> I'm not a chem engineer, but a friend that /is/ tells me fossil fuels > require four times the yield of energy to recover it from the earth > and process it. then ask him where the hell that energy comes from. I'm not saying that all fossil fuel recovery that happens is positive in terms of usefull energy output to usefull energy input but on average they must be otherwise fossil fuels could not be the dominant contributor to our supply of usefull energy. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist