And (for the avoidance of doubt) that author doesn't in any sense lack "a previous math or computer science background", although he says he's a programming beginner. He's a first-rate physicist and the author of an important book on quantum computing. So I'm not sure what XiXiDu is saying here; that Nielsen's level of insight is what it takes to deserve the label of "programmer"? (No.) Or that Nielsen is a genius? (Maybe, but so what?) Or what?