Vasili Arkhipov. Stanislav Petrov. Are the names familiar? They should be: these people saved the world by refusing to use nuclear weapons under incredible circumstances of extraordinary pressure. Even if you trust every head of state in every country that has nuclear weapons - and even if you feel confident that all future heads-of-state in nuclear-armed countries can also be trusted - there's still the possibility of nuclear accidents. Over time, this possibility becomes a probability. One of the scariest things about nukes is the number of times our species has almost annihilated itself by accident. We discuss these accidents, and more, in this episode. What's life like for a species living in the shadow of the bomb? If you've enjoyed this show, you can follow us on Twitter  www.twitter.com/physicspod and you can visit the show with your comments, questions, concerns, or suggestions for future show topics at www.physicspodcast.com