NOTE: I first posted this question to the GIS StackOverflow site, but someone there said my question would be better suited to the Geography or Earth Science site. GIS seems the perfect place for the question to me, but in case that is correct I'm posting it here.
I had asked a question (which has been answered) here about finding locations halfway around the world from a given location, in the example provided from Monterey, California.
The east/west location (same latitude) is Birjand, Iran. This makes sense to me.
But the north/south location is at a location north of the south pole which, even though it is a calculation I came up with and was verified there as being correct, doesn't make sense to me.
The reason why my brain is having a meltdown is because it seems plain to me that the north pole to the south pole would be halfway around the world, whereas Monterey is well south of the north pole, and the location "agreed upon" as the halfway around the world point from there (from a north/south, same longitude standpoint) is in the South Pacific between New Zealand and the southern tip of South America, which is north of the South pole.
It seems to me that the halfway point should be as far "down" from the south pole as Monterey is from the north pole.
Am I wrong? If so, what is faulty with my logic?
If I'm right, what is the halfway point, then, from Monterey?
I am obviously not a geographer/cartographer, but this is getting to confusinate/fascifuse me more all the time. Based on Earthworm's answer, the exit point after "drilling through the earth" from Monterey is in the Pacific Ocean as shown with pushpin #2 here (same longitude as Monterey, with the reverse latitude):
However (there's almost always a "however"), based on Andy M's answer and the link he provided, these are the two points (#2 having both a different latitude AND a different longitude than Monterey, but the same longitude as Birjand, Iran):
The first antipodal point (Pacific Ocean) seems slightly more logical to me than the second one (Indian Ocean), but both differ from what my ungeometric brain was expecting before I delved into this, which was a point "south" (actually "negative north," I guess*) of the South Pole, "beyond" Antarctica (if ya know whaddi mean).
- As it is impossible to go "south" of the South Pole.
I posted a substack article tangentially/partially about this here.