Word processors with line wrap: Cascading, self-organized criticality, random walks, diffusion, and predictability

We examine the line-wrap feature of text processors. We show that adding characters to previously formatted lines leads to the cascading of words to subsequent lines. The length of these cascades shows a power-law distribution. We show that this system is in a state of self-organized criticality. The connection to one-dimensional random walks and diffusion problems is demonstrated. Of particular interest is the exponential cutoff of the power-law distribution occurring for finite line lengths. Finally we examine the predictability of large cascades.