The Sub-Critical City

A system held below its critical slope: grains settle quietly, avalanches rare. Eugene’s growth boundary has shaped a city that resists sudden cascades.

Cities often drift toward what complexity science calls the critical slope, where countless small choices accumulate into patterns of sudden avalanches—some minor, some transformative. Eugene has resisted that drift, making it a useful case for thinking about self‑organized criticality in urban form. 

I first encountered the idea of self‑organized criticality in 2008, in discussions of emergent urbanism and systems thinking under the tutelage of Alder Fuller. A recent Veritasium video on power laws reignited my interest and prompted me to consider how these ideas apply to Eugene’s development. 

Self‑organized criticality describes the way certain systems—sandpiles, forests, stock markets, earthquakes—drift toward a balance point where tiny disturbances can produce anything from nothing to catastrophe. At that balance point, the size of events follows a power‑law distribution: countless small events, far fewer medium ones, and a rare but inevitable handful of giants. These “heavy tails” mark a critical system. The same mathematical signatures appear across wildly different domains, a phenomenon physicists call universality. Cities belong to that list, and Eugene’s exception makes the concept especially revealing. 

No large city grows in a vacuum. All face shaping by topography, zoning, land prices, infrastructure budgets, and political decisions. Yet worldwide, power‑law patterns appear with remarkable consistency: in street lengths, traffic congestion, building heights, rates of innovation, even the spacing of coffee shops. The driver lies not in the absence of rules, but in the presence of millions of small, local, decentralized choices: where to build a house, extend a road, or open a business. Those choices act like grains of sand dropped onto a pile. Over time, cities tune themselves toward a threshold slope, even if aspects of that slope are far from perfectly free. 

Eugene’s growth has been pressed by constraints tighter than those shaping many other cities. The Willamette and McKenzie rivers, the Coburg Hills, and Spencer Butte already form a natural bowl. Oregon’s statewide land‑use program, enacted in 1973, was the first of its kind in the nation. It required every city to draw an urban growth boundary, a bold experiment in curbing sprawl and preserving farmland. Typically, a city’s boundary expands in response to population growth; in Eugene, such expansions have been small and infrequent. From the air, the city still shows a discernible edge: roofs and streetlights give way to fields and oak savanna more abruptly than in most American cities of comparable size and wealth, though ragged in places. 

A walk from the downtown grid toward the South Hills reveals streets that begin to branch and loop like tributaries. Cul‑de‑sacs and winding lanes mark a departure into branching patterns that resemble fractals. One accident on the Beltline at rush hour can paralyze half the city. Housing prices jump in ways that feel disproportionate to the trigger. Even in sub‑critical systems, small avalanches still occur. 

Explosive rings of subdivisions and sudden satellite towns have been kept at bay, leaving Eugene’s sandpile noticeably flatter than most cities of comparable size and wealth. In the language of complexity science, the city qualifies as sub‑critical: orderly, green, bikeable, and still livable. Most other cities, even with their own zoning codes, greenbelts, and natural barriers, live closer to the slope that complexity science describes. 

Eugene's urban growth boundary.

Whether such restraint proves beneficial remains uncertain. The gains are clear: farmland and wetlands preserved, infrastructure costs contained, weekend rides across town that still feel relaxed. Most residents value these outcomes and would not trade them for the unchecked suburban expansion visible in other regions. 

The concerns are less visible. Critical systems acquire remarkable properties—rapid adaptation, outsized creativity—precisely because they tolerate extremes. When a city holds back more forcefully than most, it intervenes in a process that has proved robust at finding its own balance. In Eugene, the muted tails stand out in housing: supply has lagged demand, and affordability has eroded more sharply than in cities that allowed broader expansion. 

Complexity science offers no prescription; it only reminds us that every path carries its own heavy‑tailed consequence. One set of consequences is visible now: open fields west of Bertelsen Road, a skyline that ends where the hills begin. Another set may lie ahead: reduced adaptability, economic stagnation, or exclusion dressed up as preservation. 

The urban growth boundary undergoes periodic review, and the same public process that set it can still adjust it. Eugene has not become locked into permanent sub‑criticality, only into a prolonged and unusually deliberate constraint as the region decides what it values more: the known benefits of containment or the unknown potentials that most cities, despite their own rules, still manage to reach. 

Eugene’s growth boundary has kept the city flatter than the slope that complexity science describes. Whether this restraint preserves resilience or erodes adaptability remains uncertain. Self‑organized criticality only reminds us that even deliberate interventions cannot escape heavy‑tailed consequences.

Architecture is Awesome: #42 Framing Long Views

Villa Rotunda (photo by Andrew Hopkins from his essay Neither Perfect Nor Ideal: Palladio's Villa Rotonda)

Framing a long view is choreography, not accident. Good architecture composes foreground, middleground, and distant horizon so that seeing becomes an intentional act: a measured approach, a threshold, a framed aperture, or a dissolving boundary. Let’s consider four strategies—classical porticoes, sequential garden choreography, glass pavilion, and intimate apertures—each a different way buildings make long views legible and memorable.

Villa Rotunda (photo by Marco Bagarella, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons)

Perched on a gentle rise with a perfectly centered plan, Andrea Palladio’s Villa Rotonda turns each portico into a picture frame. The portico sets up a designed foreground and a measured interval before the countryside. Terrace, approach, and panorama read as a deliberate triptych. The experience is ordered: the building does not merely reveal the land; it arranges the act of looking into classical perspective. 

Katsura Imperial Villa (photo by Raphael Azevedo Franca - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1527734) 

The Katsura Imperial Villa stages long views through movement and sequence. Rooms, engawa verandas, sliding screens, and planted sightlines craft a collection of composed tableaux. Each threshold recasts the foreground and repositions focal points so distant features and garden elements become destinations in a carefully paced visual narrative. 

Farnsworth House (photo by Victor Grigas - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=42288805)

Ludwig Mies van der Rohe’s Farnsworth House pursues the opposite move: panoramic extension. A thin slab elevated above the floodplain, featuring full-height glass walls and a minimal structural frame, dissolves the threshold between the interior and the landscape. Instead of isolating discrete images, the house produces a continuous picture plane; its power lies in letting the eye move unbroken to the horizon and treeline, amplifying distance and continuity. 

Mount Angel Abbey Library (photo source: The Aalto Architecture - Mount Angel Abbey)

Alvar Aalto’s Mount Angel Abbey Library near Silverton, here in Oregon, resists spectacle in favor of intimate, painting-like views. Small, carefully placed windows and carrels frame clipped foregrounds, middle fields, and distant ridges, each opening embraced by warm, tactile surrounds. The building choreographs slow looking: the landscape becomes a sequence of shaped images to be read over time rather than consumed at once. 

Together, these examples describe a compositional spectrum. Palladio and Katsura use borders, thresholds, and procession to create discrete, framed vistas; Farnsworth dissolves the border to produce an immersive panorama; Aalto occupies a middle ground, shaping compact, outward-facing views that remain intimate. Each choice shapes attention differently—how long we look, what we remember, and how distant places enter the life of a building. 

Notice framed views in ordinary places: a porch that offers an agreeable perspective, a hallway that narrows the horizon, a small window that turns a distant ridge into a painted scene. Those everyday framings are the same compositional moves architects use at larger scales. Recognize them, and architecture becomes a reliable tool for making the world more legible—and, yes, AWESOME. 

Next Architecture is Awesome: #43 Market Halls and the Bustle of Commerce

Flight 93 National Memorial

 

Flight 93 National Memorial (all photos by me unless noted otherwise).

My recent trip across Pennsylvania, from Philadelphia to Pittsburgh, included three days of leisurely driving across the state. Along the way, I stopped at the Flight 93 National Memorial outside Shanksville. I wondered whether the visit would be worthwhile, especially since the Visitor Center was closed due to the federal government shutdown. I left thankful I had made the stop, as the experience was quietly profound.
 
The memorial recalls one of the most tragic and heroic moments of September 11, 2001. That morning, forty passengers and crew aboard the hijacked United Flight 93 realized what was happening and acted together. Their stand prevented the al-Qaeda extremists from reaching their intended target, though at the cost of every life on board. The crash site became a place of national mourning and remembrance.
 
Congress authorized the memorial in 2002, and an international design competition followed two years later, drawing more than 1,000 submissions. In 2005, the jury—comprised of family members, design professionals, and community leaders—selected Crescent of Embrace by Paul Murdoch Architects. The design evolved into the circular form seen today, emphasizing the flight path and place of impact. Working with Nelson Byrd Woltz Landscape Architects, Paul Murdoch Architects transformed the site of a tragedy into a landscape of environmental and symbolic healing.(1)

Aerial plan view (source: Flight 93 National Memorial — Paul Murdoch Architects)

Entrance to the closed Visitor Center.

View back toward the Visitor Center from the overlook.
 

Minimalism has become the accepted language of contemporary memorials, and the Flight 93 Memorial follows suit. Tall concrete walls and a black granite walkway trace the flight path, directing visitors toward an overlook above the crash site. Below lies a field of wildflowers, designated by the National Park Service as the Sacred Ground. At the edge of the hemlock grove, a sandstone boulder marks the location of Flight 93’s impact, though visitors see it only from a distance. The simplicity of the materials and the clarity of the geometry allow the landscape itself to carry meaning.
 

Wall of Names. The Visitor Center commands the high ground in the distance.

The Wall of Names stands along the flight path. Forty panels of polished white granite rise in sequence, each inscribed with the name of a passenger or crew member. The wall is straightforward in its form, and its presence is unmistakable. Walking its length, one feels the accumulation of lives remembered, each distinct but joined. The wall ends at a gate that frames the view of the crash site, linking the names to the place in a solemn, direct way.
 
What struck me most was the quiet. The only sound was the wind across the fields and through the trees, and even that seemed to deepen the hush. Visitors moved in silence; even a busload of schoolchildren remained respectfully quiet. The atmosphere carried the weight of memory.
 

The Tower of Voices.

The Tower of Voices, a ninety-three-foot structure holding forty wind chimes—one for each of the passengers and crew—stands at the entrance. When I visited, the tower was silent. The wind was steady, but the chimes did not move. Whether locked or awaiting stronger gusts, their silence seemed fitting, reinforcing the quiet that defined the entire site. The tower, while striking, is one part of a composition whose scale is measured in miles and thousands of acres. The Wall of Names, the flight path walkway, the overlook, the restored wetlands and groves of trees—all work together to create a memorial landscape that is monumental yet restrained.
 
My high regard for the Flight 93 Memorial is personal, limited since I’ve visited only a handful of other contemporary memorials. Still, among those I have seen—including the 9/11 Memorial at the site of the former World Trade Center in New York, and the Vietnam Veterans Memorial in Washington, D.C.—this one stands out. It honors the heroism of the forty and transforms a scarred landscape into a place of healing. It is both vast and intimate, monumental and quiet. I left with a deep respect for what was accomplished here. 

(1)    I was not previously familiar with the work of Paul Murdoch Architects. This surprised me, given how impressive the firm’s portfolio is, which includes civic and cultural projects.  

Henry Chapman Mercer’s Quixotic Castles and Caves

Fonthill Castle (all photos by me)

During my recent trip to Pennsylvania, I visited three remarkable buildings in Doylestown, Bucks County: the Mercer Museum, the Moravian Pottery and Tile Works, and Fonthill Castle. Archaeologist, artifact collector, and tilemaker Henry Chapman Mercer (1856–1930) designed and built the buildings to embody his interests in history, craft, and storytelling, innovatively employing reinforced, cast-in-place concrete throughout.
 
I’ve previously written on Mercer’s architecture, particularly drawing from University of Oregon professor Bill Kleinsasser’s insights. Like Mercer, Bill critiqued the effects of modernization and industrialization on design, especially the rise of standardization and the loss of diversity found in historical buildings. As a figure associated with the Arts and Crafts movement, Mercer championed vernacular architecture, nature-inspired motifs, and the craftsman-designer’s role. He stood out for his ability to weave legend, literature, Americana, and archaeology into his work. His three buildings are not only unique but also deeply personal and evocative. Bill appreciated their visual qualities, the lessons they offer, and their creator’s eccentricity.
 

The Mercer Museum rises an imposing six stories, housing Mercer’s immense collection of pre-industrial tools. The central atrium is crammed with objects, many of which are hung vertiginously from the ceiling above. Narrow staircases and abrupt transitions shape the experience. The building doesn’t guide visitors through a clear sequence; instead, it asks them to navigate on their own terms. The density of artifacts and the verticality of the atrium create a kind of spatial compression. It may lack legibility, but it is undeniably absorbing.

 

The Mercer Museum.

Inside the museum.

The Tile Works operates to this day. Its architecture is low-slung, with thick concrete walls, a ground-level loggia bordering a central courtyard, and a roofline punctuated by numerous kiln chimneys—each one slightly different in shape and tile adornment. Inside, the layout follows the logic of production, with workspaces, kilns, and drying rooms arranged in a straightforward manner. The building extends the tradition of Pennsylvania German potters and continues to produce tiles using Mercer’s original molds and methods. Mercer drew inspiration from Spanish Mission-style architecture when designing the Tile Works—an unusual reference for Bucks County, but one that lends the structure a sense of restraint and clarity. That restraint stands in contrast to the more elusive formal logic of the Mercer Museum and Fonthill, where spatial organization feels less tied to function.

The Moravian Pottery and Tile Works.

Courtyard.

Reception Hall.

 

Fonthill served as Mercer’s home. The labyrinthine building sprawls across the site, fully enveloping an older stone farmhouse. It holds forty-four rooms of varying shapes and sizes, eighteen fireplaces, and thirty-two staircases. Mercer embedded tiles, inscriptions, and found objects throughout. The stairs shift direction, ceilings rise and fall, and windows frame fragments of landscape. Bill remarked on Mercer’s fascination with caves, castles, and literary imagery. That influence is evident in the building’s spatial unpredictability and whimsical turns.
 

Fonthill roofscape. The separate garage building (now the visitor center) is in the background.

Windows.

Fonthill's saloon (living room). Every one of the irregularly spaced columns is unique.

Section through a digital model of Fonthill. Click on the image to view an enlarged version. The complexity and level of detail evident in this section are remarkable. Big thanks to Jim Givens for allowing me to share this image here.

Now that I’ve been to all three of Mercer's buildings, I’ve thought again about Bill’s interest in them and their broader relevance to today’s architectural discourse: He clearly wasn’t asking us to emulate their forms; rather, he saw them as (pardon the pun) concrete expressions of personal conviction and lived experience. That was the takeaway. He noted their complexity and resistance to straightforward interpretation. In Bill’s words, each Mercer edifice emerges from “images, first recalled and then carefully developed, from his travels and studies . . . places real, and places imaginary.”

Bill recognized that an architect’s internal landscape—the memory, narrative, and inquiry it might encompass—can shape architectural form in ways that are both personal and coherent. Mercer drew inspiration from his extensive travels and the archaeological sites he explored. I certainly considered how his subjective preferences translated into the spatial and material decisions I experienced as I moved through each building. As Mercer did, we can all reflect upon our own memories, values, or narratives when designing. Such an approach can foster buildings that carry individual significance and sensory richness, shaped by our own story and those for whom we design.
 
Ultimately, I left Doylestown with impressions of buildings that resist easy interpretation but richly reward one’s attention. Mercer’s buildings don’t yield readily transferable design strategies. They resist reductive generalization, yet they epitomize what’s possible when architecture is inspired by memory and shaped by craft and conviction. The Mercer Museum, Moravian Pottery and Tile Works, and Fonthill each convey Henry Mercer’s personal inspiration, improvisation, and principles. That’s what Bill saw in them, and what I tried to keep in view at each site.

Fallingwater, Finally

Fallingwater (all photos by me).
 

In a post I wrote back in 2009, I described how a photograph of Frank Lloyd Wright’s Fallingwater left me, an impressionable 5^th grader, awestruck. It was an image unlike anything I had ever seen: A dramatic composition consisting of concrete terraces cantilevered seemingly weightless over a waterfall, masonry piers of locally quarried sandstone, and horizontal expanses of windows dissolving boundaries between interior and exterior. It was a bold, fully realized expression of Wright’s organic design principles. That image didn’t just spark an interest in architecture; it defined the course my life would follow from that point forward.
 
Last Friday, I visited Fallingwater for the first time.
 
Seeing the house in person didn’t change my understanding, but it added something. The setting was familiar. The scale felt right. As acquainted as I was with its design, Fallingwater didn’t surprise, but it did affect me in a way that drawings and photographs never could.

Inside, the sound of the waterfall is steady. It’s not loud, but it is always present. That sound affects the experience of the house. It connects the interior to the site in a way that’s hard to describe but easy to notice. The house doesn’t invite interpretation as it presents itself directly. The built-in furniture, the narrow passages, the low ceilings—they all reflect Wright’s intent to guide how the space is used and understood.
 
I didn’t take notes or try to analyze every detail. I moved through the house and simply took it in. It felt familiar, but also new. I was happy to be there. Not giddy, but reverent. This was the place that first showed me what architecture could be and now I had seen it firsthand. It met the standard I had carried with me since childhood.
 

There’s a plaque near the entrance noting Fallingwater’s inclusion on UNESCO’s World Heritage List. It talks about “Outstanding Universal Value” and Wright’s contribution to organic architecture. That’s all true, but for me the value was personal. I finally had traveled to see the building that shaped my thinking before I even knew what architecture was. My visit gave me exactly what I hoped for.

 

I took some photos, which I’ve included here. They’re not exhaustive, and they’re not meant to be. They’re just a record of the visit. Proof for myself that I made the pilgrimage. That the house is real. That the path I chose all those years ago still makes sense.