In this episode, Xavier Bonilla has a dialogue with Geoffrey West about scale and sustainability. They begin by discussing scale and how it is typically defined. They give an overview of the major relevant scaling laws including the logarithmic scale. They discuss the importance of metabolic rate and the magic number four. They talk about growth and scale and how these concepts are applied with aging along with the role of temperature on metabolism. They discuss fractals and how they work with scale in cities. They talk about the social connectedness of cities, rural areas, and a grand unified theory of sustainability. 
Geoffrey West is the Shannan Distinguished Professor and past President at the Santa Fe Institute. He is a theoretical physicist and has done extensive research in elementary particles and general scaling phenomena. He is Fellow of the American Physical Society and was one of their Centenary Speakers in 2003. He has won the Mercer Award from the Ecological Society of America, the Weldon Memorial Prize (2005), and the APS Szilard Award (2013). He was named Time magazine's "100 Most Influential People in the World" in 2006 and is the author of several books. His most recent book, Scale: The Universal Laws of Growth, Innovation, Sustainability, and the Pace of Life IN Organisms, Cities, Economies, and Companies, can be found here. You can also find his work at his website.