Papers on the notion that physics can help us articulate our understanding of cities are not new but there are several recent commentaries worth looking at. There is a short sharp one pager that articulates the new science of cities as being a new urban physics from the folks at CUSP. Download it here. And at MIT, Franz-Josef Ulm considers cities to be structured like various forms of materials. See the summary of his thinking in MIT Spectrum and the article in The Boston Globe. There are many different views of how physics can help us understand cities from their materials to their sociology and economy. This has only just started and I will post more about it as it emerges.