Physics

Renormalization is a principled coarse-graining of space-time. It shows us how the small-scale details of a system may become irrelevant when looking at larger scales and lower energies. Coarse-graining is also crucial, however, for biological and cultural systems that lack a natural spatial arrangement. I introduce the notion of coarse-graining and equivalence classes, and give a brief history of attempts to tame the problem of simplifying and "averaging" things as various as algorithms and languages. I then present state-space compression, a new framework for understanding the general problem. At the end, I present recent empirical results, in an animal social system, that show evidence for the coupling of scales: the reaction of coarse-grained facts about a system "downwards" to influence the microphysics. 

Interstellar Voyaging

The discovery of countless exoplanets and new ideas in propulsion physics have resurrected international interest in the ancient concept of humanity traveling far beyond Earth. Such voyages will take place over many generations, requiring careful attention to both biological and cultural change over time. In this talk I will outline the foundations of a biocultural science of long-term space settlement.