The first major gravitationalwave observatory to be built under Earth’s surface—KAGRA in Japan—is set to turn on
IN THE PIPELINE: Cocooned in stainless steel and surrounded by waterlogged rock, one of two three-kilometer-long vacuum chambers sprawls down a damp, dripping tunnel bored underneath Mount Ikenoyama in Japan. An intricate system of lasers and mirrors inside the chambers is designed to tune in to gravitational waves moving through our planet from across the cosmos. Enrico Sacchetti
