Analogy is turning left in a car. You slightly turn the wheel and car starts turning. Unless you turn the wheel back to the right you'll continue turning. Thus even if there were a curvature to compensate for it would only require one minute adjustment but a constant recalibration. So it really comes back to examining the distance traveled and whether it indicates spherical geometry imo
You can feel the car turning though. Every regular plane trip goes through this process: taxi (level to ground), takeoff (at incline), level (except for turbulence, which you definitely feel), descent (at decline), landing (level). If your theory were true, then the higher altitude you fly at, the longer the trip would be.
Analogy is turning left in a car. You slightly turn the wheel and car starts turning. Unless you turn the wheel back to the right you'll continue turning. Thus even if there were a curvature to compensate for it would only require one minute adjustment but a constant recalibration. So it really comes back to examining the distance traveled and whether it indicates spherical geometry imo
You can feel the car turning though. Every regular plane trip goes through this process: taxi (level to ground), takeoff (at incline), level (except for turbulence, which you definitely feel), descent (at decline), landing (level). If your theory were true, then the higher altitude you fly at, the longer the trip would be.