Could We Store Our Data in DNA?

A zettabyte is a trillion gigabytes. That's a lot--but, according to one estimate, humanity will produce a hundred and eighty zettabytes of digital data this year. It all adds up: PowerPoints and selfies; video captured by cameras; electronic health records; data retrieved from smart devices or collected by telescopes and particle accelerators; backups, and backups of the backups. Where should it all go, and how much of it should be kept, and for how long? These questions vex the computer scientists who manage the world's storage. For them, the cloud isn't nebulous but a physical system that must be built, paid for, and maintained.