“Our world is rich,” Lisa Randall has written, “so rich that two of the most important questions particle physicists ask are: Why this richness? How is all the matter that I see related?” As one of the most influential theoretical physicists working today, she's increasingly interested in the interconnectedness between fields that have previously operated more autonomously: astronomy, biology, and paleontology. She’s pursuing a theory that “dark matter” might have created the cosmic event that led to the extinction of the dinosaurs — and hence humanity’s rise as a species. We explore what she’s discovering, as well as the human questions and takeaways her work throws into relief.