Hi Andrew,

Regarding 'geodesic' I found some answers here:
https://www.etymonline.com/word/geodesic

So, 'geodesic' is from 'geodesy' which means "surveying".
Then 'geodesy' is built from 'ge' (pertaining to the Earth) and 'daiein' meaning "to divide".

This is just my limited summary, see https://www.etymonline.com/word/geodesy for the fuller definition.

Enjoying the series; more please!

Dave