Re: [Phys-l] What's happening here?

[John Denker <jsd@av8n.com>]

On 11/13/2009 06:24 AM, Josh Gates wrote:

> After I finished working with a benchtop scroll saw, I noticed this 
> pattern in the sawdust on the work bench. The saw vibrates quite a bit, 
> so I'm pretty confident that the vibration is the root cause, but I 
> don't quite get why this apparent fractal pattern emerged. Ideas?
> http://imagecloset.com/tiny/874159

1) Short answer:  I don't know for sure what's going on
 in this situation.

2) In some possibly-similar situations, it is possible for
 fractals to grow due to _self-organized criticality_. 
 Indeed, the _sandpile model_ is perhaps the leading
 pedagogical model of self-organized criticality.

 I don't know if this line of inquiry will answer the
 original question, but I can guarantee that spending
 some time on critical phenomena in general and self-
 organized criticality in particular will be worthwhile;
 it is interesting as well as important.

On a purely pedagogical note:  SOC is an example of good
physics that was only rather recently discovered, but
does not involve hbar and does not require decades of
specialist training to understand it.