What's the biggest atomic bomb to ever exist?
Bomb
The power of large bombs is typically measured in kilotons (kt) or megatons of TNT (Mt). The most powerful bombs ever used in combat were the two atomic bombs dropped by the United States to attack Hiroshima and Nagasaki, and the most powerful ever tested was the Tsar Bomba. The most powerful non-nuclear bomb is Russian "Father of All Bombs" (officially Aviation Thermobaric Bomb of Increased Power (ATBIP)) followed by the United States Air Force's MOAB (officially Massive Ordnance Air Blast, or more commonly known as the "Mother of All Bombs").
Nuclear weapon design
The picture below shows the Shrimp device, detonated on March 1, 1954 at Bikini, as the Castle Bravo test. Its 15-megaton explosion was the largest ever by the United States. The silhouette of a man is shown for scale. The device is supported from below, at the ends. The pipes going into the shot cab ceiling, which appear to be supports, are actually diagnostic light pipes. The eight pipes at the right end (1) sent information about the detonation of the primary. Two in the middle (2) marked the time when x-radiation from the primary reached the radiation channel around the secondary. The last two pipes (3) noted the time radiation reached the far end of the radiation channel, the difference between (2) and (3) being the radiation transit time for the channel.
From the shot cab, the pipes turned horizontally and traveled 7500 ft (2.3 km) along a causeway built on the Bikini reef to a remote-controlled data collection bunker on Namu Island.
Political views of Albert Einstein
By 1942 this effort had become the Manhattan Project, the largest secret scientific endeavor undertaken up to that time. By late 1945, the U.S., with support from the United Kingdom and Canada, had developed operational nuclear weapons, and used them on the Japanese cities of Hiroshima and Nagasaki. Einstein himself did not play a role in the development of the atomic bomb other than signing the letter although he did help the United States Navy with some unrelated theoretical questions it was working on during the war.
Walter Wolfgang
Before CND, Wolfgang had been a member of the Direct Action Committee and in 1961 he joined the more radical section of CND in seceding to the Committee of 100 where he became Chairman of the London Executive. He organised a protest on 1 November 1961 in which he delivered a milk bottle labelled "Danger – Radioactive" to the Soviet Union embassy in London in protest at the detonation of Tsar Bomba, at 50 megatons the largest nuclear explosive to ever be tested.
Uranium
As little as 15 lb (7 kg) of uranium-235 can be used to make an atomic bomb. The first nuclear bomb used in war, "Little Boy", relied on uranium fission, but the very first nuclear explosive (the "Gadget" used at Trinity) and the bomb that destroyed Nagasaki ("Fat Man") were both plutonium bombs.
Hanford Reach National Monument
Hanford Reach is home to nine nuclear reactors of which B Reactor is the most famous; constructed in 13 months during World War II, it was the world’s first full scale reactor. Plutonium from the reactor was used in the first nuclear explosion at the Alamogordo Bombing and Gunnery Range in New Mexico (July 16, 1945) and in the Fat Man atomic bomb dropped on Nagasaki, Japan (August 9, 1945). The reactor’s significance has led to many distinctions including a place on the National Historic Mechanical Engineering Landmark, National Register of Historic Places, Nuclear Historic Landmark, National Civil Engineering Landmark and National Historic Landmark.
History of the Marshall Islands
From 1946 to 1958, the early years of the Cold War, the United States tested 67 nuclear weapons at its Pacific Proving Grounds located in the Marshall Islands, including the largest atmospheric nuclear test ever conducted by the U.S., code named Castle Bravo. "The bombs had a total yield of 108,496 kilotons, over 7,200 times more powerful than the atomic weapons used during World War II." With the 1952 test of the first U.S. hydrogen bomb, code named "Ivy Mike," the island of Elugelab in the Enewetak atoll was destroyed. In 1956, the United States Atomic Energy Commission regarded the Marshall Islands as "by far the most contaminated place in the world."
B41 nuclear bomb
The B-41 (also known as Mk-41) was a thermonuclear weapon deployed by the United States Strategic Air Command in the early 1960s. It was the most powerful nuclear bomb ever developed by the United States, with a maximum yield of 25 megatons. The B-41 was the only three-stage thermonuclear weapon fielded by the U.S.
New Mexico during World War II
The most important of all the secret weapons programs in New Mexico was the Manhattan Project, which was the codename for the nuclear weapons experiments taking place across the United States, Canada, and Britain. It began in 1942 after Physicist J. Robert Oppenheimer assembled "the greatest concentration of scientific resources and brainpower in history" to build the world's first atomic bomb. To do this, the government had the army construct the giant Los Alamos National Laboratory twenty miles northwest of Santa Fe in 1943 and then sealed off the entire area to keep it secret. By the war's end in 1945, some 5,000 people lived at Los Alamos, which led to the founding of the present-day town.
Nangarhar Province
On April 13, 2017, U.S. President Donald Trump ordered a targeted strike on ISIL-KP by use of the second largest non-nuclear bomb in the U.S. arsenal at the time. The bomb was a 21,000 lb. weapon called the Massive Ordnance Air Blast Bomb; nicknamed the "Mother Of All Bombs" (MOAB). The intended target was ISIL militants hiding inside tunnels, most of whom came "from Bangladesh, Pakistan, Tajikistan, Russia, India and other countries." Mohammad Radmanish, spokesman for the Afghan Ministry of Defense stated: "Most militants killed in the attack were from Pakistan, India, Philippines, and Bangladesh." It was the first time the MOAB had been used in combat.
Asteroid Terrestrial-impact Last Alert System
Throughout recorded history, hundreds of Earth impacts (and exploding bolides) have been reported, with some small fraction causing deaths, injuries, property damage, or other significant localised consequences. Stony asteroids with a diameter of enter Earth's atmosphere approximately once per year. Asteroids with a diameter of 7 meters enter the atmosphere about every 5 years with as much kinetic energy as the atomic bomb dropped on Hiroshima (approximately 16 kilotons of TNT), of which their air burst represents about one third or 5 kilotons. These relatively small asteroids ordinarily explode in the upper atmosphere and most or all of the solids are vaporized. Asteroids with a diameter of strike Earth approximately twice every century.
One of the best-known recorded impacts in historical times is the 50 meter 1908 Tunguska event, which leveled several thousand square kilometers of forest in a very sparsely populated part of Siberia, Russia, and which over a more populous region would have caused catastrophic damage. The 2013 Chelyabinsk meteor event is the only known impact in historical times to have resulted in a large number of injuries, with the possible exception of the poorly documented 1490 Ch'ing-yang event in China. The approximately 20 meter Chelyabinsk meteor is the largest recorded object to have impacted a continent of the Earth since the Tunguska event. Future impacts are bound to occur, with much higher odds for smaller regionally damaging asteroids than for larger globally damaging ones. The 2018 final book of physicist Stephen Hawking, "Brief Answers to the Big Questions", considers a large asteroid collision the biggest threat to our planet. In April 2018, the B612 Foundation reported "It's a 100 per cent certainty we'll be hit [by a devastating asteroid], but we're not 100 per cent sure when." In June 2018, the US National Science and Technology Council warned that America is unprepared for an asteroid impact event, and has developed and released the ""National Near-Earth Object Preparedness Strategy Action Plan"" to better prepare.
Largest artificial non-nuclear explosions
There have been many extremely large explosions, accidental and intentional, caused by modern high explosives, boiling liquid expanding vapour explosions (BLEVEs), older explosives such as gunpowder, volatile petroleum-based fuels such as petrol, and other chemical reactions. This list contains the largest known examples, sorted by date. An unambiguous ranking in order of severity is not possible; a 1994 study by historian Jay White of 130 large explosions suggested that they need to be ranked by an overall effect of power, quantity, radius, loss of life and property destruction, but concluded that such rankings are difficult to assess.
Mark 21 nuclear bomb
The Mark 21 nuclear bomb was a United States nuclear gravity bomb first produced in 1955. It was based on the TX-21 "Shrimp" prototype that had been detonated during the Castle Bravo test in March 1954. While most of the Operation Castle tests were intended to evaluate weapons intended for immediate stockpile, or which were already available for use as part of the Emergency Capability Program, Castle Bravo was intended to test a design which would drastically reduce the size and costs of the first generation of air-droppable atomic weapons (the Mk 14, Mk 17 & Mk 24). At long, in diameter, and weighing , the Mk-21 was half the length and one-third the weight of the Mk-17/24 weapons it replaced. Its minimum yield was specified at four megatons.
USS Ulysses (ARB-9)
Ironically, on the very day - 6 August 1945 - "Ulysses" arrived at Saipan, only away on Tinian Island, a plane named the Enola Gay took off and flew to Hiroshima, Japan, and dropped the world's first atomic bomb on that city. The sailors aboard "Ulysses" knew nothing of this at the time, nor for several days afterwards.
During the remainder of 1945, she carried out repair assignments while based in turn at Saipan and at Okinawa. At Buckner Bay, on 9 and 10 October 1945, she weathered a devastating typhoon (Typhoon Louise (1945)) during which she collided three times with . The repair ship lost three anchors in attempting to hold her position in the anchorage during the height of the storm and emerged from the ordeal with a hole in one side.
Seabees in World War II
On 6 August 1945 the new weapon was loaded into a U.S. Army Air Force B-29 bomber, named the Enola Gay. A short time later, the Enola Gay took off with its secret load from Tinian's North Field, The largest airfield of the WWII, which the Seabees had built, and started on her mission to Japan. Later in the day, the mission ended with the dropping of the first atomic bomb on Hiroshima.
History of nuclear weapons
In the end, President Truman made the final decision, looking for a proper response to the first Soviet atomic bomb test in 1949. On January 31, 1950, Truman announced a crash program to develop the hydrogen (fusion) bomb. At this point, however, the exact mechanism was still not known: the classical hydrogen bomb, whereby the "heat" of the fission bomb would be used to ignite the fusion material, seemed highly unworkable. However, an insight by Los Alamos mathematician Stanislaw Ulam showed that the fission bomb and the fusion fuel could be in separate parts of the bomb, and that "radiation" of the fission bomb could first work in a way to "compress" the fusion material before igniting it.
History of nuclear weapons
Its explosion yielded energy equivalent to 10.4 megatons of TNT—over 450 times the power of the bomb dropped onto Nagasaki— and obliterated Elugelab, leaving an underwater crater 6240 ft (1.9 km) wide and 164 ft (50 m) deep where the island had once been. Truman had initially tried to create a media blackout about the test—hoping it would not become an issue in the upcoming presidential election—but on January 7, 1953, Truman announced the development of the hydrogen bomb to the world as hints and speculations of it were already beginning to emerge in the press.
Mark 13 nuclear bomb
The Mark 18 nuclear bomb also known as the Super Oralloy Bomb (or its initials SOB) utilized the 92-point Mark 13 implosion system, but a different fissile core with around 60 kilograms of highly enriched uranium (Oralloy). This was the largest pure fission nuclear bomb ever tested, with a yield of more than 500 kilotons. The Mark 18 was produced in moderate quantities (90 units) and in service from 1953 to 1956.
Halifax Explosion
The Halifax Explosion was one of the largest artificial non-nuclear explosions. An extensive comparison of 130 major explosions by Halifax historian Jay White in 1994 concluded that "Halifax Harbour remains unchallenged in overall magnitude as long as five criteria are considered together: number of casualties, force of blast, radius of devastation, quantity of explosive material, and total value of property destroyed." For many years afterward, the Halifax Explosion was the standard by which all large blasts were measured. For instance, in its report on the atomic bombing of Hiroshima, "Time" wrote that the explosive power of the Little Boy bomb was seven times that of the Halifax Explosion.
Cretaceous–Paleogene boundary
Using estimates of the total amount of iridium in the K–Pg layer, and assuming that the asteroid contained the normal percentage of iridium found in chondrites, the Alvarez team went on to calculate the size of the asteroid. The answer was about in diameter, about the size of Manhattan. Such a large impact would have had approximately the energy of 100 trillion tons of TNT, or about 2 million times greater than the most powerful thermonuclear bomb ever tested.
Novaya Zemlya
Novaya Zemlya was a sensitive military area during the Cold War years, and parts of it are still used for airfields today. The Soviet Air Force maintained a presence at Rogachevo on the southern part of the southern island, on the westernmost peninsula (). It was used primarily for interceptor aircraft operations, but also provided logistical support for the nearby nuclear test area. Novaya Zemlya was the site of one of the two major nuclear test sites managed by the USSR, used for air drops and underground testing of the largest of Soviet nuclear bombs, in particular the October 30, 1961 air burst explosion of Tsar Bomba, the largest, most powerful nuclear weapon ever detonated.
Soviet atomic bomb project
The Tsar Bomba (Царь-бомба) was the largest, most powerful thermonuclear weapon ever detonated. It was a three-stage hydrogen bomb with a yield of about 50 megatons. This is equivalent to ten times the amount of all the explosives used in World War II combined. It was detonated on October 30, 1961, in the Novaya Zemlya archipelago, and was capable of approximately 100 megatons, but was purposely reduced shortly before the launch. Although weaponized, it was not entered into service; it was simply a demonstrative testing of the capabilities of the Soviet Union's military technology at that time. The heat of the explosion was estimated to potentially inflict third degree burns at 100 km distance of clear air.
Nuclear fission
One class of nuclear weapon, a "fission bomb" (not to be confused with the "fusion bomb"), otherwise known as an "atomic bomb" or "atom bomb", is a fission reactor designed to liberate as much energy as possible as rapidly as possible, before the released energy causes the reactor to explode (and the chain reaction to stop). Development of nuclear weapons was the motivation behind early research into nuclear fission which the Manhattan Project during World War II (September 1, 1939 – September 2, 1945) carried out most of the early scientific work on fission chain reactions, culminating in the three events involving fission bombs that occurred during the war. The first fission bomb, codenamed "The Gadget", was detonated during the Trinity Test in the desert of New Mexico on July 16, 1945. Two other fission bombs, codenamed "Little Boy" and "Fat Man", were used in combat against the Japanese cities of Hiroshima and Nagasaki in on August 6 and 9, 1945 respectively.
Evsei Rabinovich
Evsei M. Rabinovich was a Soviet nuclear physicist and mathematician. He was a co-developer of the two-stage RDS-37 thermonuclear bomb and its successor, the RDS-220, the largest-ever bomb.
Chicxulub crater
The Chicxulub impactor had an estimated diameter of , and delivered an estimated energy of 21–921 billion Hiroshima A-bombs (between formula_1 and formula_2 joules, or 1.3–58 YJ). By contrast, the most powerful man-made explosive device ever detonated, the Tsar Bomba, had an energy of only 210 petajoules (formula_3 joules, the yield of 50 megatons of TNT). The object dug a hole wide and deep, leaving a crater mainly under the sea and covered by of sediment by the 21st century.
Castle Bravo
In terms of TNT equivalence, "Castle Bravo" was about 1,000 times more powerful than each of the atomic bombs that were dropped on Hiroshima and Nagasaki during World War II. "Castle Bravo" is the fifth largest nuclear explosion in history, exceeded by the Soviet tests of "Tsar Bomba" at approximately 50 Mt, "Test 219" at 24.2 Mt, and two other ~20 Mt Soviet tests in 1962 at Novaya Zemlya.
Nuclear triad
It is estimated that the US currently has around 475 B-61 and B-83 bombs. The B61-7 is carried by the B-2, whereas the B61-3, 4, and 10 are lighter and can be carried by the F-16, F-35, and other light aircraft. These smaller bombs also yield smaller payloads due to their decreased size. The B61-11 is a more hardened bomb that can be used to destroy hardened targets such as bunkers, however it is unlikely that it can penetrate steel or concrete. The B83 is currently the largest bomb in the US arsenal. The US plans to retire it by the year 2025 after the new B61 LEP is completed.
Mark 18 nuclear bomb
The Mark 18 nuclear bomb, also known as the SOB or Super Oralloy Bomb, was an American nuclear bomb design which was the highest yield fission bomb produced by the US. The Mark 18 had a design yield of 500 kilotons. Noted nuclear weapon designer Ted Taylor was the lead designer for the Mark 18.
The Mark 18 was tested once, in the Ivy King nuclear test at the Enewetak atoll in the Pacific Ocean. The test was a complete success at full yield.
Bristol Blitz
On 3 – 4 January 1941 Bristol had its longest raid, lasting 12 hours; during which the "Luftwaffe" dropped their biggest bomb on the city. It was nicknamed "Satan", and weighed , measuring over long (without the tail), and in diameter. It did not explode, and was recovered in April 1943. The bomb disposal crew had to dig down to get to it. The bomb was later paraded through the streets of London during the VE Day Victory Parade at the end of the war.
2017 North Korean nuclear test
Others have been skeptical that it was a completely successful test of a true hydrogen bomb as North Korea claimed. Determining whether it is a two-stage thermonuclear bomb or a fusion-boosted fission weapon may not be possible without radionucleide emission data. The yield estimates of less than 300 kT would be lower than any other nation's first test of a fusion-primary thermonuclear device, which would typically be in the 1000 kT range, while boosted fission weapons and variable-yield nuclear devices can be as low as hundreds of tons, but are not considered true hydrogen bombs; meanwhile the largest pure-fission bomb tested was Ivy King at 500 kT. An October 2 "Scientific American" article said the test was "estimated to have been a 160-kiloton detonation — far below an H-bomb's capabilities." Martin Navias of the Centre for Defence Studies at King's College London noted that the breakthroughs needed to get from a fission to a fusion device would have to be done by the North Koreans on their own – China, Russia, Pakistan, and Iran would not or could not help.
Nuclear weapons and the United Kingdom
Aldermaston had plenty of ideas about how to follow up Grapple X. A new design used lithium deuteride that was less enriched in lithium-6 (and therefore had more lithium-7), but more of it, thereby reducing the amount of uranium-235 in the core. Because of the possibility of an international moratorium on atmospheric testing, plans for the trial, codenamed Grapple Y, were given verbal approval by the Prime Minister, and known only to a handful of officials. The bomb was dropped off Christmas on 28 April 1958. It had an explosive yield of about , and remains the largest British nuclear weapon ever tested. The design of Grapple Y was notably successful because much of its yield came from its thermonuclear reaction instead of fission of a uranium-238 tamper, making it a true hydrogen bomb, and because its yield had been correctly predicted—indicating that its designers understood what they were doing.
Raemer Schreiber
Raemer Edgar Schreiber (November 11, 1910 – December 24, 1998) was an American physicist from McMinnville, Oregon who served Los Alamos National Laboratory during World War II, participating in the development of the atomic bomb. He saw the first one detonated in the Trinity nuclear test in July 1945, and prepared the Fat Man bomb that was used in the bombing of Nagasaki. After the war, he served at Los Alamos as a group leader, and was involved in the design of the hydrogen bomb. In 1955, he became the head of its Nuclear Rocket Propulsion (N) Division, which developed the first nuclear-powered rockets. He served as deputy director of the laboratory from 1972 until his retirement in 1974.
Operation Mosaic
G2 was detonated from a tower on Alpha Island at 02:14 UTC (10:14 local time) on 19 June. It produced a yield of , making it the largest nuclear device ever detonated in Australia. At the time of the Royal Commission into British nuclear tests in Australia in 1985, Joan Smith, a British investigative journalist, published a book, "Clouds of Deceit: Deadly Legacy of Britain's Bomb Tests", in which she alleged that the G2 test had a significantly higher yield than suggested by available figures— as compared to the official figure of . She based this claim on "secret documents released to the Public Record Office in 1985", but the text was uncited, and the documents have never been found. British official historian Lorna Arnold reported that she had never seen any such documents.
Nassau Agreement
During the early part of the Second World War, Britain had a nuclear weapons project, codenamed Tube Alloys. At the Quebec Conference in August 1943, the Prime Minister, Winston Churchill and the President of the United States, Franklin Roosevelt, signed the Quebec Agreement, which merged Tube Alloys with the American Manhattan Project to create a combined British, American and Canadian project. The British government trusted that the United States would continue to share nuclear technology, which it regarded as a joint discovery, after the war, but the United States Atomic Energy Act of 1946 (McMahon Act) ended technical cooperation. Fearing a resurgence of United States isolationism, and Britain losing its great power status, the British government restarted its own development effort, now codenamed High Explosive Research. The first British atomic bomb was tested in Operation Hurricane on 3 October 1952. The subsequent British development of the hydrogen bomb, and a favourable international relations climate created by the sputnik crisis, led to the McMahon Act being amended in 1958, resulting in the restoration of the nuclear Special Relationship in the form of the 1958 US–UK Mutual Defence Agreement, which allowed Britain to acquire nuclear weapons systems from the United States.
Britain's nuclear weapons armament was initially based on free-fall bombs delivered by the V-bombers of the Royal Air Force (RAF), but the possibility of the manned bomber becoming obsolete by the late 1960s due to improvements in anti-aircraft defences was foreseen. In 1953, the Assistant Chief of the Air Staff (Operational Requirements), Air Vice Marshal Geoffrey Tuttle, requested a specification for a ballistic missile with range, and work commenced at the Royal Aircraft Establishment in Farnborough later that year. At a North Atlantic Treaty Organization (NATO) meeting in Paris in December 1953, United States Secretary of Defense, Charles E. Wilson, raised the possibility of a joint medium-range ballistic missile (MRBM) development programme. Talks were held in June 1954, resulting in the signing of an agreement on 12 August 1954. The United Kingdom with United States support would develop an MRBM of range. This was called Blue Streak. It was initially estimated to cost £70 million, with the United States paying 15 per cent. By 1958, the project was in trouble. Its deployment was still years away, but the United States was supplying American-built Thor intermediate-range ballistic missiles under Project Emily, and there were concerns about liquid fuelled Blue Streak's vulnerability to a pre-emptive nuclear strike.
Uranium
Two major types of atomic bombs were developed by the United States during World War II: a uranium-based device (codenamed "Little Boy") whose fissile material was highly enriched uranium, and a plutonium-based device (see Trinity test and "Fat Man") whose plutonium was derived from uranium-238. The uranium-based Little Boy device became the first nuclear weapon used in war when it was detonated over the Japanese city of Hiroshima on 6 August 1945. Exploding with a yield equivalent to 12,500 tonnes of TNT, the blast and thermal wave of the bomb destroyed nearly 50,000 buildings and killed approximately 75,000 people (see Atomic bombings of Hiroshima and Nagasaki). Initially it was believed that uranium was relatively rare, and that nuclear proliferation could be avoided by simply buying up all known uranium stocks, but within a decade large deposits of it were discovered in many places around the world.
1958 US–UK Mutual Defence Agreement
The first British atomic bomb was successfully tested in Operation Hurricane on 3 October 1952, 
but although it was more advanced than the American bombs of 1946, Britain was still several years behind in nuclear weapons technology. The United States conducted Ivy Mike, the first nuclear test of a true thermonuclear device (also known as a hydrogen bomb). The JCAE saw little benefit for the United States from sharing technology with Britain. The Soviet Union responded with the test of Joe 4, a boosted fission weapon on 12 August 1953. This prompted President Dwight Eisenhower, who was inaugurated in January 1953, to inform the United States Congress that the McMahon Act, which he considered a "terrible piece of legislation" and "one of the most deplorable incidents in American history of which he personally felt ashamed", was obsolete.
At the three-power Bermuda Conference in December 1953, Eisenhower and Churchill discussed the possibility of the United States giving Britain access to American nuclear weapons in wartime. This came to be called Project E. There were technical and legal issues that had to be overcome before American bombs could be carried in British aircraft. The United States would have to disclose their weights and dimensions, while their delivery would require data concerning their ballistics. Further down the track, there would also be issues of custody, security and targeting. The release of such information was restricted by the McMahon Act.
Yuri Babayev
Yuri Nikolaevic Babayev (Russian: Юрий Николаевич Бабаев)(21 March 1928 – 6 October 1986) was a Soviet nuclear physicist, engineer and mathematician. He was a co-designer of the RDS-220, the largest-ever nuclear weapon.
Pacific Proving Grounds
Six very large nuclear tests were conducted at the Bikini Atoll and the Enewetak Atoll as part of Operation Castle in 1954. The most notable was Castle Bravo, which was the first deployable (dry fuel) hydrogen bomb developed by the United States. Its yield, at 15 Mt, was over twice as powerful as was predicted, and was the largest weapon ever detonated by the United States. It spread nuclear fallout over a wide area, including the Enewetak Atoll, Rongerik Atoll, Ailinginae Atoll, and Rongelap Atoll. The U.S. Navy evacuated the islanders within the next few days, but many of the natives exposed suffered from cancers and a high incidence of birth defects in the years following the event. The fishermen aboard the Japanese fishing vessel, the "Daigo Fukuryu Maru", were additionally exposed and one man died soon after from complications of radiation sickness, resulting in considerable international controversy.
List of nuclear weapons tests
On 12 February 2013, North Korean state media announced it had conducted an underground nuclear test, its third in seven years. A tremor that exhibited a nuclear bomb signature with an initial magnitude 4.9 (later revised to 5.1) was detected by both Comprehensive Nuclear-Test-Ban Treaty Organization Preparatory Commission (CTBTO) and the United States Geological Survey (USGS). The tremor occurred at 11:57 local time (02:57 UTC) and the USGS said the hypocenter of the event was only one kilometer deep. South Korea's defense ministry said the event reading indicated a blast of six to seven kilotons. However, there are some experts who estimate the yield to be up to 15 kt, since the test site's geology is not well understood. In comparison, the atomic (fission) bombs dropped by the "Enola Gay" on Hiroshima (Little Boy, a "gun-type" atomic bomb) and on Nagasaki by "Bockscar" (Fat Man, an "implosion-type" atomic bomb) had blast yields of the equivalents of 13 and 21 kilotons of TNT, respectively.
History of nuclear weapons
An improved version of 'Fat Man' was developed, and on 26 February 1952, Prime Minister Winston Churchill announced that the United Kingdom also had an atomic bomb and a successful test took place on 3 October 1952. At first these were free-fall bombs, intended for use by the V Force of jet bombers. A Vickers Valiant dropped the first UK nuclear weapon on 11 October 1956 at Maralinga, South Australia. Later came a missile, Blue Steel, intended for carriage by the V Force bombers, and then the Blue Streak medium-range ballistic missile (later canceled). Anglo-American cooperation on nuclear weapons was restored by the 1958 US-UK Mutual Defence Agreement. As a result of this and the Polaris Sales Agreement, the United Kingdom has bought United States designs for submarine missiles and fitted its own warheads. It retains full independent control over the use of the missiles. It no longer possesses any free-fall bombs.
Yulii Khariton
In 1949, he and Kirill Shchelkin reported to the Special Committee on the progress of the first Soviet nuclear weapon, the RDS-1, which was tested on 29 August that year. He was deferential to political superiors but supported the scientists under him in a politic and diplomatic way. Physicist and departmental head Andrei Sakharov referred to him as being "zealous and unsparing of himself." ; he spoke for scientists when they changed their focus a two-stage nuclear device with initial compression from 1954 (the RDS-37) and supported requests not to detonate the RDS-220 (the largest-ever bomb) because of the calculated number of deaths due to radioactive fallout. He would not support similar requests to halt a duplicate test by a second 'Installation' at Snezhinsk which he felt was divisive, and wouldn't intercede in certain politically-charged personal cases.
Atomic bombings of Hiroshima and Nagasaki
The discovery of nuclear fission by German chemists Otto Hahn and Fritz Strassmann in 1938, and its theoretical explanation by Lise Meitner and Otto Frisch, made the development of an atomic bomb a theoretical possibility. Fears that a German atomic bomb project would develop atomic weapons first, especially among scientists who were refugees from Nazi Germany and other fascist countries, were expressed in the Einstein-Szilard letter. This prompted preliminary research in the United States in late 1939. Progress was slow until the arrival of the British MAUD Committee report in late 1941, which indicated that only 5 to 10 kilograms of isotopically enriched uranium-235 were needed for a bomb instead of tons of natural uranium and a neutron moderator like heavy water.
Tunguska event
The 15-megaton (Mt) estimate represents an energy about 1,000 times greater than that of the atomic bomb dropped on Hiroshima, Japan—roughly equal to that of the United States' Castle Bravo (15.2 Mt) ground-based thermonuclear detonation on 1 March 1954, and about one-third that of the Soviet Union's Tsar Bomba explosion on 30 October 1961 (which, at 50 Mt, is the largest nuclear weapon ever detonated).
Largest artificial non-nuclear explosions
In this article, explosion means "the sudden conversion of potential energy (chemical or mechanical) into kinetic energy", as defined by the US National Fire Protection Association, or the common dictionary meaning, "a violent and destructive shattering or blowing apart of something". No distinction is made as to whether it is a deflagration with subsonic propagation or a detonation with supersonic propagation.
The most powerful non-nuclear weapons ever designed are the United States' MOAB (standing for "Massive Ordnance Air Blast", also nicknamed "Mother Of All Bombs", tested in 2003 and used on April 13, 2017, In Achen Province, Afghanistan) and the Russian Father of All Bombs (tested in 2007). The MOAB contains of the H6 explosive, which is 1.35 times as powerful as TNT, giving the bomb an approximate yield of 11 t TNT. It would require about 250 MOAB blasts to equal the Halifax explosion (2.9 kt).
Balance of terror
In this counterintuitive way, the existence of the most powerful weapons ever created actually supported a kind of peace: while many wars were fought around the world during the Cold War, the superpowers never fought each other directly, nor have atomic bombs been dropped in war since the atomic bombing of Nagasaki in 1945.
Viktor Adamsky
Viktor Borisovich Adamsky [also Adamskii] (Russian:Ви́ктор Бори́сович Ада́мский} (30 April 1923 – 14 December 2005) was a Soviet theoretical physicist and mathematician. He was a chief researcher at Arzamas-16, now the All-Russian Scientific Research Institute of Experimental Physics in the closed city of Sarov, Nizhny Novgorod region. He was a theorist involved with the RDS-37, the first Soviet two-stage thermonuclear bomb and, with Vyacheslav Feodoritov, was the project leader of the RDS-220, the largest-ever-yield bomb, and also its co-designer.
Fat Man
"Fat Man" was the codename for the nuclear bomb that was detonated over the Japanese city of Nagasaki by the United States on 9 August 1945. It was the second of the only two nuclear weapons ever used in warfare, the first being Little Boy, and its detonation marked the third nuclear explosion in history. It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site, and it was dropped from the Boeing B-29 Superfortress "Bockscar" piloted by Major Charles Sweeney.
The name Fat Man refers to the early design of the bomb because it had a wide, round shape; it was also known as the Mark III. Fat Man was an implosion-type nuclear weapon with a solid plutonium core. The first of that type to be detonated was the Gadget in the Trinity nuclear test less than a month earlier on 16 July at the Alamogordo Bombing and Gunnery Range in New Mexico. Two more were detonated during the Operation Crossroads nuclear tests at Bikini Atoll in 1946, and some 120 were produced between 1947 and 1949, when it was superseded by the Mark 4 nuclear bomb. The Fat Man was retired in 1950.
Alvarez hypothesis
Using estimates of the total amount of iridium in the K–Pg layer, and assuming that the asteroid contained the normal percentage of iridium found in chondrites, the Alvarez team went on to calculate the size of the asteroid. The answer was about 10 kilometers (6 mi) in diameter, about the size of Manhattan. Such a large impact would have had approximately the energy of 100 million megatons, i.e. about 2 million times as great as the most powerful thermonuclear bomb ever tested.
2004 Indian Ocean earthquake and tsunami
The energy released on the Earth's surface ("M", which is the "seismic potential for damage") by the 2004 Indian Ocean earthquake was estimated at 1.1×10 joules, or 26 megatons of TNT. This energy is equivalent to over 1,500 times that of the Hiroshima atomic bomb, but less than that of Tsar Bomba, the largest nuclear weapon ever detonated; however, the total physical work done "M" (and thus energy) by the quake was 4.0×10 joules (4.0×10 ergs), the vast majority underground, which is over 360,000 times more than its "M", equivalent to 9,600 gigatons of TNT equivalent (550 million times that of Hiroshima) or about 370 years of energy use in the United States at 2005 levels of 1.08×10 J. The only recorded earthquakes with a larger "M" were the 1960 Chilean and 1964 Alaskan quakes, with 2.5×10 joules (250 ZJ) and 7.5×10 joules (75 ZJ) respectively.
List of states with nuclear weapons
The Soviet Union tested its first nuclear weapon ("RDS-1") in 1949. This crash project was developed partially with information obtained via espionage during and after World War II. The Soviet Union was the second nation to have developed and tested a nuclear weapon. The direct motivation for Soviet weapons development was to achieve a balance of power during the Cold War. It tested its first megaton-range hydrogen bomb ("RDS-37") in 1955. The Soviet Union also tested the most powerful explosive ever detonated by humans, ("Tsar Bomba"), with a theoretical yield of 100 megatons, intentionally reduced to 50 when detonated. After its dissolution in 1991, the Soviet weapons entered officially into the possession of the Russian Federation. The Soviet nuclear arsenal contained some 45,000 warheads at its peak (in 1986); the Soviet Union built about 55,000 nuclear warheads since 1949.
Operation Crossroads
Their desire to return to Bikini was thwarted indefinitely by the U.S. decision to resume nuclear testing at Bikini in 1954. During 1954, 1956, and 1958, twenty-one more nuclear bombs were detonated at Bikini, yielding a total of , equivalent to more than three thousand "Baker" bombs. Only one was an air burst, the 3.8 megaton Redwing "Cherokee" test. Air bursts distribute fallout in a large area, but surface bursts produce intense local fallout. The first after Crossroads was the dirtiest: the 15 megaton "Bravo" shot of Operation Castle on March 1, 1954, which was the largest-ever U.S. test. Fallout from "Bravo" caused radiation injury to Bikini islanders who were living on Rongelap Atoll.
Amchitka
"Cannikin" was detonated on November 6, 1971 , as the thirteenth test of the Operation Grommet (1971–1972) underground nuclear test series. The announced yield was 5 megatons (21 PJ) – the largest underground nuclear test in US history. (Estimates for the precise yield range from 4.4 to 5.2 megatons or 18 to 22 PJ). The ground lifted , caused by an explosive force almost 400 times the power of the Hiroshima bomb. Subsidence and faulting at the site created a new lake, several hundred meters wide. The explosion caused a seismic shock of 7.0 on the Richter scale, causing rockfalls and turf slides of a total of . Though earthquakes and tsunamis predicted by environmentalists did not occur, a number of small tectonic events did occur in the following weeks, (some registering as high as 4.0 on the richter scale) thought to be due to the interaction of the explosion with local tectonic stresses.
Grand Slam (bomb)
It was the most powerful non-atomic aerial bomb used in combat until 2017, when a US GBU-43/B MOAB was used in a 2017 attack against ISIL forces in Afghanistan.
History of nuclear weapons
The first atomic bombs dropped on Hiroshima and Nagasaki were large, custom-made devices, requiring highly trained personnel for their arming and deployment. They could be dropped only from the largest bomber planes—at the time the B-29 Superfortress—and each plane could only carry a single bomb in its hold.
Polaris Sales Agreement
During the early part of the Second World War, Britain had a nuclear weapons project, codenamed Tube Alloys. In August 1943, the Prime Minister of the United Kingdom, Winston Churchill and the President of the United States, Franklin Roosevelt, signed the Quebec Agreement, which merged Tube Alloys with the American Manhattan Project. The British government trusted that the United States would continue to share nuclear technology, which it regarded as a joint discovery, but the 1946 McMahon Act ended cooperation. Fearing a resurgence of United States isolationism, and Britain losing its great power status, the British government restarted its own development effort, now codenamed High Explosive Research. The first British atomic bomb was tested in Operation Hurricane on 3 October 1952. The subsequent British development of the hydrogen bomb, and a favourable international relations climate created by the Sputnik crisis, led to the McMahon Act being amended in 1958, and the restoration of the nuclear Special Relationship in the form of the 1958 US–UK Mutual Defence Agreement (MDA), which allowed Britain to acquire nuclear weapons systems from the United States.
Manhattan Project
The first nuclear device ever detonated was an implosion-type bomb at the Trinity test, conducted at New Mexico's Alamogordo Bombing and Gunnery Range on 16 July 1945. Little Boy and Fat Man bombs were used a month later in the atomic bombings of Hiroshima and Nagasaki, respectively. In the immediate postwar years, the Manhattan Project conducted weapons testing at Bikini Atoll as part of Operation Crossroads, developed new weapons, promoted the development of the network of national laboratories, supported medical research into radiology and laid the foundations for the nuclear navy. It maintained control over American atomic weapons research and production until the formation of the United States Atomic Energy Commission in January 1947.
Torino scale
The biggest hydrogen bomb ever exploded, the Tsar Bomba, was around 50 megatons.
The 1883 eruption of Krakatoa was the equivalent of roughly 200 megatons.
Gerboise Bleue
With Gerboise Bleue, France became the fourth nuclear power, after the United States, the USSR, and the United Kingdom. Prior to this test, there had been no nuclear detonations for 15 months. Gerboise Bleue was by far the largest first test bomb up to that date, larger than the American "Trinity" (20 kt), the Soviet "RDS-1" (22 kt), or the British "Hurricane" (25 kt). The yield was 70 kilotons, bigger than these three bombs put together.
Walter Kauzmann
In 1944, Kauzmann was recruited into the top secret Manhattan Project and he moved to Los Alamos, New Mexico. Eventually, Kauzmann was put in charge of producing the detonator for the Trinity test, which was the first detonation of an atomic bomb, and of the (Fat Man) plutonium bomb that was dropped on Nagasaki, Japan. Kauzmann witnessed the Trinity test on July 16, 1945, and his memories were recorded in a newspaper article. Fifty years later, Kauzmann discussed why he worked on the atomic bomb:
Nuclear arms race
Behind the scenes, the Soviet government was working on building its own atomic weapons. During the war, Soviet efforts had been limited by a lack of uranium but new supplies in Eastern Europe were found and provided a steady supply while the Soviets developed a domestic source. While American experts had predicted that the Soviet Union would not have nuclear weapons until the mid-1950s, the first Soviet bomb was detonated on August 29, 1949, shocking the entire world. The bomb, named "First Lightning" by the West, was more or less a copy of "Fat Man", one of the bombs the United States had dropped on Japan in 1945.
Gerboise Bleue
However, the nation faced many international critics following the nuclear test, especially from the African continent. Just days after Gerboise Bleue, all French assets in Ghana were frozen, “until such time as the effects of the present explosion and the future experiments referred to by the French Prime Minister become known.” Morocco, who lays claim to the portion of the Sahara where the bomb was detonated, withdrew its ambassador from Paris just two days after the event. Other African nations expressed their disappointment with France’s decision to test nuclear weapons in the Sahara, citing fears of radioactive fallout and the safety of their citizens.
Five months after the last Gerboise A-bomb, the Soviet Union responded by breaking its atmospheric tests moratorium, settled "de facto" since late 1958 with the United States and the United Kingdom. The USSR conducted many improvement tests, starting in September 1961 with a series of 136 large H-bombs. The series included the most powerful bomb ever tested, the 50-megaton (50,000 kt) "Tsar Bomba", which was detonated over Novaya Zemlya.
Nuclear weapon design
On July 19, 1956, AEC Chairman Lewis Strauss said that the Redwing Zuni shot clean bomb test "produced much of importance ... from a humanitarian aspect." However, less than two days after this announcement, the dirty version of Bassoon, called Bassoon Prime, with a uranium-238 tamper in place, was tested on a barge off the coast of Bikini Atoll as the Redwing Tewa shot. The Bassoon Prime produced a 5-megaton yield, of which 87% came from fission. Data obtained from this test, and others, culminated in the eventual deployment of the highest yielding US nuclear weapon known, and the highest yield-to-weight weapon ever made, a three-stage thermonuclear weapon with a maximum "dirty" yield of 25 megatons, designated as the B41 nuclear bomb, which was to be carried by U.S. Air Force bombers until it was decommissioned; this weapon was never fully tested.
Nuclear arms race
Both governments spent massive amounts to increase the quality and quantity of their nuclear arsenals. Both nations quickly began the development of a hydrogen bomb and the United States detonated the first hydrogen bomb on November 1, 1952, on Enewetak, an atoll in the Pacific Ocean. Code-named "Ivy Mike", the project was led by Edward Teller, a Hungarian-American nuclear physicist. It created a cloud 100 miles wide and 25 miles high, killing all life on the surrounding islands. Again, the Soviets surprised the world by exploding a deployable thermonuclear device in August 1953 although it was not a true multi-stage hydrogen bomb. However, it was small enough to be dropped from an airplane, making it ready for use. The development of these two Soviet bombs was greatly aided by the Russian spies Harry Gold and Klaus Fuchs.
Nuclear entombment
The Chernobyl Nuclear Incident is one of the most notable nuclear disasters. The current containment building, known as the sarcophagus, does not classify as a proper entombment device. However, due to lack of repair and maintenance, because of extremely high levels of radiation, a new tomb is in the process of construction and will be considered a proper tomb. Upon completion in 2017 the structure will measure 110 meters tall and span 260 meters. The main arch will be composed of triple-layered radiation resistant panels made up of stainless steel coated in polycarbonate, this will provide the shielding necessary for radioactive containment. The structure will weigh over 30,000 tons and completely cover Reactor number 4. This new tomb is designed to last over 100 years and has special ventilation and temperature systems to prevent condensation of radioactive fluids on the inside which could result in a compromised containment. Overall this new containment structure will act as band-aid and only buy time for the Ukrainian Government to develop ways of properly cleaning up the site.
Nuclear testing at Bikini Atoll
The United States was engaged in a Cold War Nuclear arms race with the Soviet Union to build more advanced bombs from 1947 until 1991. The first series of tests over Bikini Atoll in July 1946 was code named Operation Crossroads. The first test was dropped from an aircraft and detonated above the target fleet. The second, "Baker", was suspending under a barge. It produced a large Wilson cloud and contaminated all of the target ships. Chemist Glenn T. Seaborg, the longest-serving chairman of the Atomic Energy Commission, called the second test "the world's first nuclear disaster."
History of nuclear weapons
The first fusion bomb was tested by the United States in "Operation Ivy" on November 1, 1952, on Elugelab Island in the Enewetak (or Eniwetok) Atoll of the Marshall Islands, code-named "Mike." Mike used liquid deuterium as its fusion fuel and a large fission weapon as its trigger. The device was a prototype design and not a deliverable weapon: standing over 20 ft (6 m) high and weighing at least 140,000 lb (64 t) (its refrigeration equipment added an additional as well), it could not have been dropped from even the largest planes.
Operation Crossroads
There were only seven nuclear bombs in existence in July 1946. The two bombs used in the test were Fat Man plutonium implosion-type nuclear weapons of the kind dropped on Nagasaki. The "Able" bomb was stenciled with the name "Gilda" and decorated with an "Esquire" magazine photograph of Rita Hayworth, star of the 1946 movie, "Gilda". The "Baker" bomb was "Helen of Bikini." This femme-fatale theme for nuclear weapons, combining seduction and destruction, is epitomized by the use in all languages, starting in 1946, of "bikini" as the name for a woman's two-piece bathing suit.
1958 Tybee Island mid-air collision
Some sources describe the bomb as a functional nuclear weapon, but others describe it as disabled. If the bomb had a plutonium nuclear core installed, it was a fully functional weapon. If the bomb had a dummy core installed, it was incapable of producing a nuclear explosion but could still produce a conventional explosion. The 12-foot (4 m) long Mark 15 bomb weighs and bears the serial number 47782. It contains of conventional high explosives and highly enriched uranium. The Air Force maintains that the bomb's nuclear capsule, used to initiate the nuclear reaction, was removed before its flight aboard B-47. As noted in the Atomic Energy Commission "Form AL-569 Temporary Custodian Receipt (for maneuvers)", signed by the aircraft commander, the bomb contained a simulated 150-pound cap made of lead. However, according to 1966 Congressional testimony by then Assistant Secretary of Defense W.J. Howard, the Tybee Island bomb was a "complete weapon, a bomb with a nuclear capsule," and one of two weapons lost by that time that contained a plutonium trigger. Nevertheless, a study of the Strategic Air Command documents indicates that in February 1958, Alert Force test flights (with the older Mark 15 payloads) were not authorized to fly with nuclear capsules on board. Such approval was pending deployment of safer "sealed-pit nuclear capsule" weapons, which did not begin deployment until June 1958.
History of nuclear weapons
Because of the difficulties in making a working plutonium bomb, it was decided that there should be a test of the weapon. On July 16, 1945, in the desert north of Alamogordo, New Mexico, the first nuclear test took place, code-named "Trinity", using a device nicknamed "the gadget." The test, a plutonium implosion-type device, released energy equivalent to 22 kilotons of TNT, far more powerful than any weapon ever used before. The news of the test's success was rushed to Truman at the Potsdam Conference, where Churchill was briefed and Soviet Premier Joseph Stalin was informed of the new weapon. On July 26, the Potsdam Declaration was issued containing an ultimatum for Japan: either surrender or suffer "complete and utter destruction", although nuclear weapons were not mentioned.
After hearing arguments from scientists and military officers over the possible use of nuclear weapons against Japan (though some recommended using them as demonstrations in unpopulated areas, most recommended using them against built up targets, a euphemistic term for populated cities), Truman ordered the use of the weapons on Japanese cities, hoping it would send a strong message that would end in the capitulation of the Japanese leadership, and avoid a lengthy invasion of the islands. Truman and his Secretary of State James F. Byrnes were also intent on ending the Pacific war before the Soviets could enter it, given that Roosevelt had promised Stalin control of Manchuria if he joined the invasion. On May 10–11, 1945, the Target Committee at Los Alamos, led by Oppenheimer, recommended Kyoto, Hiroshima, Yokohama, and Kokura as possible targets. Concerns about Kyoto's cultural heritage led to it being replaced by Nagasaki.
On August 6, 1945, a uranium-based weapon, Little Boy, was detonated above the Japanese city of Hiroshima, and three days later, a plutonium-based weapon, Fat Man, was detonated above the Japanese city of Nagasaki. To date, Hiroshima and Nagasaki remain the only two instances of nuclear weapons being used in combat. The atomic raids killed at least one hundred thousand Japanese civilians and military personnel outright, with the heat, radiation, and blast effects.
Many tens of thousands would later die of radiation sickness and related cancers. Truman promised a "rain of ruin" if Japan did not surrender immediately, threatening to systematically eliminate their ability to wage war. On August 15, Emperor Hirohito announced Japan's surrender.
Bomb
Atomic bombs are based on the theory of nuclear fission, that when a large atom splits, it releases a massive amount of energy. Thermonuclear weapons, (colloquially known as "hydrogen bombs") use the energy from an initial fission explosion to create an even more powerful fusion explosion.
Project Grab Bag
The first nuclear detonation was an above-ground test, “Trinity”, conducted in New Mexico on July 16, 1945. It represented an important accomplishment of the Manhattan Project that had been initiated at Los Alamos National Laboratory in 1943. In less than two months following this test, nuclear weapons assembled at Los Alamos were used in the Pacific War against Japan. Hiroshima was devastated on August 6, 1945 with a uranium-235 gun device with a fission product yield of about 15 kilotons. Three days later, on August 9, 1945, a plutonium-239 implosion device with a yield of about 22 kilotons was detonated over Nagasaki. These events significantly influenced the conclusion of World War II as the incredibly destructive power of these new weapons became apparent. The Manhattan Project brought together scientists from the US and Britain to collaborate on this nuclear weapons development program. Los Alamos was the epicenter of this activity, and, in spite of high-level security, it was realized in 1948 that security of the program had been breached. Klaus Fuchs, a British theoretical physicist intimately involved in some of the most sensitive aspects of the program, had supplied the USSR with key information via outside contacts beginning in 1945. This information substantially advanced the Soviet effort in developing nuclear weapons. As the US became aware of the loss of key ideas and design concepts, it was important to reassess the state of the Soviet program in fission devices, and to monitor extensions of their program to fusion devices. One concern was the extent of progress made by the Soviets in producing fissionable material through reactor operations. Of even greater importance was the state of development of fission-fusion devices capable of orders of magnitude greater destructive power than the fission devices used against Japan.
Amchitka
Amchitka was selected by the United States Atomic Energy Commission to be the site for underground detonations of nuclear weapons. Three such tests were carried out: "Long Shot", an blast in 1965; "Milrow", a blast in 1969; and "Cannikin" in 1971 – at , the largest underground test ever conducted by the United States. The tests were highly controversial, with environmental groups fearing that the "Cannikin" explosion, in particular, would cause severe earthquakes and tsunamis. Amchitka is no longer used for nuclear testing. It is still monitored for the leakage of radioactive materials.
British hydrogen bomb programme
Air Vice Marshal John Grandy succeeded Oulton as Task Force commander. The bomb was dropped off Christmas at 10:05 local time on 28 April 1958 by a Valiant piloted by Squadron Leader Bob Bates. It had an explosive yield of about , and remains the largest British nuclear weapon ever tested. The design of Grapple Y was notably successful because much of its yield came from its thermonuclear reaction instead of fission of a heavy uranium-238 tamper, making it a true hydrogen bomb, and because its yield had been closely predicted—indicating that its designers understood what they were doing.
Tsar Bomba
However the development of such weapons also required mandatory and practical aerial bombardment methods, as for a high-yield (thermo-)nuclear explosion to reach maximal effect, the payload has to be detonated at an optimal height for the shock wave to reach the greatest force and range of propagations. In addition, ultra-large-yield thermonuclear bombs were considered by the Long Range Aviation units of the USSR, as their use fits the "cause the greatest damage to the enemy with a minimal number of carriers (i.e. bombers)" doctrine, while it was also necessary to consider the practical feasibility of such heavy thermonuclear weapons with reliably predictable characteristics. Before this, however, a massive underwater "doomsday weapon" considered by Soviet military and technical experts--essentially a giant torpedo launched by a dedicated nuclear submarine--was planned for development, which would detonate its nuclear warhead near the US coast, causing a massive tsunami. However, this project (known as the T-15 torpedo) was soon abandoned as its actual combat effectiveness was questionable after more detailed consideration.
British contribution to the Manhattan Project
Britain contributed to the Manhattan Project by helping initiate the effort to build the first atomic bombs in the United States during World War II, and helped carry it through to completion in August 1945 by supplying crucial expertise. Following the discovery of nuclear fission in uranium, scientists Rudolf Peierls and Otto Frisch at the University of Birmingham calculated, in March 1940, that the critical mass of a metallic sphere of pure uranium-235 was as little as , and would explode with the power of thousands of tons of dynamite. The Frisch–Peierls memorandum prompted Britain to create an atomic bomb project, known as Tube Alloys. Mark Oliphant, an Australian physicist working in Britain, was instrumental in making the results of the British MAUD Report known in the United States in 1941 by a visit in person. Initially the British project was larger and more advanced, but after the United States entered the war, the American project soon outstripped and dwarfed its British counterpart. The British government then decided to shelve its own nuclear ambitions, and participate in the American project.
Ted Taylor (physicist)
Theodore Taylor was involved in many important projects and made numerous contributions to nuclear development for the United States. During his time at Los Alamos, He was responsible for designing the smallest fission bomb of the era, named Davy Crockett, which weighed only 60 pounds, measured approximately 12 inches across, and could produce between 10 and 20 kilotons of TNT equivalent. This device was formerly known as the M28 Weapons System. The Davy Crockett itself was the M388 Atomic Round fired from the weapons system, which functioned similarly to how any other modern rocket propelled round would (see RPG-7). It was a mounted weapons system, which means that it would be set up, aimed, and fired as a crew-served weapon. Taylor also designed fission bombs even smaller than Davy Crockett, but those were not developed until long after he left Los Alamos. Furthermore, he even designed a nuclear bomb so small that it weighed only 20 pounds, but it was never actually developed and tested. Additionally, Taylor designed the Super Alloy Bomb, also known as the "SOB". It still holds the record for the largest fission explosion ever tested (as the Ivy King device tested during Operation Ivy), producing over 500 kilotons of TNT equivalent. Furthermore, Taylor was credited with developing multiple techniques that improved the fission bomb. For example, he was largely responsible for the development of fusion boosting, which is a technique that improves the reaction yield and efficiency of a nuclear reaction. This technique was a re-invention of the implosion mechanism that was used in the bomb detonated at Nagasaki. He theorized a series of nuclear reactions within the implosion mechanism that, in combination, trigger the large chain reaction to detonate. This eliminated much of the energy waste and necessity for precision of the original reaction mechanism. This technique is still found in all U.S. fission nuclear weapons today. He also developed a technique that greatly reduced the size of atomic bombs. First tested in a bomb called "Scorpion", it utilized a reflector made of beryllium, which was drastically lighter than the metals that generally were used as reflectors, such as tungsten carbide (WC). Taylor recognized that although a low-atomic-number element like beryllium did not "bounce" neutrons back into the fissile core as efficiently as heavy tungsten, its propensity for neutron spallation (in nuclear physics the so-called "(n,2n)" reaction) more than compensated in overall reflector performance.
Thermobaric weapon
In September 2007, Russia exploded the largest thermobaric weapon ever made. Its yield was reportedly greater than the smallest dial-a-yield nuclear weapons at their lowest settings. Russia named this particular ordnance the "Father of All Bombs" in response to the United States developed Massive Ordnance Air Blast (MOAB) bomb whose backronym is the "Mother of All Bombs", and which previously held the title of the most powerful non-nuclear weapon in history. The Russian bomb contains an approximate 7 ton charge of a liquid fuel, such as pressurized ethylene oxide, mixed with an energetic nanoparticle, such as aluminium, surrounding a high explosive burster that when detonated created an explosion equivalent to of TNT.
Thomas H. Chilton
Chilton worked at DuPont from 1925–1959, leading its chemical research. During World War II, he worked with the Manhattan Project and he was involved with the original design of the first atomic energy plant, the Hanford Engineer Works. At the invitation of his colleague and friend, Enrico Fermi, Chilton was among the select group of scientists to witness the first self-sustaining nuclear reaction at Stagg Field on December 2, 1942. After the war, he became involved in the Savannah River Plant, then the largest nuclear power plant ever built by the Atomic Energy Commission.
Bomb (book)
Bomb: The Race to Build—and Steal—the World's Most Dangerous Weapon is a 2012 adolescent non-fiction book by author Steve Sheinkin. The book won the 2013 Newbery Honor and Sibert Medal from the American Library Association.
This book follows the process of building the nuclear bomb by the discovery of nuclear fission by German scientist Otto Hahn in December 17, 1938.
United States and weapons of mass destruction
The United States is known to have possessed three types of weapons of mass destruction: nuclear weapons, chemical weapons, and biological weapons. The U.S. is the only country to have used nuclear weapons in combat, when it detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki during World War II. It had secretly developed the earliest form of the atomic weapon during the 1940s under the title "Manhattan Project". The United States pioneered the development of both the nuclear fission and hydrogen bombs (the latter involving nuclear fusion). It was the world's first and only nuclear power for four years (1945–1949), until the Soviet Union managed to produce its own nuclear weapon. The United States has the second largest number of deployed nuclear weapons in the world, after Russia.
History of nuclear weapons
On March 1, 1954, the U.S. detonated its first practical thermonuclear weapon (which used isotopes of lithium as its fusion fuel), known as the "Shrimp" device of the Castle Bravo test, at Bikini Atoll, Marshall Islands. The device yielded 15 megatons, more than twice its expected yield, and became the worst radiological disaster in U.S. history. The combination of the unexpectedly large blast and poor weather conditions caused a cloud of radioactive nuclear fallout to contaminate over . 239 Marshall Island natives and 28 Americans were exposed to significant amounts of radiation, resulting in elevated levels of cancer and birth defects in the years to come.
Trident (UK nuclear programme)
During the early part of the Second World War, Britain had a nuclear weapons project, code-named Tube Alloys, which the 1943 Quebec Agreement merged with the American Manhattan Project to create a combined American, British, and Canadian project. The British government expected that the United States would continue to share nuclear technology, which it regarded as a joint discovery, but the United States Atomic Energy Act of 1946 (McMahon Act) ended technical co-operation. Fearing a resurgence of United States isolationism, and Britain losing its great power status, the British government resumed its own development effort. The first British atomic bomb was tested in Operation Hurricane on 3 October 1952. The subsequent British development of the hydrogen bomb, and a fortuitous international relations climate created by the Sputnik crisis, facilitated the amendment of the McMahon Act, and the 1958 US–UK Mutual Defence Agreement (MDA), which allowed Britain to acquire nuclear weapons systems from the United States, thereby restoring the nuclear Special Relationship.
During the 1950s, Britain's nuclear deterrent was based around the V-bombers of the Royal Air Force (RAF), but developments in radar and surface-to-air missiles made it clear that bombers were becoming increasingly vulnerable, and would be unlikely to penetrate Soviet airspace by the mid-1970s. To address this problem, the United Kingdom embarked on the development of a Medium Range Ballistic Missile called Blue Streak, but concerns were raised about its own vulnerability, and the British government decided to cancel it and acquire the American Skybolt air-launched ballistic missile. In return, the Americans were given permission to base the US Navy's Polaris boats at Holy Loch in Scotland. In November 1962, the American government decided to cancel Skybolt. The President, John F. Kennedy, and the Prime Minister, Harold Macmillan, then negotiated the Nassau Agreement, under which the US would sell to the UK, Polaris systems for UK-built submarines. This was formalised in the Polaris Sales Agreement.
Tupolev Tu-95
A series of nuclear surface tests were carried out by the Soviet Union in the early to mid 1960s. On October 30, 1961 a modified Tu-95 carried and dropped the AN602 device named "Tsar Bomba", which was the most powerful thermonuclear device ever detonated. Video footage of that particular test exists since the event was filmed for documentation purposes. The footage shows the specially adapted Tu-95V plane – painted with anti-flash white on its ventral surfaces – taking off carrying the bomb, in-flight scenes of the interior and exterior of the aircraft, and the detonation. Along with the "Tsar Bomba", the Tu-95 proved to be a versatile bomber that would deliver the RDS-4 Tatyana (a fission bomb with a yield of forty-two kilotons), RDS-6S thermonuclear bomb, the RDS-37 2.9-megaton thermonuclear bomb, and the RP-30-32 200-kiloton bomb. The bomb was attached underneath the aircraft, which carried the weapon semi-externally since it could not be carried inside a standard Tu-95's bomb-bay, similar to the way the B.1 Special version of the Avro Lancaster did with the ten-tonne Grand Slam "earthquake bomb".
Hunters Point Naval Shipyard
The key fissile components of the first atomic bomb were loaded onto in July 1945 at Hunters Point for transfer to Tinian. After World War II and until 1969, the Hunters Point shipyard was the site of the Naval Radiological Defense Laboratory, the US military's largest facility for applied nuclear research. The yard was used after the war to decontaminate ships from Operation Crossroads. Because of all the testing, there is widespread radiological contamination of the site. After the war, with an influx of blue collar industry, the area remained a naval base and commercial shipyard.
List of states with nuclear weapons
The United Kingdom tested its first nuclear weapon ("Hurricane") in 1952. The UK had provided considerable impetus and initial research for the early conception of the atomic bomb, aided by Austrian, German and Polish physicists working at British universities who had either fled or decided not to return to Nazi Germany or Nazi controlled territories. The UK collaborated closely with the United States and Canada during the Manhattan Project, but had to develop its own method for manufacturing and detonating a bomb as U.S. secrecy grew after 1945. The United Kingdom was the third country in the world, after the United States and Soviet Union, to develop and test a nuclear weapon. Its programme was motivated to have an independent deterrent against the Soviet Union, while also maintaining its status as a great power. It tested its first hydrogen bomb in 1957 (Operation Grapple), making it the third country to do so after the United States and Soviet Union. The UK maintained a fleet of V bomber strategic bombers and ballistic missile submarines (SSBNs) equipped with nuclear weapons during the Cold War. It currently maintains a fleet of four 'Vanguard' class ballistic missile submarines equipped with Trident II missiles. In 2016, the UK House of Commons voted to renew the British nuclear weapons system with the "Dreadnought"-class submarine, without setting a date for the commencement of service of a replacement to the current system.
History of nuclear weapons
Nuclear weapons possess enormous destructive power from nuclear fission or combined fission and fusion reactions. Building on scientific breakthroughs made during the 1930s, the United States, the United Kingdom and Canada collaborated during World War II, in what was called the Manhattan Project, to counter the suspected Nazi German atomic bomb project. In August 1945, two fission bombs were dropped on Japan, standing to date as the only use of nuclear weapons in combat. The Soviet Union started development shortly thereafter with their own atomic bomb project, and not long after that both countries developed even more powerful fusion weapons known as "hydrogen bombs".
History of nuclear weapons
The atomic bombings of Hiroshima and Nagasaki and the end of World War II quickly followed the 1945 Trinity nuclear test, and the Little Boy device was detonated over the Japanese city of Hiroshima on 6 August 1945. Exploding with a yield equivalent to 12,500 tonnes of TNT, the blast and thermal wave of the bomb destroyed nearly 50,000 buildings and killed approximately 75,000 people. Subsequently, the world’s nuclear weapons stockpiles grew.
Nuclear explosion
The primary application to date has been military (i.e. nuclear weapons), and the remainder of explosions include the following:Only two nuclear weapons have been deployed in combat—both by the United States against Japan in World War II. The first event occurred on the morning of 6 August 1945, when the United States Army Air Forces dropped a uranium gun-type device, code-named "Little Boy", on the city of Hiroshima, killing 70,000 people, including 20,000 Japanese combatants and 20,000 Korean slave laborers. The second event occurred three days later when the United States Army Air Forces dropped a plutonium implosion-type device, code-named "Fat Man", on the city of Nagasaki. It killed 39,000 people, including 27,778 Japanese munitions employees, 2,000 Korean slave laborers, and 150 Japanese combatants. In total, around 109,000 people were killed in these bombings. (See "Atomic bombings of Hiroshima and Nagasaki" for a full discussion). Nuclear weapons are largely seen as a 'deterrent' by most governments; the sheer scale of the destruction caused by a nuclear weapon has prevented serious consideration of their use in warfare, rendering the concept of total war completely useless.
Minor Scale
The test took place at the Permanent High Explosive Testing Grounds () of the White Sands Missile Range in the state of New Mexico, for which 4744 tons of ANFO explosive (ammonium nitrate and fuel oil), equivalent to 4 kilotons of TNT, were used to roughly simulate the effect of an eight kiloton air-burst nuclear device. With a total energy release of about (or 4.2 kilotons of TNT equivalent), Minor Scale was reported as "the largest planned conventional explosion in the history of the free world", surpassing another large conventional explosion, the "British Bang" disposal of ordinance on Heligoland in 1947, reported to have released of energy (about 3.2 kilotons of TNT equivalent).
Nuclear weapons testing
The first nuclear device was detonated as a test by the United States at the Trinity site on July 16, 1945, with a yield approximately equivalent to 20 kilotons of TNT. The first thermonuclear weapon technology test of engineer device, codenamed "Ivy Mike", was tested at the Enewetak Atoll in the Marshall Islands on November 1, 1952 (local date), also by the United States. The largest nuclear weapon ever tested was the "Tsar Bomba" of the Soviet Union at Novaya Zemlya on October 30, 1961, with the largest yield ever seen, an estimated 50–58 megatons.
History of the Teller–Ulam design
The Soviets demonstrated the power of the "staging" concept in October 1961 when they detonated the massive and unwieldy "Tsar Bomba", a 50 Mt hydrogen bomb which derived almost 97% of its energy from fusion rather than fission—its uranium tamper was replaced with one of lead shortly before firing, in an effort to prevent excessive nuclear fallout. Had it been fired in its "full" form, it would have yielded at around 100 Mt. The weapon was technically deployable (it was tested by dropping it from a specially modified bomber), but militarily impractical, and was developed and tested primarily as a show of Soviet strength. It was the largest nuclear weapon developed and tested by any country.
Nuclear warfare
For six months before the atomic bombings, the U.S. 20th Air Force under General Curtis LeMay executed low-level incendiary raids against Japanese cities. The worst air raid to occur during the process was not the nuclear attacks, but the "Operation Meetinghouse" raid on Tokyo. On the night of March 9–10, 1945, "Operation Meetinghouse" commenced and 334 Boeing B-29 Superfortress bombers took off to raid, with 279 of them dropping 1,665 tons of incendiaries and explosives on Tokyo. The bombing was meant to burn wooden buildings and indeed the bombing caused fire that created a 50 m/s wind, which is comparable to tornadoes. Each bomber carried 6 tons of bombs. A total of 381,300 bombs, which amount to 1,783 tons of bombs, were used in the bombing. Within a few hours of the raid, it had killed an estimated 100,000 people and destroyed of the city and 267,000 buildings in a single night — the deadliest bombing raid in military aviation history other than the atomic raids on Hiroshima and Nagasaki. By early August 1945, an estimated 450,000 people had died as the U.S. had intensely firebombed a total of 67 Japanese cities.
William D. Leahy
According to Truman's "Memoirs: Years of Decisions" (1955), Leahy had stated in 1945 to President Truman: "That is the biggest fool thing we have ever done. The atomic bomb will never go off, and I speak as an expert in explosives." Once the bomb was tested, Leahy became strongly opposed to its use in Hiroshima and Nagasaki. In his own memoirs, Leahy wrote:
Shadow (Babylon 5)
Before doing so, he remotely piloted his ship, the "White Star", to crash into the Shadows' capital city, which he was visiting. The "White Star" was carrying two nuclear bombs in its cargo bay, each with a yield of over 500 megatons. (The strongest nuclear bomb to be detonated as of 2011 was the Tsar Bomb, which had a yield of 50 megatons.)
Nuclear weapons testing
The first atomic weapons test was conducted near Alamogordo, New Mexico, on July 16, 1945, during the Manhattan Project, and given the codename "Trinity". The test was originally to confirm that the implosion-type nuclear weapon design was feasible, and to give an idea of what the actual size and effects of a nuclear explosion would be before they were used in combat against Japan. While the test gave a good approximation of many of the explosion's effects, it did not give an appreciable understanding of nuclear fallout, which was not well understood by the project scientists until well after the atomic bombings of Hiroshima and Nagasaki.
Fukushima Daiichi nuclear disaster (Unit 1 Reactor)
The was a series of equipment failures, nuclear meltdowns, and releases of radioactive materials at the Fukushima I Nuclear Power Plant, following the Tōhoku earthquake and tsunami on 11 March 2011. It is the largest nuclear disaster since the Chernobyl disaster of 1986.
German Goncharov
He was a co-author of a detailed feasibility study undertaken by a team in 1954 and 1955, involving the theory, design and calculations of the next-generation RDS-37 device, an air-delivered two-stage thermonuclear bomb which was detonated in 1956: in the first stage, x-ray radiation was produced from a primary nuclear charge; in the second stage the radiation compressed a thermonuclear core resulting in a fusion reaction. The development of this more-efficient and more-powerful Soviet thermonuclear weapon was galvanized by reports of American success with a high-yield device on 1 March 1954, the first of the Castle Bravo tests. The design was what Sakharov referred to as "the third idea" which he'd originally mulled over in 1949 (the two-stage model was initiated by Stanislaw Ulam; an original patent application for the invention was submitted by Klaus Fuchs and John von Neumann who were employed at Los Alamos in May 1946). For this work, Goncharov was awarded the Order of the Red Banner of Labour in 1956. In 1958, his co-design of a further improved device was tested and then put into production. Between 1959 and 1961, he developed original technical ideas, later credited to him as inventions, which were included in all further Soviet nuclear devices, and he co-designed and was involved in the testing several new bombs. He was involved in the design of the principal physical scheme of the RDS-220 bomb, 'Tsar Bomba', the largest-ever nuclear device. For his creative efforts in the work from 1959, he received the Lenin Prize in 1962.
Father of All Bombs
Robert Hewson, an editor for Jane's Information Group, told the BBC it was likely that FOAB indeed represented the world's biggest non-nuclear bomb. "You can argue about the numbers and how you scale this but the Russians have a long and proven history of developing weapons in the thermobaric class", he says. UPI claimed the device "would enormously boost Russia's conventional military capabilities".
Chelyabinsk meteor
With an estimated initial mass of about 12,000–13,000 metric tons (13,000–14,000 short tons, heavier than the Eiffel Tower), and measuring about in diameter, it is the largest known natural object to have entered Earth's atmosphere since the 1908 Tunguska event, which destroyed a wide, remote, forested, and very sparsely populated area of Siberia. The Chelyabinsk meteor is also the only meteor confirmed to have resulted in a large number of injuries. No deaths were reported.
Partial Nuclear Test Ban Treaty
Much of the stimulus for the treaty was increasing public unease about radioactive fallout as a result of above-ground or underwater nuclear testing, particularly given the increasing power of nuclear devices, as well as concern about the general environmental damage caused by testing. In 1952–53, the US and Soviet Union detonated their first thermonuclear weapons (hydrogen bombs), far more powerful than the atomic bombs tested and deployed since 1945. In 1954, the US Castle Bravo test at Bikini Atoll (part of Operation Castle) had a yield of 15 megatons of TNT, more than doubling the expected yield. The Castle Bravo test resulted in the worst radiological event in US history as radioactive particles spread over more than , affected inhabited areas (including Rongelap Atoll and Utirik Atoll), and sickened Japanese fishermen aboard the "Lucky Dragon" upon whom "ashes of death" had rained. In the same year, a Soviet test sent radioactive particles over Japan. Around the same time, victims of the atomic bombing of Hiroshima visited the US for medical care, which attracted significant public attention. In 1961, the Soviet Union tested the Tsar Bomba, which had a yield of 50 megatons and remains the most powerful man-made explosion in history, though due to a highly efficient detonation fallout was relatively limited. Between 1951 and 1958, the US conducted 166 atmospheric tests, the Soviet Union conducted 82, and Britain conducted 21; only 22 underground tests were conducted in this period (all by the US).
Hugh Bradner
After receiving his doctorate from Caltech, Bradner worked at the US Naval Ordnance Laboratory where he researched naval mines until 1943. He was recruited by Robert Oppenheimer to join the Manhattan Project in 1943 at the Los Alamos Laboratory in New Mexico, which helped to develop the first atomic bomb. Bradner helped to develop a wide range of technology needed for the bomb, including research on the high explosives and exploding-bridgewire detonators needed to implode the atomic bomb, developed the bomb's triggering mechanism, and even helped design the new town around the laboratory. He worked closely with some of the most prominent scientists including Luis Alvarez, John von Neumann and George Kistiakowsky. He witnessed the Trinity test, the first nuclear weapons test, at Alamogordo on July 16, 1945.