你可以在南北方向去世界各地旅行…但是你也可以旅行的东西。绕赤道一半不会看到南北变化,但仍有大半个地球…所以应该明确两个对映点可以更少的南北之间的变化比北极南极。他们甚至可以管理同一纬度。太平洋点关于你的第一个地图图像不能被正确的如果你看看地球仪。或者它可以帮助考虑挖山的一个类比的反思大致表示地球3 d \弯曲……在蒙特雷和如果你挖出来在同一经度在太平洋,它非常类似于戳进你的山向中心……,在你开始的同一侧。如果你要通过中心,您需要出来对面,看着地球仪,蒙特雷和SH太平洋点并不这样做。 Sort of like these crude diagrams: [![enter image description here][1]][1] [![enter image description here][2]][2] Likewise with digging through the Earth... there's a latitudinal component (north-south) and a longitudinal component (east-west) to all surface motion, and the ≈ 13,000 mile trip to get to the other side of the Earth will be some sort of combination of the two. The North pole to south pole trip is the extreme case where all motion is latitudinal north-south. The equator trip is the extreme case where all motion is longitudinal east-west. All other cases will require some of each, in the right proportions to aim the line between them through the center. Not unlike trying to cross from one side of a flat circular wall clock to the other. On it, you must be on the "opposite side" of the center both "up-down" and "left-right" to have passed through that center. So is the concept on the globe. [![enter image description here][3]][3] [1]: https://i.stack.imgur.com/TlXww.png [2]: https://i.stack.imgur.com/2XBZpm.png [3]: https://i.stack.imgur.com/ZW6MVm.png