self-replicating machines could satisfy the world’s energy needs, and, more or less at the same time, clean up the mess humans had created by burning fossil fuels. They called the machines “auxons,” from the Greek αυξάνω, meaning “grow.” The auxons would be powered by solar panels and, as they multiplied, they’d produce more solar panels, which they’d assemble using elements, like silicon and aluminum, extracted from ordinary dirt. The expanding collection of panels would produce ever more power, at a rate that would increase exponentially.
