eric8476 wrote:ah, but what are the compensatory adjustments that an airplane pilot does?
It's pretty simple: If you follow a great-circle course, you end up back where you started. Review your geometry and describe for me how that's possible on a flat (not curved) 2D surface. The compensatory adjustments a pilot makes to do that anywhere but on the equator involve changes of heading. It's trivial to work out that a great circle that starts out headed northwest must eventually head southwest. And so on. The surface curvature model that explains this is the (approximately) spherical one. In real life, the earth's magnetic poles do not coincide with the geographic ones, and you need maps to tell you the meaning of compass-north. A lot of this shit has been known for a few centuries and is on the books, as we say. Catch up, please.
eric8476 wrote:i tried googling this once and i didnt get into it in detail but when an airplane flies around the earth does it adjust its altitude to compensate for the circumference of the earth or not?
So, you didn't get into it in detail. Like spoon-feeding much? The practice of trying to work things out from first principles includes mathematics and philosophy. One of these two actually works, in real life. That's a puzzle, innit?