A nuclear weapon or nuclear weapon ("nuclear weapon") is a weapon of enormous and destructive power that releases energy from nuclear reactions. A single nuclear weapon can destroy an entire city, as was proven during World War II, when the United States bombed the Japanese cities of Hiroshima and Nagasaki in August 1945. These are the only times nuclear weapons have been used in war, but a large number of nuclear test explosions have been carried out by several countries.
Nuclear weapons are divided into two main classes: based on fission or fusion.
The explosive power of nuclear weapons is given in the unit "kilotons" (thousand tonnes of tnt), by implication how many kilotons of TNT (conventional explosive) would theoretically give the same explosive power. The first nuclear explosion was test-detonated in New Mexico, USA, on 16 July 1945.
The known nuclear powers are (chronologically according to the year before the first test explosion) the United States, Russia (then the Soviet Union), Great Britain, France, China, India, Pakistan and North Korea. In addition, Israel is believed to have nuclear weapons, although the country neither confirms nor denies this.
Tactical nuclear weapons are weapons with a limited range and explosive charge, while strategic nuclear weapons are weapons with a long range and high explosive power. They have nuclear warheads that are so powerful that they will be able to destroy entire cities or large areas where enemy army units are stationed. Strategic weapons can be used by intercontinental missiles to reach targets all over the world, but they can also be carried by larger bombers.
Nuclear weapons are divided into two main classes: fission weapons and fusion weapons.
Fission weapons utilize the energy from a fission (splitting) of heavy atomic nuclei (uranium or plutonium), where they are split into smaller units when they absorb neutrons. The fission produces more neutrons, which in turn can be absorbed by other atomic nuclei (a nuclear chain reaction).
Fission bombs were previously referred to as "nuclear weapons" in the technical language and are still referred to as this in everyday speech. This should be avoided as it is scientifically misleading, as the reactions take place in the atomic nuclei themselves (not in the atoms).
Fusion weapons release energy using the fusion of light atomic nuclei, most often hydrogen. These weapons are also called thermonuclear weapons (because extremely high temperatures are required for fusion to take place). A nickname for fusion weapons is also "hydrogen bombs".
So-called neutron bombs are a variant of the fusion weapon. The weapon is designed with the aim of creating penetrating and deadly neutrons, while other effects (including fission and explosive power) are reduced.
Research into nuclear weapons came as a result of Albert Einstein's discovery of the connection between mass and energy and arose after the outbreak of the Second World War. The Manhattan Project, a secret, large-scale research project in the United States to develop nuclear weapons, was started in 1942. The project culminated in the first test explosion in the Alamogordo Desert in New Mexico in the United States on July 16, 1945.
The nuclear arms race
The overview shows some important dates for some important events in the nuclear race between especially the USA and NATO on the one hand, and the Soviet Union and the Warsaw Pact on the other.
1945-16 July: The first nuclear test explosion in New Mexico in the USA.
6 August: The US uses nuclear weapons in war for the first time and drops a bomb on Hiroshima in Japan.
9 August: The USA's second nuclear weapon is dropped over Nagasaki in Japan. 1946
24 January: The International Atomic Energy Agency (IAEA) is established at the initiative of the United States, Great Britain and Canada.
The USA's fourth nuclear explosion occurs on the island of Bikini in the Pacific Ocean. 194929. August: The Soviet Union's first nuclear test.
The United States uses bombers (B-50 and B-36) that can carry nuclear weapons from the United States to the Soviet Union. Corresponding aircraft are deployed