The twelve-year-old just asked a series of three questions, the last of which was one of the Ultimate Questions: What is this ln - e^x button on my calculator? What is e=2.718281828... good for? If e is defined as the number for which the curve y=e^x has everywhere a slope equal to its y-axis value, why is e=2.718281828... ? Needless to say, I could not answer the third question. Fathers really don't know very much, do they?...

I'm tired of maps of world population that lazily represent a country's population as evenly distributed throughout its territory. Who in India lives in the Thar Desert? How many people in Egypt live outside the Nile Valley? The map below is an attempt to show the real human population distribution in 2000