Instruct: Given a question, retrieve relevant passages that answer the question.
Query: What's the biggest atomic bomb to ever exist?
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").
The United States was in a Cold War Nuclear arms race with the Soviet Union to build bigger and better bombs. The next series of tests over Bikini Atoll was code named Operation Castle. The first test of that series was Castle Bravo, a new design utilizing a dry fuel thermonuclear hydrogen bomb. It was detonated at dawn on March 1, 1954.
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.
During the 1930s, innovations in physics made it apparent that it could be possible to develop nuclear weapons of incredible power using nuclear reactions. When World War II broke out, scientists and advisors among the Allies feared that Nazi Germany may have been trying to develop its own atomic weapons, and the United States and the United Kingdom pooled their efforts in what became known as the Manhattan Project to beat them to it. At the secret Los Alamos laboratory in New Mexico, scientist Robert Oppenheimer led a team of the world's top scientists to develop the first nuclear weapons, the first of which was tested at the Trinity site in July 1945. However, Germany had surrendered in May 1945, and it had been discovered that the German atomic bomb program had not been very close to success.The Allied team produced two nuclear weapons for use in the war, one powered by uranium-235 and the other by plutonium as fissionable material, named "Little Boy" and "Fat Man". These were dropped on the Japanese cities of Hiroshima and Nagasaki on August 6 and 9, 1945 each. This, in combination with the Soviet invasion of Japanese-controlled territory, convinced the Japanese government to surrender unconditionally. These two weapons remain the only two nuclear weapons ever used against other countries in war.
On August 6, 1945, the uranium-type nuclear weapon codenamed "Little Boy" was detonated over the Japanese city of Hiroshima with an energy of about , destroying nearly 50,000 buildings (including the headquarters of the 2nd General Army and Fifth Division) and killing approximately 70,000 people, including 20,000 Japanese combatants and 20,000 Korean slave laborers. Three days later, on August 9, a plutonium-type nuclear weapon codenamed "Fat Man" was used against the Japanese city of Nagasaki, with the explosion equivalent to about , destroying 60% of the city and killing approximately 35,000 people, including 23,200–28,200 Japanese munitions workers, 2,000 Korean slave laborers, and 150 Japanese combatants. The industrial damage in Nagasaki was high, partly owing to the inadvertent targeting of the industrial zone, leaving 68–80 percent of the non-dock industrial production destroyed.
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.
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.
Since the atomic bombings of Hiroshima and Nagasaki, nuclear weapons have been detonated over two thousand times for testing and demonstration. Only a few nations possess such weapons or are suspected of seeking them. The only countries known to have detonated nuclear weapons—and acknowledge possessing them—are (chronologically by date of first test) the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, China, India, Pakistan, and North Korea. Israel is believed to possess nuclear weapons, though, in a policy of deliberate ambiguity, it does not acknowledge having them. Germany, Italy, Turkey, Belgium and the Netherlands are nuclear weapons sharing states. South Africa is the only country to have independently developed and then renounced and dismantled its nuclear weapons.
So far, two nuclear weapons have been used in the course of warfare, both by the United States near the end of World War II. On August 6, 1945, a uranium gun-type device (code name "Little Boy") was detonated over the Japanese city of Hiroshima. Three days later, on August 9, a plutonium implosion-type device (code name "Fat Man") was detonated over the Japanese city of Nagasaki. These two bombings resulted in the deaths of approximately 120,000 people.
After the bombings of Hiroshima and Nagasaki, the world’s nuclear weapons stockpiles grew, and nuclear weapons have been detonated on over two thousand occasions for testing and demonstration purposes. Countries known to have detonated nuclear weapons—and that acknowledge possessing such weapons—are (chronologically): the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, the People's Republic of China, India, Pakistan, and North Korea.
As thermonuclear weapons represent the most efficient design for weapon energy yield in weapons with yields above , virtually all the nuclear weapons of this size deployed by the five nuclear-weapon states under the Non-Proliferation Treaty today are thermonuclear weapons using the Teller–Ulam design.
In July 1954, the Cabinet decided to develop the hydrogen bomb. The United Kingdom Atomic Energy Authority Atomic Weapons Research Establishment at Aldermaston produced three designs: Orange Herald, a large boosted fission weapon; Green Bamboo, an interim thermonuclear design; and Green Granite, a true thermonuclear weapon. The first test series consisted of three tests in May and June 1957. In the first, Grapple 1, a version of Green Granite known as Short Granite was dropped from a Vickers Valiant bomber flown by Wing Commander Kenneth Hubbard. The bomb's yield was estimated at , far below its designed capability. Despite its failure, the test was hailed as a successful thermonuclear explosion, and the government did not confirm or deny reports that the UK had become a third thermonuclear power. The second test was Grapple 2, of Orange Herald. Its yield made it technically a megaton weapon. It was the largest ever achieved by a single stage device. Grapple 3 tested Purple Granite, a Short Granite with some fixes. Its yield was a very disappointing .
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.
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.
The United States developed the first nuclear weapons during World War II in cooperation with the United Kingdom and Canada as part of the Manhattan Project, out of the fear that Nazi Germany would develop them first. It tested the first nuclear weapon on July 16, 1945 ("Trinity") at 5:30 am, and remains the only country to have used nuclear weapons in war, devastating the Japanese cities of Hiroshima and Nagasaki. It was the first nation to develop the hydrogen bomb, testing an experimental prototype in 1952 ("Ivy Mike") and a deployable weapon in 1954 ("Castle Bravo"). Throughout the Cold War it continued to modernize and enlarge its nuclear arsenal, but from 1992 on has been involved primarily in a program of Stockpile stewardship. The U.S. nuclear arsenal contained 31,175 warheads at its Cold War height (in 1966). During the Cold War, the United States built approximately 70,000 nuclear warheads, more than all other nuclear-weapon states combined.
The first full-scale thermonuclear test was carried out by the United States in 1952; the concept has since been employed by most of the world's nuclear powers in the design of their weapons. The design of all modern thermonuclear weapons in the United States is known as the "Teller–Ulam configuration" for its two chief contributors, Edward Teller and Stanislaw Ulam, who developed it in 1951 for the United States, with certain concepts developed with the contribution of physicist John von Neumann. Similar devices were developed by the Soviet Union, United Kingdom, France, and China.
Second, and more powerful plutonium implosion atomic bomb, Fat Man, is dropped on Nagasaki from a different "Silverplate" B-29 named "Bockscar", flown by Maj. Charles Sweeney (Atomic bombing of Nagasaki)
A New Weapons Committee was established at Aldermaston on 15 October 1951 to examine improvements to their atomic bombs. John Corner, the head of the theoretical group at Aldermaston, suggested producing a device in the "megaton range"—one with a yield of or more. In this he was thinking not of a thermonuclear weapon, but of a large fission one. The idea was not pursued at that time, because the RAF wanted more, not bigger, atomic bombs. Meeting in Bermuda in December 1953 with Dwight D. Eisenhower, who had replaced Truman as president earlier that year, Churchill told him that the RAF had reckoned that fission bombs would be sufficient for most targets, and therefore that Britain had no intention of developing hydrogen bombs.
On 12 and 19 March 1954, Penney briefed the Gen 475 Committee meetings, attended by the Chiefs of Staff, senior officials from the Ministry of Defence and Foreign Office, and Sir Edwin Plowden, about recent developments in thermonuclear weapons. Sir Frederick Brundrett, the chairman of the Chiefs of Staff's Working Party on the Operational Use of Atomic Weapons (OAW), then asked Penney on 25 May for a working paper for an OAW meeting on 31 May. In turn, OAW sent a report to the Chiefs of Staff, who recommended that the United Kingdom develop its own thermonuclear weapons. Admiral of the Fleet Sir Rhoderick McGrigor, the First Sea Lord, recalled that:
The notion of using a fission weapon to ignite a process of nuclear fusion can be dated back to 1942. At the first major theoretical conference on the development of an atomic bomb hosted by J. Robert Oppenheimer at the University of California, Berkeley, participant Edward Teller directed the majority of the discussion towards Enrico Fermi's idea of a "Super" bomb that would use the same reactions that powered the Sun itself.
With the basic fusion reactions confirmed, and with a feasible design in hand, there was nothing to prevent Los Alamos from testing a thermonuclear device. On 1 November 1952, the first thermonuclear explosion occurred when Ivy Mike was detonated on Enewetak Atoll, within the US Pacific Proving Grounds. This device, which used liquid deuterium as its fusion fuel, was immense and utterly unusable as a weapon. Nevertheless, its success validated the Teller–Ulam design, and stimulated intensive development of practical weapons.
Virtually all thermonuclear weapons deployed today use the "two-stage" design described above, but it is possible to add additional fusion stages—each stage igniting a larger amount of fusion fuel in the next stage. This technique can be used to construct thermonuclear weapons of arbitrarily large yield, in contrast to fission bombs, which are limited in their explosive force. The largest nuclear weapon ever detonated, the Tsar Bomba of the USSR, which released an energy equivalent of over , was a three-stage weapon. Most thermonuclear weapons are considerably smaller than this, due to practical constraints from missile warhead space and weight requirements.
Fusion reactions do not create fission products, and thus contribute far less to the creation of nuclear fallout than fission reactions, but because all thermonuclear weapons contain at least one fission stage, and many high-yield thermonuclear devices have a final fission stage, thermonuclear weapons can generate at least as much nuclear fallout as fission-only weapons.
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."
Years after the Civil War, Allan sells the pistol to buy a work permit to travel to America. When informed that the worlds biggest bomb is being assembled, Allan's passion for explosions is re-ignited and he helps Robert Oppenheimer (Philip Rosch) in successfully developing the atomic bomb. For his work, Allan receiving praise from Harry S. Truman (Kerry Shale) for 'building a bomb that will stop all wars'. During a drunken dinner, Truman is informed by telephone that Franklin Delano Roosevelt, then President of the United States, has died, Truman being immediately sworn in as President.
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.
Then, in 1885, Flood Rock, a reef that Newton had begun to undermine even before starting on Hallert's Rock, removing of rock from the reef, was blown up as well, with Civil War General Philip Sheridan and abolitionist Henry Ward Beecher among those in attendance, and Newton's daughter once more setting off the blast, the biggest ever to that date, and reportedly the largest man-made explosion until the advent of the atomic bomb although the detonation at the Battle of Messines in 1917 was several times larger. Two years later, plans were in place to dredge Hell Gate to a consistent depth of .