Decades before the atom bomb was though of by Einsten, H.G. Wells had already written a novel about it, 1914’s The World Set Free. Note that Wells didn’t know at this time that a nuclear detonation was actually possible — he just knew a little bit about radioactive decay and thought that, if we ever figured out a way to blow it all up at once, it would probably make a really big bang and be bad, real bad.
He also figured out it would be bad news for anyone who got drenched in uranium fallout:
“In the map of nearly every country of the world three or four or more red circles, a score of miles in diameter, mark the position of the dying atomic bombs and the death areas that men have been forced to abandon around them. Within these areas perished museums, cathedrals, palaces, libraries, galleries of masterpieces and a vast accumulation of human achievement, whose charred remains lie buried, a legacy of curious material that only future generations may hope to examine.”
H.G. Wells coined the term “atomic bomb.” And immediately after reading this book, Leo Szilard figured an atomic bomb might be a profitable commodity to control, so he patented it in 1934, though it was still just a weird, way-out-there science fiction idea, like flying cars.