The Cosmic Gravitational Wave Background was discovered! Spacetime is vibrating with the constant thrum of gravitational waves from supermassive black hole b...

This channel, Launchpad Astronomy, is great and first came to my attention for its coverage of the James Webb Space Telescope launch. IIRC, the speaker used to work on Hubble.

At 11:50 he covers the Final Parsec Problem, which I commented about in response to this post a few weeks ago.