https://hackerpaper.kaipfister.de/p/2102.11156/Collected HN comments and submissions linking this paper.enMon, 02 Nov 2026 11:16:22 GMThttps://news.ycombinator.com/item?id=29604889urn:hackerpapers:mention:2102.11156:29604889Sat, 18 Dec 2021 14:56:26 GMT<p>One important caveat to all this is that the gravitational redshift for a galaxy or galaxy cluster is an incredibly tiny effect. For example, the mean gravitational redshift for massive galaxy clusters has been measured (e.g., link below), and has a value of ~ 10 or 15 km/s. This can be compared with the typical motions of galaxies within a cluster (dispersions of ~ 1000 km/s) and the cosmological redshift of the clusters (for the sample in the paper I linked to, it&#x27;s equivalent to an average Doppler shift of ~ 50,000 km/s). In order to make that measurement, the authors had to combine…</p><p><a href="https://hackerpaper.kaipfister.de/p/2102.11156/">Paper and discussion history</a>. A mention is not an endorsement.</p>astro-ph.CO