Two points on the equator

Problem statement

If you have two points both lying on the equator of the Earth, why is following the equator (in whichever direction is closer) not always a shortest path between them? (Ignore mountains and such!)

Solution to metapuzzle: show

Restated puzzle: show

Solution to puzzle: show

Comments: show

Source: Nick Krempel

This is one of several pages on puzzles and metapuzzles .