Calculating the distance to the horizon


Adri, trying to pose very focused

Last weekend my friend Adri came by to Fuengirola, a nice area of Málaga by the sea where I am currently living. It was Sunday morning and we were chatting on the terrace after breakfast when we noticed a big ship that seemed to be suspended on the horizon. I said “I wonder how far away that ship is. It doens’t look very hard to calculate….” That was the trigger! Adri and I studied Mathematics together at Málaga University and since then we haven’t had the chance to discuss anything related to mathematics whilst having a piece of paper in front of us. This looked like a good opportunity to reconcile that.


First the obvious: Due to the curvature of the Earth Continue reading