Mike Brown's Planets

Back in something like seventh grade, I learned how science works. Scientists formulate a hypothesis and then they do experiments, and if enough experiments support the hypothesis, eventually the hypothesis becomes a theory. Right? Only, in my twenty-something years of actually doing science, things have rarely worked that way. Usually the process is more like this: do observations; discover something; develop explanation; repeat. This new paper, though, is a real live old fashioned hypothesis. It even has the word in the title: A hypothesis for the color diversity of the Kuiper belt.