How can you work out height loss relative to your starting position?
This is an obscure question so it's only out of curiousity I ask:
How can you work out how much distance you travel towards a position directly below you as you move around a circle?
So for example, if you move from A to B and B is one quarter of the way around the earth, for example, you travel 5400 nm great circle and you move vertically downwards by 3437.74 nm (or one radius of the earth). In other words you could travel directly down to the center of the earth at point A and then travel forward towards B and you'd end up at B (vertical) having travelled 3437.74 nm "down".
Does the question make any sense?
Thanks for any replies,
Screwballs (who needs to get out more)