Hmm.. nice question.
It all started when i studied astrophysics (one of subjects I must learn in Geoscience). A senior taught us about "How to determine the position of a star". There are 3 ways of "Tata Koordinat" and the one of them called Horizon. In this way,if we want to determine the position of a star, we need to know the pole spots. The first spot called Zenith. This spot is above our head. The second spot is Nadir which is located under our feet.
The first time I heard the name of those poles, I was interested. How unique they are. So I named my page as their name. Zenith-Nadir.
BTW, to find the number of zenith distance, there's a formula....
a is the height of star
90 is a constant number(degree) of this formula
I'm getting confuse xP
okay, that's all. The background of this page's name.
ZENITH, NADIR, AND THE HORIZON