About the Artwork

Mirage is an outdoor sculpture, created by artist Katie Paterson and architectural studio Zeller & Moye for Apple Park, comprising cylinders of pure cast glass, made of sand collected from deserts across the Earth.

Over four hundred cast glass columns combine the world’s deserts into a wave-like form, mimicking desert dunes. The glass pillars connect Earth and sky. Olive trees and grasses within the sculpture create an interior garden. The sculpture curves around the trees, its form fading in and out of view. The glass subtly melts into the landscape, like a desert mirage. Inside, visitors gaze into deep time through each of these distant epochs and places, the material of time fused together, millions of years merged. Mirage has been cast in whole single glass cylinders — each 6’ 7” high — by expert glass makers, with guidance from material scientists. Unique glass recipes were formulated for each desert — and innovative methods of working with glass at this scale were invented and combined with ancient glassmaking techniques.

The desert is often experienced as sublime, endless, and harsh. In this sculpture, the desert expanse is unexpectedly transformed into a liquid-like, translucent material, flowing like a dune shaped by the wind. The cast glass is smooth, with characteristic bubbling. Desert sands create subtle variations in the color of the pillars. The artwork appears like an apparition: blurring the visible and invisible, inside and outside, near and far. In daylight the sculpture varies in iridescence, and in the evening it gently glows.

Visitors can interact with the artwork, meandering alongside and through it. Touching the cylinders is not only a tactile sensory experience, but also an opportunity for an imaginative journey through the many and varied places from which they were created. Visitors can move past mountainous deserts, subtropical deserts, coastal deserts, rain-shadow deserts, volcanic deserts, polar deserts, even fossilized deserts, dating back millions of years.

Mirage is set within a small park facing Apple Park and the Apple Park Visitor Center. Curved walls composed of glass columns meander through the grid of olive trees like an aura. Three entrances invite residents, passers-by and Apple visitors in, who can stroll on curved paths that follow the walls of glass. Mirage is a social space and an invitation to interact with others. The inner space is sheltered from noise and action where visitors can get together, sit on the grass or under a tree. Shifting layers of translucency and colour within the glass create illusionary effects – blurring the trees, the sky, and one another.

Mirage is a global artwork. In the spirit of co-operation, sand was sustainably collected in partnership with UNESCO International Geoscience and Geoparks programme, geologists, and communities across the world’s desert regions. The artwork celebrates each of the lands from which it is created, and the people who nurture, conserve, and sustain these places.

Mirage blends art, architecture, science and nature. Social and connective, it creates an unexpected gathering place. The practice of watching light fall through the columns is a form of meditation. Interacting with the sculpture creates connections to nature, deep time and the beyond. Mirage provides a moment of pause, inviting visitors to slow down, and tune into the immensity and preciousness of our planet.

Artist & Architects

Katie Paterson

Katie Paterson (born 1981, Scotland) is widely regarded as one of the leading artists of her generation. Collaborating with scientists and researchers across the world, Paterson’s projects consider our place on Earth in the context of geological time and change. Combining a romantic sensibility with a research-based approach, conceptual rigor and coolly minimalist presentation, her work collapses the distance between the viewer and the most distant edges of time and the cosmos. Her artworks make use of sophisticated technologies and specialist expertise to stage intimate, poetic and philosophical engagements between people and their natural environment.

Katie Paterson has exhibited internationally, from London to New York, Berlin to Seoul, and her works have been included in major exhibitions including Turner Contemporary, Hayward Gallery, Tate Britain, Kunsthalle Wien, MCA Sydney, Guggenheim Museum, and The Scottish National Gallery of Modern Art.


Zeller & Moye

Zeller & Moye was founded by Christoph Zeller (born 1974, Germany) and Ingrid Moye (born 1984, Mexico) as an architectural studio that operates with an interdisciplinary and global approach, with offices in Mexico City and Berlin.Their practice covers a wide range of typologies and scales, from object design to large buildings, working frequently at the boundaries of architecture, art and design. Zeller & Moye's projects aim to engage with the public realm and address social and sustainability issues while seeking for opportunities to go beyond boundaries and striving for the unexpected.

The studio has won the Panamerican Architecture Biennial of Quito in 2020, has been awarded as Design Vanguard by Architectural Record in 2023, and was recognized as one of the 100 influential designers worldwide by AD magazine. Christoph Zeller and Ingrid Moye are program directors of the Visiting School Mexico for the Architectural Association London. As writers, lecturers and guest critics at various universities they frequently contribute to the discourse on architecture and design.


Credits & Contributors

Mirage, by artist Katie Paterson and architectural studio Zeller & Moye, is commissioned by Apple. The artwork has been created over a number of years, involving the collaboration of hundreds of people globally. The expert team comprises Dr. Telesilla Bristogianni and Dr. Faidra Oikonomopoulou, glass experts at the Delft University of Technology, the Netherlands, who analysed the multitude of wild desert sands from every corner of the globe and performed elaborate studies in order to predict the composition and coloration of each glass column and create bespoke recipes of glass with the artists. The material was then mixed by Jim Meyer at East Bay Batch & Color, and the team at John Lewis Glass (Oakland, California) then created hundreds of columns of cast glass made from seventy desert sands. Mirage has been engineered by Eckersley O'Callaghan. Apple engaged the services of Artsource Consulting as the public art consultant who conducted a targeted global search for artists and guided the project through completion.

The sand collection was led by the artists, and has been generously supported by hundreds of people across the globe, in partnership with UNESCO’s International Geoscience and Geoparks programme.

  • Apple
  • Agency Projects: Kade McDonald
  • Ahmad Al-Zahrani
  • Aldo Repertto
  • Alejandro Herrera
  • Alexander Ugay
  • Ali Farah Abdo
  • Andri Snær Magnason
  • Andy Hubbard
  • Antonio Epul
  • Arif Arif
  • Arthur Moura
  • Artsource Consulting: Tessa Wilcox, Jody Knowlton
  • Barbara Núñez Jerez
  • Batsuren Jamiyansuren
  • Battuul Myagmar
  • Borja Alexandra
  • Bridget Grant Pirrie
  • British Council, Argentina: Valeria Zamparolo
  • British Council, Kazakhstan: Galina Koretskaya
  • Cavince Odhiambo
  • Cristina Becker
  • Dan Mutua
  • Dan Smernicki
  • Delft University of Technology: Dr. Telesilla Bristogianni, Menandros Ioannidis, Prof. Dr. Mauro Overend, Dr. Faidra Oikonomopoulou
  • Dina Salcedo Brush
  • Divino
  • Dr. Akram Akram
  • Dr. Ali Mahaqui
  • Dr. Catherine Russell
  • Dr. Diana Contreras Mojica
  • Dr. Edgardo Ancajima Salvatierra
  • Dr. Emese Bordy
  • Dr. Hilal Said Al-Zeidi
  • Dr. Jane Cook
  • Dr. Lydia Olaka
  • Dr. Maysoon Al-Damluji
  • Dr. Moussa Dabo
  • Dr. Niki Evelpidou
  • Dr. Paul Macey
  • Dunedin Stone
  • Eckersley O’Callaghan
  • East Bay Batch and Color: Mark Derrick, Aurelia Emma, Luis Guzman, Matthew Harvey, Emily Meyer, James Meyer, Kathy O'Brien, Pamela Smith
  • Elise Dillingham
  • Ellie Bush
  • Emily Lennox
  • Faycal Yacin Ahmed
  • Francisco Gonzalez Vera
  • Fundació Sonrigué: Gemma Avinyó, Ana Vallés, Pedro Vergel, Arctica
  • Gayrat Bayjonov
  • Gilberto Oliveira
  • Gustavo Flórez Salcedo
  • HGA
  • Hans Baumann
  • Haroon Assadi
  • Heather Winterer
  • Helen Nagomara
  • Holder
  • ISP Design
  • Indigenous Desert Alliance: Gareth Catt and Hamish Morgan
  • Ingleby Gallery
  • Iran do Espírito Santo
  • Isabel Paterson
  • Ivana Vasic
  • James Cohan Gallery
  • James McKee, Earwax Productions
  • James Okura
  • Jan Kruger
  • Jane Gimme
  • Jeanne Fromm
  • Jelena Rubil
  • Jerry Bergosh
  • Jessica Gallardo
  • Johanna Featherstone
  • John Lewis Glass:
  • John Lewis, Lynn Zboyovsky, Juan Cazares, Lawrence Huff
  • Juliana Engberg
  • Juliane Gomes
  • Justin Duance Jewellery: Issy Carreira
  • Karim Moselhi
  • Kasey Millsap
  • Khalid Mohamed Osman
  • Kira Wainstein
  • Leibniz Institute for Baltic Sea Research Warnemünde (IOW): Dr. Kristin Beck, Dr. Olaf Dellwig
  • Lena von Goedeke
  • Lisa Le Feuvre
  • Luiz Zerbani
  • Luz Martínez Santamaría
  • MARe/The Museum of Recent Art, Bucharest: Carola Chișiu, Erwin Kessler, Gabriel Popa
  • Manolis Lykouropoulos
  • Manu Rapoport
  • Marat Yuldashev
  • Marius Oldja
  • Mark Little
  • Martin Callanan
  • Martín Sabattini
  • Material Girlz: Shay Gerassy, Adi Tal
  • Matthew Hutchinson
  • Micga Onyango
  • Mikayla Whitmore
  • Mohamed Guireh Galab
  • Naiknam Karim
  • Nerson Tjelos
  • Nina Miall
  • Nýlistasafnið: Sunna Astthosdottir, Sigthora Odins
  • Omar Houssein Tata
  • Pablo Dominguez
  • Padre Yenner Yair Orozco Gomez
  • Prof. Amera Hussain
  • Prof. Brennan T. Jordan
  • Prof. Craig Carey
  • Prof. Guillermo Chong
  • Prof. Iftikhar Ahmed
  • Prof. Jan Zalasiewicz
  • Prof. Mashael Al Saud
  • Prof. Robin Griffith
  • Prof. Talal Al-Hosni
  • Rachel Strickland
  • Ruben Castillo
  • SOAS: Dr. Gloria Lee, Dr. Ali Alavi, Dr. Maria Flouraki, Simangaliso Mpofu, Beatrice-Lorena Gorcia, Ida Hadjivayanis, Marina Martínez Diez, Milena Stajic, Mohammed Alturayri, Naresh Sharma
  • Rair Ribeiro
  • Sculpture and Design
  • Simone Nascimento
  • Siobhan Maguire
  • Sociedad Geológica de Chile: José Cabello
  • Susanna Garcia
  • Suzie Fraser
  • Svalbard: Lisa Bakk Bøen, Charlotte Hetherington
  • Tania Pereira
  • Teddy Grant Pirrie
  • The Akimat of Kyzylorda
  • The Olin Studio
  • UNESCO’s International Geoscience and Geoparks programme: Ozlem Adiyaman Lopes, Marie-Laure Faber, Kristof Vandenberghe
  • Untamed Borders: James Wilcox
  • Vicki McInnes
  • Victoria White
  • Warlayirti Art Centre: Poppy Lever
  • Wendyn Cadden
  • Ximena Moreno
  • Youssouf Abdi Barkad

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Being in, on, and of place By Lisa Le Feuvre

Mirage is an artwork that celebrates the power of perception and place. Created by artist Katie Paterson and the architecture studio Zeller & Moye, this sculpture is simultaneously a singular and a multiple landscape that, with generous grace, offers an invitation to pause, to think, and to be in place. Mirage is formed of desert sand collected from all over the world. It is a gathering of transnational deserts, a collection of geological times, a pluriverse. Sand is a material that is everywhere – it can be found in the corner of shoes, at the edge of the sea, in industry, architecture, silicon chips, playgrounds, and glass. It is everywhere in art too, both materially and metaphorically. It is in painting, in photography, in film, in sculpture, in Land Art.

Landscape is first shaped by geological history, and secondly by human history. We human beings occupy and mark the surface of the Earth and the surrounding atmosphere with our activities. We claim to know nature through our invented ideas of ‘landscape’ and, as we fear we are losing that very nature, we form nostalgic stand-ins that have little to do with the facts of nature. Sometimes we even seem to forget that we are a part of nature, ignoring the imperatives of reciprocal existence.In the realm of the arts, centuries ago, the idea of landscape was created – a representational protocol making nature controllable, picturesque, distant, and mobile.

An important break to this landscape-fiction came in the late 1960s as Land Art came in to being, developing from the first wave of conceptual art and expanding the possibilities of sculpture. Artists such as Beverly Buchanan, Nancy Holt, Ana Mendieta, Fina Miralles, and Robert Smithson turned their attention to the materiality of landscape, directly working with the matter and material of our planet. For more than two decades, Paterson has addressed these legacies with an erudite and critical sensibility, forming a Land Art for this version of the present. Land Art is a complex and contested art historical term. Zeller & Moye create architecture that breathes with its environment. The ground we stand on is a site of deep-rooted power imbalances between earth-beings, a situation that the artist and architects are acutely sensitive to. Across their powerful practices, they consistently observe, paying attention to what is, amplifying the network of relations on, above, and below this rotating sphere that we inhabit.

Sand is a fragment of landscape, a trace, and evidence of entropic dissolution. It has its own beginnings and biographies that are as varied as the land from which it is formed. It comes from rock, shells, minerals, fossils; from remains of volcanic eruptions, meteorite collisions, tectonic plate movements, weather events, desiccated mountains. Sand is multitude in its form and use - after water it is the most-consumed natural resource on the planet. When weathered by water, the shape of each grain of sand is angular. When weathered by desert wind, it is round and soft, individuated; its shape useless for the composition of concrete – one of the most prolific industrial uses of sand. Desert sand is resistant, and it holds on to its agency, working in concert with the wind. Desert winds endlessly relocate and deposit sand, moving it like a gas, like an unleashed spirit, ephemeral and never still. Desert sand embodies relational ways of being: it is multitude, relative, insubordinate; it is the result of weathering, and it is an active agent of entropy.

Deserts are the ultimate shifting landscapes, they are in constant change and transformation, crossing continents and borders. A grain of sand is an entire topography, and it can quickly accumulate to form dunes that, to vision, seem infinite. Deserts are locations teeming with life and histories, they are places where scale is subverted, yet these expanses of sand are so often misrepresented as empty projection screens for imagined futures and pasts; sites for movies, novels, Land Art, military operations, and mythmaking. Sand too is replete with symbolism – it finds its way into aphorisms and origin stories, superstitions, and belief structures. Every grain of desert sand has a story and has a place, it is a fragment that collapses the past, present and the future into each other. A single grain of sand is a nomad, it comes from place, it leaves place, it is rooted in its relationship with everything surrounding it, and it brings together the immense and the intimate. Around a billion sand grains are born around the world every second; trillions of sand grains are on the move at every moment. Sand is always simultaneously here and elsewhere; moving from one place to then create another. This flow is reciprocal, circular, never unidirectional. Sand knows no borders; it is a material always in process.

The sand Paterson and Zeller & Moye have chosen has been subjected to alchemical processes to become glass, shaped into more than four hundred solid columns – one of the most basic architectural forms – gathered into an undulating wave seeming to defy gravity. When pressed into function, glass is a material that modernist architects and designers projected the future through, deploying its ability to draw light into space when transparent and to reflect with no shadow when opaque. Here, though, each element has been handcrafted in celebration of tactility and presence. In Mirage the glass simply is: it sits in its slow liquid form – so slow that no person could ever see it change in a lifetime – between the earth and the sky on its own terms, confidently of and on the surface of our planet. It is in place and made of many places. It is subject to gravity and revealed in light. These verticals are almost, but not quite, touching; each a different color, the hue dependent on the material properties of the sand. The grains from the Thar Desert of Gujarat and White Sands in New Mexico are white; from the Antarctic Polar Desert grey; from Israel's Negev Desert and Australia’s Great Victoria Desert orange; from Iceland’s Sprengisandur Desert black.

Mirage is something magical, something imponderable. It moves between the visible and the invisible, while enduing in a constant tactile form. It pays attention to the how and the what of perception; it insists on a situated understanding of being in the world. To be situated is both to understand the time, place, context of being in the world and to comprehend such situations are plural, not universal.

In 1971, a short book by Rudolf Arnheim titled Entropy and Art: An Essay on Disorder and Order, addressed relationships between art and entropy – a term taken from the Second Law of Thermodynamics. Entropy slipped into the vernacular during the 1950s, as fears of energy depletion became a mainstream concern, and it is an idea that became central to the formation of the new ‘landscape art’. Arnheim opens his discussion stating: “order is a necessary condition for anything the human mind is to understand. Arrangements such as the layout of a city or a building, a set of tools, a display of merchandise, the verbal exposition of facts or ideas, or a painting or piece of music are called orderly when an observer or listener can grasp their overall structure and the ramification of the structure in some detail. Order makes it possible to focus on what is alike and what is different, what belongs together and what is segregated”. Order makes sense; it enables assumptions to be made about what can and cannot be perceived, opens a perceptual choice, and suggests that a tendency to seek balance is fundamental to human, or indeed living, operations. Order is generally seen as something to praise: an indicator of good management, efficiency, and care over scarce resources. A desire for order is indicative of a concern with both perception of things and things themselves.

Entropy is the measure of the dispersal of energy in a system that indicates tendencies to and away from equilibrium. In 1973 Robert Smithson, a foundational artist for Land Art, declared in an interview with Alison Sky: “On the whole I would say that entropy contradicts the usual notion of a mechanistic world view. In other words, it’s a condition that is irreversible, it’s a condition that’s moving towards a gradual equilibrium in many ways. Perhaps a nice succinct definition of entropy is Humpty Dumpty. Like Humpty Dumpty sat on a wall, Humpty Dumpty had a great fall, all the king’s horses and all the king’s men couldn’t put Humpty Dumpty back together again”. Smithson was an artist who prized the power of sand for its ubiquitous, fragmentary, and scale-shifting qualities. In 1966 he was invited to be an artist consultant on the development of Dallas Fort Worth airport, and with this project he developed a sense of the possibilities of an expanded notion of large-scale sculpture, one that would later be defined by art historians as Land Art, and of the power of artistic collaborations with industry.

Smithson had a particular understanding of ecological thinking. For him, turning the clock back to reverse the ravages of industry was a naïve myth, instead he believed a productive environmental approach was to show the human impact on the world. Like Paterson, he was an observer; like Zeller & Moye he worked in concert with what was there already. In 1967, Smithson encountered a sandbox in Passaic, a now densely populated New Jersey, and described it as a “vast deposit of bones and stones pulverized into dust. Every grain of sand was a dead metaphor that equaled timelessness, and to decipher such metaphors would take one through the false mirror of eternity”. In A Tour of the Monuments of Passaic, a visual essay on a field trip to the New Jersey location where he was born, Smithson refers to this sandbox as a ‘monument’. He singles out bridges, pumping derricks, and pipes, along with the sandbox, as memory holders, as shrines to industrial progress and entropy.

Through an image of this sandbox monument he took with his Kodak Instamatic 400 – the square frame fixing time and showing an unremarkable playground empty of play – he asks his reader to imagine this granular landscape in a before-time, to think about its contents carefully divided into pristine halves of white sand (that would, surely, be either gypsum or crushed coral) and black sand (basalt, most likely). He then asks, in what he calls a “jejune experiment,” us to imagine a child running “hundreds of times clockwise in the box until the sand gets mixed and begins to turn grey; after that we have him run anti-clockwise, but the result will not be the restoration of the original division but a greater degree of greyness and an increase of entropy”.

Mirage pays attention to such concerns, re-engaging discussions of entropy with a contemporary urgency. Forms of growth and bursts of energy are at the heart of Paterson’s artistic practice. She harnesses scientific processes to create artworks that are proposals for thought, investigating how the rules of entropy impact on process, event, and perception of space. She looks to the imponderables of time and space, concepts we try to understand through the vagaries of language. An imponderable is something beyond comprehension; descriptive terms can only harness such slippery concepts for a moment.

Paterson looks to the stars, the seas, the earth and, with an ethical generosity, invites consideration of how we might attempt to understand these limits. Zeller & Moye create an architecture that steps aside from imposition, moving instead to form a reciprocal dialogue with place and perception. Mirage is a reminder that art matters. An art that matters makes ideas and questions material by thinking with the difficulties of being in the world. An art that matters is an art that anticipates what is to come, that harnesses burgeoning ideas still to be settled into language. An artist’s task is to add ideas into the world that extend and confound what is thought to be known, repurposing assumptions, colliding systems of understanding and proposing models of perception that extend thought. An architect’s task is to consider how adding something to the world can be an action that is formed by thinking with others, and sustained into the future with that very value. Accumulation of knowledge is an endless and immeasurable process. Art enhances what exists by going beyond what exists and by intensifying what exists. The purpose of art is not to provide beautiful relief from an unfathomable world; rather it is to address paradoxes and uncertainties, to make the world yet more complicated. Art can create a force to raise questions and open thought. An art that matters does not create the future, rather it vibrates with what is already tingling in the nerve endings. Mirage matters.

July 2023

  1. In 2016 Paterson and Zeller & Moye developed their first collaboration with Hollow, an immersive environment that brings together more than ten thousand tree species, from the earliest and the most recent forests.
  2. See Marisol de la Cadena (2015) Earth Beings: Ecologies of Practice across Andean Worlds. Durham: Duke University Press.
  3. See Michael Welland (2009) Sand: the never-ending story. Oakland: University of California Press.
  4. See Lyle Massey and James Nisbet (eds.) (2021) The Invention of the American Desert: Art, Land, and the Politics of the Desert. Oakland: University of California Press.
  5. William Tucker (1992) The Condition of Sculpture. London: Thames & Hudson, p. 7.
  6. Rudolf Arnheim (1971) Entropy and Art: An Essay on Disorder and Order. Berkley: University of California Press, p. 1.
  7. Robert Smithson (1973) Entropy Made Visible, an interview with Alison Sky. In: Jack Flam (ed.) (1996) The Collected Writings of Robert Smithson. Berkley: University of California Press, p. 301.
  8. Robert Smithson (1967) A Tour of the Monuments of Passaic, New Jersey. Artforum December, 6(4): 55.
  9. Ibid.


Interview with Katie Paterson and Zeller & Moye, by Alice Otieno

At the core of Katie Paterson and Zeller & Moye’s recent collaborative project, Mirage, is the desert landscape covering a third of the earth’s land area.Featuring over 400 glass columns, Mirage mimics wave-like forms inspired by sand dunes. Bringing together themes of time, space, and the interconnectedness of the planet, each pillar of pure-cast glass is made with sand collected from 70 deserts across the Earth.

Deserts often signify a journey. These seemingly barren yet vast landscapes provide a place where one can gather and wander, alone or in unison. They beckon a stillness and allow us to be captivated by wonder and awe. What is seen in a deserted place, and most importantly, what is reflected back? Perhaps a chance for us to see in a new way, to welcome what lies in the between, in the opaque and translucent. They slow us down, providing new insight into ourselves, others, and the world.

Mirage challenges the idea that deserts are simply empty, or devoid of life.

AO: How did the idea for Mirage begin? Take us through the process.

KP: California is steeped in astonishing geological history, and we responded to that. We had several ideas on the table but discovered quickly which we wanted to develop for Apple’s olive grove: a sculpture made of glass formed from every desert on Earth. Glass is made from liquid sand. I pictured gathering together sand from across Earth’s vast wilderness; and transforming it into a translucent material. Together, Zeller & Moye and I formed a team and developed the artwork’s form. After much experimentation, Mirage developed into curved walls of glass, flowing like desert dunes. From early childhood we understand that sand marks time. Grains of sand form when rocks break down by the weathering of waves, wind, and rain, eroding over millions of years. Deserts are formed through the evaporation of oceans, forming clouds swept inland by winds. I associate sand with transience, and find glass fascinating because it is both solid and liquid: sand and glass exist in liminal states. By working with sand, so ubiquitous across Earth, gathered from every corner of the globe, we wanted to create an experience of being enveloped by Earth’s vast spaces, connected to the elements. Mirage became a series of pure cast glass columns, hovering between ground and sky, made of the raw materials of the Earth. The artwork is dreamlike. It creates a wide open space that is both intimate and enveloping. The colors are contemplative: lime and apple greens, blue-blues and aquamarine-blues, vibrant turquoise through to subtle light tints to sharp clear. Nestled within trees, the sky reflected in the glass, Mirage is a light space, which encourages slowing down. Each bar of glass has its own characteristics, visitors can get lost in time gazing into them. CZ: In 2016 we, the architectural studio Zeller & Moye, formed a team with the artist Katie Paterson to develop and design a walk-in sculpture named Hollow made of all the woods of the world in Bristol, UK. For Mirage we came together once again to develop a walk-in installation. Once the idea was set to transform desert sand into glass we experimented with all sorts of forms and concepts for a space that would fully surround the spectator, a space that one could enter, and become immersed in a world of glass. Soon the choice for solid cast glass crystallised. It is a primal type of glass, a hot liquid poured by hand into a form, as opposed to the contemporary float glass that we see every day around us. IM: After developing many different spatial approaches with cast glass including tall compressed and low widespread structures; fragile entangled compositions; open and fully enclosed spaces; and basic geometrical shapes, we concluded with a simple yet multifaceted form that was possible to manufacture and feasible to build on site. Three-dimensional computer models and physical scale models helped finalise the precise shape and extent of the structure in relation to the surrounding landscape; the urban environment; and likewise to the human scale.

AO: The idea of gathering different contexts and people in one central place, appears to be a consistent thread throughout your work Katie, and even more so important in a piece such as Mirage. What are some of the sensations you hope people will experience while interacting with the artwork?

KP: In previous artworks I’ve brought together all the dead stars across the universe; every solar eclipse; 10,000 tree types; and a compendium of life strung in fossil beads. Similarly, Mirage collapses together the immense and the intimate. Generally my artworks seek to expand our time horizons, to enable us to develop a sense of the ‘overview effect’ where we can see the Earth as a single living system, with humans as just one part of its interconnected web of life. In creating Mirage, Zeller & Moye and I were drawn to the sublimity of desert landscapes; endless spaces which situate us in a wider perspective. California's geology is varied and complex. California formed gradually over a billion years, as a series of small island arcs, and deep-ocean sediments producing deep basins and high mountain ranges. Its oldest rocks date back 1.8 billion years and are found in the Mojave Desert. The desert sands we have collected for Mirage are from the most extraordinary places: mountainous deserts, subtropical, coastal, rain-shadow deserts, volcanic deserts, polar deserts, underwater deserts, and even fossilized deserts dating back millions of years. Sand, so ubiquitous across Earth, is a marker of time. Mirage creates an experience of being enveloped by Earth’s sublime spaces. Each piece of glass is a portal to otherworldly landscapes. Visitors are encouraged to touch the glass. We want those experiencing Mirage to feel the depth of time emanating through the materials. Our hope is that Mirage creates a sensory experience that will ignite the imagination, and connect visitors to the vastness of the Earth and its precious wilderness. IM: We expect guests from all over the world to visit Mirage. Some may try to identify which glass pillars are made of sand from their home desert, others may look out for deserts that they have visited while on vacation. I imagine many personal stories and memories will resurface when looking at the cast glass. Spaces have the power to bring back memories. But rarely can they speak about as many places simultaneously as are represented here in this installation. Mirage brings together people from all over the world. CZ: The individual glass pillars refer to places from all over the planet. And all of them come together in one condensed form in one unique place: Cupertino, California. The playful shape stands out in the urban context of office buildings and street landscapes. Apart from people enjoying the artwork and the various stories about deserts there is a second layer of perception. The glass wall fragments frame a part of the existing park thus turning it into a secluded garden. Visitors have the opportunity to look at their surroundings in a different way; their attention is drawn to its elements such as the trees, plants, birds, insects, the light and the sky.

AO: One thing I particularly love about the piece is how multi-layered it is: at the core is its reflection of the desert landscape, and then the materiality of the sand removed from that context, which then creates the glass columns that make up the artwork. I’m curious to know how all these different pillars informed the artwork’s name?

KP: The desert is a place where human senses can be distorted. A mirage is a type of optical illusion, most common in deserts. The desert sun heats the sand, which heats the air above it. Hot air bends light rays and reflects the sky. These shimmering heat hazes disappear as you approach. The word mirage comes to English via the French (se) mirer, from the Latin mirari, meaning "to look at, to wonder at”. The title captures the experience of the artwork: it is both present and absent, tangible and intangible - hazy, dreamlike, and illusory. CZ: The glass has a natural radiance and creates infinite reflections. Glass distorts views, it reflects and mirrors what is around it. All of these effects happen at the same time. Glass can trick your vision and suggest something that is not - like a mirage. In particular the solid cast glass with its thick transparent mass and textures on its surface make for a wide range of specular effects and reflections. The refraction of light bounces off the cast-in bubbles in the glass creating miniature rainbows. IM: The material glass originates from deserts. It is proposed that the first glass known to mankind was accidentally created by lightning flashes striking desert sand, melting the sand into small pieces of solid transparent consistency. The inventor of the material glass was nature. Glass and deserts are interconnected.

AO: You have both worked together on another project prior to Mirage (Hollow). How did your disciplines and interests come together in the making of this piece?

KP: Our visions are aligned; after working together for years, Zeller & Moye and I have a tacit understanding. That is hard to come by. We share a minimalistic approach, and have a similar drive in our work and approach to detail. I tend to work in ideas, and it works so well to collaborate formalising these often complex, intangible thoughts into real, embodied, physical experiences. Zeller & Moye’s architectural vision and understanding of space, embodiment, scale, light and immersion blends well with the ideas I create, particularly for Mirage. CZ: We share a way of thinking as well as a preference for reduced aesthetics. Our different disciplines complement each other. We approach a project together as one team that oscillates between strategic and systematic thinking, experimental and at times intuitive making. We each work with our own means of expression such as words, drawings, collages, computer models, then at certain intervals come together to exchange and discuss our ideas and drafts before returning to our studios to develop those further. IM: As with our previous project Hollow our starting point for Mirage was to combine art, science, nature and space. To tell a story that would gradually unfold through physical exploration of the space. Both Mirage and Hollow are created as permanent structures within public parks. Both are based on the idea of an outer appearance that is interwoven with the park landscape and an intimate interior offering space for contemplation and focus.

AO: Throughout your practices, there’s a real intertwining of the tangible and intangible, material and immaterial. How do you find a balance between these two worlds? Where are moments of harmony and dissonance found?

CZ: We are drawn to glass as a material. The rich interplay of transparency, reflection and juxtaposition can be used to create illusions and add layers to spaces. Glass can create the perception of being surrounded by nature whilst sitting indoors, it can visually connect but also acoustically cut off. We like to use glass in unusual proportions and sizes like a window that sits uncommonly low above the floor level giving the feeling of being half inside and half outside at the same time. The cast glass in Mirage is glass as we hardly ever see it - in its original form as a solid mass. It is at the opposite end of the material's range compared to the invisible glass of the surrounding architecture. KP: Glass is stone that flows. It is made from liquid sand. We were fascinated by the unfixed nature of glass: it is made from opaque sand, yet it is transparent. Sand grains are not really solids, they are not really liquids. And glass is a liquid, yet it behaves like a solid material. Mirage reflects this fluidity. The glass even has a water-like quality.

AO: What brought you to the shape of Mirage?

IM: With a lovely park landscape of olive trees as a site of intervention our first impulse was to create a structure with minimal impact on the existing vegetation. We aimed to keep all trees and developed the artwork around them in balance with the landscape. The artwork frames a section of the park with a series of curved walls that meander around the olive trees. Gently bent like desert dunes, the walls make visible the aura of each tree that they are playfully curved around. The resulting semi-open spaces of concave and convex shape create niches on both sides of the walls offering protection from street noise and direct sun. The wall fragments have been placed in the park with the flow of people and sight lines inside the park in mind. Last but not least, Mirage's dynamic shapes deliberately contrast with the regular geometries of the surrounding buildings along the street. KP: In developing the form for Mirage, it was important to us to thoroughly investigate the different visitors’ view points when experiencing the artwork: the curved spaces, inside and out, the nooks, the pathways, entrance ways, the vistas, panoramas, the height of the glass, and the relationship of the glass bars to the trees, the grass, and to each other. We wanted to create a balance with the very weighty, pure-cast glass and its inherent lightness and translucency, and for this to translate into the form. It is a journey, meandering from desert-to-desert, the whole planet brought together into this space. There are various vistas in the artwork where colors overlap; a hint of clear glass is glimpsed round a bend of deep greens, creating contrasts. In places the glass seemingly melts into the sky. From the highway, the artwork appears like an apparition.

AO: Why are the glass columns arranged as color gradients?

IM: At one point we considered replicating the geographical positions of the desert sands within the floor plan of Mirage so that individual glass pillars would be placed according to their geographical places on the World map, Instead, we decided to follow another logic of organization, as geography is only one aspect under which the deserts could be looked at. The chemical composition of each desert sand resulted in specific glass colors, a direct expression of the amount of certain substances in the sand such as copper or iron. We wanted to draw attention to these similarities between the sands that may be from opposite ends of the world. The chemical analysis by material scientists at the TU Delft added an element of surprise to the design process. In order to identify the range of colors that we could expect during the actual production of the glass, the scientists cast small glass samples based on the desert sands. It resulted in reams of shades of greens, blues, and aquamarines as well as clear glass. Based on those samples we tested different scenarios of color gradients across the curved walls in drawings on the computer and as scale models before settling on the current gradient design with different centers of greens and blues with the ends of each wall fading off into clear glass. The color gradients refer to the color spectrum of light. CZ: The color palette of the glass pillars matches the surrounding colors; both the green of the park landscape and the blue of the Californian sky are found again in the glass. Like a camouflage effect the glass structure blends seamlessly into its surroundings allowing the artwork to appear and disappear like a mirage in the desert.

AO: What is the relationship to glass and sand?

KP: Glass has always been found in nature. The technology of glassmaking is an ancient one. It has been suggested that the first glass was created by our ancestors about 4000 years ago, by craftspeople in Mesopotamia. Rumor has it that Syrians first discovered glass quite accidentally while cooking in pots placed over fierce fires on desert sand. Ancient glass was shaped by heating it in open molds. The earliest glassworks discovered were excavated in the Nile Delta; they date from around 1250 B.C. Nowadays, silicate glass is the most common form of glass in use, we can see it all around us. And though abundant, desert sands are largely of no use in glass making; desert sand is eroded by wind rather than water, and the grains are too smooth and rounded. Intrigued by this history, and drawn to the elemental nature of wild sand, we looked to ancient methods of glass making to create Mirage.

AO: What did the community involvement look like while sourcing the sand from each location?

KP: Gathering the sand took over a year. We collected various amounts from seventy deserts worldwide, with generous support from hundreds of people from communities across the world. We worked with stakeholders to collect and transport the sand in a sustainable way that was mindful of environmental and social impact. UNESCO was our partner in making a call-out to trusted geologists and geoparks all over the world. Mostly the sand collectors were geologists who practiced mindful sampling in the field to minimize environmental impact. We worked closely with our contacts on the ground to establish suitable locations for the sand collection, taking into consideration permissions, sand quality, access and environment. Our priority was to minimize disturbance to the local ecology; we collected sand from areas with previously disturbed ground or dunes which were well and continually sorted via wind, restoring the sampled area, and restoring dunes to their previous contour to avoid destabilising the slope, so there was no lasting visual impact. We ensured that the sand was sieved so no organic matter was removed from the environment and discussed additional socially respectful practices with local people. The community involvement collecting the sand for Mirage has been incredible. People from all across the world have contributed, from Mongolia to Patagonia; from the salty expanses of Utah, to the vast savannahs of the Kalahari Desert, the Arctic Circle and some of the harshest places on Earth. Together we have carefully gathered sand from high desert plateaux, shrubland biomes, snow covered sandy deserts, coral pink dune fields, deserts that were once ancient oceans, and the sands around active volcanos. Deserts with rugged and varied topography, sandy plains, scattered shrubland, unique rock formations, the oldest and highest deserts in the world. Geologists, scientists, sheep herders, artists, writers, mystics, and Antarctic explorers have all contributed - it’s been a truly global, collaborative and enriching process. Mirage is part of a long tradition of creating artwork with the raw materials of the Earth. Sand is an infinitely expressive medium, and is used widely across geography, cultures, and time. It can be used to tell stories of the past and of the future, and portray the constantly changing present. The intricate sand mandalas of Tibetan Buddhism depict harmony, a view of the universe, and a cosmic map; they are a reconsecration of the Earth and its people. Pitjantjatjara is one of the many languages of the many Aboriginal communities in the region around Uluru in Australia, a natural monument of ancient sandstone. Milpatjunanyi, in the Pitjantjatjara language, means the art of telling stories in the sand. It is a heritage deeply rooted in the land, in journeys, maps, and the dreamtime, in a culture of stories whose narratives are actively interwoven with drawing in the sand.

AO: Geologists and scientists have grappled with key characteristics that decide what a “desert” is, due to their constant movement and adaptation throughout time, as well as factors of location, language etc. After working on this project, how would you define a “desert”?

KP: Deserts are found on every continent and cover about one-fifth of the Earth. Deserts are somewhat anomalous; one thing they have in common is that they are arid, or dry. Geologically, they are defined by a lack of water. There is little water available for plants and other organisms. Some deserts are mountainous, others are dry expanses of rock, sand, or salt flats. And most deserts, far from being empty and lifeless, are home to a variety of plants, animals, and other organisms. Deserts are also home to around 1 billion people—one-sixth of the Earth’s population - whose way of life is dependent on coexisting with the sand. Except in the most extremely hyper-arid regions, people make a way of life in the desert, developing agriculture and communities around the desert margins. We worked with a number of scientists to define the deserts included in Mirage, at first using the Köppen Geiger classification system which broadly looks at temperature and precipitation. Later we opened up to include some semi-arid locales as well. The more we discovered, we broadened the criteria to include polar deserts, underwater deserts, desert islands, ancient fossil deserts and ‘new’ deserts formed by growing desertification. There are so many definitions and the deserts included aim to represent the global desert of the past, present and near future.

AO: Desert landscapes can often be associated with empty and barren lands, but Mirage presents a real life-force to them. What were some of the stories you were hoping to be conveyed through the piece?

KP: We are fascinated by the trans-continental journey of sand. Around a billion sand grains are born around the world every second, and trillions of sand grains move at every moment. Deserts are the ultimate shifting landscapes - in constant change and transformation - crossing countries and continents. Dunes migrate constantly. After being picked up by the wind, sand can travel over incredibly long distances - the particles are light and can remain suspended above the Earth’s surface for hundreds or thousands of miles. Sand from the Sahara is carried by wind as far as the Amazon, where it nourishes the rainforest and helps its plants and trees to thrive. Every sand grain in the world is unique, an individual. Sand grains are micro landscapes, they contain multitudes. For millennia sand has represented numbers too large to grasp, the passage of time, and eternity; at the same time, it is a symbol of things almost too small to see. Within its minuteness a grain of sand encapsulates greater things, it is a metaphor for a grander scale. Sand is a quintessential symbol of impermanence. It is a powerful symbol of origins, and is part of our collective subconscious. In myths from around the world grains of sand are the fundamental components of the Earth’s creation. For Rachel Carson "The sediments are a sort of epic poem of the Earth.” (The Sea Around Us). David Jasper describes “a landscape that both kills and redeems and is absolutely indifferent and pure. It is never and always.” (In The Sacred Desert: Religion, Literature, Art, and Culture). Sand grains reveal clues from the farthest reaches of deep time, close to the Earth’s beginnings. Aeolian processes can be seen in geologic record as long ago as the Precambrian era - billions of years before life formed, a time far before humans existed. So, sand grains can be a means of approaching the concepts of infinity and eternity. The desert has never lost its sense of vastness, its mystery, and its power over the human imagination. The life-force of sand and its endless journeys is something we wanted to convey in Mirage.

AO: I’m curious as to what role language played within the piece, as it pertains to naming the deserts?

KP: The naming of the deserts is an important aspect of the artwork. Deserts are borderless, liminal zones. They span countries, continents, nations, and a great diversity of peoples’ lands and languages. We researched and discussed this with organizations such as Australia’s Indigenous Desert Alliance, and with a team of linguists from SOAS, UCL, who rigorously worked through our lists examining the geo-social and geo-political aspects of naming and how we refer to the desert regions with respect and honor. Many of the translations of desert names are evocative. The name Namib is of Khoekhoegowab origin and translates to "vast place". Gobi Desert, from Mongolian gobi, means “waterless place”. Wadi rum is known as “Valley of the Moon” in Jordan.

AO: What is the relationship of the artwork within its location at Apple Park?

IM: The artwork is set back from the surrounding streets within a densely planted olive grove, like a secret. Seen from within a car on the street it remains a brief blurry vision. When approaching by foot visitors are invited to slow down from the urban pace and their daily routines and enter through one of the three entrances, evoking an effect of discovery. On one hand it is an opportunity for people to contemplate the artwork, on the other hand it allows them to focus their attention on the existing natural context like the trees and plants, the sky and the clouds, the sounds of the wind and the birds that pass by. CZ: In order to appreciate the beauty of the glass without distraction the pillars are cleared of all details so that only the pure glass cylinders are visible. The supporting structure is fully embedded below ground. The glass columns seem to rest on the ground like a rock in the landscape but in fact they are fixed in underground steel cassettes, which sit on a subterranean linear concrete foundation. The whole construction is highly precise but designed to be earthquake resistant at the same time. The pillars have a distance of 15 mm (1/2 inch) between each one of them allowing just enough space that was required to install the heavy elements. Integrated LED lights below the glass illuminate the artwork from within during nighttime.

AO: What were some of the challenges or complexities you encountered while making the pieces?

KP: Foreseeing the technical complexities in creating an artwork at this scale, Zeller & Moye and I formed a team comprising many specialists. Glass engineers and material scientists from the Technical University in Delft ran analysis on the desert sands before they were melted in the foundry. This allowed us to create bespoke ‘recipes’ with the sand - allowing the desert sand to affect the color and texture of the glass, whilst at the same time performing as a stable material, now and into the future. It was certainly a challenge to cast glass at this scale. We were really pleased to discover the glass foundry locally in Oakland who could produce glass on this scale and were willing to experiment with unusual materials going into their oven. John Lewis Glass pour molten glass into molds from the ceiling. No other foundry like this exists. IM: A project like Mirage requires a large team of experts to collectively work together. This project was so special because not only was a new material utilized for the installation, but the source material was also collected specifically for this project from across the world. The project brought together the best in each field, from glass scientists to bespoke glass manufacturers and structural glazing engineers. Designing and planning with a material that you don't know exactly what it will look like posed a challenge for the design approach. The involvement of material scientists testing the raw desert sands for feasibility to produce glass was vital. But still casting glass from desert sands was an ongoing experiment in the workshop, pouring by pouring. Firstly, we decided on using a cylindrical module for all the glass pillars. Secondly, a flexible layout was developed that allowed for various glass color schemes to be accommodated. Since it was unpredictable which colors the numerous sand mixes would produce we employed the idea of arranging the glass in color gradients ensuring all color shades were embedded in a larger narrative. In order to further bring into focus the qualities of the individual cast glass columns we decided to avoid an arrangement that would replicate the geographical desert locations within our floor plan layout but rather display the enormous spectrum and the subtle variations. CZ: The glass pillars seem to rest effortlessly on the grass. What looks like the most basic, straight forward configuration required a complex planning and testing process for its location in a zone with seismic activity. Each glass pillar is fixed below ground to a highly sophisticated anchoring cassette that allows the heavy solid cylinders to stand freely in a precise position cantilevering towards the top. It required careful thinking to find the right dimension for the small gaps between the pillars that would achieve a good balance between solid material and slender openings allowing glimpses; and on the other hand practical installation technique for the heavy but delicate objects. Arranging ultra-heavy glass as a series of free-standing columns in an area with seismic activity was certainly a challenge. Placing the heavy but delicate glass elements close to each other into a precise spot with cranes felt like driving through a china shop trying to not smash anything.

AO: Why did you use a circular profile for the glass pillars?

CZ: It was necessary to develop a module from which the curved walls could be assembled, that was feasible to be produced in cast glass at the same time. A circular profile extruded to a cylinder was the best fit. A pure geometrical form, in fact the most basic architectural element in history: a column. Therefore Mirage could be read as a homage to the fundamentals of architecture. Composed of 448 individually erected columns Mirage may appear closer to an ancient Greek temple or the first man-made structures such as Stonehenge than the architectural expression of today. IM: The height of the pillars of 2 metres (6 feet and 7 inches) relates directly to the scale of the visitor. Slightly taller than the height of a person the pillars visually block off the immediate surroundings and shift the visitor's focus not only to the visual qualities of the translucent walls but also to the earth and sky. Likewise, the walls are porous due to small distances between the pillars resulting in a playful juxtaposition of mirroring reflections and actual images behind the glass.

Do you expect the glass to age or change over time?

CZ: The artwork has been specifically designed for its location and its type of nature and climate. The translucid qualities of the solid glass is enhanced by the strong sunlight. The mostly dry weather and warm temperatures preserve the cast glass throughout the year. IM: Even though the cast glass has distinct textures on its surface we don't expect it to change noticeably with time. Most likely some erosion will occur but on a microscopic scale that is presumably invisible to the eye. The glass colors are inherent to the material and won't change.

What have been the greatest joys and surprises throughout this project?

CZ: It surprised me to see how the glass columns absorb the mood of the sky. The material oscillates between transparent and solid, colorless and colorful, clear and textured. The artwork melts together with the green park landscape and at the same time adds a new material in the form of diaphanous membranes of glass bars that come in a multi-faceted range of colors. For a moment the enclosed space makes you aware of the plants, the trees, the sky and the birds. Depending on the weather Mirage changes. On a clear day the powerful Californian sun charges the glass structure with light and makes it glow from within. The different colors of the glass appear intense and lively. Whereas on a grey day with overcast sky Mirage appears like a cloud with its colors fading to more subtle variations of white, light green and aquamarine. Mirage is designed to work with the weather not against it. The glass stands exposed to the elements changing its character as the weather changes. IM: Once the construction was complete, right after the fence was removed, residents on their evening stroll entered curiously and immediately engaged with their new 'neighbor'. A small group used the space for a brief picnic. That moment seemed to suggest that we achieved the creation of a space that would become an integral part of the local urban life, a place to meet and to come together, for visitors and the local community alike. KP: It was always a surprise and a great moment when the glass columns emerged from the oven, and we could see how the desert sand had affected the glass. The iron levels in the sand had the greatest impact on the coloration - more iron tended to mean darker, more colorful bars. The black sand deserts created the bluest blues. Mirage is never static: it changes continually through sunrise to sunset. This was a great joy to discover. Moody grey clouds cast a particular kind of light and affect the experience of the glass, bright Californian sunlight another. Through early morning light to evening dusk, moonlight and darkness, it is always a new experience. The glass pillars are arranged carefully in a gradient of hues. At times the colors stand out vibrantly, at others they fade away, and the bubbles in the glass shine through. We love that each piece of glass has its own quality; some contain torpedo-like air bubbles, others have very light specks of air like stars.

How do you hope to see the project evolve?

KP: The environment in Apple Park has been a great inspiration whilst we’ve worked through the creation of Mirage. It is a truly innovative and cross-disciplinary place; a melting pot of people, ideas, design, technology, science and aesthetics. Apple is constantly pushing boundaries. A strong influence in Steve Job’s vision and Norman Foster’s design for Apple Park is connection to nature which can be seen throughout the beautiful native planting and vistas to the surrounding landscape inside and out. Mirage feels at home in this environment. We’re excited to see how the project evolves in this context through visitor involvement and experience. The artwork is free and open to everyone; visitors from all over the world, local diverse communities in Cupertino and staff at Apple. We’re looking forward to learning about how children will respond to the piece; hopefully with playfulness and delight. We hope people will gather together in a shared place for reflection, discovery, and inspiration. CZ: We are looking forward to seeing Mirage becoming an integral part of the local community, the public realm and the wider urban fabric of Cupertino. It is an offer to the public to engage with the artwork and to appreciate it as a special place in the neighbourhood where one can rest, relax, or observe the sunset through the glass reflections, sitting under a tree. We hope that people from all over the world will come together in and around Mirage, filling it with life, adding their silhouettes to the perception of the artwork. Despite its very prominent location facing the Apple Visitor Center and the entrance of Apple Park we deliberately didn't design it to stand out as a landmark calling for attention. With its translucency and blending colors Mirage is a rather subtle intervention, a place that wants to be discovered.