<Hungarian accent> "Now, class, ve see zat ze sqvare root of x prime eez..." </Hungarian accent>

TAP-TAP TAP TAP SCREEEEEEECH!

<HA> "Oops, I have made ze mistake." </HA>

PAT PAT PUF PUF PUF PUF

As clouds of white dust fly around in yet another low-tech classroom, we begin to see the need for a chalkless presentation system. Large, flat-panel LCDs are hardly feasible, cost-wise, at this point. Projectors are expensive and prone to overheating / outright failure, at least in my experience as repairperson on said devices.

This leaves at least one obvious choice: dry-erase marker boards. These miraculously useful Godsends are appearing in classrooms all over as schools see fit to dispense their hard-earned nickels toward something other than another 10% raise to members of the budget committee.

One problem with these boards, though: unsightly black (or blue, or green) marks on one's hands after the eraser is lost again, and the time-consuming quality of having to erase the entire board intermittently.

I propose that we develop a gadget that emits extremely high- or low- frequency sound waves, vibrating the entire board and dislodging the very dry erase molecules of the markup theiron, instantly causing them to fall into the waiting waste tray below the board. Press a button and >blink< the board is erased.

The mechanism need not be large. Though I am no expert, I believe it could even be realtively small and still generate sufficient vibration to clear the board, provided the marker was specially designed to cling to the board somewhat tenuously.

Obviously there are issues with harmonics, etc etc etc. that individuals smarter than myself would have to work out, i.e. avoiding the "in-step soldiers on a bridge" problem. However, I have confidence in the ingenuiety of my fellow HBers to toddle around this dilemma with minimal difficulty.

On additional application: yes, it would probably be stolen as soon as it was lain down, but what about some sort of sonic gun that erased the board in a similar but localized manner? "ZZOT! NO MORE X SQUARED! HAHAHAHAHAHAAA!"
-- jester, Oct 03 2001

I was told that the reason whiteboards are not more common is that they are more expensive than their chalk oriented brethren. Something tells me that the shoestring budgets that don't allow for dry erase also won't have the cash for high tech erasers...
-- cmeador, Oct 03 2001


Sounds like an interesting idea, but what I want to know is, do they come with free Hungarian phrasebooks to translate the teacher's accent?
-- cp, Oct 03 2001


[cp]: It's only the effect of all that chalk dust on the vocal cords that makes them talk like that. Give them a nice clean environment, and perfect English results. (Who knows what all that magic marker residue in the air will do though.)
-- pottedstu, Oct 03 2001


Or scale up Etch-A-Sketch technology...you could still have a built in facility to vibrate the board as well.
-- -alx, Oct 04 2001


actually so far as I'm aware you don't get any marks on your hand from dry wipe pens. Unless of course you're using permanent marker, which is what some of the idiot teachers in my school have done in the past. You could've gotten drunk just inhaling the white spirit fumes emanating from some rooms the next morning. ol
-- kaz, Oct 04 2001


My university purchases markers from some sadistic, generic, non Sanford-or-MarksALot company who adds extraneous skin dye to the markers in addition to their dry-erase component.

But, yes, you do get gunk on your hands from those things, in the form of an odd, clingy "dust". It's not permanently staining and wipes off easily, but it still clings to clothes, etc. Or even one's nose, if one is given to erasing the board with one's nose or to falling asleep in Calculus class near a mischevious Hungarian professor armed with dry-erase markers.
-- jester, Oct 05 2001


It seems to me that the "in-step soldiers on a bridge" problem is exactly what you want here, to build up enough vibration to shake off the marker (supposing that's possible).

Another possible way of doing this is to develop a marker that releases charged dye, then giving the whiteboard a static charge as well. The polarity of the whiteboard can be changed so that the dye is either attracted or repelled.

[pottedstu] re: magic marker residue

<HA>and ze sqvare root is… ach! ze room iz melting! Now, class, ve vill leesten to ze colors! Vith a knick knack paddyvack, geeve a dog a bone…</HA>
-- magnificat, May 13 2002



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