| > If there are real engineering applications for GR, especially in optics Large-frame optical Sagnac gyroscopes for precision geodesy: https://www.frontiersin.org/articles/10.3389/fspas.2020.0004... And some detail on the GINGER project, "Sagnac Effect, Ring Lasers, and Terrestrial Tests of [post-Newtonian] Gravity" (clarification mine), https://www.mdpi.com/2075-4434/3/2/84/htm I imagine there is some literature on higher order modes in dispersion compensating fibre spools placed over underground flows (magma, water) but don't really have time to think about what decade practical engineering problems might emerge. Of possible interest to you, quoting preface of following: "These few words should make it clear that quantum optics, experimental gravitation and measurement theory are not nearly as far apart as one might first have thought. However, there has traditionally been little contact between physicists working in these various fields." (which is a little less true now because of e.g. LIGO) https://link.springer.com/book/10.1007%2F978-1-4613-3712-6 Next, I'm pretty sure that the emissions spectra of galactic magnetars (https://en.wikipedia.org/wiki/SGR_1935%2B2154 , one of Arecibo's last big detections, ยง2.1 of https://arxiv.org/abs/2103.06052v1 ) are far from the cosmological scale (see https://arxiv.org/abs/1507.02924 n.b. figure 24). > gravitational lensing ... is a cosmological effect Also pretty sure the Magellanic Clouds, other non-naked-eye Milky Way satellites, and some galactic targets aren't "cosmological", https://en.wikipedia.org/wiki/Gravitational_microlensing#Obs... Finally, it strikes me as unfair to to invoke Initial Conditions as a way to discount the relevance of gravitational observations. What, if not Intial Conditions, determines the frequency of your HeNe laser? Where did the neon in particular come from? (spoiler: https://en.wikipedia.org/wiki/Neon#Occurrence) And that helium is mostly a cosmological effect! ("The vast majority of helium was formed by Big Bang nucleosynthesis one to three minutes after the Big Bang. As such, measurements of its abundance contribute to cosmological models.") |
Strong evidence that God loves helium, and considers it a good party trick to have some on hand! But I always thought He was generated from fusing two H into an He in a Sun somewhere.