This will undoubtedly deform the area of each country, and it is basically impossible to have a map with the desired length, angle and area unchanged. Gauss, the prince of mathematics, proved this long ago. More than 65,438+0,500 years ago, predecessors tried to transform the earth into a plane in various ways. Belgian geographers put forward an idea, assuming that the earth is enclosed in a hollow cylinder, and its datum line is tangent to the cylinder, plus there is a lamp in the center of the earth, which projects the figure on the spherical surface onto the cylinder, then unfolds the cylinder and draws it by a selected extremely accurate line.
Under the dark equiangular condition of Mercator projection, the crosshair is projected on the cylindrical surface, and the embedded cylindrical surface is expanded into a plane to get the plane tail. After the projection, it is found that a set of horizontal latitude and longitude lines with equidistant values is a set of parallel lines perpendicular to the golden string. The length ratio of any point on Mercator projection in any direction is equal, and there is no angle distortion, which means that this map navigation can provide accurate angles between two points on the map. Equiangular routes are characterized by straight lines, which makes them widely used in compiling nautical charts and aviation charts, which is also the reason why Google Maps adopts this projection method.
Mercator projection map, first of all, ensures that the shape of each country remains unchanged, but the area deformation is very obvious, and it increases with the increase of the standard distance from latitude. If circles with the same area are evenly distributed on the earth, these delayed areas will change on the Mercator map, but the shape of the circle will not change, but the closer to the pole, the larger the area. An example can reflect this phenomenon. In fact, Greenland is much smaller than Africa, but in fact,