Ground Zero
In relation to nuclear explosions and other large bombs, ground zero (also called surface zero) is the point on the Earth's surface closest to a detonation. In the case of an explosion above the ground, ''ground zero'' is the point on the ground directly below the nuclear detonation and is sometimes called the hypocenter (). Generally, the terms ''ground zero'' and ''surface zero'' are also used in relation to earthquakes, epidemics, and other disasters to mark the point of the most severe damage or destruction. The term is distinguished from the term zero point in that the latter can also be located in the air, underground, or underwater. Trinity, Hiroshima and Nagasaki The origins of the term "ground zero" began with the Trinity (nuclear test), Trinity test in Jornada del Muerto, Jornada del Muerto desert near Socorro, New Mexico, and the atomic bombings of Hiroshima and Nagasaki in Japan. The United States Strategic Bombing Survey of the atomic attacks, released in June 194 ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Nuclear Explosion
A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, though to date all fusion-based weapons have used a fission device to initiate fusion, and a pure fusion weapon remains a hypothetical device. Nuclear explosions are used in nuclear weapons and nuclear testing. Atmospheric nuclear explosions are associated with mushroom clouds, although mushroom clouds can occur with large chemical explosions. It is possible to have an air-burst nuclear explosion without those clouds. Nuclear explosions produce radiation and radioactive debris that is harmful to humans and can cause moderate to severe skin burns, eye damage, radiation sickness, radiation-induced cancer and possible death depending on how far from the blast radius a person is. Nuclear explosions can also have detrimental effects on the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Manhattan Project
The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the United States Army Corps of Engineers, U.S. Army Corps of Engineers. Nuclear physicist Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the actual bombs. The Army component of the project was designated the Manhattan District as its first headquarters were in Manhattan; the placename gradually superseded the official codename, Development of Substitute Materials, for the entire project. Along the way, the project absorbed its earlier British counterpart, Tube Alloys. The Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US$2 billion (equivalent to about $ billion in ). Over 90 percent of th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
United States Department Of Defense
The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national security and the United States Armed Forces. The DoD is the largest employer in the world, with over 1.34 million active-duty service members (soldiers, marines, sailors, airmen, and guardians) as of June 2022. The DoD also maintains over 778,000 National Guard and reservists, and over 747,000 civilians bringing the total to over 2.87 million employees. Headquartered at the Pentagon in Arlington, Virginia, just outside Washington, D.C., the DoD's stated mission is to provide "the military forces needed to deter war and ensure our nation's security". The Department of Defense is headed by the secretary of defense, a cabinet-level head who reports directly to the president of the United States. Beneath the Department of Defense are th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
The Pentagon
The Pentagon is the headquarters building of the United States Department of Defense. It was constructed on an accelerated schedule during World War II. As a symbol of the U.S. military, the phrase ''The Pentagon'' is often used as a metonym for the Department of Defense and its leadership. Located in Arlington County, Virginia, across the Potomac River from Washington, D.C., the building was designed by American architect George Bergstrom and built by contractor John McShain. Ground was broken on 11 September 1941, and the building was dedicated on 15 January 1943. General Brehon Somervell provided the major impetus to gain Congressional approval for the project; Colonel Leslie Groves was responsible for overseeing the project for the U.S. Army Corps of Engineers, which supervised it. The Pentagon is the world's largest office building, with about of floor space, of which are used as offices. Some 23,000 military and civilian employees, and another 3,000 non-defense sup ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Cold War
The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because there was no large-scale fighting directly between the two superpowers, but they each supported major regional conflicts known as proxy wars. The conflict was based around the ideological and geopolitical struggle for global influence by these two superpowers, following their temporary alliance and victory against Nazi Germany and Imperial Japan in 1945. Aside from the nuclear arsenal development and conventional military deployment, the struggle for dominance was expressed via indirect means such as psychological warfare, propaganda campaigns, espionage, far-reaching embargoes, rivalry at sports events, and technological competitions such as the Space Race. The Western Bloc was led by the United States as well as a number of other First W ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Nagasaki
is the capital and the largest city of Nagasaki Prefecture on the island of Kyushu in Japan. It became the sole port used for trade with the Portuguese and Dutch during the 16th through 19th centuries. The Hidden Christian Sites in the Nagasaki Region have been recognized and included in the UNESCO World Heritage List. Part of Nagasaki was home to a major Imperial Japanese Navy base during the First Sino-Japanese War and Russo-Japanese War. Near the end of World War II, the American atomic bombings of Hiroshima and Nagasaki made Nagasaki the second and, to date, last city in the world to experience a nuclear attack (at 11:02 am, August 9, 1945 'Japan Standard Time (UTC+9)'). , the city has an estimated population of 407,624 and a population density of 1,004 people per km2. The total area is . History Nagasaki as a Jesuit port of call The first contact with Portuguese explorers occurred in 1543. An early visitor was Fernão Mendes Pinto, who came from Sagres ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Aioi Bridge
The is an unusual "T"-shaped three-way bridge in Hiroshima, Japan. The original bridge, constructed in 1932, was the aiming point for the 1945 Hiroshima atom bomb because its shape was easily recognized from the air and also because the bridge was close to the center of the city. Although the bridge was not destroyed by the atomic blast, it did sustain heavy damage. After the war, the bridge was repaired and remained in service for nearly four decades, before it was replaced by a new bridge (built as a replica) in 1983. A surviving portion of a floor girder from the original bridge was subsequently donated to the Hiroshima Peace Memorial Museum. The longer part of the bridge crosses the Ōta River just to the north of the island containing the district of . The downstroke of the "T" links the main bridge to the island, and is also the north entrance to the Hiroshima Peace Memorial Park is a memorial park in the center of Hiroshima, Japan. It is dedicated to the legacy of H ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Shima Hospital
is a Japanese hospital, now clinic, in Hiroshima, Japan. It was the exact location where the atomic bombing of Hiroshima took place on August 6, 1945. Shima Hospital is considered to be ground zero. In 1948, the hospital was rebuilt from the ground up by Dr. . The reconstructed Shima Surgery is still in operation to the present day under the name Shima Internist Hospital ( ''Shima naika iin'').Shima Naika Iin (Japanese) Specialities of the present Shima Hospital are surgery, orthopaedics, internal medicine, and endoscopic treatment of the digestive organs. Adjacent to the Shima Hospital is a monument marking the hypocenter ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Nuclear Weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to . The first thermonuclear ("hydrogen") bomb test released energy approximately equal to . Nuclear bombs have had yields between 10 tons TNT (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent). A thermonuclear weapon weighing as little as can release energy equal to more than . A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been d ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
|
Hiroshima
is the capital of Hiroshima Prefecture in Japan. , the city had an estimated population of 1,199,391. The gross domestic product (GDP) in Greater Hiroshima, Hiroshima Urban Employment Area, was US$61.3 billion as of 2010. Kazumi Matsui has been the city's mayor since April 2011. Hiroshima was founded in 1589 as a castle town on the Ōta River delta. Following the Meiji Restoration in 1868, Hiroshima rapidly transformed into a major urban center and industrial hub. In 1889, Hiroshima officially gained city status. The city was a center of military activities during the imperial era, playing significant roles such as in the First Sino-Japanese War, the Russo-Japanese War, and the two world wars. Hiroshima was the first military target of a nuclear weapon in human history. This occurred on August 6, 1945, at 8:15 a.m., when the United States Army Air Forces (USAAF) dropped the atomic bomb "Little Boy" on the city. Most of Hiroshima was destroyed, and by the end of th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |