Rather than relying on a cheek swab or a little blood, however, these cosmic DNA tests utilize tiny ripples in the fabric of spacetime called gravitational waves, first proposed by Albert Einstein 110 ...

Sgr A*, at the heart of the Milky Way and clocking in at 4.3 million solar masses, is the closest supermassive black hole we have access to. It's also on the quiescent end of the activity scale, which ...