Propinquity

= concept in urbanism, "the networks of physical contact and interaction"

Discussion

Michael Mehaffy:

"As is often the case with metabolic networks, feedback loops seem to be a key. Also, redundancy is key (which is closely related, i.e. allowing circular connections). Chris Alexander's paper "A City is Not a Tree" is a good example of he need for this redundancy and overlap. Concentration is also a key factor -- in effect, the city is a kind of "social reactor" that requires a "critical mass" to multiply its interactions. Another key factor is the pattern of connections and disconnections, including key nodes that form -- so-called "small world networks." In effect, there is an "urban connectome" that governs what can happen, and how metabolic relationships form.

So I think the elements ... are gradually coming together, into a kind of "science of cities" -- not only as a planning discipline, but as a discipline of study and understanding, in ways we had not previously recognized. In previous eras we perhaps could take these processes for granted, as they worked quite well in older cities. But like other challenges of our time (climate change comes to mind) we now have no choice, in my view, but to study these phenomena more carefully, the better to understand how to intervene and to reform what is failing and pathological. Like a good doctor, we must use this knowledge to heal the city, and the planet." (p2p-urbanism list, email, January 2016)