The science question. In its “How Does the Man of Steel Shave?” campaign, Gillette asked how Superman shaves if he’s nearly invincible? Gillette asked celebrities — including director, actor, and comic book aficionado Kevin Smith; Jamie Hyneman and Adam Savage, hosts the “Myth Busters” television program, Bill Nye, the science guy; and “The Big Bang Theory” actress and real-life neuroscientist Mayim Bialik – to proffer their opinions.