Martin Krieger, University of Southern California – Gravitation and Architecture

Martin Krieger

Martin Krieger

Does the city draw you in?

Martin Krieger, professor of planning at the University of Southern California, delves into how cities and gravitation go together.

Martin H. Krieger is professor of planning at the Sol Price School of Public Policy at the University of Southern California. He is trained as a physicist, and has taught in urban planning and policy at Berkeley, Minnesota, MIT, Michigan, and USC. His nine books are about mathematical modeling, environmental policy, and about theories of planning and design. He has been a fellow at the Center for Advanced Study in the Behavioral Sciences and at the National Humanities Center. He is a Fellow of the American Physical Society.

Gravitation and Architecture


Geographers and urban planners explain how parts of the city influence other parts using a formula much like Newton’s law of gravitation. Einstein’s extension of Newton again shows how the paths of falling objects determine the distribution of mass-energy, and vice versa. Correspondingly, in a city being nearby matters, and where and when you go depends on what there is to do there.

We really have no such precise theory for cities as we do for the universe. Still, we might think of cities as modeled by the cosmos.

The Big Bang’s expanding universe rapidly cools down, in stages not unlike steam becoming water becoming ice. And eventually, it is cool enough and there is time enough to form stars and galaxies as bits of dust gravitate toward each other. So cities form and expand, and as they expand people and developers form neighborhoods–as people and activities gravitate, so to speak, toward each other. And, just as stars might eventually die or explode, perhaps to eventually form new stars, so neighborhoods may dissipate as they become too dense and chaotic for their residents, leading to new neighborhoods.

In a patterned history, the stars’ individual ages are indicated by their color and brightness. So in neighborhoods, time is marked by patterned histories of development and decay (and rebirth). And, like Black Holes, cities attract everything in their region. As for Black Holes, much of the detailed particulars of each person so attracted are erased by city life and its anonymity.

These city-cosmos analogies participate in a long tradition of notional correspondences of the microcosm and the macrocosm.