In May 2019, astronomers picked up something strange in the fabric of spacetime. The LIGO and Virgo detectors recorded a gravitational wave that lasted just one-tenth of a second. The signal, known as GW190521, was unusual straight away because it didn’t look like the normal “chirps” usually produced when two black holes orbit one another before colliding. Instead, it sounded …
Read More »A wormhole from another universe? Scientists revisit the puzzling black hole GW190521
