Why do we stop growing, live for 100 years and sleep 8 hours a day?  Why do all companies (and people!) die whereas cities keep growing and the pace of life continues to accelerate.  Are cities and companies "just" large organisms? How are these questions related to innovation, wealth creation and global sustainability? Life is very likely the most complex phenomenon in the Universe manifesting an extraordinary diversity of form and function over an enormous range. Yet, many of its most fundamental and complex properties scale with size in a remarkably simple fashion: for example, metabolic rate (the 2000 food calories you need each day to stay alive) scales in a systematically predictive way from cells to whales. Similarly, time-scales, from lifespans to growth-rates, and sizes, from genome lengths to tree heights, scale systematically with size. These "universal" scaling laws, which constrain much of the organization and dynamics of life, are consequences of generic mathematical properties of networks that sustain life at all scales, such as circulatory systems of mammals, tumors and forests. Cities and companies also exhibit systematic scaling: wages, profits, patents, crime, police, disease, pollution, gas stations and roads all scale in an approximately "universal", predictive fashion suggesting that hidden quantifiable principles based on properties of social network dynamics govern their generic structure and life history independent of their individuality.

Many of the most challenging, exciting and profound questions facing science and society, from the origins of life to global sustainability, fall under the banner of "complex adaptive systems.”  This talk explores how scaling can be used to begin to develop physics-inspired quantitative, predictive, coarse-grained theories for understanding their structure, dynamics and organization based on underlying mathematisable principles. Remarkably, most physiological, organizational and life history phenomena in biology and socio-economic systems scale in a simple and "universal" fashion: metabolic rate scales approximately as the 3/4-power of mass over 27 orders of magnitude from complex molecules to the largest  organisms. Time-scales (such as lifespans and growth-rates) and sizes (such as genome lengths and RNA densities) scale with exponents which are typically simple multiples of 1/4, suggesting that fundamental constraints underlie much of the generic structure and dynamics of living systems. These scaling laws follow from dynamical and geometrical properties of space-filling, fractal-like, hierarchical branching networks, presumed optimized by natural selection. This leads to a general framework that potentially captures essential features of diverse systems including vasculature, ontogenetic growth, cancer, aging and mortality, sleep, cell size, and DNA nucleotide substitution rates. Cities and companies also scale: wages, profits, patents, crime, disease, pollution, road lengths scale similarly across the globe, reflecting underlying universal social network dynamics which point to general principles of organization transcending their individuality. These have dramatic implications for global sustainability: innovation and wealth creation that fuel social systems, left unchecked, potentially sow the seeds for their inevitable collapse.