SERIES Neural networks power today’s AI boom. To understand them, all we need is a map, a cat and a few thousand dimensions. James O’Brien for Quanta Magazine Look at a picture of a cat, and you’ll instantly recognize it as a cat. But try to program a computer to recognize cat photos, and you’ll quickly realize that it’s far from straightforward. You’d need to write code to pinpoint the quintessential quality shared by countless cats in photos with distinctive backgrounds and taken from differen...