Both bomb types release large quantities of energy from relatively small amounts of matter. Nine sovereign states are believed to possess nuclear weapons as of 2026: United States, Russia, the …

5 days ago · Atomic bombs work with nuclear fission. Two subcritical masses of uranium or plutonium are quickly put together to form a critical mass —that is, enough material to start a runaway fission …

Interactive nuclear blast simulator. Calculate blast radius, casualties, and fallout zones for any location worldwide. Explore effects of Tsar Bomba, Little Boy, and modern nuclear weapons with real …

Sep 6, 2017 · Scientists first developed nuclear weapons technology during World War II. Atomic bombs have been used only twice in war—both times by the United States against Japan at the end of …

Jun 18, 2025 · Nine countries currently either say they have nuclear weapons or are believed to possess them. The first to have nuclear arms were the five original nuclear weapons states — the United …

Of the world’s approximate 12,187 nuclear warheads, roughly 9,745 are in military stockpiles for use by missiles, aircraft, ships, and submarines. The remaining warheads have been retired but are still …

At the dawn of the nuclear age, the United States hoped to maintain a monopoly on its new weapon, but the secrets and the technology for building the atomic bomb soon spread. The United States …