I'm imagining a post near-apocalyptic world where the near-future MAGAmorlocks watch ElonMuskishEloi flying machines traveling high in the sky (with or without contrails) and set their crude sextants on the problem of shooting a trajectory and from that guestimating which known megaCity Enclaves they are traveling between.
Thanks to Barry for the Gnomonic projection prompt... I seem to remember that the Gnomonic is the earliest known map projection and is derived from the traces of time-arcs cast by the sundial's gnomon. Am I wrong that Rhumblines are reasonable approximations of great circles, with the added convenience of providing a very simple navigational technique (constant angle to north)? https://en.wikipedia.org/wiki/Rhumbline_network turning the problem inside out (Ed Angel/SteveG), we have the rectilinear lens? https://en.wikipedia.org/wiki/Rectilinear_lens On 9/19/21 7:20 PM, Barry MacKichan wrote: > In the northern hemisphere a great circle route between two points > with the same latitude will be north of the parallel, so if the > latitudes are close, the great circle will arch above the straight > line (for most map projections that keep “parallels” parallel). A > gnomonic projection of the world centered on Charlotte or Honolulu > would show the great circle route as a straight line. I’m sure none of > those were printed, but I thought I might find a site that allowed the > user to select a tangent point (Charlotte or Honolulu) and then show > the map. The closest I got was https://bl.ocks.org/mbostock/3795048 > <https://bl.ocks.org/mbostock/3795048> and > https://observablehq.com/@d3/gnomonic > <https://observablehq.com/@d3/gnomonic>. It turns out that d3.js, a > graphics library has a function geoGnomonic(). > > —Barry > > Sent from my iPad > >> On Sep 19, 2021, at 3:50 PM, Frank Wimberly <wimber...@gmail.com> wrote: >> >> >> Not to change the subject but... >> >> A large airliner recently, 15 minutes ago, flew over Santa Fe headed >> west. My Flight Radar app tells me that it's a Boeing 777 going from >> Charlotte to Honolulu at an altitude of 38000 feet. I wouldn't have >> thought that Santa Fe was on a great Circle route between those two >> cities. But maybe it is. >> >> --- >> Frank C. Wimberly >> 140 Calle Ojo Feliz, >> Santa Fe, NM 87505 >> >> 505 670-9918 >> Santa Fe, NM >> >> .-- .- -. - / .- -.-. - .. --- -. ..--.. / -.-. --- -. .--- ..- --. >> .- - . >> FRIAM Applied Complexity Group listserv >> Zoom Fridays 9:30a-12p Mtn UTC-6 bit.ly/virtualfriam >> un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com >> FRIAM-COMIC http://friam-comic.blogspot.com/ >> archives: >> 5/2017 thru present https://redfish.com/pipermail/friam_redfish.com/ >> 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/ > > .-- .- -. - / .- -.-. - .. --- -. ..--.. / -.-. --- -. .--- ..- --. .- - . > FRIAM Applied Complexity Group listserv > Zoom Fridays 9:30a-12p Mtn UTC-6 bit.ly/virtualfriam > un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com > FRIAM-COMIC http://friam-comic.blogspot.com/ > archives: > 5/2017 thru present https://redfish.com/pipermail/friam_redfish.com/ > 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/
.-- .- -. - / .- -.-. - .. --- -. ..--.. / -.-. --- -. .--- ..- --. .- - . FRIAM Applied Complexity Group listserv Zoom Fridays 9:30a-12p Mtn UTC-6 bit.ly/virtualfriam un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com FRIAM-COMIC http://friam-comic.blogspot.com/ archives: 5/2017 thru present https://redfish.com/pipermail/friam_redfish.com/ 1/2003 thru 6/2021 http://friam.383.s1.nabble.com/
