[sdiy] OT: Blackboards

[David Ingebretsen]

I like chalk because it affords a great demonstration of shear planes and
brittle torsion fracture when I've taught fracture mechanics. Just take a
nice long piece and twist it fast. A beautiful brittle torsion fracture
results.

Unfortunately, I go through a lot of chalk that way...

David

David M. Ingebretsen M.S., M.E.
Collision Forensics & Engineering, Inc.
2469 East Fort Union Blvd. STE 114
Salt Lake City, UT 84121
www.CFandE.com

801 733-5458 Office
801 842-5451 Cell

dingebre at CFandE.com
dingebre at 3dphysics.net




-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Wiltshire
Sent: Tuesday, June 30, 2009 12:55 PM
To: David Panseri
Cc: synth diy
Subject: Re: [sdiy] OT: Blackboards

Another "Agree". I used to be a teacher and used whiteboards, which  
were a constant pain. The pens never seem to work properly, even when  
new. Chalk never fails to write, and a boxful seems to last for ages.  
Plus you can get more pretty colours!

T.