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Longest Straight Line Paths on Water or Land on the Earth (2018)
- ventana 18d agoThe paper is basically like this (spoiler alert): “Some random user on Reddit posted a picture claiming that this is the longest straight line path on water possible on the Earth. We implemented a smart algorithm to solve this problem, found the elevation data, ran our algorithm... yes, that random user was right. Also, here's the longest path on land.” Thanks, I really enjoyed reading it, even though I hoped that they would disprove the original claim! Edit: here are the gcmap links to the two paths: sea [1], land [2]. [1]: http://www.gcmap.com/mapui?P=25%B017%27N+66%B040%27E-58%B037%27N+162%B014%27E%0D%0A&MS=wls&PC=red&PT=l&RC=navy&DU=nm http://www.gcmap.com/mapui?P=25%B017%27N+66%B040%27E-58%B037... [2]: http://www.gcmap.com/mapui?P=24%B033%27N+118%B038%27E-37%B02%27N+8%B055%27W&MS=wls&PC=red&RC=navy&DU=nm http://www.gcmap.com/mapui?P=24%B033%27N+118%B038%27E-37%B02...
- comrade1234 17d agoI opened Apple Maps in globe mode and I still have trouble visualizing the water path.
- pdpi 17d agoDoes it help to point out that the water path looks suspiciously like the day/night line on a map? Like this: https://svs.gsfc.nasa.gov/5477/ https://svs.gsfc.nasa.gov/5477/
- newtwentysix 17d agoyes!! why is that ? :)
- yorwba 17d agoThe day/light line is a great circle. The "straight line paths" are great-circle segments.
- srean 17d agoIt's going South and then trying to close the loop from behind. It gets interrupted by land before the loop closes. Hope it makes sense.
- turbocon 17d agoOpen the linked paper and scroll down, they have images of the path on a globe as well as the flat map view.
- cubefox 17d agoThey only identify the Reddit user as "kepleronlyknows", but in the Reddit thread [1] he links to his video visualization [2], where his user name is Patrick Anderson. Before he made the video visualization using Google Earth, he actually went to the library and used a string on a real globe. [3] 1: https://www.reddit.com/r/MapPorn/comments/15mwai/the_longest_straight_line_you_can_sail_almost/ https://www.reddit.com/r/MapPorn/comments/15mwai/the_longest... 2: http://www.youtube.com/watch?v=VpQwuGueeoA http://www.youtube.com/watch?v=VpQwuGueeoA 3: https://imgur.com/a/great-circle-2hYFM https://imgur.com/a/great-circle-2hYFM
- alok-g 17d agoAdding: The two paths respectively are about 80% and 28% of the earth's circumference.
- kromokromo 17d agoKudos to whoever built tiled clouds background on the gcmap site.
- paganel 17d agoThe Portugal to (approximately) Macao one is quite interesting, thanks for the links!
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- shrx 17d ago> Figure 9: Longest Drivable Straight Line Path on Earth. Walkable, maybe, but definitely not drivable (it crosses directly over the Alps, for example).
- pbhjpbhj 17d agoThere might be icebergs or sandbars or rocks or volcanic activity or wars blocking the sailing route too. They seem like equivalents. The longest mettled straight route with minimal deviation would also be an interesting exercise.
- kakacik 17d agoExtremely highly inprobable vs 100% there and directly impassable unless walking & doing some proper alpinism is hardly equivalent
- mikeaskew4 17d agoPresume for a moment that you don’t drive on tyres…
- chabska 17d agoThis is mathematics, the Alps is drivable like a manifold is smooth.
- dr_dshiv 17d agoIf it is undrivable in a straight line, why does that count? I’d assume the longest you could drive in a perfectly straight line would either be the longest straight highway or some drivable desert.
- loloquwowndueo 17d ago“Drive”. Use your feet, car centric person.
- mrgriscom 17d agoI made a "first person" perspective rendering of this: https://mrgris.com/img/landfall/longest.png https://mrgris.com/img/landfall/longest.png
- paufernandez 17d agoNerd sniping at its best... ;)
- OscarCunningham 17d agoThere's a longer land path that starts in or near Senegal and ends in China. But they miss it because it goes near the Dead Sea, and they treat anything below sea level as water.
- cubefox 17d agoThat would an interesting finding!
- Anduia 17d agoIf you are talking about the trail from Cape Town to Vladivostok, that one is not a straight line.
- evanb 17d agoThey aren't, as clicking through on a sibling's link demonstrates. Moreover, Senegal is nowhere near Cape Town.
- ahazred8ta 17d agoIn passing, https://en.wikipedia.org/wiki/Paul_Salopek https://en.wikipedia.org/wiki/Paul_Salopek is walking from Ethiopia to Tierra del Fuego, tracing the path of human migration out of Africa. Walking the coast, not a straight line.
- maratc 17d agoIndeed, this route would be about 13,250 km, or about 2,000 km longer than the one TLA suggests. http://www.gcmap.com/mapui?P=10%B0+24%27+41.4%22+N,+14%B0+31%27+59.3%22+W-21%B0+53%27+27.4%22+N,+112%B0+44%27+43.6%22+E&PC=%23ff0000&RC=%23000080&DU=nm http://www.gcmap.com/mapui?P=10%B0+24%27+41.4%22+N,+14%B0+31... Or, using nearby airports: https://www.greatcirclemap.com/?routes=gucy-vmmc https://www.greatcirclemap.com/?routes=gucy-vmmc
- ahazred8ta 16d agoAlmost 7200 nautical miles from Macau, China to Conakry, Senegal, west africa, through Suez. 8253 miles.
- metalman 17d agoit would be interesting if it was a list of actual journeys with the sub lists of deviations required. a special club for the brutaly determined and persistant the "strait liners" things like having to beg, bluff, bribe, your way through someones house
- shrx 17d agoWikipedia has an article listing some of the notable (walking) straight line missions: https://en.wikipedia.org/wiki/Straight_line_mission https://en.wikipedia.org/wiki/Straight_line_mission edit: and the article already notes this longest possible path from Portugal to China, citing a 2023 article: https://bigthink.com/strange-maps/these-are-the-worlds-longest-straight-lines/ https://bigthink.com/strange-maps/these-are-the-worlds-longe...
- fhars 17d agoNote that the 2023 article also cites the submission, which is five years older.
- 1313ed01 17d agoBut what would flat-earthers consider the longest possible paths to be? Not the ones shown in the article, presumably?
- madcaptenor 17d agoOver water, probably something like the entire 60th parallel south. Over land, I think you want to start near the westernmost point of the African continent and thread the needle of the Isthmus of Suez, and stay south of the Caspian Sea. At least in the projection gcmap.com uses (plate carree - essentially the x-coordinate and y-coordinate are just raw longitude and latitude), this keeps you south of Lake Baikal and allows you to get very far east in far eastern Russia. Something like 17.5 N, 16 W to 69 N, 178.5 E seems to work: http://www.gcmap.com/mapui?P=17.5n16w-21.79n0.21e-26.08n16.42e-30.38n32.63e-34.67n48.83e-38.96n65.04e-43.25n81.25e-47.54n97.46e-51.83n113.67e-56.13n129.88e-60.42n146.08e-64.71n162.29e-69n178.5e&MP=rect&DU=mi http://www.gcmap.com/mapui?P=17.5n16w-21.79n0.21e-26.08n16.4... Of course this depends on the projection you use! This is different from the Portugal-to-China path that is the longest over land in reality, which a flat-earther would have crossing the Mediterranean.
- Anduia 17d agoFlat earthers don't use Mercator projection, they use polar azimuthal equidistant (AEQD) projection centered in the north pole. I think it would be something like Portugal-Kamchatka: https://i.ibb.co/9mqz8fvb/image.png https://i.ibb.co/9mqz8fvb/image.png
- madcaptenor 17d agoI didn't know that. Makes more sense than a rectangular projection at least.
- 1718627440 17d ago> Of course this depends on the projection you use! But if you do not believe in a globe how do you understand projections?
- semessier 17d ago[dead]
- kimberlysatterf 17d ago[flagged]
- Eridanus2 17d agoHi, ig?
- rotringlvr 17d agoBefore I opened the solution, I knew it had to pass through the beagle straight. It is the only choke point separating the largest oceans, about both their empties areas, the far south. I guess my biggest surprise is that there is a straight line through the Beagle straight.
- gus_massa 17d agoBeagle Channel is very narrow and has islands both on the north and the south. This path goes thought the Drake Passage that is south of the islands that are south of the Beagle Channel. The Drake Passage is very wide.
- rotringlvr 17d agoRight, the Drake.
- joebig 17d agoI myself walked the longest path to 1200 karma. It was painful. Blisters of delta_karma=f*vote_points, where f could be 0.5 or 0.3 or unknown lower no. I'm tired, boss.
- trencedamp 17d agoIf it's the longest straight path on water OR land then surely it's just the circumference of the earth
- mdritch 17d agoIt reminds me of a bit I did a few years ago trying to find the "longest straightest" line in Atlanta [PDF]: https://matthewritch.com/pages/LongestStraightestLine.pdf https://matthewritch.com/pages/LongestStraightestLine.pdf
- gcanyon 17d agoI know the globe is unintuitive (it still blows my mind that Muslims in New York City face roughly northeast to point toward Mecca) but it still seems bizarre that the water route can start near the arctic circle, cross the Pacific ocean, nearly touch Antarctica, cross the Atlantic ocean, and cross the Indian ocean to end well north of the equator and still travel only 80% of the way around the globe. This view of the rest of that great circle helped me visualize it: http://www.gcmap.com/mapui?P=58%B037%27N+162%B014%27E-25%B017%27N+66%B040%27E%0D%0A&MS=wls&PC=red&RC=navy&DU=nm http://www.gcmap.com/mapui?P=58%B037%27N+162%B014%27E-25%B01...
- globular-toast 17d ago> it still blows my mind that Muslims in New York City face roughly northeast to point toward Mecca It never occurred to me they would face the shortest distance to Mecca. I've looked it up and apparently it's a point of contention in North America, although the great circle seems to be standard. Interestingly there are landmasses around the antipode of Mecca, which means your direction would vary wildly as you travel around.
- pavel_lishin 17d agoI like the idea of there being a place on land where a Muslim can look anywhere, and be looking toward Mecca. But apparently, it's the middle of the ocean, although there does appear to be an atoll very close by: https://en.wikipedia.org/wiki/Tematagi https://en.wikipedia.org/wiki/Tematagi
- SamBam 17d agoIf you're in New York and you look due East across the Atlantic, what country are you looking at? Most people would assume Portugal. Nope, you're looking (over the curve of the earth, of course), at Morocco. Look just a tiny bit to the south and you're looking at the rest of West Africa. Look Southwest and you're looking at Australia, or even Brazil.
- hnx0rqy49u 17d agoLearned this the expensive way
- divbzero 17d agoThis geographic puzzle feels like the modern day version of the Seven Bridges of Königsberg: https://en.wikipedia.org/wiki/Seven_Bridges_of_Königsberg https://en.wikipedia.org/wiki/Seven_Bridges_of_Königsberg
- WorseIsBetter 17d ago[dead]
- cookie0 17d agoA new challenge for GeoWizard [1]? :D [1]: https://www.youtube.com/geowizard https://www.youtube.com/geowizard