What different world maps get right - and what they get wrong

"He wanted a straight line to be drawn on a map to look like a straight line in reality if you followed a compass bearing," he told the BBC. "That was what it was intended to do, and that's what it does brilliantly well."To keep those angles correct on a flat map, Mercator had to stretch the grid lines wider as they moved away from the equator toward the poles.His map accommodates for the curvature of the Earth by making countries near the equator seem much smaller than they are, with countries nearer the poles appearing stretched.The distortion is a result of it being impossible to accurately represent the surface of a globe on a two-dimensional chart.More than 450 years on, Mercator's creation is still the basis for many of the maps we see in classrooms, on TV and online, including Google Maps.But critics of the Mercator map say there is a psychological effect to viewing some places as smaller than they actually are and others as larger, as we instinctively view bigger things as more important.For Kenyan geographer Kioko Muendo, this has implicitly downplayed Africa's vast resources, population and investment opportunities."Maps are more than just guides for travellers - they shape how regions are perceived politically and economically," he told the BBC.