nanotechnology

What is Grey Goo? Not necessarily grey, and not necessarily gooey, “grey goo” is both a nanotechnological substance which increases exponentially without practical limit, and a hypothetical scenario in which the mass of planet Earth – or the universe – is ecotophaged into self-replicating nanobots. Mathematician John von Neumann originally described macroscopic self-replicating robots. These replicators are sometimes called “von Neumann machines.” In turn, nanotechnology pioneer Eric Drexler coined the term “grey goo” in his book Engines of Creation. Drexler described the exponential growth and inherent limits of such highly specialized nanomachines: “…the first replicator assembles a copy in one thousand seconds, the two replicators then build two more in the next thousand seconds, the four build another four . . in less than two days, they would outweigh the Earth; in another four hours, they would exceed the mass [...]