Regular coordinate systems for Schwarzschild and other spherical spacetimes · HackerPapers discussionshttps://hackerpaper.kaipfister.de/p/gr-qc_0001069/Collected HN comments and submissions linking this paper.enMon, 02 Nov 2026 11:16:22 GMTRegular coordinate systems for Schwarzschild and other spherical spacetimes — mentioned by raattgifthttps://news.ycombinator.com/item?id=44917769urn:hackerpapers:mention:gr-qc_0001069:44917769Fri, 15 Aug 2025 22:02:14 GMT<p>No, not really. To boil it down to thinner text, and to focus on your &quot;Space becomes timelike&quot;, I think you are stuck on (a) a particular system of coordinates that (b) are not regular across the horizon and (c) thinking that either of these does anything physical to free-falling infalling test particle. The huge flashing red warning sign on (a) &amp; (c) is that you drop in the words &quot;&#x27;upward&#x27; direction&quot;, &quot;{toward, closer to, away from} the singularity&quot; and most especially &quot;slower&quot;: you are clearly implicitly slicing spacetime into space and time. If you can handle thicker text, Unruh has a nice…</p><p><a href="https://hackerpaper.kaipfister.de/p/gr-qc_0001069/">Paper and discussion history</a>. A mention is not an endorsement.</p>gr-qc