Point of Criticality

by Juanita Miller


Like a child's sand castle, seeds rain down onto a mound that grows until it can't grow any more. A complex balancing act keeps the mound stable until it reaches the "point of criticality"-the point at which the system "fails," creating avalanches that change the mound's shape. Scoop through the mound to make your own avalanches, or watch the system rise and fall on its own. Each avalanche relieves pressure on the pile, allowing it to begin growing again. Similar patterns of alternating growth and failure show up in many complex systems, from the stock market to people's emotional stability.

Dimensions: 9' x 12' x 9' Weight: 250 lbs.

Artist's Comments:

In making "Point Of Criticality" I was interested in a number of things. I first became interested in looking for a metaphor for the accumulative events in someone's life that might lead to mental or physical breakdown - ie. a critical point. I also realized that there were other systems in the world that were self-organizing and unpredictable such as the stock market and political and social situations.

A large pile of sand or grain is a self-organizing system in the way that particles fall and fit together, resting on top of one another. If they are allowed to pile on to a space with no sides they form as high as they can given their shape and weight. This is called their 'angle of repose'. When the pile reaches a height that is no longer sustainable it avalanches. But - and heres the really interesting thing to me - the same amount of grain falling can cause a large avalanche or a small one depending on the point of criticality of the pile.

This is the basic concept behind the piece which visitors will perhaps understand in part. I think and hope that there are other levels of enjoyment and interaction. The grain is wonderfully tactile and people of all ages are able to play in it. Farmers may appreciate the machinery and others the color and smell.