Nuclear testing
Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...

s. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them. Testing nuclear weapons can yield information about how the weapons work, as well as how the weapons behave under various conditions and how structures behave when subjected to nuclear explosions.

1953    Nuclear testing: At the Nevada Test Site, the United States conduct their first and only nuclear artillery test.

1954    Nuclear testing: The Castle Bravo, a 15-megaton hydrogen bomb, is detonated on Bikini Atoll in the Pacific Ocean, resulting in the worst radioactive contamination ever caused by the United States.

1957    First American underground nuclear bomb test.

1961    Nuclear testing: The Soviet Union detonates the hydrogen bomb Tsar Bomba over Novaya Zemlya; at 58 megatons of yield, it is still the largest explosive device ever detonated, nuclear or otherwise.

1964    Cold War: Indian Prime Minister Jawaharlal Nehru appeals to the United States and the Soviet Union to end nuclear testing and to start nuclear disarmament, stating that such an action would "save humanity from the ultimate disaster".

1998    India carries out two nuclear tests at Pokhran, following the three conducted on May 11. The United States and Japan impose economic sanctions on India.

1998    Nuclear testing: Pakistan responds to a series of nuclear tests by India with five of its own, prompting the United States, Japan, and other nations to impose economic sanctions.