(77) If all humans died, when would the last light go out? - YouTube(77) If all humans died, when would the last light go out? - YouTube External linkGet a copy of What If? 2 and Randall’s other books at: https://xkcd.com/booksMore serious answers to absurd questions at: https://what-if.xkcd.com/If every h...TagsxkcdContent typeLINK