Amid growing concern about high gasoline prices, global warming, and limited resources of petroleum, scientists and engineers around the world are on a quest for new fuels — alternatives to conventional petroleum, natural gas, and coal. On their radar screens are new sources of familiar old ethanol that do not strain the food supply and futuristic fuels like “green gasoline” and “designer” hydrocarbons. Intro theme and music by Kevin MacLeod (incompetech.com), Darkroom and M12 (ccmixter.org); Creative Commons licensed audio from freesound.iua.upf.edu includes sounds by LG, Halleck, Han1, Heigh hoo, Gorgee de biere, dkelly99, kjackson and reinsamba.