My latest book, How Software Works, covers a lot of the most interesting secrets behind the software we use every day. Even so, there were a lot of cool topics that I wasn't able to include. So I've decided to "showcase" my "animation skills" (have I downplayed that enough?) by making videos to cover them instead. The first of these is about random numbers. Few people know how many types of programs depend upon random numbers—or that it's impossible for a program to create them. Sound like a paradox?