Being fat is like a virus  I'm going to take this excerpt out of context to elaborate on something I'm excited about. I've been studying networks (social networks, collaboration networks, road networks, all kinds of networks) for a few months now, and one of its applications is to foresee contagious diseases. Obesity fits the epidemic model almost perfectly. Which means that it's formally a contagious disease: people get fatter the more fatties around them, the more fat friends their friends have, and the more fat friends their friends' friends have.  The downside is that, assuming the humanity is a completely connected network, we'll all get fat at some point in the future. I hope we begin fat concentration camps long before this.