Re: sugar vs. salt

[brian whatcott <inet@INTELLISYS.NET>]

At 17:26 3/30/99 -0500, John Denker wrote:
> You ought to be able to do fairly well with an air column.
> Air columns are used to separate particles by size during the manufacture
> of laser-printer toner.
> If you wanna get really fancy combine it with a centrifuge:  gravity down,
> airflow up, .....


Hmmm...this is evidently a list with a sharp focus on physics
 - I refuse to say 'narrow' :-)

There ARE science students who have the pleasure of sifting sand from
wind-blown dunes to investigate how the SALTatory action of the wind
sorts sand grains by size. Much the same action is seen in stream beds.
The beautiful brass sieves of various calibrated apertures are shaken
in a 'leaning tower of Pisa' style stack to sort these materials.

To be fair, this activity would have more relevance for geology students.
 It seems to me like a wonderful example of drawing science out of very
 modest experimental materials. But look: an engineer or materials
physicist can find a use for this information too - as John Denker
illustrates.

Brian
brian whatcott <inet@intellisys.net>
Altus OK