Getting a bird's eye view of the globe. Photo: Marcelo da Mota Silva. The commonplace view of the earth from an airplane at 35,000 feet -- a vista that would have astounded Dickens or Darwin -- can be instructive when we contemplate the fate of our earth. We see faintly, or imagine we can, the spherical curve of the horizon and, by extrapolation, sense how far we would have to travel to circumnavigate, and how tiny we are in relation to this home suspended in sterile space. When we cross the Canadian northern territories en route to the American West …