Japan’s pioneering detector set to join hunt for gravitational waves

By Davide Castelvecchi Inside a house-sized scaffolding wrapped in thick plastic sheets, Takayuki Tomaru is in full clean-room attire. The physicist is performing one of the most delicate and crucial tasks in the construction of a gravitational-wave observatory: installing one of the machine’s four mirrors, each a 23-kilogram cylinder of solid sapphire known as a test …