Ancient Mystic Magical Mathematical Mumbo Jumbo

The usual deal: Click for larger and clearer.

Oboy oboy have I found some weird old crap from the remains of an ancient dead hard disk!

Check out this Magic Trick:

Forget Honolulu and San Francisco; they're just examples. This stuph works for any two points on the surface of the Earth. (In theory ... there is a Special Condition that will make the formula explode and blow up my computer and my office. But that hardly ever happens.)

First two Comments that give me your Latitude and Longitude, I will use this Incomprehensible Mystic Mumbo Jumbo to compute the Great Circle distance between them.