Flying Cars, Zombie Dogs, and Robot Overlords

Every time you chew a stick of Juicy Fruit, eat a hamburger, slip on a nylon, plug your phone into a wall socket, flick on a TV, withdraw money from an ATM, lick an ice-cream cone, switch on a computer, ride an escalator, play a DVR, watch a movie about dinosaurs, or pop a tranquilizer, you’re doing something that originated at a world’s fair or trade expo. In fact, each new technology and every novel product that rocked America and rolled the world, from the Colt revolver and the Corvette to fa