announcement

Update: Check new design of our homepage!

Atomic Bomb Facts

Atomic Bomb Facts

The atomic bomb changed warfare and geopolitics of the world, handing humanity its very own self-destruct button. This article is a compilation of facts about these weapons of mass destruction, with latest information about the size of the world's nuclear stockpile.
ScienceStruck Staff
The Lost Nuclear Bombs
Yes, you read that right. Till date, the United States of America has lost six nuclear weapons and they haven't been recovered. Since the end of World War II, USA has recorded 32 'Broken Arrows' (Nuclear weapons accidents involving theft, detonation, launching, or firing). The 'A-word' changed everything. When the atomic bomb was first used in the Second World War, bringing it to an end, it also led to the beginning of a new era. The power locked inside the atomic nucleus was unleashed upon the world, in the form of an atom bomb. The cold war began and with it, a newer and deadlier arms race was initiated. The bomb announced the Super Power status of United States of America.

For the first time, human race possessed the power to annihilate itself and in fact, all life from the planet. The facts presented here, are intended to shed light on the status of nuclear weapons and the history of their development. These facts are a reminder of the triumph of human intellect and also its suicidal tendencies. 

To measure the explosive power of nuclear weapons or any explosion, a unit called the TNT equivalent (ton of TNT) is used. This is because Trinitrotoluene (TNT) is the most powerful chemical explosive. A ton of TNT as a unit, is equal to 4.184 Gigajoules. A Megaton of TNT is equal to 4.184 x 1015 J.

The Hiroshima and Nagasaki Bombings (1945)

Neither the ones who used the nuclear bomb for the first time, nor the ones on whom it was used, can ever forget that moment in human history. It left a deep scar on the collective human psyche.


Partly stung by Japan's attack on Pearl harbor and to end Japanese aggression in the Pacific region, United States dropped the atomic bomb, code named 'Little Boy', on the Japanese city of Hiroshima, on August 6, 1945. The bomb was dropped through a B-29 aircraft, named 'Enola Gay', piloted by Colonel Paul W. Tibbets.

'Little Boy' exploded at about 1,900 feet (580 m) above the city, with an energy output of 16 kilotons of TNT, which was a result of the conversion of 600 mg to 860 mg of matter, into energy. It was a gun-type fission weapon, that derived its explosive energy from the fission of Uranium-235. Designed and developed by the Los Alamos Laboratory, it was the second nuclear explosion in history and the first to be actually detonated as a weapon of mass destruction.

The Hiroshima bombing killed 135,000 people. A majority were killed instantly, while others succumbed to injuries and the aftereffects of nuclear radiation. The bomb killed about 30% of Hiroshima population. About 4.7 square miles of the city were completely destroyed.

As Japan remained defiant, despite the Hiroshima bombing, another bomb, code named 'Fat Man', was dropped over the city of Nagasaki on August 9, 1945. It exploded at 1,650 feet (500 m) above the city, unleashing 21 Kilotons of TNT equivalent energy and instantly killing about 40,000 people and many more in the following days. The blast radius was 1 mile. Needless to say, Japan surrendered unconditionally in a few days and the Second World War came to an end.

'Fat Man' was released through a Boeing B-29 Superfortress Bockscar aircraft, piloted by Major Charles W. Sweeney. Nagasaki wasn't the primary target of the second atomic bomb. In fact, it was supposed to be dropped over the city of Kokura. However, due to the bad weather conditions and smoke due to previous bombings, the city could not be targeted. Hence the aircraft headed towards Nagasaki, which was the secondary target. Despite being comparatively powerful than 'Little Boy', the damage inflicted on Nagasaki was lesser, as the bomb missed its target by almost 2 miles.

A factory, known as Mitsubishi-Urakami Ordnance Works, was destroyed in the blast. This was the place, where the type 91 torpedoes, used in the attack on Pearl Harbor, were manufactured.

A Japanese engineer, Tsutomu Yamaguchi was one of the few who survived both the atomic bombings, at Hiroshima and Nagasaki.

Discovery of Fission and the Manhattan Project

The atomic bomb was made possible due to new discoveries in nuclear physics, which unlocked the immense power, locked in radioactive atoms. Here are some facts about the creation of the first atom bomb and the advances in science and technology, that made it possible.

This type of bomb is based on the artificially induced phenomenon of nuclear fission. The atoms of radioactive elements like Uranium or Plutonium are bombarded with slow neutrons, which makes them unstable and they split into lighter elements, releasing tremendous amount of energy in the process. Along with the energy release, more neutrons are released in the process, which subsequently cause the fission of more atoms, triggering a 'Chain Reaction'. The explosion of the atomic bomb is caused by the triggering of such an uncontrolled chain reaction.

Nuclear energy plants or nuclear reactors are based on the same principle as the atom bomb. The only difference is their use of controlled fission chain reaction for the generation of electricity.

The process of nuclear fission was discovered by Otto Hahn and Fritz Strassmann in 1938. The first such bomb was created by the United States of America and the allied forces, through the 'Manhattan Project', which involved thousands of scientists, engineers, and technicians, working under the leadership of J. Robert Oppenheimer in Los Alamos.

The allied forces, led by USA, started the project to develop the bomb, partly out of fear that the Nazi government of Germany was developing one too. On 16th of July 1945, the first successful test of an atomic bomb was conducted in the desert, situated North of Alamogordo in New Mexico. The test was code named 'Trinity' and the exploded bomb was a plutonium implosion device. It released heat and energy, equivalent to almost 19 kilotons of TNT explosions.

The total estimated cost, invested in building the first nuclear bomb at the Manhattan project, adjusted for inflation, in today's terms, was USD 20 billion.

Today, an even more deadlier nuclear weapon, in the form of the Hydrogen bomb has been developed, which is thousands of times more deadlier than a fission-based atomic bomb. Classified as a thermonuclear device, a hydrogen bomb uses both fission and fusion reactions to unleash hell, when detonated. These thermonuclear weapons can deliver an explosive energy output, which is equivalent to or more than 50 million tons of TNT explosives.

In 1966, during the cold war, as many as 32,193 nuclear warheads and bombs were built and ready for deployment.

Based on nuclear fusion and fission, the thermonuclear bomb or Hydrogen bomb is more powerful, compared to purely fissile bombs. The first hydrogen bomb, to be tested, was Ivy Mike, which had a total energy output of 11 Megatons of TNT.

Tsar Bomba: The Largest Hydrogen Bomb Ever Built

The most powerful nuclear weapon ever built and detonated was the Tsar Bomba (Tsar Bomb). The 50 Megaton AN602 hydrogen bomb was tested on October 30, 1961, by the Soviet Union, in Sukhoy Nos, a cape, that is part of the Novaya Zemlya archipelago, situated in the Arctic Ocean, towards the North of today's Russia.

This hydrogen bomb weighed about 27,000 kilograms (60,000 lb), had a length of 8 meters (26 ft), and a diameter of 2.1 meters (6.9 ft).

The explosive energy unlocked by it, was 1350 to 1570 times the energy released through the bombs that annihilated Hiroshima and Nagasaki, during the last World War. Its energy yield was about 1.4% of the Sun's power output.

The Tsar Bomba detonation, due to its energy output, became the most powerful artificial explosion, in mankind's history.

The three-stage thermonuclear weapon was based on a Tellar-Ulam design, which incorporated a chemical and fissile nuclear weapon to trigger nuclear fusion in the warhead.

Nuclear Weapons in USA

Here are some facts about the current status of nuclear weapons usage, in USA.

Since 1951, the total number of nuclear missiles developed by USA is 67,500. In the process, the country has conducted 1030 nuclear tests between 1945 and 1992.

Currently, USA has 2,200 strategic nuclear warheads and it spends about 52.4 billion dollars on activities that are related to their security, maintenance, and infrastructure.

A total of 15,357 square miles of the country is devoted to nuclear weapons bases and connected facilities.

About 104 million cubic meters of radioactive waste has been generated from nuclear weapons related activities.

President Obama and the erstwhile Russian President Dmitry Medvedev signed a treaty in 2010, pledging the reduction of strategic nuclear warheads to 1,550 ready-to-use weapons in both nations. This will reduce the current US nuclear arsenal by about 30%, resulting in savings of USD 9.69 billion every year. All this data is sourced from information provided by the Carnegie Endowment for World Peace and Brookings Institution.

Current Nuclear Weapons Status in the World

Since the Second World War, the countries who possess nuclear weapons have increased in number. World is an even more dangerous place now, than it was in the war years. Within minutes, more than half the population of the world could be wiped out, if a nuclear war is triggered. These facts are a status update of nuclear weapons proliferation in the world.

Today, as many as eight nations acknowledge the possession of nuclear weapons. This nuclear club includes USA, UK, Russia, France, People's Republic of China, India, Pakistan, and North Korea. Israel is also known to possess nuclear weapons, though officially, the country has never accepted it. As of 2013, more than 17000 nuclear weapons exist, of which, 4,300 warheads are known to be operational. Among these operational warheads, US and Russia have 1800 weapons, which are ready to be deployed at short notice, if need be. Here are the estimated numbers of warheads, built by every known nuclear power state.

Country Nuclear Weapons Stockpile (2013)
Russia 8500
USA 7700
France 300
China 250
United Kingdom 225
Israel 80
Pakistan 100-120
India 90-110
North Korea < 10
Total ~17300

Source: Federation of American Scientists

With the development of intercontinental ballistic missiles, the delivery of atom bombs has become even easier and deadlier. Many countries possess the capability of launching nuclear-tipped warheads, targeting places which are thousands of miles away.

Many more developing countries are in the process of acquiring the technology to build nuclear weapons through covert means. International efforts are underway to undertake large-scale voluntary nuclear disarmament.

Till human aggression and greed is cured, newer and deadlier weapons of mass destruction will keep on being created. Nuclear weapons have the capacity to wipe out entire cities in a few seconds. There can be nothing deadlier than an atom bomb strike. Sadly, Hiroshima and Nagasaki bear testimony to this fact. When will the merchants of death feel the prick of conscience? Only time will tell.

The facts about nuclear weapons, presented above, emphasize the need to push for nuclear disarmament on a global scale. Hope they serve as a reminder to coming generations, of the cruelty and destruction, that humanity is capable of. May they be wiser than their previous generations and realize the importance of tolerance and peaceful coexistence.