| In the autumn of 1948, while experimenting
with ways to build flexible modular towers, a young artist named
Kenneth Snelson constructed a sort of sculpture that had never been
seen before. Etheral in appearance and with no obvious weight-bearing
elements, it nonetheless retained its shape and stability. The following
summer Snelson showed the enigmatic form to his mentor, R. Buckminster
Fuller, who had been thinking about the possibilities of structures
held together by tension. Fuller adopted Snelson’s invention
as the centerpiece of his system of synergetics and, acknowledging
its integrity under tension, gave it the name tensegrity.
Made up of two types of elements called cables and struts - which
may be modeled with rubber bands and pieces of dowel - tensegrity
structures embody a balance of tensional and compressional forces.
Cables pull vertices together; struts hold them apart. Tensegrities
may be seen in such diverse manifestations as cabled roofs, robot
arms, the folding of proteins, the packing of granular materials,
the internal structure of glass, and the architecture of living
cells. A spider web can also be viewed as a tensegrity, albeit one
with no rigid parts. In the 1970’s mathematicians began a
general study of tensegrities, creating a theory with special regard
to their geometry. In this lecture Dr. Robert Connelly will discuss
tensegrities from spider webs to the carpenters rule and explore
the underlying geometry of why things don’t fall down. The
audience will be invited to build their own tensegrity structures.
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