copyright: Ralph L. Knowles, 2008
SOLAR AESTHETIC II
Ralph L. Knowles
USC School of Architecture
Key Words: aesthetic, architecture, energy, form, nature, perception, solar.
This paper describes the second of two related design research projects that graph the effects of sunlight in three dimensions. The first paper, appearing separately on this website, gives an account of the aesthetic consequences of controlling sunlight on the surfaces of selected building forms. This second paper, instead of beginning with existent forms, describes the aesthetic consequences of generating uniquely adaptive forms by following the sun's path to satisfy specified conditions of incident solar energy.
The first paper was based on design research done at Auburn University in1962 under a grant from the Graham Foundation.
|1. SUN||2 & 3. SUN-GRAVITY||4. BUILDING|
Studies by R. Biggers, J. Coykendall, D. Egger, B. Hagler, J. Reagan, and W. Savage.
Click on images to enlarge.
The above models, based on the tetrahedron, represent work as it progressed through several phases. The first phase graphed the impact of sunlight on form, the second and third, combined forces of sunlight and gravity. The fourth phase sought to apply the concept of form differentiation to a simple program for an office building. The study, though limited to an examination of only two natural forces and completed almost 50 years ago, evokes images of differentiated form that we can identify with and understand today.
The second paper, presented here, is based on design research done at the University of Southern California (USC) between 1967 and 1969 under a grant from the National Endowment for the Arts.
|SUMMER: 8AM-4PM||SUMMER, EQUINOX, WINTER: 8AM-4PM||GENERATED FORM|
Models by M. Pearce
Instead of beginning with basic geometric forms as in the Auburn study, the USC study worked directly with the earth-sun geometry to generate form. In the example, linear elements representing the summer rays of the sun, first generate a single warping surface between 8 AM and 4 PM at 34 degrees north latitude. Similar generations at three seasons result in separate surfaces inclined southwards at different angles toward the sun. Finally, converting the solar lines into a smooth form results in a particular incident energy profile over the course of time.
FORM IN NATURE
If we are to confront aesthetic questions of solar form, we must begin with nature.
PLANKTON REDWOODS GROUSE OXBOWS
A new aesthetic was not the original purpose of the two earlier studies, but a fresh look at the work has been prompted by a lifelong wonder at the differentiated patterns and forms of nature. Vertical differentiation of color in plankton responds to separate portions of the sunlight spectrum penetrating to different ocean depths. A similar phenomenon can be observed in a rural wood or great redwood forest. In contrast to such vertical changes, horizontal differentiation can be observed in the feeding territories of Scottish red grouse or in the sideways ambulation of a river. To be aware of these differences is the beginning of a solar aesthetic.
PATTERNS OF LIFE
The differentiated patterns of nature helped set the patterns of indigenous human life.
OWENS VALLEY TREES PLANTS PIUTES
The Owens Valley of California is cradled between the precipitate granite heights of the Sierra Nevada escarpment on the west, and the more gentle sedimentary slopes of the Inyo-White Mountains on the east. Vegetation changes in quick steps from sub-alpine forest at the higher elevations to grassland on the valley floor. Over centuries, in response to this richly diversified world, Piute families migrated yearly, following exclusive pathways from one side of the valley to the other and back again, stopping in a different plant community to fish, to hunt or to forage, depending on the season.
PATTERNS OF PERCEPTIONS
More relevant to the subject of this paper, differentiated nature also helped set the patterns of our perceptions.
ORDER STRUCTURE FORM
Our understanding of the environment through physical sensation evolved in a differentiated natural world. The proof lies in our survival. Over evolutionary time, we learned to notice the differences essential to our orientation and free movement. Our survival required that we understand more than merely an orderly repetition of parts in a landscape, where we might have to guess to find our way. We would have looked for a structural relationship of some kind in which there was a clear choice among parts or sets of parts suggesting boundaries and directionality. Finally, we would surely have felt best oriented and most comfortable if we could understand the form, implied or actual, of what was critical to our survival. With that understanding, we could go on to other things.
A desire to learn and to teach more about ecology and the differentiated natural world led in 1967 to establishing the USC Natural Forces Laboratory.
SUN MACHINES WIND TUNNELS WATER CASTING
With a grant from the National Endowment for the Arts, the laboratory was first set up as an essential part of the 3rd-year architecture design studio. Three kinds of simulation tools were designed, built and used by students as integral to the design process. Sun machines, wind tunnels, and water tables of various types occupied the studio space along with traditional drafting tables. (This integrated function of the laboratory has since been transferred to a bigger space occupied by the USC Graduate Program in Building Science.)
Why do north and south slopes look different? To help answer this question, topographic models were built of real sites, placed on the sun machine and studied over virtual time.
SHADOWS: Summer; winter. LANDSCAPE
Why are windward and lee slopes different? To understand these effects, sand was eroded in the wind tunnel to simulate dune formation.
EARLY LATE DUNES
Why do streams ambulate? To understand this and other differentiated effects of water acting on the earth, soils of different composition were eroded on water tables.
EARLY MIDDLE LATE EROSION
SYNTHESIZING SOLAR FORM
Synthesizing solar form in the laboratory needs a purpose.
Sand and soil will automatically transform in a laboratory wind tunnel or on a water table. But producing a sun form on a sun machine requires an objective. Some of the pyramids of ancient Egypt were designed with very specifically placed openings leading deep into the tomb, allowing the penetration of a celebratory shaft of sunlight at one instant on a particular day of the year. But to make a solar form that acts purposely over time, the process of generation must relate hours to days and days to seasons. The form above is generated to equalize summer and winter solar incident energy, a strategy inherently applicable to passive solar design.
The structure of a solar form has a most favorable perceptual scale.
1 CUBE 64 CUBES 4,096 CUBES OPTIMIZATION
Pure shapes can be purposely generated in relation to the dynamic geometry of earth and sun but eventually, for habitable forms at least, architectural reference must be made to the ordering principles of construction and to the scale implications of use. Consider the hypothetical example of an oblate spheroid, a form that when inclined southward at the correct angle presents approximately the same silhouette area to the sun over time. As the size of the constructing increment decreases while maintaining a constant overall volume, an approximation of the pure form is approached. A plot of volumetric subdivisions of space against the desired behavior of the whole form shows that eventually the curve stabilizes, requiring no further subdivision. Experimentation shows that this phenomenon coincides with our visual recognition of an oblate spheroid. This has been taken to suggest an inherent scalar relationship between form and function in this work on solar form.
Habitable solar forms will likely require a differentiated structuring increment.
|VIEW FROM SOUTHWEST||VIEW FROM WEST||VIEW FROM SOUTHWEST||CUTAWAY|
Models by P. Ohannesian, G. Shigamura, and J. Talski
Click on images to enlarge.
A large model of the earlier form equalizing summer and winter incident solar energy helps to demonstrate three-dimensional differentiation of the form. Structuring increments at the surface of the form are relatively small, scaled to maintain the perceptual and functional boundaries of the pure solar form. Interior increments would likely get progressively larger for the collective use of shared space. (Structuring increments shown in the examples are all based on the cube, but further study might well suggest alternative space-filling geometries.)
Complexity of the resulting forms implies large projects.
Whether we are conceiving a single building or an entire community, constructing great frames and trusses or sculpting the earth and major landfills, today's building technology allows larger structures with greater shaping freedom than have heretofore been available to architecture. The result is an unprecedented ability through form to respond with subtlety to the sun’s energy. As communities of plants and animals vary in the natural landscape, so we might expect diverse ecological domains to evolve on the surface of such large solar forms. Depending on slope and orientation, ecological domains will be systematically different from each other and will have an overall contextual role to play. (All of the following examples are shown as simple mass models, but further study would likely suggest the need for systematic penetration of the masses to expose deep spaces.)
Above model generated and built by M. Klingerman, D. Moser, and R. Selvidge
Above model generated and built by G. Freedman, S. Paanja, and R. Yanagawa.
Above model generated and built by J. Black, M. Chen, R. Werner, and D. Malone.
Clearly there are aesthetic consequences to large size.
Time has changed the meaning of this work. It began over forty years ago with a single objective: To control incident solar energy, both light and heat, through adaptive form. Then, as the pure forms developed during the following two years, perceptual problems of scale emerged that were never resolved during the course of study. Now, with regard to the aesthetic consequences of the original work, it becomes clear that structuring the pure shapes can be a nature-based way to humanize scale on several levels. First, as nature sets the patterns of our perception through differentiation, so a repeated structuring increment provides the beginning of visual order; second, natural variations of the increment offer visual clues to ecological domains, providing directionality and choice; finally, actual or implied visual limits provide an awareness of form, and of our place in the environment. The aesthetic implications of large size can thus be architecturally resolved by applying the scale of our evolved patterns of perception.
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Acknowledgements: Professors Pierre Koenig and Emmet Wemple and the many USC architecture students who participated in this design research.