[Phys-L] straight path through curved space

[John Denker <jsd@av8n.com>]

Hi--

I wrote up a discussion of what it means to follow a straight path in a
curved space. This requires a clear understanding of what we mean by
"straight". Given that, it is easy to demonstrate that the shortest
path between two points is necessarily straight. We also discuss how
to not get fooled by map projections. Sometimes a straight line on a
map does not correspond to a straight line on the ground, and vice
versa.

This is somewhat simpler than some other stuff I have written, using
the most prosaic example of a curved space, namely the surface of the
earth.

Tissot Indicatrix.
Geodesic versus rhumb line.

https://av8n.com/physics/short-straight-path-curved-space.htm