The fundamentals of earthquake mechanics are simple: Pieces of rock slip past one another along a fault to release pent-up energy. Some of that energy ripples outward, causing seismic waves that shake the earth. But how long it takes and exactly how the energy dissipates has remained elusive. To discern these processes, researchers recently built a machine at the University of Oklahoma to mimic what happens inside the earth’s crust.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.