This picture was taken near Meguro Station in downtown Tokyo at 7PM on June 9, 2011. Ordinarily, the street light in the foreground would have been on, as would have lights in almost all of the signs and windows in the buildings in the distance. For younger students, you might have them try to find all of the signs that have their lights out. Turning lights out, including many street lights, is part of an effort to utilize less energy due to the loss of much nuclear power following the earthquake and tsunami of March 11, 2011.