Petroleum makes the world go around. In the realm of global economics and politics, that statement is hard to dispute. Petroleum is uniquely versatile. When wisely handled, it is safe and clean compared to most alternatives. It is still abundant, and it can be stored for years at a time simply by leaving it in the ground. Under ambient conditions, it is a liquid and relatively noncompressible, so it can be carried across oceans in large tankers or pumped through pipelines hundreds of miles long. Its distilled products have high energy densities. Fifteen gallons of gasoline can move a 3300-pound automobile across 350 flat miles at 65 miles per hour. (In metric units, those values are 57 L, 1480 kg, 565 km, and 105 kph.) We transform petroleum into thousands of useful substances: fuels, lubricants, and chemicals with exceedingly different properties—from baby oil to pesticides, from adhesives to laxatives, from artificial sweeteners to sulfuric acid.