The most basic and universal use of human technology is to light the dark places. Yes, heat is nice, but not necessary for so many who live in tropical zones. The need for illumination made fire a turning point in human civilization. Thomas Edison invented hundreds of useful items such as the phonograph and the municipal power grid, but he's remembered first as the inventor of the light bulb. Anyone with children, or who has ever been a child, knows that a little bit of light does a great job of warding... READ ON