In a few weeks, sensors in Indiana will go online that will record, in the words of Bryan Pijanowski, every sound the Earth makes. The array of microphones, geophones, and barometric gauges will run for a year, taping everything from the songs of birds arriving in the spring to the vibrations of the continent as ocean waves pound the Atlantic and Pacific coasts. They will measure earthquakes on the other side of the world and the stomping of cattle nearby, the ultrasonic whistles of bats and the barometric drop of cold fronts. “I joke to my physicist friends that if I had a microphone small enough, I could record the Higgs boson,” Pijanowski says.