February 6, 2001
This is my technical (and informal) note on classification of static solutions of a pyramid formed by rigid disks.
It is written in an informal style, but the subject really is a mathematical classification of solutions of a set of linear equations. The arugument here does not look like a mathematical proof, but it indeed is a proof. (Trust me. I am a mathematical physicist.)
I learned about this problem from Shin-ichi Sasa. The idea that the complete classification of (highly degenerate) static solutions may help understanding the history dependence is due to Sasa. My contribution (if any) is only technical.
Here are scanned images of my hand-written note.
Hal Tasaki
