I spent most of my career doing high-energy physics, quarks, dark matter, string theory and so on.

If you ask people why they move to the city, they always give the same reasons. They've come to get a job or follow their friends or to be at the center of a scene. That's why we pay the high rent. Cities are all about the people, not the infrastructure.

My provocative statement is that we desperately need a serious, scientific theory of cities and scientific theory means quantifiable, relying on underlying generic principles that can be made in a - put into a predictive framework. That's the quest.

You could not have evolved a complex system like a city or an organism - with an enormous number of components - without the emergence of laws that constrain their behavior in order for them to be resilient.