The shape of tensegrity in Nature

Kenneth Snelson is a sculptor. He explores the intricate structures found in Nature by contemplating with, ‘ the idea of form bound and defined by structure.’  He has said, “Structure to me is involved with forces, the stressing of pieces together, the kind of thing you find in a suspension bridge, for example. It is a definition of what is going on to cause that space to exist.” In an essay A Perspective on the Science and Art of Modeling Atoms the physiologist Robert Root-Bernstein wrote, “It seems a mistake to me to categorize Snelson’s work as one thing or another-as art or science, truth or imagination. Snelson’s work is a new perspective on structure in Nature and the Nature of structure.”

I quote from the informative, photo essay book , KENNETH SNELSON forces made visible an Essay by Elanor Heartney which,’ …follows the trajectory of Snelson from a childhood in Pendelton, Oregon, where his passion for model making began to his formative early art education as a young man involving a summer encounter with Buckminister Fuller at Black Mountain College, North Carolina which led to Snelson’s discovery of the principle of tensegrity that informs his sculptures and his investigations of atomic structure.”

“Building models offered Snelson a feeling of mastery over the world and a sense that he might construct an alternate universe. The models were also a way to work out abstract principles of balance and tension through objects that could be experienced with the senses. Thus, from an early age, it was clear that Snelson’s interest in structure, mathematics and physics would be grounded in physical materials and that he would be a ‘builder,’ rather than a theoretician or physicist.”

After the first summer at Black College Snelson returned to the University of Oregon as part of the GI Bill for having met the minimum requirement of serving in the US Army at the end of the Second World War for just over one year. ” Snelson began working with wire sculptures that consisted of stacked elements and moved on swivel points. He achieved a major breakthrough with a work he titled Early X Piece (1948), in which two wooden  X forms were held together without touching by a matrix of nylon tension lines much in the way a kite frame is constructed with sticks held together by taut strings. This work was a rudimentary example of a principal for which Buckminister Fuller later coined the word ‘tensegrity’  (from a combination of the words tension a nd integrity). Essentially it refers to structures composed of bars or tubes that don’t touch and are held in place by tension cables. Simple as this pioneering work was, it pointed ahead to the possibility of structures in which form and function are in Frank Lyod Wright’s formulation, one, and the visible configuration of the sculpture is simply the revelation of otherwise invisible forces. The essence of tensegrity is flexibility-things maintain their form through the outward push of the compression tubes and the inward pull of the tension cables. As a result the tubes, which in a more conventional sculpture would form a rigid armature, here never touch one another. The resulting rigid armature will bend, rather than snap, when subjected to pressure. And they will hold together independent of gravity. As Snelson describes it,’ The sculpture could be put into orbit in outer space and it would maintain its form. Its forces are internally locked. These mechanical forces, compression and tension or push and pull are invisible– just pure energy–in the same way that magnetic or electric fields are invisible.”

The second summer at Black Mountain Snelson showed his new sculptures to Fuller who immediately recognized their potential and Snelson feels, adapted the sculptures into his own work without credit to Snelson. Fuller, who would later become known as the master of the geodesic dome, was a mesmerizing lecturer who enlisted his students in realizing his elaborate visionary projects.”

“The principle of tensegrity would become a central theme in Snelson’s mature work as he plunged himself into the midst of the New York City art world in the late 1950s. Snelson, who has always maintained a position which is both inside and outside the mainstream art world, threw himself into work that elaborated on his tension-compression models, experimenting with materials like wood dowels, fishing line, aluminum tubes and bead chain to create structures that were held together by their own internal tension. The works in this vein took many forms, resembling at times, crystalline structures, suspension bridges, snowflakes and three-dimensional spider webs. However, they were united by the delicate dance of tension and compression in which the cables, served in a sense, as musculature and the cylinders as bones, held together in configurations that often were as miraculous as they were beautiful. Snelson (notably not Fuller) applied for and received a patent for his discoveries, which he dubbed, Continuous Tension, Discontinuous Compression Structures.’ (The publication of patents keeps these discoveries in circulation, and they are now available free on his web site, http://www.kennethsnelson.net/ )”

In the distant past curious humans discovered probably playing with grass blades that strands could be weaved together to form a material. Snelson has an interesting observation concerning weaving. “The ancient invention of weaving reveals in a direct way the basic and universal properties of natural structure such as modularity, left and right helical symmetry, and elemental structural geometry.

Two and only two fundamental fabric weave structures exist: the standard two way plain weave forming squares and the three-way triangle/hexagon weave seen most often in basketry. A single weaving event, passing one strand over another creates a mini-structure: two filaments crossing and in contact with one another, each warping the other where they press in contact. When two objects cross one another, two axes are created along the diagonals; one has a right handed, clockwise helix and the other a left handed counter clockwise helix. This along with magnetism with its north and south pole polarities, electrons with positrons is the very root of binariness. This duality which occurs at every crossing teaches the first lesson about the nature of structure. The helical phenomenon plays a vital role in determining how things get connected together.”

The above figures transformations convert static rigid structures into a tension envelope pre-stressed tensegrity structure. The beauty of Snelson’s discovery is that as an artist he was trying to balance sticks with elastic members discovering everything could suddenly hold together suspended yet with no touching. His first models were an inspiration like all art work. What is magical is that his models capture the shape that Nature uses to assemble things, which biologists have puzzled over for a long time. Snelson has revealed the Nature of shape in the structure as the shape senses itself as a coherent sense, a net of sensing. Although hisinsight happened in 1948 we are still coming to grips with the magnitude of his discovery of how Nature shapes itself. I will now go to a biologists thoughts on shape and tension from D’Arcy Wentworth Thompson’s book  first published in 1942, ON GROWTH AND FORM , six years before Snelson’s breakthrough with tensegrity structures.

‘The cell, which Goodsir spoke of as a centre of force, is in reality a sphere of action of certain more or less localised forces; and of these, surface-tension is the particular force which is especially responsible for giving to the cell its outline and its morphological individuality. The partially segmented differs from the totally segmented egg, the unicellular Infusorian from the minute multi-cellular Turbellarian, in the intensity and the range of those surface-tensions which is the one case succeed and in the other fail to form a visible separation between the cells.

From the moment that we enter on a dynamical conception of the cell, we perceive that the old debates were in vain as to what visible portions of the cell were active or passive, living or non-living. For the manifestations of force can only be due to the interaction of the various parts, to the transference of energy from one to the other. Certain properties may be manifested, certain functions may be carried on, by the protoplasm apart from the nucleus; but the interaction of the two is necessary, that other and more important properties or functions may be manifested.

Indeed we may say, with E.B. Wilson, go further, and say that that ‘the terms ‘nucleus’ and cell-body’ should probably be regarded as only topographical expressions denoting  two differentiated areas in a common structural basis.’

On the contrary it is quite certain that, whether visibly differentiated into a semi-permeable membrane or merely constituted by a liquid film, the surface of the cell is the seat of important forces, capillary and electrical, which play an essential part in the dynamics of the cell.

But if the cell acts, after this fashion, as a whole, each part interacting of necessity with the rest, the same is certainly true of the entire multicellular organism: as Schwann said of old, in very precise and accurate words, ” the whole organism subsists only by means of the reciprocal action of the single elementary parts.”

Discussed almost wholly from the concrete, or morphological point of view, the question has for the most part been made to turn on whether actual protoplasmic continuity can be demonstrated between one cell and another, whether the organism be an actual reticulum or syncytium. But from the dynamical point of view the question is much simpler. We then deal not with the material continuity, not with little bridges of connecting protoplasm, but with a continuity of forces, a comprehensive field of force, which runs through and through the entire organism and is no means restricted in its passage to a protoplasmic continuum. And such a continuous field of force, somehow shaping the whole organism, independently of the number, magnitude and form of the individual cells, which enter like a froth into its fabric, seems to me certainly and obviously to exist.” D’ Arcy Wentworth Thompson just speculated on the obvious need for a tensegrity pre–stress network, don’t you think?

I think it is fitting that such a gifted artist, Kenneth Snelson discovered tensegrity revealing objects from sculptures to brains, to be  held together without being in direct contact but maintaining a tension relationship within the essence of the basic unit of the structure, acting as a signaling/sensing unit. Like all great jumps of understanding  of how things work together, you realize  after that the observation of the significance that tensegrity is has always been there, it took  someone real special, like Kenneth Snelson  to reveal its essence the very first time for all of us to learn from.

Go look at yourself in a mirror, you are a tensegrity sculpture.

Converting brain map into tensegrity transposition overlap

 

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Montreal Grandmother, Agnes Kent was saved by Raul Wallenberg from certain death, when he provided papers for her and her Mom to escape away from the Nazis. Today when asked what that escape meant, she replied,"Remind people, that while statesmen and whole countries remained silent and did nothing, a single individual chose to act, with ramifications that proved enormous. Similar choices confront us today. Write that simple truth she said, it can never be repeated often enough because the world keeps forgetting it."
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