Tag: 2005

Arcosanti detail

The Relevance of Arcosanti in Today’s “Eco-Conscious” Society

Arcosanti, envisioned by Paolo Soleri, exemplifies sustainable urban living but faces challenges in realization, scalability, and contemporary relevance.

MichaelStephenWills4 Comments

Arcosanti, the brainchild of architect Paolo Soleri, was conceived as an experimental laboratory for urban design and ecological principles—a built embodiment of his vision of Arcology (a fusion of “architecture” and “ecology”). Over fifty years since its groundbreaking in 1970, Arcosanti remains a significant cultural and architectural artifact. However, the meaning and relevance of both Arcosanti and Arcology in today’s context invite critical examination.

The accompanying photographs are a presentation of the history of Arcology from Arcosanti signage
Arcosanti 5000 — Soleri’s Ultimate Vision

Historical Context and the Vision of Arcology

Soleri’s concept of Arcology emerged during the mid-20th century, an era of increasing environmental awareness, urban sprawl, and population growth. His vision was radical: compact, self-sustaining urban environments that minimized ecological impact while fostering human interaction and creativity. Arcology sought to challenge the sprawling, resource-intensive models of urban development that dominate the modern world.

Today’s population of the Earth is about 5 billion people. By the year 2050 the population of the Earth will be 10 billion people.* With the same human condition of today and the same stresses imposed on the biosphere, there would be the need for 2 Earths. Since the American Dream society has an average per capita “consumption” about 20 times the average per capita consumption of the whole human society, for the 10 billion people of the year 2050 to be “elevated” to the American Dream’s affluence level, there would be the need of 2 x 20 = 40 Planet Earths. Assuming that by then we all will be twice as efficient in our production-consumption-gratification pursuits, we would need only 19 more planets. Where are we going to get 19 additional Planet Earths? The American Dream physically embodied in the single-family house has to be scrapped and reinvented in terms which are coherent with the human and biospheric reality. Toward a Possible Resolution Only a true, lean urbanization strung along a highly efficient, i.e., frugal logistical grid combining superconductivity-maglev transportation of people and freight, viaducts, aqueducts, power grids, sewage and solid waste grids, etc., compensating for the loss of consumption-gratification unlimited by the way of an intense social, convivial, natural, esthetic, productive, sane life; only such novel structure will be able to translate the American Dream into a democratic, planetary reality. The alternative, to persist in the dying American Dream, is a planetary-human catastrophe. The subject matter of this exhibit is about one aspect of the possible resolution. It would couple indissolubly the well-being of Homo sapiens, 10 billion of us, with the well-being of the only planet we can inhabit for the time being. All statistics based on 1993 United Nations data cited by the Worldwatch Institute. (signed) Paolo Soleri

Arcosanti was intended to be a prototype—a proof of concept for dense urban living within a minimal environmental footprint. Its design embraced verticality, integration with natural surroundings, and multi-use spaces to reduce resource consumption. Soleri’s philosophy rejected wasteful consumerism and emphasized communal living, self-sufficiency, and harmony with nature.

Arcosanti as a Realization of Arcology

While Soleri’s ideas were visionary, Arcosanti itself never fully realized its original ambitions. Planned to house 5,000 people, it currently accommodates fewer than 100 residents. This gap between aspiration and reality reflects several challenges:

Paolo Soleri had established his residence and studios in Paradise Valley, Arizona, before he embarked on developing alternative urban theories. Although the Cosanti structures are small, Soleri experimented with various innovative construction techniques, including silt casting, to demonstrate effective use of building materials. His imaginative forms were adapted to the desert environment, and Cosanti became the exploratory launching pad for the Arcosanti project.

Scale and Funding: Building a sustainable community of this scale required vast financial and organizational resources. Arcosanti, largely constructed through volunteer labor and workshops, lacked the momentum to expand at the pace Soleri envisioned.

Upon completion of his theoretical work MESA CITY, whose purpose was the quest for an environment in harmony with man, Soleri established the Cosanti Foundation, a non-profit educational foundation. He was determined to continue his investigations into more efficient urban systems. To demonstrate his theories, Soleri proposed an urban-scale community MACRO COSANTI, envisioned for Arizona high desert.

Cultural Shifts: The communal living and austerity championed by Soleri contrast sharply with the consumer-driven values of contemporary society. The rise of globalized capitalism, suburban expansion, and digital individualism has made the communal ethos less appealing to many.

The term ARCOLOGY was coined to describe a series of urban designs for ecologically sound human habitats, as elaborated in “The City in the Image of Man,” published by MIT Press. This thesis outlines the concept of ARCOLOGY and its design variations for different settings. ARCOSANTI was introduced as the last (30th) example of this exercise, and originally planned to house a relatively small population of 500. The physical construction of ARCOSANTI began in 1970.

Technological Advances: Soleri’s designs were innovative for their time, but modern advancements in sustainable technology—such as solar power, green building materials, and decentralized energy systems—have surpassed some of his ideas. Today, sustainable urbanism focuses on retrofitting existing cities rather than building entirely new ones.

The Relevance of Arcology Today

Despite its limitations, Arcology remains profoundly relevant in the face of 21st-century challenges such as climate change, resource scarcity, and urban overpopulation. Soleri’s principles offer a framework to address these crises, particularly through:

The Xerox Corporation sponsored a major Soleri exhibition featuring a series of new arcology designs that suggested a sustainable urban habitat employing alternative energy sources. The project was called “TWO SUNS ARCOLOGY: The Cities Energized by the Sun.” The Arcosanti master plan went through a major overhaul reflecting this methodology. In the following year, PLANT SHOW venues gave Soleri additional funding to update the Arcosanti design. The projected population was increased to 5,000.

Compact Urbanism: Cities worldwide are grappling with the environmental toll of urban sprawl. Arcology’s emphasis on vertical, compact cities with reduced land usage aligns with the modern push for urban densification.

Ten years into the construction of the first prototype arcology, a developmental adjustment was made in order to gain momentum for the project. The CRITICAL MASS concept was introduced as an incremental phase to house 10 percent of the projected population of 5,000. A series of small-scale structures providing various amenities was designed to support a viable community, a critical population of 500 people. This would hopefully function as a springboard to the next major step, the completion of Arcosanti.

Mixed-Use and Communal Spaces: The COVID-19 pandemic underscored the importance of walkable, mixed-use neighborhoods and shared green spaces. Arcology’s model of integrated living and working spaces anticipates these needs.

Sustainability and Circular Systems: Soleri’s focus on minimizing waste and resource use aligns with today’s circular economy principles. Arcology’s ideas resonate with efforts to design cities as closed-loop systems that reuse resources.

The apse initiative was a result of an expanded version of the Third Generation Arcology using Soleri’s signature forms: Apse and Exedra. This initiative suggests possible solutions to the existing urban renewal opportunities (Presidio, Stapleton, Phoenix, and Hanover Expo 2000) as well as hypothetical rural development opportunities. ARCOSANTI 2000 consists of 3 major units. The design was modified later with an addition of SUPER CRITICAL MASS (THE WAVES), three superstructure apses combined and placed behind Critical …

A Philosophical Challenge: Beyond practical urban design, Arcology challenges us to rethink our relationship with the planet and with each other. It invites a fundamental shift from individualistic consumption to collective stewardship.

Critique of Arcosanti Today

Arcosanti, while iconic, serves more as a symbol than a fully functioning example of Arcology. Its limited population and incomplete development highlight key shortcomings:

Lack of Scalability: Arcosanti has not demonstrated how Arcology principles can scale to meet the needs of modern cities with millions of inhabitants.

ARCOSANTI 5000 2001 – present Developed from the SUPER CRITICAL MASS in ARCOSANTI 2000 with the design elements of NUDGING SPACE ARCOLOGY added, ARCOSANTI 5000 features seven phases of truncated superapse structures. It re-establishes the macro nature of this prototype arcology for 5,000 people. This design is still in development, waiting on the architectural and structural resolutions.

Dependence on External Systems: Despite its aspirations for self-sufficiency, Arcosanti relies on external power grids, supply chains, and tourism, which limits its autonomy.

Cultural Niche: Arcosanti appeals primarily to a niche audience of artists, architects, and environmentalists, making it less accessible or appealing to broader populations.

However, these critiques do not negate its value as a learning tool. Arcosanti’s enduring presence serves as a physical and philosophical case study for those seeking alternatives to conventional urbanism.

A Way Forward?

The future of Arcology lies not in building new Arcosanti-like prototypes but in applying its principles to existing cities and communities. Initiatives such as urban vertical farming, passive solar building design, and car-free city centers echo Soleri’s vision in modern contexts.

Additionally, Arcosanti itself could pivot toward becoming a research hub for sustainable practices, a cultural landmark, or a retreat for those seeking inspiration in Soleri’s ideas. By focusing on education and experimentation, it could remain relevant in contemporary discussions about urbanism and ecology.

Conclusion

Arcosanti and Arcology are more than relics of a bygone architectural movement—they are reminders of humanity’s potential to live in balance with nature. While the practical implementation of Arcology faces significant hurdles, its core philosophy continues to inspire efforts to create more sustainable and harmonious urban environments. In a world increasingly shaped by environmental urgency, Soleri’s vision holds lessons we cannot afford to ignore.

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Exploring Arcosanti: A Model for Sustainable Living

In 2005, I explored Arcosanti’s model, envisioning an eco-architectural future that promotes community and harmony with nature.

MichaelStephenWills22 Comments

The desert air was sharp, dry, and oddly invigorating as I stepped into the gallery at Arcosanti, Arizona. The year was 2005, and I had long dreamed of visiting this experimental micro-city—a fusion of architecture and ecology conceived by Paolo Soleri. Amidst the array of sketches, photographs, and miniature prototypes stood the centerpiece of my curiosity: the sprawling, intricate scale model of “Arcosanti 5000.” It was as though the future had been condensed into a tangible artifact, whispering promises of an alternative way of living.

The model was perched on a wooden table, surrounded by blueprints and diagrams. Its sweeping curves and layered structures evoked the natural patterns of a canyon or the unfurling petals of a desert flower. I leaned in, drawn to its labyrinthine details: the arches that seemed to embrace the air itself, the layered grids suggesting terraces and communal spaces, and the towering central spire—a striking focal point that anchored the design. The model was an architectural plan, a vision made tactile, a conversation between the human spirit and the earth it inhabits.

As I circled the table, I tried to imagine life within these walls. Here was the apse architecture that Soleri had championed—a structural form both futuristic and deeply rooted in the land. Its curves seemed to reject the cold rigidity of modern urbanity, embracing instead a harmonious fluidity. What would it feel like to wake up in one of these units, to look out through those sweeping arches and see the desert alive with light and shadow?

The plaque nearby described this design as part of a “Super Critical Mass” initiative, envisioned for a population of 5,000. The model represented an evolution from earlier prototypes, incorporating what Soleri called “nudging spaces”—areas designed to encourage spontaneous human interaction. I thought of my own neighborhood back home, how it felt fractured and isolated by its grids of asphalt and fenced-off yards. Could this model offer a blueprint for healing that divide?

I moved closer, tracing the pathways with my eyes. The tiny staircases, the shaded atriums, the terraced gardens—they spoke of a life integrated with nature, of a city that tread lightly upon its environment. The thought was thrilling, but also sobering. The challenges of realizing such a vision in the sprawling chaos of modern development loomed large in my mind. Could humanity ever truly embrace such radical simplicity?

In that moment, the gallery was silent except for the soft click of my camera. I wanted to capture not just the model, but the feeling it evoked—the delicate balance of hope and humility. The metadata on the image files would later remind me of the precise day and hour I stood there, absorbing this vision of what might be. But no timestamp could fully capture the spark it ignited—a sense that, even in a world burdened by consumption and waste, there remained a path forward, winding like a desert trail through arches of light and shadow.

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Exploring Paolo Soleri’s Vision for the Pulse Bridge

The Pulse Bridge model embodies Paolo Soleri’s vision, merging architecture and philosophy to inspire adaptability, connection, and beauty in urban landscapes.

MichaelStephenWills13 Comments

For me room was hushed, as if holding its breath in reverence for the dreams of a man who dared to reimagine not just buildings, but entire landscapes. I stood before the model of the Pulse Bridge, a work envisioned by the inimitable architect and philosopher Paolo Soleri. This was a living, breathing entity in miniature—a whisper of the city’s heartbeat rendered in metal and form.

PULSE BRIDGE is conceived for the New York cityscape and designed so as to alter its own stress configuration according to the traffic loads it carries and the temperature and wind variations. It does not so much react to such stresses as it dynamically adapts to them. This is achieved by suspending the whole structure on two sets of hinges and altering the weight distribution by way of four ballast spheres, constantly changing in weight because of the water volume they contain and is pouring in or spilling out of each. Temperature differential and wind loads will suggest asymmetrical ballast content.

The bridge stretched across the table, a golden ribbon suspended in perpetual motion. Its delicate cables, taut and slender, mirrored the veins of a great urban organism. I leaned closer, catching the glint of light on the brass framework, which seemed to hum with possibility. The slanted pylons, bold and angled at 45 degrees, rose like colossal compass points charting a path into a future yet unbuilt. Their elegant incline gave the structure a sense of poise and power, as though it were both rooted in the earth and ready to leap skyward.

At either end of the model, spherical ballast weights gleamed like captive suns, their surfaces smooth and luminous. These orbs symbolized adaptability, a dynamic response to the unpredictable forces of wind, weight, and weather. Soleri’s genius was palpable in these spheres—each a small, controlled impulse that could tip, pour, or hold water to balance the bridge’s pulse, much like the human heart adjusts its rhythm to life’s demands.

As I circled the model, I noticed how the bridge’s levels—three distinct layers—seemed to invite a diversity of life. The uppermost level promised a vista for pedestrians and the rhythmic flow of cars. Beneath, a middle layer hinted at a mix of vehicles and trucks, and the lowest level seemed destined for the silent hum of trains, utilities, and unseen infrastructure. It was a symphony of movement, each level contributing its own notes to the city’s harmony.

And yet, the most captivating feature was not the mechanics or the engineering marvels, but the philosophy embedded within. Soleri’s vision was not just to build a bridge, but to craft an experience—a structure that could breathe, flex, and adapt to the ever-changing pulse of New York. He imagined the pylons as cultural hubs, housing optical museums, exhibitions on bridge history, and even gift shops. The bridge was as much about connecting people as it was about connecting places.

Standing there, I felt the weight of Soleri’s ambition. The Pulse Bridge was a manifesto, a declaration that utilitarian structures could inspire wonder and nurture life. I imagined walking across its span, the city stretching out on either side, the bridge subtly shifting beneath my feet as it responded to the flow of traffic and the gusts of wind. It would be a conversation between structure and environment, a dialogue that reminded me of the living world we so often take for granted.

The longer I stood before the model, the more I realized it was not just a reflection of Soleri’s imagination but a challenge to our own. Could we build a future where beauty and function danced together, where even a bridge could sing of resilience and grace? The Pulse Bridge dared us to try.

In that quiet room, with sunlight streaming through the windows and casting delicate shadows across the model, I felt the profound allure of what could be. Soleri’s bridge was an idea—a luminous thread connecting visionaries across time, urging us all to dream bigger, build better, and embrace the pulse of life in all its complexity.

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Arcosanti detail

Exploring Arcosanti: Paolo Soleri’s Vision in the Arizona Desert

Arcosanti embodies Paolo Soleri’s vision of sustainable living, merging architecture and ecology in harmony with the Arizona desert landscape.

MichaelStephenWills11 Comments

Under a strong early spring desert sun I turned from Arcosanti Road, a ribbon of asphalt threading through the arid Arizona landscape. Ahead, the architectural vision of Paolo Soleri emerged like an oasis of ideas etched into the barren desert. My mind drifted back to the 1970s, to the University of Arizona lecture hall where Soleri, full of vigor, had introduced us to his concept of “Arcology.” That hour left an indelible mark—a vision of dense human habitation harmonizing with the environment, reducing our ecological footprint toward a sustainable whole.

Arcosanti detail
Arcosanti detail

That memory had stayed with me, a beacon of idealism. Over the years, Soleri’s Arcosanti had grown, not with the speed of cities, but with the deliberate rhythm of an organic organism. Today, after decades of curiosity and connection, I found myself at its gates.

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Arcosanti detail
Pam checking her equipment before a Summer 2008 visit

The first steps into Arcosanti struck me with a sense of balance. A sign, simple yet bold, announced the name: ARCOSANTI. It was embedded into a wooden facade, juxtaposed with the rugged modernity of concrete forms. Below, soft plumes of desert grass swayed, echoing the harmony Soleri envisioned—a human footprint gently integrated into the natural world. The sunlit entrance spoke of the potential for design to soothe rather than overpower.

Entrance and a Tower of the Crafts III building

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Inside, the bold lines and unique details captivated me. In one space, I craned my neck to admire a ceiling adorned with terracotta-colored circular forms, each embedded in angular panels radiating like the sun’s rays. These circular elements acted as focal points, their symmetry grounding the expansive, textured design. The play of light and shadow across the surface was mesmerizing, a reminder of Soleri’s mastery in turning the utilitarian into the poetic.

Ceramics Apse Sand Cast Panels I

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Each space in Arcosanti seemed crafted to evoke reflection. A splash of ochre-red pigment adorned another portion of the ceiling, forming a half-circle bordered by precise ridges. It was more than architectural detail—it was an abstract sun, warm and full of energy, radiating from its place above. The deliberate asymmetry, the interplay of form and texture, seemed to breathe with the desert itself.

Ceramics Apse Sand Cast Panels II

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Ceramics Apse Sand Cast Panels III

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Walking further, I encountered an outdoor arch framing a bell, its heavy bronze form suspended against a panel of sky-blue. The simplicity was striking: a geometric dialogue between the natural and the constructed, a kind of meditative pause within the bustle of ideas. I lingered, allowing my thoughts to settle as the bell swayed gently in the wind.

Bell and Panel from the Colly Soleri Amphitheater

Bell Casting was and continues to be a major source of income.

Ceramics – CLICK ME for more Arizona Photography.

Each turn at Arcosanti revealed yet another viewpoint, another carefully composed alignment of architecture and nature. The sweeping views of the Arizona desert, framed by bold circular cutouts, were a reminder of our smallness in the grand scheme of things. The cypress trees standing tall against the rugged cliffs offered a contrast of textures—natural and man-made—that felt uniquely Solerian. His vision was alive in every corner: the terraces, the staircases, the unassuming balance between the earth’s rawness and humanity’s imagination.

View from the East Housing complex to the East Across Arcosanti

View Across Arcosanti – CLICK ME for more Arizona Photography.

As I stood gazing through one of the monumental circular frames at the horizon, I reflected on how Soleri’s ideas, abstract in the present, are also tangible, concrete, and inspiring—literally and figuratively. Despite his passing, the project he began decades ago continues to evolve, a living experiment in how we might reimagine our relationship with the planet.

View to the South with Cypress Trees from a Portal of the Crafts III Building

Portal View – CLICK ME for more Arizona Photography.

The journey to Arcosanti is a physical one and a rediscovery of ideals. Soleri’s Arcology—a fusion of architecture and ecology—reminded me of our potential to create something not only functional but also deeply meaningful. Here, amidst the Arizona desert, was proof of a life’s work that still speaks to humanity’s potential for coexistence and creativity.

As I prepared to leave, the weight of Soleri’s vision stayed with me, much like that lecture hall memory from all those years ago. The sun was setting, casting long shadows across the concrete forms. Arcosanti stood resolute, a tribute to one man’s dream and a reminder to all of us: change is not instantaneous, but with patience, vision, and humanity, it is possible.

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Exploring the Vision of Arcosanti

In the Arizona desert, structures harmonize with nature, embodying creativity and purpose while inviting reflection on balance and coexistence.

MichaelStephenWills14 Comments

Approaching Arcosanti from afar, a cluster of forms rising from the Arizona desert like a mirage of human imagination. Against the cobalt sky, the buildings seemed to breathe with the land itself, their curves and edges echoing the undulations of the hillside. From this distance, the structures were both distant dream and solid reality, their symmetry a whispered promise of order amidst the chaos of the wild.

As I moved closer, the buildings revealed their intricate secrets. Circular windows stared like unblinking eyes, portals to a world shaped by creativity and purpose. Towers and cubes jutted confidently into space, their bold geometry softened by the earthen hues of concrete and weathered wood. These materials, neither foreign nor intrusive, seemed born of the very soil beneath my feet. There was an undeniable rhythm to the place—a harmony where art, function, and the timeless desert converged.

I walked among the structures, their forms towering above me like sentinels of some ancient philosophy reborn for a modern age. The elevated walkways beckoned with a quiet invitation, connecting one sanctuary of thought to another. Circular motifs repeated like a mantra, reminding me of the cycles of life, of the sun and the moon, of the unbroken circles that hold us together. Here, design was not merely a tool but a hymn, sung in concrete and glass.

Then, I turned my gaze outward, to the land that cradled this creation. The desert was alive, though its voice was quiet and deliberate. Rocks, worn smooth by the patient hand of time, rested among tufts of sage and grasses that swayed in the breeze. The light played its own game, casting shadows that danced across the ground, a choreography as old as the sun. Paths meandered through this terrain, their curves a gentle suggestion rather than a command, inviting me to wander but not to conquer.

Arcosanti

The trees stood tall and still, their presence both steadfast and serene. The cypress trees, their slender forms reaching toward heaven, seemed like exclamation points on the landscape, their verdant green cutting through the sky’s azure expanse. Beside them, olive trees spread their silvered arms, their gnarled trunks telling stories of endurance and quiet strength. One cypress, in particular, caught my attention—so perfectly straight, so impossibly regal, as if it had been planted by the hand of a god.

Beneath the olive trees, I paused, tracing my fingers along the bark’s intricate patterns. The sunlight filtered through the leaves in golden shards, dappling the earth beneath with shifting shapes. The air carried the scent of something ancient and vital—a blend of dry earth, sun-warmed bark, and the faintest hint of blooming life. It was a reminder that even in this place of human creation, nature reigned supreme.

I wandered to the edge of a canyon, its rugged walls carved by time’s relentless flow. The raw power of the landscape stretched out before me, a tapestry of stone and shadow that humbled and awed. Here, the boundaries between human vision and natural grandeur blurred. The olive and cypress trees, so carefully placed, seemed less an intrusion and more a part of the desert’s rhythm. They were a bridge, a whispered conversation between what is made and what simply is.

Finally, the paths called me back, their winding lines leading me deeper into reflection. Each step felt deliberate, as though I were tracing the lines of a poem etched into the earth. The trails curved gently, like the desert’s own breath, and I followed, not as an intruder but as a guest. The buildings now stood behind me, a testament to the balance we strive for—between the ephemeral dreams we build and the eternal landscape that cradles them.

This place is a meeting of stone and sky, a meditation: reminding us that, if we listen, the land will teach us how to live in harmony. Here, in the desert’s embrace, I found space to ask better questions, my heart as open and unbroken as the endless horizon before me.

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Winter Dream Homestead

Capturing Winter’s Whisper: A Photographic Journey by Fall Creek’s Historic Esker Ridge

Join me in the mesmerizing world of photography as we capture the ethereal beauty of a frosty January morning, where history meets nature’s artistry. Explore more on our blog.

MichaelStephenWills56 Comments

Continue reading “Capturing Winter’s Whisper: A Photographic Journey by Fall Creek’s Historic Esker Ridge” →

Ad Astra

To The Stars

MichaelStephenWills

A mass of lavender asters produced for a painterly, restful esthetic. Over the years I have tended beds of these wildflowers. The sunlight of late August/early September here in the Finger Lakes is especially clear and this is when these asters bloom. This were caught on a clear September evening with the sun just behind a stand of large Ash trees.

Click Me to visit this image in my fine art gallery

“Symphyotrichum novi-belgii (formerly Aster novi-belgii), commonly called New York aster. Symphyotrichum, a genus in the family Asteraceae, whose species were once considered to be part of the genus Aster. Plants in both these genera are popularly known as Michaelmas daisy because they bloom around September 29, St. Michael’s Day. The Latin specific epithet novi-belgii (literally “New Belgium”) refers not to modern Belgium, but the 17th century Dutch colony New Netherland which was established on land currently occupied by New York state (as Belgica Foederata was the Latin term for the United Netherlands at the time).“

Reference: Wikipedia “Symphyotrichum novi-belgii.”

Copyright 2023 Michael StephenWills All Rights Reserved

McMath-Pierce Solar Telescope – 3

Adaptive optics

MichaelStephenWills

These views within the McMath–Pierce solar telescope enclosure were captured during a guided tour of the instrument, April 20, 2005. By way of orientation, the observation room we visited is near the location labeled “4” on the model of the following photograph or the “Observation Room” of the drawing.

We learned each of the sets of mirrors is considered a separate telescope. The first step in designing the new solar telescope was to determine the optimal image scale. Working on the spectra of the solar granules, on the physical structure of the sunspots and their associated magnetic fields, requires a considerable image size. Past experience has shown that the optimal image of the sun should be approximately 0.91 meters. The highlight of our visit to the Main Observation room was meeting with the technician operating the recently developed low-cost adaptive optics system.

Tip-tilt correction and low order wavefront correction is available with a number of portable optical benches.  These are primarily used with the Main spectrograph and the Solar Stellar spectrograph on the Main telescope, but due to their compact mounting they could be used with other telescopes and instruments in the facility.

This configuration uses a rapidly deformable mirror to correct distortions introduced by the turbulent atmosphere. Using sensors to measure the degree of image distortion, the adaptive optics system adjusts the shape of the mirror accordingly and converts a blurred image into a clear one. The following image demonstrates the correction. “Low-cost” = $25,000 in 2003 US dollars. Under references is a link to a full description of the device by the creator.

Christopher Keller, Public domain, via Wikimedia Commons

A main area of ​​study in the observatory is the structure of sunspots, which are relatively cold, dark spots on the surface of the Sun created by intense magnetic activity.

Some of the most important discoveries made at McMath-Pierce include the detection of water vapor in the Sun, the measurement of kilogauss magnetic fields (thousands of times stronger than those on Earth) outside sunspots and the detection of a natural maser (like a laser, but with a microwave instead of visible light) in the Martian atmosphere.

Over the years and technological advances, the National Solar Observatory has moved its headquarters from Tucson to Boulder, Colorado. The organization abandoned its solar telescopes at Kitt Peak and in New Mexico for a larger instrument in Hawaii, the Daniel K. Inouye Solar Telescope on the island of Maui, which began operating in 1919.

References:
Wikipedia “McMath–Pierce solar telescope”

“Low Cost Adaptive Solar Optics” by Christopoher Kellar

Insights into the architectural design.

National Solar Observatory website..

Copyright 2022 Michael Stephen Wills All Rights Reserved

McMath-Pierce Solar Telescope – 2

The Mirrors

MichaelStephenWills1 Comment

These views within the McMath–Pierce solar telescope enclosure were captured during a guided tour of the instrument, April 20, 2005. By way of orientation, think of yourself at the location labeled “4” on this model. This is the only large telescope where humans can view the interior and visually experience the light paths “bouncing” between the mirrors.

McMath–Pierce solar telescope has three heliostats mounted on a 110-foot tower adjacent to a slanted enclosure. The 2.03-meter heliostat feeds a 1.61-meter primary mirror, there are 1.07-meter and 0.91-meter primary mirrors fed by a pair of 0.81-meter heliostats. Here we are inside the slanted enclosure, looking up the shaft to the tower mounted heliostats, readily identified as the three circles, the largest at center (3.51 feet in diameter). The smaller (2.66 feet) heliostats named “East” (on left) and “West.”

Built in 1962, the building was designed by American architect Myron Goldsmith and Bangladeshi-American structural engineer Fazlur Rahman Khan. It was the largest solar telescope and the largest unobstructed aperture telescope in the world. It is named after the astronomers Robert Raynolds McMath and Keith Pierce. Painted white to reflect sunlight to reduce heat accumulation, the enclosure is water cooled to prevent convection currents through the column of air within the slanted enclosure, keeping the air as still as possible along the light path between the mirrors.

In the three photographs following, we face the underground portion of the slanted shaft and (what looks to be) the 0.91 meter (2.99 feet) primary concave mirror. I say that because in some of the photographs a beam of light, to the left of the mirror, can be seen travelling further underground, presumably to the largest primary mirror. As there is only one such light beam, I conclude the west heliostat is inactive.

Here we looking up the slanted enclosure. Look carefully at the first photograph, below, to see reflections on the glass partition. The observation platform was separated from the light paths to maintain the stillness of the air column. The two mirrors of the first photograph are the third mirror, reflecting concentrated sunlight from the 0.91 and 1.61-meter primary mirrors into the observatory rooms. The mirror for the 1.07-meter primary is out of sight in foreground, I believe this set of three mirrors (West heliostats, primary and third) was out of service.

The second photograph, on right, is a close up of the third mirror for the largest primary. A foreshortened, perfectly round light disk is clearly visible.

Here we are inside the slanted enclosure, facing the underground portion of the slanted shaft and (what looks to be) the 0.91-meter primary concave mirror. In the lower right corner is the reverse side of the third mirror for the largest primary mirror, the 1.61-meter.

Reference: Wikipedia “McMath–Pierce solar telescope”
Copyright 2022 Michael Stephen Wills All Rights Reserved

McMath-Pierce Solar Telescope – 1

The Exterior

MichaelStephenWills1 Comment

These views of the McMath–Pierce solar telescope enclosure are the preliminary to a guided tour of the instrument, April 20, 2005.

On the tower are three heliostats, plane (flat) mirrors mounted on computer-controlled platforms to follow the sun across the sky to direct sunlight to primary mirrors underground, beneath the base of the slanted shaft

Built in 1962, the building was designed by American architect Myron Goldsmith and Bangladeshi-American structural engineer Fazlur Rahman Khan. It was the largest solar telescope and the largest unobstructed aperture telescope in the world. It is named after the astronomers Robert Raynolds McMath and Keith Pierce.

The slanted shaft, looking toward the tower.
View of the slanted shaft, looking toward the tower.
View from underneath the slanted shaft, looking toward the tower.

Inside the McMath–Pierce solar telescope is this keyed model of the observatory. Our docent for the morning tour stands alongside.

Reference: Wikipedia “McMath–Pierce solar telescope”
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