What was once the size of a grapefruit is now so small that Intel fits about 500 million of them into an area no bigger than a postage stamp. That’s just one chip in your typical desktop computer of 2008 vintage. You need lots of transistors because they don’t do much individually. It takes at least six of them to make one AND gate, a logic device that says True if and only if both of its inputs are True. And how far does that get you?