Talk:Ellis wormhole

This article ("Ellis wormhole") is said to be an Orphan, but it is linked to by the article "Ellis drainhole". Turningwoodintomarble (talk) 02:54, 14 February 2016 (UTC)[reply]

Sources for these details?

The article needs more detailed source information, in particular citing the source of the detailed mathematics of geodesics and for the dynamic wormhole solution. I'm curious because I'm reasonably confident that the article is in error when it claims that "every circle of latitude is a geodesic": the only case in which dρ/ds=0 remains a solution for all s is when ρ=0 (as can be verified from the geodesic equation for ρ). (Otherwise, that condition merely signals a turning point, as mentioned a few lines later.) That error leads me to mistrust the rest of the conclusions here at least a little! Steuard (talk) 03:08, 13 April 2020 (UTC)[reply]

"Spatial lensing" is not a thing

The bottom this page used to claim that the Ellis wormhole featured "spatial lensing", as distinct from "gravitational lensing", because there was "no gravity" in the Ellis wormhole. This is inconsistent both with standard language in the academic literature and with the actual concept of lensing in general relativity. From an ultra-strict WP:NOR perspective, you can just look at the papers cited on this very page: "Gravitational lensing by wormholes", "Gravitational microlensing by the Ellis wormhole", "Wave effect in gravitational lensing by the Ellis wormhole". You can also check that "spatial lensing" doesn't have any hits on Google Scholar in relation to wormhole or general relativity. From the physics perspective, trying to draw a distinction between curved space time caused by mass ("gravitational") and not caused by mass ("spatial") is non-sensical. Gravitational lensing comes from the curvature of spacetime and it doesn't care whether that curvature was sourced by conventional mass. You can have gravitational waves that (if really huge) could cause lensing but have been propagating since the beginning of the universe and so one couldn't even tell if they were "originally" sourced by mass. And indeed, even pure curvature will appear to have mass from far away; all of our evidence for mass takes this form! (Hence the reason many people wondered whether the mass of elementary particles are actually all tiny blackholes with no "true" mass anywhere. This doesn't work, but it illustrates the issue.) Jess_Riedel (talk) 03:30, 22 November 2023 (UTC)[reply]