A great talk about simple laws that govern growth

I especially like the part starting at 9.3 min. where he talks about how cities are network:

"cities are network and the most important network of cities is you. Cities are just a physical manifestation of your interactions, our interactions, and the clustering and grouping of individuals"

However, a word of warning: read the comments and the critical discussion! 

"Physicist Geoffrey West has found that simple, mathematical laws govern the properties of cities -- that wealth, crime rate, walking speed and many other aspects of a city can be deduced from a single number: the city's population. In this mind-bending talk from TEDGlobal he shows how it works and how similar laws hold for organisms and corporations.

Physicist Geoffrey West believes that complex systems from organisms to cities are in many ways governed by simple laws -- laws that can be discovered and analyzed."