Explore the fascinating connections between physics, biology, and information theory in this thought-provoking lecture from the Santa Fe Institute. Delve into the nature of variational principles and their applications across diverse fields, from quantum mechanics to living systems. Discover how efficiency and specialization shape the architecture of biological structures, with a focus on the retina and the brain's sense of place. Examine the binary number system and its relevance to grid cells, uncovering optimal ratios in nature. Investigate the principles governing visual space and prairie ecosystems, and consider how natural selection influences these complex systems. Gain insights into the fundamental principles of complexity that underlie life, scale, and civilization.