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Time Between Antipodal Positions on the Earth’s Surface

-- Dubravko | November 27, 2024

Question:

My name is Filipas Dubravko, and I am Master Mariner and in command of ocean going ships for many, many years now. Recently being bored and curios I have engaged some funny flat earth people for personal amusement… But today I have encountered a question I probably should know the answer to, but I do not. And it goes like this ” Why the ”daylight time” on antipodal position in earth does not give exactly 24 hours?” FOE 45 deg N / 15 deg E daylight time +
45 deg S / 15 deg E = 24h 22 min ? I was expecting the result to be 24 hours… Thank You in advance!

-- Dubravko

Answer:

I believe that the definition of antipodal positions is that for a (latitude,longitude) position on the Earth’s surface its antipodal position is (-latitude,longitude+-180). Using usual geographic coordinates, the transformation between antipodal positions is given by

(x deg N/S, y deg E/W) <=> (x deg S/N, 180-y deg W/E)

For your example, I believe that (45 deg N, 15 deg E) <=> (45 deg S, 165 deg W). I believe that the time between these two positions is 24 hours.

-- Jeff Mangum

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