https://hackerpaper.kaipfister.de/p/gr-qc_0412019/Collected HN comments and submissions linking this paper.enMon, 02 Nov 2026 11:16:22 GMThttps://news.ycombinator.com/item?id=17757057urn:hackerpapers:mention:gr-qc_0412019:17757057Tue, 14 Aug 2018 11:55:19 GMT<p>&gt; what most people would consider to be fundamental Most people should then have it explained to them that frame-dependent quantities are not fundamental. This is something that arises even in their first exposure to Newtonian physics: kinetic energy is just such a frame-dependent quantity. Generally covariant and invariant quantities are candidates for fundamental quantities. The stress-energy tensor is, for example, generally covariant. However, one tends to want to slice it up into energy, pressure, stress, and so forth, and the fluxes of those in various directions. Those &quot;sliced&quot;…</p><p><a href="https://hackerpaper.kaipfister.de/p/gr-qc_0412019/">Paper and discussion history</a>. A mention is not an endorsement.</p>gr-qc