Last weekend, a fascinating act in the history of humanity played out on Reddit. For April Fool's Day, Reddit launched a little experiment. It gave its users, who are all anonymous, a blank canvas called Place. The rules were simple. Each user could choose one pixel from 16 colors to place anywhere on the canvas. They could place as many pixels of as many colors as they wanted, but they had to wait a few minutes between placing each one. Over the following 72 hours, what emerged was nothing short of miraculous. A collaborative artwork that shocked even its inventors.