Navigation is the art of finding one's way from one location to another. This appears pretty simple in the age of interstate highways and well-marked street intersections: follow the road signs or a map and the task should be easy. But imagine you are in an aircraft or a ship and all you can see is the blue sky above you and the clouds below you or nothing but waves. Now, imagine it is night and you can not see a thing! In our computer-centered society, we have the digital means to use satellite technology and other electronic tools to help us figure out where we are and how to get where we want to go. Long before these were available, however, mathematical navigational systems were devised to guide ship captains and travelers of centuries past; these time-tested tools provide the foundation upon which...