Gravitational waves are ripples in the fabric of space and time, usually created when massive, dense objects like black holes collide. Now, researchers think this strange signal, dubbed GW190521, could have arrived from a parallel universe. When objects like black holes or neutron stars violently accelerate in collisions, they squeeze and stretch the space in their path. When the wormhole snaps shut, the signal would be cut off to leave a very brief burst of gravitational waves. But a wormhole is still a viable explanationThat means the wormhole model is still a viable explanation for the GW190521 collision.