Take a standard piece of copier paper (80 g/m^2) and carefully peel it into two sheets. Listen out for the way it tears  and watch how fast the peel line creeps.

What you’ll see and hear is a stick-slip phenomenon in which the creep velocity varies over many orders of magnitude, with small movements of the peel line interspersed with huge avalanches.

So say Jari Rosti and pals at the Helsinki University of Technology in Finland, who have meticulously measured the way paper peels and developed statistical models to better understand what’s going on (those long winter evenings in Finland must fly by).

Why bother? It turns out that  the physics of peeling paper almost exactly mimics the stick-slip movement of tectonic plates, right down to the statistics of the time between “quakes” and the correlations between released energy and aftershock activity.

It’s tempting to imagine that peeling paper could  therefore be used as a simple model in which to study earthquake statistics. Sadly no. Rosti and co admit there are some subtle but surprising differences between the two systems which would make that impossible.

But it does raise questions about how such subtle differences arise in systems that are otherwise statistically so similar. Rosti hopes future work will reveal all. And with the Finish winter coming all too soon after summer, they should have plenty of time to get peeling.

Ref: arxiv.org/abs/0805.3284: Line creep in paper peeling

This entry was posted on Tuesday, May 27th, 2008 at 12:47 am and is filed under Changin' the world. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.