How is Jacksonville larger than Atlanta?
The largest city in each 10x10 degree latitude/longitude box
121–130 of 164 posts
Re: The largest city in each 10x10 degree latitude/longitude box
#122I think something more interesting might be like a voronoi diagram of all cities such that the city is in like the top 5 within a 1000 miles radius or something (or just that but without the voronoi part). This should preserve the fact that only the largest cities in some area are present, but eliminate the arbitrariness of the boundaries. I think you would want to compute this with a sweep line algorithm.
This isn't exactly what you asked for, but it seems pretty relevant to your stated interests: https://www.jasondavies.com/maps/voronoi/capitals/
My head nearly exploded trying to position the globe in the rotation I wanted :-) Neat though, thanks for sharing!
Re: The largest city in each 10x10 degree latitude/longitude box
#123The largest city in Canada as I remember is Edmonton the Capital of Alberta this is based on per Sq.M. just find that interesting trivia.
Interestingly the most populous cities in Canada--Toronto, Vancouver, and Montreal, are not there.
Re: The largest city in each 10x10 degree latitude/longitude box
#124Earlier quoted context omitted.
> their adjacent sides certainly aren't at right angles They certainly are. Parallels and meridians always meet at 90 degrees. https://www.geogebra.org/m/kNtNZzsS
Right angles with regard to the latitude-longitude coordinate system, but not with regard to the surface of the earth. Recall that all meridians intersect at the poles.
@tantalor is technically correct; meridians and parallels intersect at right angles, even with respect to the (idealized) surface of the earth. Proof sketch: if the angles involved in a crossing were not all 90°, then either the crossing would not be symmetric about the meridian (it is), or one or both lines must have a sharp "kink" (i.e., have a non-smooth first derivative) at the intersection (neither does).
However, parallels, while smooth, are not straight, they "curl" toward the nearest pole (i.e., non-zero second derivative, relative to the earth's surface). This accounts for the non-"rectangular" shape of quadrangles and can be replicated on a 2D plane.
Re: The largest city in each 10x10 degree latitude/longitude box
#125Earlier quoted context omitted.
Meanwhile, neither Sweden’s nor Norway’s capital is in the map. But two smaller Norwegian cities are. I think this just teaches you the issue with discretization.
There are in fact five small Norwegian towns on this map. Vadsø, Hammerfest, Trondheim, Bergen and Longyearbyen.
Denmark has a funnier case. There are 6 cities/town within the Kingdom of Denmark with 0 of them in Denmark. (5 in Greenland and 1 in The Faeroe Islands; Iceland belonging to the Kingdom until 1944 has 2)
Re: The largest city in each 10x10 degree latitude/longitude box
#126Earlier quoted context omitted.
> their adjacent sides certainly aren't at right angles They certainly are. Parallels and meridians always meet at 90 degrees. https://www.geogebra.org/m/kNtNZzsS
Right angles with regard to the latitude-longitude coordinate system, but not with regard to the surface of the earth. Recall that all meridians intersect at the poles.
Yes with regard to the surface of the earth.
Take the lines tangent to the meridian & parallel at the point of intersection. Observe these lines are perpendicular. Hence the meridian & parallel meet at a right angle.
Re: The largest city in each 10x10 degree latitude/longitude box
#127I quibble with the description of the shapes bounded by 10 degrees of longitude and latitude as "rectangles" - they're not even planar shapes, and their adjacent sides certainly aren't at right angles. Some of them don't even have four sides. This bears considering when looking at the map, because some of those regions are much, much smaller than others.
Maybe the author should have gone with the faces of a Disdyakis triacontahedron
For anyone else not familiar with the exact shape:
Re: The largest city in each 10x10 degree latitude/longitude box
#128How is Jacksonville larger than Atlanta?
pop(Jacksonville) > pop(Atlanta)
903,889 > 498,044
Re: The largest city in each 10x10 degree latitude/longitude box
#129Earlier quoted context omitted.
You can even request a query from the community: https://wikidata.org/wiki/Wikidata:Request_a_query
That's handy! To be honest, SPARQL is definitely not easy to use.
I have worked with SPARQL professionally. The biggest problem: Quality if the data. Yes it is amazing, but if stuff is missing annotations, it is hard to get meaningful results.
Re: The largest city in each 10x10 degree latitude/longitude box
#130I quibble with the description of the shapes bounded by 10 degrees of longitude and latitude as "rectangles" - they're not even planar shapes, and their adjacent sides certainly aren't at right angles. Some of them don't even have four sides. This bears considering when looking at the map, because some of those regions are much, much smaller than others.
> their adjacent sides certainly aren't at right angles They certainly are. Parallels and meridians always meet at 90 degrees. https://www.geogebra.org/m/kNtNZzsS
I'm not 100% sure about that. Are angles between circles on a sphere defined by the angles between their tangent lines? If it were true, you could for each point/meridian combination construct an infinite amount of different circles that would all meet at right angles with that meridian (just vary the circle's radius). That doesn't feel quite right.
According to Wikipedia [1], "in spherical geometry, angles are defined between great circles". Meridians are great circles, but parallels are not. Possibly the angle is simply not defined for circles that are not great circles?