Chaos theory throws it right out the window. It says that you can never predict certain phenomena at all. You can never predict the weather more than a few days away. All the money that has been spent on long-range forecasting--about half a billion dollars in the last few decades--is money wasted. It's a fool's errand. It's as pointless as trying to turn lead into gold. We look back at the alchemists and laugh at what they were trying to do, but future generations will laugh at us the same way. We've tried the impossible--and spent a lot of money doing it. Because in fact there are great categories of phenomena that are inherently unpredictable.