Look at that cloth monstrosity above. Was it designed by an irradiated walrus? A hypochondriac Cthulhu? The creators of an upcoming swamp-themed Fallout sequel?Despite its alt-future aesthetic, this alarming piece of apparel is actually a 16th-century scuba* suit, dreamt up by none other than Leonardo da Vinci. Although there's no record that he actually built one himself, da Vinci considered the suit so powerful that he refused to divulge its details, fearing the technology would be abused by the "evil nature of men." When we discuss da Vinci's prescient inventions, we often focus on the high-flying ones—his dreamy, if literally unflappable, bird-shaped ornithopter, or his "aerial screw," which has spun into the modern helicopter.