of having communist sympathies. He would lose his security clearance by 1952. Oppenheimer was just one of many of the A-bomb’s creators who would have been happy to stuff the genie back into the bottle after the bombings of Hiroshima and Nagasaki. In 1950, Niels Bohr, another Manhattan Project scientist, would plead for the United Nations to help create a world free of atomic weapons. He dedicated the rest of his life to speaking out against nuclear research. Leo Szilard and Albert Einstein were both instrumental in the discovery of nuclear fission, and in the creation of the Manhattan Project and the atomic bomb, though Einstein was not part of the Manhattan Project. The two men had once written to President Franklin D. Roosevelt asking for research money to study fission.

Einstein’s letter, which Roosevelt received in August 1939, stated that new technology would make possible "extremely powerful bombs of a new type." He noted that Germany had stopped selling uranium from Czechoslovakian mines and" that some of the work American scientists had done on uranium was being replicated in Berlin. Later, Einstein would describe this letter as one of the great mistakes of his life–though the threat of Germany building the bomb first, he said, provided "some justification." Szilard was one of 70 scientists who wrote a letter to President Harry S. Truman late in the war to protest the use of the bomb. "We believe that the United States ought not to resort to the use of atomic bombs in the present phase of the war, at least not unless the terms which will be imposed upon Japan after the war are publicly announced and subsequently Japan is given an opportunity to surrender," the letter stated. "Atomic bombs are primarily a means for the ruthless annihilation of cities. Once they were introduced as an instrument of war it would be difficult to resist for long the temptation of putting them to such use." Like Bohr, Szilard spent the rest of his life working to curtail the development of nuclear arms.

Still, says Ray Crist, he and the other developers of the bomb believed they had little choice. A 1916 graduate of Messiah Bible School (now Messiah College) near Harrisburg, Pennsylvania, Crist graduated from Dickinson College in nearby Carlisle in 1920. While at Dickinson, Crist went to Plattsburg, New York, to train to become a sergeant in Dickinson’s equivalent of the Army Reserve Officer Training Corps. He had to teach other students how to use a bayonet, which he found repugnant, says his son Delanson. Crist earned his doctorate in chemistry from Columbia University and taught there until 1941, when he joined what was formally called the Manhattan District Project, after the Manhattan Engineer District of the US Army Corps of Engineers, based in New York City, where much of the early research was done. The original name had been Development of Substitute Materials, a title the military feared might reveal too much. Crist retired in 2004 from a research post at Messiah College. In his later years, he worked as a researcher in the field of bioremediation, a method of using biological materials such as algae to remove heavy-metal contaminants from water and soil.

In 2001 he collaborated with Delanson on a paper on the topic. The paper was presented to a meeting of scientists in, of all places, Nagasaki. At 105, Crist still firmly believes the atomic bomb was a necessary evil. That was especially true, he said, after scientists found a way to make uranium-235 (the radioactive substance used in early bombs) pure enough to use in a bomb. "After that, there was really no [question of] morality. There was a real chance of the Germans getting it, and we knew they were working on it…. Everybody was terrified of the Germans finding this first. It was a matter of life and death." In the summer of 1945, Crist was in charge of part of the Manhattan Project, with 600 people working under his direction. By that time, the bombs and the decisions made regarding their use were out of the hands of scientists and in the grasp of politicians and the military. The project had lasted about four years and had cost nearly $2 billion, roughly equivalent to more than $20 billion in today’s dollars.

Crist decided to take a vacation to visit his parents in the little Pennsylvania farming community of Shepherdstown in early August 1945: It was not going to be much of a vacation. "My parents did not have a very good radio," he recalls, "so that afternoon I was visiting neighbors, listening to theirs. We heard that a bomb was dropped in Hiroshima. I realized what had happened. I thought, oh, there they go!" He was rushed back to Columbia. After the war, Crist was one of a group of scientists invited to travel to the Far East and witness a demonstration of an atomic bomb blast. He declined. "I didn’t want to go," he says. "I didn’t want to get a personal sense of what the bomb would do." Terry W. Burger has worked as a reporter and columnist for the The Patriot-News in Harrisburg, Pennsylvania, and has written for Civil War Times and other magazines. This article originally appeared in the August 2005 issue of America in WWII accompanied by an A-bomb timeline and a written exchange between President Harry S. Truman and Senator Richard B. Russell of Georgia. Find out how to order a copy of this issue here .

To get more articles like this one, subscribe to America in WWII magazine. Top pair of photos: The first atomic bomb lights up the desert near Alamogordo, New Mexico, in a test on July 16, 1945, and Colonel Paul Tibbetts waves from the cockpit of the B-29 Enola Gay, which he would pilot over Hiroshima, Japan, to make history’s first atomic-bomb drop. NATIONAL ARCHIVES Middle two photos: The atomic bomb known as Fat Man, destined for Nagasaki, and the one known as Little Boy, destined for Hiroshima. NATIONAL ARCHIVES Bottom photo: A statue of Buddha lies among the ruins of Nagasaki. NATIONAL ARCHIVES Copyright 310 Publishing, LLC. All rights reserved. Designs of Two Bombs | The Story of Hiroshima | Tale of Two Cites: Hiroshima and Nagasaki | History of the Atomic Age | atomicarchive.com The Story of Hiroshima Designs of Two Bombs The Manhattan Project produced two different types of atomic bombs, code-named Fat Man and Little Boy. Fat Man, which was dropped on Nagasaki, was the more complex of the two. A bulbous, 10-ft.

bomb containing a sphere of the metal plutonium 239, it was surrounded by blocks of high explosives that were designed to produce a highly accurate and symmetrical implosion. This would compress the plutonium sphere to a critical density and set off a nuclear chain-reaction. Scientists at Los Alamos were not entirely confident in the in the plutonium bomb design, so they scheduled the Trinity test. The Little Boy type of bomb, which was dropped on Hiroshima, had a much simpler design than the Fat Man model that had been tested at Trinity. Little Boy triggered a nuclear explosion, rather than implosion, by firing one piece of uranium 235 into another. When enough U235 is brought together, the resulting fission chain reaction can produce a nuclear explosion. But the critical mass must be assembled very rapidly; otherwise, the heat released at the start of the reaction will blow the fuel apart before most of it is consumed. To prevent this inefficient pre-detonation, the uranium bomb uses a gun to fire one piece of U235 down the barrel into another. The bomb's gun-barrel shape was believed to be unquestionably reliable and had never been tested.

In fact, testing was out of the question since producing Little Boy had used all of the purified U235 produced to date; therefore, no other bomb like it has ever been built. Detonated by a mechanism that resembled a cannon, Little Boy had a muzzle or target that was a hollowed-out subcritical mass of uranium. The cannon ball was another subcritical mass of uranium, which fit perfectly into the hollow of the target as a plug. The plug was propelled down the cannon barrel by several thousand pounds of high explosive. When it hit, the combination of compression and increased mass pushed the uranium to the supercritical level and the bomb went off. Page 2 of 15 SparkNotes: J. Robert Oppenheimer: Fat Man and Little Boy Fat Man and Little Boy Fat Man and Little Boy → Fat Man and Little Boy, page 2 page 1 of 2 Once discovered, the basic physics underlying the bomb seemed almost simple: bombard a uranium nucleus, and the resulting split atom would release a huge amount of energy. But if the basic principle was simple, the physics entailed in the construction of the bomb itself was anything but.

The physicists needed to figure out how to produce enough radioactive material, as there was not nearly enough to be found in nature. They needed to find a way to create a nuclear chain reaction they could control, and then they needed to figure out how to control the speed of a fast nuclear reaction, so that it would release energy quickly enough to create a super-powerful bomb but not so quickly that the bomb would explode too soon. And, of course, they needed to figure out what would happen after a nuclear explosion; there was a question at the outset, for example, whether such an explosion would vaporize the atmosphere and destroy all life on earth. Perhaps the most difficult and most crucial problem that Oppenheimer and his team faced was the design of the bomb mechanism itself. How could they create a mechanism that would release the immense power of nuclear fission on command? In a triumph of theoretical and applied physics, the Los Alamos group eventually came up with two workable bomb designs, code-named "Little Boy" and "Fat Man." Little Boy, the U-235 bomb, had the simpler design of the two, and the physicists were certain that it would work.

The mechanism used a gun-assembly method, in which one subcritical mass of U-235 is fired at another subcritical mass of U-235. When the two join, they form a critical mass and ignite in a nuclear reaction. This is the type of bomb which was dropped over the Japanese city of Hiroshima. Fat Man, the plutonium bomb, used a different method: the implosion method. In the Fat Man bomb, a subcritical sphere of plutonium is surrounded by explosives, and when the explosives fire, a shock wave compresses the plutonium into a critical mass, setting off a nuclear reaction. It was the Fat Man bomb that was dropped over Nagasaki, Japan. As this method was somewhat more complicated than the gun-assembly method, scientists were less sure it would work, and decided to test it out. As the scientists were celebrating their breakthrough, foremost in their mind was the thought that they had done it, they had beaten Germany to the creation of the bomb. After all, the race against Germany had been the driving purpose of the Manhattan Project and the reason given by many of the physicists involved for why they were so passionately committed to the bomb effort. But how real was the German threat?

In 1944, as the Los Alamos physicists were readying themselves for a test of the nuclear bomb, the American government finally learned the status of the German nuclear program. 1 Fat Man and Little Boy (1989) - IMDb IMDb There was an error trying to load your rating for this title. Some parts of this page won't work property. Please reload or try later. X Beta I'm Watching This! Keep track of everything you watch; tell your friends. Error Fat Man and Little Boy ( 1989 ) PG-13 | This film reenacts the Manhattan Project, the secret wartime project in New Mexico where the first atomic bombs were designed and built. Director: 74th Golden Globe Awards Jimmy Fallon may be hosting, but let IMDb be your guide to the 2017 Golden Globes with galleries, videos, lists, and more. Don't miss our live coverage of the Golden Globes beginning at 5 p.m. PST on Jan. 8 in our Golden Globes section.

a list of 25 titles created 27 Mar 2011 a list of 45 titles created 26 Feb 2012 a list of 23 titles created 30 Jan 2013 a list of 47 titles created 17 Aug 2013 a list of 25 titles created 12 Nov 2014 Title: Fat Man and Little Boy (1989) 6.5/10 Want to share IMDb's rating on your own site? Use the HTML below. You must be a registered user to use the IMDb rating plugin. A middle-aged Louisiana governor falls in love with a young stripper, which jeopardizes his political career and the radical policies which have made him a controversial figure. Director: Ron Shelton Hazari Pal lives in a small village in Bihar, India, with his dad, mom, wife, Kamla, daughter, Amrita, and two sons, Shambhu and Manooj. As the Pal are unable to repay the loan they had ...

See full summary » Director: Roland Joffé In 1671, with war brewing with Holland, a penniless prince invites Louis XIV to three days of festivities at a chateau in Chantilly. The prince wants a commission as a general, so the ... See full summary » Director: Roland Joffé In New York, South Bronx's main police precinct is nicknamed Fort Apache by its employees who feel like troopers surrounded by hostiles in a wild west isolated outpost. Director: Daniel Petrie In Brooklyn, fishing is the hobby of the workers Jonah Goodwin and Olaf Johnson and they use to fish every night in their old boat. Jonah's daughter is the twenty-one year-old telephone ... See full summary » Director: Anatole Litvak Best friends from law school to election night, their friendship is sorely tested when one learns of another's betrayal. Director: Herbert Ross A young writer goes to Wiesbaden to write about gambling and gamblers, only to ultimately become a compulsive gambler himself. Losing all his wealth, as well as his moral fibre, he commits ...

See full summary » Director: Robert Siodmak Embittered, ambitious Helen Sherman sees an opportunity to escape her drab small-town life by becoming a 'stage mother' to her musically-talented younger sister. Director: Vincent Sherman Robert Altman's jazz-scored film explores themes of love, crime, race, and politics in 1930s Kansas City. When Blondie O'Hara's husband, a petty thief, is captured by Seldom Seen and held ... See full summary » Director: Robert Altman The account of troubled relationship between Mahatma Gandhi and his eldest son. Director: Feroz Abbas Khan Lowly hotel clerk Matthew Welch stumbles unto a chance to go on a date with supermodel Hexina by pretending he is someone else. But something goes wrong on the date, she tries to kill him! ... See full summary » Director: Alan Spencer A retired detective accepts a simple task, unaware that it will tear open old, forgotten, but deadly wounds. Director: Robert Benton Edit Storyline In real life, Robert Oppenheimer was the scientific head of the Manhattan Project, the secret wartime project in New Mexico where the first atomic bombs were designed and built. General Leslie Groves was in overall command of it.

This film reenacts the project with an emphasis on their relationship. Written by Anonymous The story of the extraordinary people who changed our world. Genres: 20 October 1989 (USA) See more » Also Known As: Did You Know? Trivia "Fat Man", according to the Atomic Heritage Foundation, "was the second plutonium, implosion-type bomb. The first was the 'Gadget' detonated at the Trinity site on July 16, 1945. In the implosion-type device, a core of sub-critical plutonium is surrounded by several thousand pounds of high-explosive designed in such a way that the explosive force of the HE is directed inwards thereby crushing the plutonium core into a super-critical state. Dropped on the Japanese city of Nagasaki on August 9, 1945, it was the second nuclear weapon used in a war".

See more » Goofs In the first shot of the experiment that Michael Merriman is performing, with the two hemispheres of beryllium surrounding a core of plutonium held slightly apart, he measures the gap between the hemispheres with a dial caliper - but the dial caliper was not developed until after the war. See more » Quotes Gen. Leslie R. Groves : We could give this country the biggest stick in the playground, and I intend to do that. The First Atomic Weapons The First Atomic Weapons Last changed 30 March 1999 In some sort of crude sense which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose. J. Robert Oppenheimer Concurrent with the preparations for the Trinity test, preparations were being made for the delivery of operational atomic weapons to Tinian Island in the Pacific for use against Japan at the earliest possible date. Two weapon designs were available for use - the gun assembly Little Boy bomb that used uranium highly enriched in U-235, and the implosion assembly Fat Man that used plutonium.

Little Boy and Fat Man On Display At the National Atomic Energy Museum, Albuquerque, New Mexico, USA, representative weapon casings for the Little Boy and Fat Man type weapons are on display. AtomicBombMuseum.org - The Bombings The Bombings Print this page (PDF) THE FIRST ATOMIC BOMBS: "Little Boy"and "Fat Man" There were actually two new bombs, one using uranium, the other plutonium, with different triggering devices for each. The main research and production sites were Los Alamos, New Mexico; Hanford, Washington; and Oak Ridge, Tennessee. The entire project operated under top secrecy, mobilizing top scientists and engineers, and at unprecedented high costs. *The world’s first plutonium factory: B-Reactor at the Hanford, Washington state, where plutonium for the Trinity test bomb and the Nagasaki bomb was made. ( DT -71) The Hiroshima bomb Nicknamed “Little Boy”(for President Franklin Roosevelt), the bomb’s size was 3 meters in length by 0.7 meter in diameter, using uranium 235 as its critical material.

Inside a shortened smooth-bore 76.2 mm (3 in.) naval gun, a subcritical projectile of U-235 was fired at a subcritical target of U-235. At the moment of impact, a supercritical mass was formed, triggering a nuclear chain reaction, or atomic explosion. The gun barrel and heavy casing gave it a weight of over four metric tons (8,900 lbs). The subcritical material was an alloy called Oralloy, a code named derived from the secret laboratory at Oak Ridge, Tennessee, where it was fabricated. For use in the gun device, the fissile materials had to be made into geometric shapes capable of withstanding the violence of being shot down the gun’s tube, then stoipped abruptly at the target, and held together long enough to detonate. *Photo of “Little Boy” ( Impact , p. 60) The Nagasaki bomb Nicknamed “Fat Man” (for England’s Prime Minister Winston Churchill), this bomb had a core of plutonium 239, was 3.5 meters in length by 1.5 meters in diameter, and it weighed 4.5 tons.

Its plutonium core was surrounded by 64 explosive charges arranged in an inner and outer shell. The explosive charges were fabricated in geometrical shapes in a configuration similar to a soccer ball—an extremely difficult and demanding procedure. When the two shells were detonated, the shockwave slammed into a tamper surrounding the plutonium nucleus, causing a rapid increase in density that compressed the slightly sub-critical plutonium core, rapidly increasing its density, making it supercritical, thus exploding in a nuclear chain reaction. *Photo of “Fat Man” ( Impact , p. 60) Fat Man and Little Boy Reviews & Ratings - IMDb IMDb 27 out of 30 people found the following review useful: The Best Engineering flick in decades, great history and melodrama, too from Somewhere in Soho 22 June 2002 It's rare for a movie to both encompass the process of problem solving and a fantastically far-reaching moral quandary AND be a fairly accurate historical movie, but Fat Man and Little Boy pulls off this trick. It's the story of the Manhattan Project -- the World War II effort to build the atom bomb, told as the conflict between the two men who made it happen, Gen.

Leslie Groves and Robert Oppenheimer. The historical figures are a great study in opposites: military vs. civilian, practical vs. idealistic, emotional vs. scientific, brute force vs. consensus-based problem solving, immediacy vs. long-term vision. A fictional character, played by John Cusack, is added as a sort of synthesis of the two historical figures, to show the humanity that oddly escapes the real people (and of course the obligatory love interest, played by Laura Dern). One looking for a straight documentary might criticize the lapses into melodrama (and occasional looseness with the facts, but that's Hollywood for ya), but the purpose of fiction is to synthesize and galvanize events into more universal truths, so I think this can be forgiven.

One of the great visuals in the movie is when Oppenheimer witnesses the first atomic explosion: it's done entirely through his reaction, and considering the awesome visuals inherent in an atomic explosion, it's a brave and entirely effective way of describing in a single moment the ambivalent effect on humans of unleashing such power (the sort of thing lost in the typical Hollywood shoot 'em up version of history.) The use of music is particularly excellent in the last third of the movie. Fairly accessible and highly recommended as both a historical movie and drama of the highest order. Was the above review useful to you? 23 out of 25 people found the following review useful: An interesting chronicle about the historic events referred to creation the first atomic bomb from Santander Spain 31 October 2006 This exciting picture is a dramatization of nuclear run and follows the development of the Manhattan project in Los Alamos from first conception of the power within the atom , the 235 uranium , with the neutrons bombing into the piles of graphite which leads to nuclear reaction that produces the atomic bomb , ¨the Trinity¨ .

The movie describes the power struggles and tensions between an idealist Robert Oppenheimer (Dwight Schulz) , the project's science leader and General Leslie Groves (Paul Newman) , the project's military commander . It was a race for the bomb because of the Nazis with the scientist Heisenberg were also making a nuclear bomb . Besides, there appears famous scientists who contributed to the atomic success with the first bomb as Leo Szilard , Enrico Fermi and Edward Teller . The film is overlong , a little bit dull and slow moving , though the semi-fictional accounts narrated are very interesting . Paul Newman as the military brain is excellent and Dwight Schulz (A team) as Oppenheimer , the head behind it , is magnificent . In real life, Newman was a liberal and Schultz is a conservative , opposites of the roles they played in this film . Furthermore , a distinguished rest cast as John Cusack , Laura Dern , Bonnie Bedelia , and Natasha Richardson , all of them are enjoyable . Director Roland Joffé cast numerous real-life scientists, including future Nobel Prize winner David Politzer, in small speaking and background roles .

Exceptional and colorful cinematography by Vilmos Zsigmond and sensitive musical score by the master Ennio Morricone . The motion picture was professionally directed by Roland Joffe (The mission) . Other films as ¨Fat man (this way called by bombing in Hiroshima) and Little boy¨ (so named by Nagasaki) are the followings : ¨Day one¨ , ¨Engola Day¨ , ¨Hiroshima¨ and for TV : ¨Oppenheimer¨ with Sam Waterson and one of the best is the Canadian series titled ¨Race for the bomb¨ with Maury Chaykin as General Groves and directed by Allan Eastman . Rating : Good and worthwhile seeing. Was the above review useful to you? 25 out of 35 people found the following review useful: We've Got The Bomb from Manitoba, Canada 8 April 2007 It was a fascinating story waiting to be told. FAT MAN AND LITTLE BOY takes us inside the trials and tribulations of a group of top American scientists handed a lofty task during the Second World War: beat everyone else to the atomic bomb.

Sequestered in a heavily-guarded New Mexico compound, the brainiacs slowly turn the idea from ambitious concept into immense reality. FAT MAN AND LITTLE BOY is one of those films that requires your close attention. It's a real thinking person's movie, not only from the scientific aspect of developing a seemingly impossible weapon, but also the moral implications of contributing to killing on a massive scale. Characters are constantly torn between that reality and their wartime duty as Americans. The film is never preachy about, however, leaving us free to marvel at the enormity of the inner turmoil these men face. The performances deserve special mention as well. Paul Newman delivers one of his great, understated performances as the Pattonesque general in charge of delivering the ultimate big stick for the Allied Forces. Where FAT MAN AND LITTLE BOY loses much of its traction is in the unnecessary romantic component. Dwight Schultz as the leader of the scientific team struggles with his affections for his family and his relentless obsession with his big project. Director Roland Joffe apparently felt the need to explore the more human angles of this story, but the romantic overtones serve primarily as a distraction.

Besides, it's the interaction among the scientists and their military hierarchy that give us the greatest insight into the thoughts and feelings of these brilliant men. Still, it's difficult not to recommend FAT MAN AND LITTLE BOY. It's a largely forgotten gem that puts a human face put on one of the most intriguing stories in human history. Was the above review useful to you? 19 out of 25 people found the following review useful: A Great Movie, Despite What They Say... from Portland, Maine 11 December 2002 Cold War enthusiasts are like Civil War enthusiasts in that they get extremely upset when something is portrayed differently than it actually happened (or differently than they THINK it happened). When you read a negative review of this movie, that is what you are seeing. It may not be 100% factual with the timeline and all of that, but who cares? It is still an excellent movie. The acting is wonderful and the message is even better. Dwight Schultz does an amazing job with his role. The entire cast must have lost 50 lbs each to look like skinny 1940s people. If you haven't seen this film, see it.

If you have and you didn't like it, please see it again and look at it with an open heart. It truly questions the moral issues of developing the bomb. It makes you think! Was the above review useful to you? 24 out of 36 people found the following review useful: One of the more accurate films about the making of the ATOMIC Bomb from Chicago, IL. - Home of the A-Bomb 3 October 2004 Having worked with all historical aspects of nuclear energy, radiation, etc.

for 11 Years ( including working with the US D.O.E - Department of Energy during the cleanup of the Chicago site ), I found this film to be VERY accurate with only several exceptions ( such as groves did not meet Szliard in a bathtub in Szliards Apartment, the Critically accident referred to in th film happened later at Los alamos to Louis Slotin and Harrry Daughlin, and groves was slightly heavier than neumann's character, and not to mention much less harsh and abusive, although he was a perfectionist, always VERY concerned about the sites security and about the public's safety and sometimes got his way without exception, and finally there were other sites in the early project that should have been mentioned more...such as Chicago ). Technically, I feel that the producers/directors created a "Perfect Feel" for the time, as most sites I've been too are simply a-lot of high-dollar, high-tech stuff in the middle of quite isolated areas - very quiet with just the sound of wind blowing and creaking steel. I've seen some peoples reviews talking about this movie as if they're reviewing a love story.....Hello, This story is about an atomic bomb !!!!!

I too feel that the brief love story romance is not really needed, but I'm sure that the directors put it in there to show you what oppenheimer was also going thru emotionally in addition to all the chaos he was already facing day-to-day on the projects sites !!! I have seen this movie on VHS, Laserdisc and FINALLY DVD, and I must say that the DVD release is the SHARPEST transfer made of the movie to-date; they did a very good job on the mastering as well ( No artifacts or blockiness - and to those Fatman and LittleBoy movie buffs, yes, they still left in the 1 or 2 screwed-up voice-overs ). Unfortunately, after waiting years for the DVD release to come out, there are really no special features aside from 4:3, Widescreen 16:9, and Dolby 5:1 ( which I was hoping for, since the soundtrack is AMAZING ), There isn't even a trailer for the movie !!! :-( What was paramount thinking ?????

Well, maybe they'll read this review and include some more special features ( Like interviews with Paul Neumann, John Cusack, Dwight Schultz, along with a TRAILER of the movie, and some behind-the-scenes making-of the lots ) if they ever release it in High-Definition 1080p !!! One can only hope. All-in-all its an excellent movie, but if your renting/buying/watching it because you thought it was a romantic movie.....DON'T BOTHER !!!! Was the above review useful to you? 12 out of 14 people found the following review useful: The Challenge Of The Problem from Buffalo, New York 17 February 2008 Fat Man And Little Boy were the code names of the two atomic bombs that were dropped in reverse order on Nagasaki and Hiroshina. How these came to be and came to be in American hands is the story of this film. The terms by the way are the code names of two bombs fueled with plutonium and uranium. Fat Man was the plutonium bomb and that one was dropped on Nagasaki and Little Boy was the one used on Hiroshima The film is primarily a conflict between General Leslie R.

Groves of the United States Army and physicist J. Robert Oppenheimer who led the team of scientists who developed the bomb under Groves's direction. With two men from as widely divergent backgrounds as these were, conflict was inevitable. Paul Newman who all his life has been a disarmament activist plays General Groves. To his credit Newman does not play a man whose views he would very little in common with as any kind of caricature. Groves is a military man first and foremost with an engineering background. He wanted a combat command as trained military professionals would naturally want in this greatest of wars. But because of his background in engineering Groves got to head the Manhattan Project which was what the effort was code named. So be it, Newman is determined to make his contribution to the war effort count. Most of us first became acquainted with Dwight Schultz from the A-Team as H.M. Murdoch the pilot whose grip on reality is tenuous at best. If one was only acquainted with the A-Team, one might think that Schultz had a great future in comic roles. Instead Dwight Schultz is one of the best actors in the English speaking world with an astonishing range of dramatic parts since leaving that television series. J.

Robert Oppenheimer in life was a complex man who recognized the dangers and benefits of atomic energy. The challenge of the problem also intrigues him. Later on Oppenheimer got into a real bind because of his left-wing political views and associates which everyone knew walking into the Manhattan Project. Some of the lesser roles that stand out are Bonnie Bedelia as Mrs. Oppenheimer, Natasha Richardson as Oppenheimer's Communist mistress whose affair with Oppenheimer got him in such a jackpot later on, and Laura Dern as a nurse at the Los Alamos site. But the best is John Cusack who as Michael Merriman is a composite of some real life scientists who might accurately be labeled as the first casualties of the atomic age. His scenes with Laura Dern, especially with what happens to him, take on a real poignancy. The debate over the bombs as the use put to them is still a matter of raging debate. Fat Man And Little Boy presents the facts and lets you decide what might have happened if an alternative use of them had been taken. Was the above review useful to you?

16 out of 22 people found the following review useful: For the scientifically inclined from Boulder, CO 3 February 1999 We watched this movie in my chemistry class, so obviously it had educational value. I thought the film did a really good job of intertwining the subjects of the science, moral issues and personal experiences of the manhattan project, but wasn't exactly focused on strong acting. I would recommend this movie for the scientifically inclined or those interested in the moral issues behind Fat Man and Little Boy, but if the subject of nuclear bombs bores you, don't see it. Was the above review useful to you? 17 out of 24 people found the following review useful: Lazy and simplistic from United States 26 March 2012 Fat Man & Little Boy plays like the Cliff's Notes version of an important period in history and science. The first moment we see a carefree, laughing Oppenheimer, it is obvious that the film is going to take quite a few liberties with characterization. When Paul Newman strides onto the scene, accompanied by "Patton"-like music, all credibility is immediately destroyed. My major problem with Fat Man & Little Boy is the character of Oppenheimer.

Oppenheimer was a complex character, a misfit, a neurasthenic polymath. This film only scratches the surface of his personality, and the actor who plays him is horribly miscast, although he tries his best. Towards the final days of the Project, Oppenheimer had become extremely thin and cadaverous. The constant hounding by Communist hunters digging into his personal life coupled with his moral qualms about the use of the Bomb threw him into a state of nervous exhaustion bordering on paranoia. There is no hint of the inner man in this portrayal. The community of physicists at Los Alamos was a collection of brilliant and unusual men. There were many conflicts and a lot of competition going on which are pretty much ignored. It was frustrating to see all of this potentially rich material cast aside in order to simplify the film and make it accessible. In addition to ignoring the real characters involved in the Manhattan Project and misinterpreting the ones it treats, the film introduces John Cusak as the "Everyman Physicist," a fictional character created to humanize(?)the subject and engage the "average viewer," along with the obligatory love interest. This slows the movie down to a crawl and it was walking pretty slowly to begin with.

This movie takes a situation rich in drama and conflict coupled with scientific and historical interest and turns it into a boring, simplistic soap opera. Was the above review useful to you? 10 out of 11 people found the following review useful: Decent from California 23 October 2008 If you know anything about the Manhattan Project, you will find "Fat Man and Little Boy" at least an interesting depiction of the events surrounding that story. The film is in all ways a very realistic portrayal of these events, and in many ways it is almost too real (such as some scenes involving radiation poisoning). Paul Newman, as usual, is brilliant in his role and always manages to come off like a real person on the screen. The supporting cast, such as John Cusack, Laura Dern, Bonnie Bedelia, and Natasha Richardson, is fairly good as well. This film is not, however, one of the best examples of turning a true story into a movie. Great films are able to take a true story and use just enough artistic license to keep its audience engaged for the entire movie.

This one, however, tends to drag a bit throughout, and some scenes (such as John Cusack and Natasha Richardson's love story) could have been eliminated entirely without causing the film to lose much. Nevertheless, there are enough interesting facts and tiny humorous bits to at least keep the audience interested enough to see the entire film. It does not always entertain, but as far as great depictions go, this is very accurate, fascinating, and will leave the audience with something to think about. *** out of **** 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.

Question: Little boy and fat man were names for what?
Answer: ATOMIC BOMBS