Bücher von Lester R. (Earth Policy Institute) Brown

The great energy transition from fossil fuels to renewable sources of energy is under way.

A lily pond, so the French riddle goes, contains a single leaf. Each day the number of leaves doubles-two leaves the second day, four the third, eight the fourth, and so on. Question: If the pond is completely full on the thirtieth day, when is it half full? Answer: On the Twenty-ninth day.