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Atomic Bombings Of Hiroshima And Nagasaki
On 6 and 9 August 1945, the United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki, respectively, during World War II. The aerial bombings killed between 150,000 and 246,000 people, most of whom were civilians, and remain the only uses of Nuclear warfare, nuclear weapons in an armed conflict. Surrender of Japan, Japan announced its surrender to the Allies on 15 August, six days after the bombing of Nagasaki and the Soviet–Japanese War, Soviet Union's declaration of war against Japan and Soviet invasion of Manchuria, invasion of Manchuria. The Japanese government signed an Japanese Instrument of Surrender, instrument of surrender on 2 September, End of World War II in Asia, ending the war. In the final year of World War II, the Allies of World War II, Allies prepared for a costly Operation Downfall, invasion of the Japanese mainland. This undertaking was preceded by a Air raids on Japan, conventional bombing and firebombing campaign that de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific War
The Pacific War, sometimes called the Asia–Pacific War or the Pacific Theatre, was the Theater (warfare), theatre of World War II fought between the Empire of Japan and the Allies of World War II, Allies in East Asia, East and Southeast Asia, the Pacific Ocean, Pacific and Indian Oceans, and Oceania. It was geographically the largest theatre of the war, including the Pacific Ocean theater of World War II, Pacific Ocean theatre, the South West Pacific theater of World War II, South West Pacific theatre, the Second Sino-Japanese War, and the brief Soviet–Japanese War, and included some of the Largest naval battle in history, largest naval battles in history. War between Japan and the Republic of China (1912–1949), Republic of China had begun in 1937, with hostilities dating back to Japanese invasion of Manchuria, Japan's invasion of Manchuria in 1931, but the Pacific War is more widely accepted to have started in 1941, when the United States and United Kingdom entered the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Raids On Japan
During the Pacific War, Allies of World War II, Allied forces conducted air raids on Japan from 1942 to 1945, causing extensive destruction to the country's cities and killing between 241,000 and 900,000 people. During the first years of the Pacific War these attacks were limited to the Doolittle Raid in April 1942 and small-scale raids on Japanese military positions in the Kuril Islands from mid-1943. Strategic bombing during World War II, Strategic bombing raids began in June 1944 and continued with increasing intensity until the end of the war in August 1945. Allied naval and land-based Tactical bombing, tactical air units also attacked Japan during 1945. The United States Army Air Forces campaign against Japan began in earnest in mid-1944 and intensified during the final months of the war. While plans for attacks on the Japanese home islands had been prepared prior to the Pacific War, these could not begin until the long-range Boeing B-29 Superfortress bomber was ready for c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mariana Islands
The Mariana Islands ( ; ), also simply the Marianas, are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly dormant volcanic mountains in the northwestern Pacific Ocean, between the 12th and 21st parallels north and along the 145th meridian east. They lie south-southeast of Japan, west-southwest of Hawaii, north of New Guinea, and east of the Philippines, demarcating the Philippine Sea's eastern limit. They are found in the northern part of the western Oceanic sub-region of Micronesia, and are politically divided into two jurisdictions of the United States: the Commonwealth of the Northern Mariana Islands and, at the southern end of the chain, the territory of Guam. The islands were named after the influential Spanish queen Mariana of Austria following their colonization in the 17th century. The indigenous inhabitants are the Chamorro people. Archaeologists in 2013 reported findings which indicated that the people who first settl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tinian
Tinian () is one of the three principal islands of the Commonwealth of the Northern Mariana Islands (CNMI). Together with uninhabited neighboring Aguiguan, it forms Tinian Municipality, one of the four constituent municipalities of the Northern Marianas. Tinian's largest village is San Jose. Tinian is just south of the Northern Marianas' most inhabited island, Saipan, but north of the populated Rota to the south. The island has many World War II historical sites, cattle ranches, and beaches. There was a 5-star casino that operated from 1998 to 2015; the remaining are other hotels/resorts and a golf course. The main Saipan access is a short airplane ride from the international airport or a charter boat. Tinian is part of the United States and the CNMI. Along with Guam, it is the westernmost U.S. island in the Pacific. History First settlers The Mariana Islands, of which Tinian is one, were the first islands settled by humans in Remote Oceania. It was also the first and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boeing B-29 Superfortress
The Boeing B-29 Superfortress is a retired American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the Boeing B-17 Flying Fortress, the Superfortress was designed for high-altitude strategic bombing, but also excelled in low-altitude night incendiary bombing, and in dropping naval mines to blockade Japan. B-29s dropped the atomic bombs on Hiroshima and Nagasaki, the only aircraft ever to drop nuclear weapons in combat. One of the largest aircraft of World War II, the B-29 was designed with state-of-the-art technology, which included a pressurized cabin, dual-wheeled tricycle landing gear, and an analog computer-controlled fire-control system that allowed one gunner and a fire-control officer to direct four remote machine gun turrets. The $3 and a half dollar cost of design and production (equivalent to $6769 billion in 400), fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silverplate
Silverplate was the code reference for the United States Army Air Forces' participation in the Manhattan Project during World War II. Originally the name for the aircraft modification project which enabled a B-29 Superfortress bomber to drop an atomic weapon, "Silverplate" eventually came to identify the training and operational aspects of the program as well. The original directive for the project had as its subject line "Silver Plated Project," but continued usage of the term shortened it to "Silverplate". Testing began with scale models at the Naval Surface Warfare Center Dahlgren Division, Naval Proving Ground in Dahlgren, Virginia, in August 1943. Modifications began on a prototype Silverplate B-29 known as the "Pullman" in November 1943, and it was used for bomb flight testing at Muroc Army Air Field in California commencing in March 1944. The testing resulted in further modifications to both the bombs and the aircraft. Seventeen production Silverplate aircraft were ord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implosion-type Nuclear Weapon
Nuclear weapons design are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types: # Pure fission weapons are the simplest, least technically demanding, were the first nuclear weapons built, and so far the only type ever used in warfare, by the United States on Japan in World War II. # Boosted fission weapons are fission weapons that use nuclear fusion reactions to generate high-energy neutrons that accelerate the fission chain reaction and increase its efficiency. Boosting can more than double the weapon's fission energy yield. # Staged thermonuclear weapons are arrangements of two or more "stages", most usually two, where the weapon derives a significant fraction of its energy from nuclear fusion (as well as, usually, nuclear fission), . The first stage is typically a boosted fission weapon (except for the earliest thermonuclear weapons, which used a pure fission weapon). Its de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plutonium
Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen. When exposed to moist air, it forms oxides and hydrides that can expand the sample up to 70% in volume, which in turn flake off as a powder that is pyrophoric. It is radioactive and can accumulate in bones, which makes the handling of plutonium dangerous. Plutonium was first synthesized and isolated in late 1940 and early 1941, by deuteron bombardment of uranium-238 in the cyclotron at the University of California, Berkeley. First, neptunium-238 (half-life 2.1 days) was synthesized, which then beta-decayed to form the new element with atomic number 94 and atomic weight 238 (half-life 88 years). Since uranium had been named after the planet Uranus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fat Man
"Fat Man" (also known as Mark III) was the design of the nuclear weapon the United States used for seven of the first eight nuclear weapons ever detonated in history. It is also the most powerful design to ever be used in warfare. A Fat Man device was Atomic bombings of Hiroshima and Nagasaki#Bombing of Nagasaki, detonated over the Japanese city of Nagasaki on 9 August 1945. It was the second and largest of the only two nuclear weapons ever used in warfare. It was dropped from the Boeing B-29 Superfortress ''Bockscar'' piloted by Major Charles Sweeney. Its detonation marked the third nuclear explosion in history. The name Fat Man refers to the wide, round shape. Fat Man was an implosion-type nuclear weapon with a solid plutonium Nuclear reactor core, core, and later with improved cores. The first Fat Man to be detonated was the gadget in the Trinity (nuclear test), Trinity nuclear test less than a month earlier on 16 July at the Holloman Air Force Base, Alamogordo Bombing an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gun-type Fission Weapon
Gun-type fission weapons are fission-based nuclear weapons whose design assembles their fissile material into a supercritical mass by the use of the "gun" method: shooting one piece of sub-critical material into another. Although this is sometimes pictured as two sub-critical hemispheres driven together to make a supercritical sphere, typically a hollow projectile is shot onto a spike, which fills the hole in its center. Its name is a reference to the fact that it is shooting the material through an artillery barrel as if it were a projectile. Since it is a slow and asymmetrical method of assembly, weapons-grade plutonium cannot be used. The presence of the isotope 240Pu, with its high spontaneous fission rate, causes predetonation. It is extremely impractical to produce plutonium of the required isotopic purity in a reactor. Additionally, the required amount of highly enriched uranium is relatively large, and thus the overall efficiency is relatively low. The main reason fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enriched Uranium
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238U with 99.2732–99.2752% natural abundance), uranium-235 (235U, 0.7198–0.7210%), and uranium-234 (234U, 0.0049–0.0059%). 235U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons. Enriched uranium is a critical component for both civil nuclear power generation and military nuclear weapons. Low-enriched uranium (20% 235U, typically >85%) is used for the cores of many nuclear weapons, as well as compact reactors for naval propulsion and research, as well as breeder reactors. There are about 2,000 tonnes of highly enriched uranium in the world. Enrichment methods were first developed on a large scale by the Manhattan Project. Its gaseous diffusion method was used in the 194 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Boy
Little Boy was a type of atomic bomb created by the Manhattan Project during World War II. The name is also often used to describe the specific bomb (L-11) used in the bombing of the Japanese city of Hiroshima by the Boeing B-29 Superfortress '' Enola Gay'' on 6 August 1945, making it the first nuclear weapon used in warfare, and the second nuclear explosion in history, after the Trinity nuclear test. It exploded with an energy of approximately and had an explosion radius of approximately which caused widespread death across the city. It was a gun-type fission weapon which used uranium that had been enriched in the isotope uranium-235 to power its explosive reaction. Little Boy was developed by Lieutenant Commander Francis Birch's group at the Los Alamos Laboratory. It was the successor to a plutonium-fueled gun-type fission design, Thin Man (nuclear bomb), Thin Man, which was abandoned in 1944 after technical difficulties were discovered. Little Boy used a charge of co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
