I always show this picture of Earth to my students at the beginning of the year. Modernity requires electricity. Electricity requires power. Unbelievable how unequal the distribution of power is on this globe. I guess we know the reason we can't see the stars at night. Too much light pollution. Do the world a favor every once in awhile and turn off the light. Click on the picture to get a larger view. This picture really says a thousand words.