[sdiy] OT: Blackboards

[Dave Manley]

I think some of my professors would have preferred it because
it is less likely to cause damage when thrown at great velocity
at a snoring or otherwise inattentive student.

This was in the unenlightened 70's and 80's, so I'm sure that
profs would never do this today.

-D

David Ingebretsen wrote:
> 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.
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> 
>