Gravitational-Wave Detector LIGO Is Back

After three years of upgrades, the gravitational-wave detector known as LIGO, or Laser Interferometer Gravitational-Wave Observatory, has resumed searching for colliding black holes and other cosmic cataclysms. "The improvements should allow the facility to pick up signals from colliding black holes every two to three days, compared with once a week or so during its previous run in 2019-20," reports Nature. From the report: The Virgo detector near Pisa, Italy, which has undergone its own $9-mill