The Atomic Model

The Atomic Model

The model illustrates the structure of metals on an atomic scale and serves as a visual metaphor for interactions of many kinds. The detail and the dynamism of this display are purely poetic for me; one, in that its motion is so intriguing and two, in the level of thought it provokes.

This model is a perfect jumping off point for lessons in crystal formation and could be accompanied by text and photographs illustrating similar patterns found in nature such as ice forming on the surface of lakes, bubbles arrayed on the surface of water, etched cross-sections of meteorites, snowflakes under a microscope, etc.

As a life metaphor, the model is kept from equilibrium by the steady input of vibration just as the energy input from the sun keeps the systems of life on earth out of equilibrium. The model is an example of a gradient reduction system, as the gradient steepens equalization occurs at the grain boundaries and through the ceaseless cracking and rending of the lattice as a whole as long as the vibration persists.

A second level of viewer interaction is achieved via the manipulation of a probe inserted into the gap between the layers of glass and on into the two-dimensional aggregate of vibrating spheres providing another method for dislocating the lattice. As the viewer pushes the probe into the ball mass the pointed tip causes multiple fractures and
tearing in the matrix. A similar phenomenon is observed when driving the prow of a boat into a thin skim of pond ice and seeing it part and fracture.

The Atomic model contains 45,000 black acrylic spheres one eighth of an inch in diameter that stack vertically in the void between two sheets of plate glass 30 inches square comprise this two- dimensional atomic model. The assembly rests upon an isolating shock mount and is driven by a variable speed vibrating electric motor controlled by the viewer. The vibration provides a uniform dislocating influence causing the ordered domains of closely packed spheres to persist and migrate throughout the plane. Regions of order form and tolerate a few internal local anomalies but
conflict on a larger scale to produce linear boundaries of connected disorder. As many crystals start to grow in the same region, sooner or later they will interfere with each other. Neighboring crystals differing in no other way save in the direction of their atom rows in space cannot join without some imperfection. Nature abhors a vacuum,
practicing imperfection and approximation.

Pinscreen Demonstration

Pinscreen Demonstration

The Pinscreen is an installation whereby an array of pins
pass through two perfectly identical perforated panels which,
held vertically, allow the viewer to make an impression in the
pins by pushing their hand/face/etc. into the array.

Vibrating Pinscreen Portrait

Vibrating Pinscreen Portrait

Mosaiced into the pinfield is a photographic portrait of the Exploratorium’s
founder Frank Oppenheimer. The pins comprising the portrait are one inch
in length and are surrounded by pins five eighths
of an inch in length that predominate the thirty square inch field.
Being of greater mass the one-inch pins lag behind their shorter
neighbors when excited at any given frequency. The light reflected off
the longer pins’ polished heads lags in reaching the viewer, thus
revealing the pertinent information. A second condition that makes the
revelation possible is that the longer pins comprising the portrait are
arranged in specifically calibrated clusters that correspond to
relative amounts of light and shade in the photo portrait. This
directly translates to there being one more long pin per cluster for
each of the ascending steps in the eight step greyscale, where, for
example, eight long pins congregate around the center of a gride
square, corresponding to the lightest value possible in the portrait.

The above is a description of a masking technique which allows the
introduction of photographic imagery into the excitable medium of the
pinscreen. The description delineates an extended use of what is
inventor, Bob Miller, refers to as a pinhole portrait. Bob’s original
intended use of the device was for masking sun rays and producing
calibrated photonic impressions. He freely made its use available to
me for this experiment. Many thanks and fond remembrance.
The field of pins is 30” square. Each pin hangs by its
head in a hold through a thin steel plate. The hole is over-sized,
allowing the pin to freely swing and rotate. The entire pinfield is
being driven by a powerful variable speed, variable force vibrator.

The emergent patterns resemble those produced by the simple rules
governing wave propagation in cellular automata. Devised in the 1960s
by mathematicians John von Neumann and Stanislaw Vlam who were
interested in modeling self-reproducing entities, each pin can exist in
one of three states: receptive (meaning that it is liable to become
excited); excited and refractory (which means that it is recovering
from a period of excitation). When in an excited state, the pins
deliver a stimulus to those around it. If any receptive cell receives
a sufficiently large stimulus from its neighbors it too becomes
excited. But, once excited, a cell eventually enters the refractory
state, during which time it remains unresponsive to stimuli regardless
of what its neighbors are doing. Thus the vibrated pinfield, being an
excitable medium, its complicated behavior as a whole depends on the
simple interactions between neighboring pins giving rise to the
traveling spiral and target patterns occurring when excitations are
initiated at a few points - the wavefronts annihilating each other in
just the same way as they do in the models of cellular automata. I am
astonished that from these few basic rules such complex and gorgeous
phenomena arise. Does life in all its bewildering complexity arise
from such simple rules? If so, what a deep implication!

Pinscreen Table Demonstration

Pinscreen Table Demonstration

This video shows the pinscreen table being touched
from beneath by two hands.

			For the first time, an architectural-scale Pinscreen is a viable application, both technologically and economically. Initially, hand-held and desktop versions were limited in size by the sheer weight of the metal pins, and the glass/plexi cover necessary to keep the pins in place. The development of lightweight, luminescent polymer pins gave rise to new possibilities in Pinscreen size and design, and prompted Fleming to experiment until he developed a method by which the plastic pins can have a second head created after insertion in the perforated metal plate (thus eliminating the need for the protective cover). The new generation Pinscreen allows raised and sunken relief impressions to exist simultaneously in a single field, and the interplay of light and shadow in the luminescent pins yields a heightened photo-reality to the images one can create. Public and residential applications are numerous, from ever-changing luminaires to entire walls of impressionable and easily-erasable panels mounted to spin on a central axis. Pinscreen panels can now be created in any combination of dimensions, and mounted in myriad ways including: freestanding displays of metal, wood or glass; inter-wall installations (accessible from either side); and folding partition screens.