pencil. The ball would always roll away from the direction of the push, first rolling one
way then the other. Push is divergent.Now imagine the difference, if you attach a string
to the ping pong ball with tape, and pull it toward you. No matter how other forces might
influence the ball to roll away from you, the string would always bring it to you more and
more directly. Pull is convergent.
car. When I am driving uphill, I am pulling against gravity. The trailer converges nicely
behind my car. If the trailer begins to sway, I can dampen it by increasing pull— simply
increasing my acceleration. Now if I am driving downhill, the trailer may begin to push.
This produces a strong side to side force — divergence. My trailer will begin to sway
from side to side. Push is divergent. When the trailer begins to push us, experts advise us
to accelerate our car in order to re-establish pull. Pull is convergent. The trailer will
straighten out and we can congratulate ourselves for being good drivers. These then are
the two always co-existing fundamentals of Universe— Push and Pull — Compression
and Tension — Repulsion and Attraction.
A more common example of atensegrityis a child's balloon. When we examine an inflated
balloon as a system, we find that the rubber skin of the balloon continuously pullswhile
the individual molecules of air are discontinuously pushingagainst the inside of the
balloon keeping it inflated. All external forces striking the external surface are
immediately and continuously distributed over the entire system. This makes the balloon
very strong. We all know how hard it is to break a good balloon with a blunt blow.
against the continuously
pulling rubber skin of the
continuous pull and
humankind. And few of us are aware that it is a tensegrity. It is the power of tensegrity in
each tire that protects us from failure and blowout despite high speeds and long miles.
balanced by discontinuous push. When these two forces are in balance a stabilized
system results that is maximallystrong. The larger the system the stronger the system.
geodesic domes are themselves tensegrities:
compression and omnicontinuous tension. Tensegrity is a contraction of tensional
integrity structuring. All geodesic domes are tensegrity structures, whether the
not.Tensegrity geodesic spheres do what they do because they have the
properties of hydraulically or pneumatically inflated structures."7
tensegrity the stronger it is. Theoretically there is no limitation to the size of a tensegrity.
Cities could be covered with geodesic domes
materials and the degree of our technologies. As Harvard physician and scientist Donald
Snelson's sculptures — map out the shortest paths between adjacent members
(and are therefore, by definition, arranged geodesically) Tensional forces
naturally transmit themselves over the shortest distance between two points, so
the members of a tensegrity structure are precisely positioned to best withstand
stress. For this reason, tensegrity structures offer a maximum amount of strength
for a given amount of building material."8
New York, Macmillan Publishing Co, 1975, 1979
My own search for tensegrities began in 1980. As a trained physician, my attention first
turned to the human body.
skeletal systemis atensegrityof muscle and bone, the muscle provides continuous pull,
the bonesdiscontinuous push.The forces between the bones and muscles are held in
constant balance. This forms the basis for all of our physical mobility.
tensegrity of sensory neurons and motor neurons. The sensory neurons always sensing
information — continuously pullingand the motor neurons only occasionally involved
in some motor action — discontinuously pushing.
However, my focus was above the cellular level. I wanted to understand how individual
organisms related to each other and again I expected that the concept of tensegrity would
help us understand.
and Humans as Energy-binders, Space-binders, and Time-binders.9
Appendix — page 59
are continuous pullingas they collect solar energy from the sky, but with the rotation of
the earth and changes in the weather the sun only discontinuously pushesits radiation
on to the leaves.
to two roles either as prey or as predator. The prey animals are continuous pulling
predators to them. While the predators are only occasionally hungry. They
discontinuously pushout seeking the occasional kill. Prey and predator must be in
balance to stabilize the ecosystem. The larger the ecosystem the more stable it is.
Female and Male operate as a tensegrity. The femalewas continuouslymaking herself
attractiveto pull on her male, but the malewas only occasionally interested and
discontinually pushingtowards her with attention.
understanding through education. The two roles of humans can then be seen to be Student
and Teacher. I am continuously learning — continuously pullingin new information, but
I am only occasionally teaching — discontinuously pushingout information to someone
Appendix — page 66
other, we can see that:
ignoreeach other and form no tensegrity.
They form an adversary tensegritywhere the prey is continuously at risk of being hurt
and the predator is discontinuously hurting other.
other. We can form a synergic tensegritywhere we are continuously being helpedand
neglecting. Our clear and distant superiority to all other forms of life on this planet have
made it easy for us to neglect our biological basis. As we have seen ourselves different and
superior to all other forms of life, we have missed the point . While we differ from plants
and animals, we share their aliveness — we are stillliving systems — we are still forms of
systems, and therefore ourpowers and our problems will be those of life.
life. Our life connection is not only relevant, it is the crucial factor in determining a safe
passage through the current human crisis. A fundamental way of looking at life is by
examiningneedsandactionsand their relationship to survival.
All living organisms have needs. The primary drive of all living organisms is to survive—
to continue to live. To accomplish survival, living organisms require a zone of
survivability. In science we call this zone of survivability the biosphere. The biosphere is
the environmental zone where a living organism can meet its needs and act to survive.
and wehumans. These three classes of life each require a different biosphere to meet their
soil. Plants are able to grow and reproduce by utilizing sunlight in the process science
calls photosynthesis to create organic tissue .
organic tissue. They must eat food either in the form of plant or animal tissue. They
further need oxygen from the air instead of carbon dioxide, and they require water.
the form of plant or animal tissue. We also need oxygen from the air instead of carbon
dioxide, and also require water.
mineralsfrom the soil. It must also provide some shelter. It must not be too hot. It must
not be too cold.
andfoodto eat either plant or animal. And for the animals as well as we humans, there