In the mid-1940s, a few brilliant people drew up the basic blueprints of the computer age. They conceived a general-purpose machine based on a processing unit made up of specialized subunits and registers, which operated on stored instructions and data. Later inventions—transistors, integrated circuits, solid-state memory—would supercharge this concept into the greatest tool ever created by humankind. So here we are, with machines that can churn through tens of quadrillions of operations per second. We have voice-recognition enabled assistants in our phones and homes.