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

[bennett bennett <bennett@oakland.edu>]

Perhaps the difference is that sawdust particles tend to stick
together as if electrostaticaly, but sand or salt doesn't



On 11/16/09, Josh Gates <jgates@tatnall.org> wrote:
> Dwight,
>
>  Thanks for the links, but my primary (unstated) reason for posting is
>  that I don't think that these are Chladni patterns. The shapes seem to
>  be more self-similar, and patterns exist over different scales; Chladni
>  patterns have pretty uniform unit size and some rough bilateral symmetry
>  (depending on the shape, I suppose).
>
>  The original link, for new readers:
>
>  http://imagecloset.com/tiny/874159
>
>  Josh
>
>
>
>  Souder Dwight wrote:
>  > These are chladni patterns.  I've also seen these as well when I'm doing woodworking, especially if I have to cut stuff like long pieces of trim and plywood sheets on a table saw or if I'm using the scroll saw.  The cutting process is causing vibrational movmement on the wood and with some standing waves.  The saw dust is knocked out of the area where it has the greatest amount of vibration, but settles in the nodes (lease amount of vibration).
>  >
>  > Here are some links to look at:
>  > http://images.google.com/images?hl=en&source=hp&q=chladni%20patterns&safe=images&um=1&ie=UTF-8&sa=N&tab=wi
>  >
>  > http://131.111.104.4/whipple/explore/acoustics/ernstchladni/chladniplates/
>  >
>  > http://www.physics.utoronto.ca/~nonlin/chladni.html  (click on the "violin shaped plate" towards the bottom)
>  >
>  > Dwight
>  > Ashland, OH
>  >
>  > This message was sent using 100% recycled electrons.
>  >
>  >
>  > ________________________________
>  >
>  > From: phys-l-bounces@carnot.physics.buffalo.edu on behalf of LaMontagne, Bob
>  > Sent: Fri 11/13/2009 11:43 AM
>  > To: Forum for Physics Educators
>  > Subject: Re: [Phys-l] What's happening here?
>  >
>  >
>  >
>  > I think I see the face of Jesus.
>  >
>  > Bob at PC
>  >
>  > ________________________________________
>  > From: phys-l-bounces@carnot.physics.buffalo.edu [phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Josh Gates [jgates@tatnall.org]
>  > Sent: Friday, November 13, 2009 8:24 AM
>  > To: Forum for Physics Educators
>  > Subject: [Phys-l] What's happening here?
>  >
>  > Hi everyone,
>  >
>  > 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
>  >
>  > Josh
>  >
>  > --
>  > Joshua Gates
>  >
>  > Physics Faculty
>  > Tatnall School - Wilmington DE
>  > Johns Hopkins Center for Talented Youth
>  >
>  >
>  >
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>  >
>  >
>  > ------------------------------------------------------------------------
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>  --
>  Joshua Gates
>
>  Physics Faculty
>  Tatnall School – Wilmington DE
>  Johns Hopkins Center for Talented Youth
>
>
>
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-- 
Clarence Bennett
Oakland University
Dept. of Physics,  (retired)
111 Hannah
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