Re: Verify and comment, please.

["Robert W. Harris" <rwharris@CATH-MEM.ORG>]

I seem to recall that if different sized marbles are shaken together the
larger ones rise to the top. This is because it is easier for the smaller
ones to work their way into the openings between the larger ones, thereby
moving downward.  This is a bit counter-intuitive, but true.  I would expect
stratification.

I can't think why the creamer would "clump" unless it absorbs water more
readily from the air than does the coffee, and that causes the grains  to
stick together.

Br. Robert W. Harris
Catholic Memorial High School
rwharris@cath-mem.org
http://www.cath-mem.org/physics/contents.htm



-----Original Message-----
From: Ludwik Kowalski <KowalskiL@MAIL.MONTCLAIR.EDU>
To: PHYS-L@LISTS.NAU.EDU <PHYS-L@LISTS.NAU.EDU>
Date: Monday, February 01, 1999 12:17 PM
Subject: Verify and comment, please.


> A strange observation. I put about 1/3 spoon of coffee (Taster's
> Choice, 100% pure Instant) into a glazed porcelain (clay ?) cup.
> Then about the same volume of Coffee Mate powder (non-dairy
> creamer Carnation, a little package from Nestle).
>
> Before adding hot water I started shaking the cup to mix two
> powders. Brown coffee grains are larger than while "milk"
> powder. NO MATTER HOW LONG I SHAKE I still do not see
> uniformity. White powder particles like to stay together, more
> or less. Two substances mix but not totally. After some shakings
> the mixture becomes nearly uniform but a clear tendency for
> clustering seems to prevail. Shaking seems to do two things:
> mixing and separating big particles from small particles.
>
> My white cup, by the way, has Einsein's face on one side and
> E=m*c^2 on the other. I am sure this is purely coincidental. The
> mean depth of my mixture is about 3 mm or so. The bottom
> is not perfectly flat.  An illusion of some kind? A wrong way of
> mixing?
>               Ludwik Kowalski