Take a look at this picture. It's a composite of lots of nighttime satellite images of the earth from space, so you get a complete picture of the lights of all the cities of the earth. This is cool in itself, but I think the most dramatic thing on it is the difference between South Korea (which is bright) and North Korea (which can hardly be seen). Also, look at the Nile snaking into Africa, and the area around Johannesburg (virtually the only part of sun-Saharan Africa which looks anything like the developed world). Note also the brilliantly bright section around both sides of the Pearl River Estuary in Southern China. (With the version of Internet Explorer I am using, you have to click on a couple of things to get the high magnification version).