Elon Musk says money may disappear entirely, and energy becomes the only currency left. His logic: money exists as a database for allocating human labor. If AI and robots grow big enough to meet every human need, that database loses its purpose. Energy can't be legislated into existence, which is why he ties Bitcoin to it. He measures civilization on the Kardashev scale: how much of a planet's, then a sun's, then a galaxy's energy gets turned into useful work. The turning point comes when AI and robots mine, build chips, and make solar panels on their own. Once that cycle closes, the economy decouples from money. Wealth only means something while humans are around to want it.