https://hackerpaper.kaipfister.de/p/0706.0622/Collected HN comments and submissions linking this paper.enMon, 02 Nov 2026 11:16:22 GMThttps://news.ycombinator.com/item?id=44565698urn:hackerpapers:mention:0706.0622:44565698Mon, 14 Jul 2025 21:44:47 GMT<p>It&#x27;s only spherical in a Schwarzschild (non-rotating) black hole. A rotating black hole is called a Kerr black hole, and stuff gets weird, such as there being an oblate event horizon, a weird outer horizon called an ergosphere where spacetime gets dragged along such that it&#x27;s impossible to stand still and you can accelerate objects using the black hole, a weirder inner horizon called the Cauchy horizon where time travel is possible, and a singularity in the shape of a ring. Your intuition is correct that during a merger it would be weirder still. https://en.wikipedia.org/wiki/Kerr_metric…</p><p><a href="https://hackerpaper.kaipfister.de/p/0706.0622/">Paper and discussion history</a>. A mention is not an endorsement.</p>gr-qc