# Spherical coordinates

SammyS
Staff Emeritus
Science Advisor
Homework Helper
Gold Member
Is the Wikipedia article posted earlier by @Mark44 wrong about ##\rho## being negative in some cases?
It's not always positive, it could be zero.

pbuk
Science Advisor
Gold Member
The point is you can use any system for spherical coordinates as long as it is well defined. For instance every time you get in an aircraft you rely on a system which uses ±90° latitude, ±180° longitude and height above (or below, in which case you are in trouble) an approximately equipotential geoid.