Russ Altendorff came on a course in the hills yesterday. He is a keen sailor, electronics guru and author of a popular blog on the more technological side of marine navigation. During our afternoon we locked horns with topics that ranged from the desert to the ocean and back to a southern England that was experiencing hail, horizontal rain and even the odd sunbeam. We also discussed ‘confirmation bias‘, or the tendency to make your observations fit your preferred hypothesis. Natural navigation is particularly susceptible to this, nature is rarely absolute and is so often open to interpretation. On a cold wet day it is even more likely that you are going to want the evidence to fit your theories.
At the end of the afternoon the sun was down, the moon and Jupiter were high in the southern sky, and it was time for Russ to take on a challenge.…