Observatories may identify the sources of our new discoveries. Over the last few years, we've witnessed the start of two radically new ways of doing astronomy. For all of human history, everything we've learned about the cosmos has come from observing photons, from high-energy gamma rays down to the cosmic microwave background. But since the opening of the IceCube observatory at the South Pole, we've been able to track ultra-high-energy cosmic neutrinos. And earlier this year