https://lifeboat.com/blog/2024/01/black-holes-all-the-way-down-new-multimessenger-evidence-for-a-binary-black-hole-merger-within-an-active-galactic-nucleus Safeguarding Humanity Mon, 22 Jan 2024 14:26:50 +0000 hourly 1 https://wordpress.org/?v=6.4.2