Uncomputables

In his 1969 book Calculating Space, the German engineer Konrad Zuse, a pioneer of modern programming languages, was the first to suggest that the universe is a giant information processor or calculator, and that the entire cosmos could be described as the computational output of a “cellular automaton.” Bacteria, fungi, whales, forests, crystals, rocks, seas, planets, stars, galaxies, cities, nations—today we know of no life form, nor any inert thing, that does not emit, receive, store, and process information. Everything computes.

In the twenty-first century, mass computation has become a new form of power. From cultural taste to global happiness, from climate change to high-frequency trading, everything is calculated using algorithms. At a time when global corporations use behavioral forecasting to capitalize on their ability to predict, and valorize, our future decisions, feelings, movements, habits, and interests, one wonders if anything remains uncomputable.

One phenomenon that does seem resistant to computation and prediction is that of emergence. The complex systems within which emergence occurs—from termite colonies to social movements and cities, from the human brain to the Internet—manifest nonlinear, unpredictable behaviors that nevertheless produce novel and coherent structures and patterns. These emergent structures, arising from the self-organizing processes of collective intelligence, are more than the sum of their components’ behaviors. Recent discoveries in complexity science have drawn attention to the fact that the same principles and patterns underlie the processes of emergence and collective intelligence observed in both nature and culture. Modeling these phenomena through computer simulations has opened new fields of science, which range from growing artificial societies and artificial life to exploring new models of political conflict resolution to evolving so-called artificial artificial intelligence.

One of the most mysterious creatures displaying signs of intelligence is the slime mold Physarum polycephalum, an organism found on most forest floors. Despite the apparent lack of a nervous system, Physarum has shown in experiments that it can navigate obstacles in its search for food, even to the extent of passing through a labyrinth. Somewhere between an individual and a swarm, Physarum spends part of its life in the form of diffuse individual cells, each of which travels on its own. But under certain conditions, these single-celled amoebae fuse into a giant cell with multiple nuclei called a plasmodium and begin to move as a single body, sending out tubes that continue to branch out to search for food. Once a source of nutrition has been located, the unsuccessful branches it has sent out shrink, leaving only the most efficient route between it and the food source. This process allows the slime mold to survive even in adverse environments by adapting to fluctuating conditions. The intelligence of the slime mold is defined by its ability to change its morphology by removing the unproductive pathways so as to optimize the transfer of nutrients from food sources while maintaining its status as an aggregated organism.