We don't have a great handle on predicting earthquakes. But we do know enough about them to know that they aren't all purely forces of nature. Humans can actually cause (or maybe just prompt) the Earth to shake. We've talked before here at BoingBoing about man-made earthquakes — caused by lubricating rocks deep underground, or by shifting the distribution of weight on the surface of the Earth in significant ways (think: building a reservoir). At Scientific American, David Biello has a short piece on what we do and don't know about this phenomenon. In light of the ruling in the L'Aquila earthquake trial, I found it particularly interesting to learn that, even when we know we're doing something that could trigger a 'quake, we still aren't very good at figuring out how strong that quake is likely to be.