Re: [Phys-l] zero width?

[Michael Porter <listmoe@gmail.com>]

On Oct 15, 2007, at 3:54 PM, John Denker wrote:
> On 10/15/2007 11:30 AM, Rauber, Joel wrote:
> > If you draw a line on the blackboard with chalk, the edge of the line
> > has zero width.  I.e. its boundary
> ...
> Chalk is an excellent medium for this, because you can turn
> the piece of chalk on its _side_ and make a nice fat mark.
> This makes it obvious even to someone in the back of the
> room that you are not trying to make a zero-width "line of
> chalk".  You are making a region whereof the _boundary_
> has zero width.

Okay, just to play devil's advocate here, how are you defining the  
boundary? Chalk is made of atoms and atoms don't have a well-defined  
edge.

---
Michael Porter
Colonel By Secondary School
Ottawa, Ontario, Canada