at least eight nations have detonated 2,056 nuclear test explosions at dozens of test sites
https://science.howstuffworks.com/nuclear-bomb.htm
https://www.atomicheritage.org/history/bombings-hiroshima-and-nagasaki-1945
https://www.atomicheritage.org/history/bombings-hiroshima-and-nagasaki-1945
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How Nuclear Bombs Work
Nine countries hold the 13,000 nuclear weapons in the global stockpile. That's less than during the Cold War but it doesn't change the fact that these bombs are still a threat to global humanity. So how do they work and are we close to nuclear war?