Re: Toilet bowl physics ???

["Paul Camp" <pjcamp@coastal.edu>]

I think this is a surface tension effect. I recall wondering about it 
years ago in the context of why the ice cubes in my tea always slam 
up against each other, as do the butter pats in my hot buttered rum. 
I figured that the water tends to creep up the side of the 
cube/butter/hair and if you think of the surface tension as a force 
vector more or less tangent to the meniscus, that could give rise to 
an essentially attractive force. I thought about making some soapy 
tea but it made my Southern knees shake. Try soaping up your toilet 
and see if it takes longer to cluster.

> In any case, the pieces fall more or less randomly and their initial 
> floating distribution is nearly uniform. But then they start clustering 
> into "galaxies of short hairs". The overall picture after about ten or
> twnty minutes is quite different from what it was at the beginning. The 
> clustering seems to be faster near the rim where the bowl is shallower. 
> The grouping of hairs (about 0.5 to 1 mm long) is not total but some 
> tendency seems to be present. Or am I am expecting too much from 
> randomness?
>                                               Ludwik Kowalski

Paul J. Camp                   "The Beauty of the Universe
Assistant Professor of Physics  consists not only of unity
Coastal Carolina University     in variety but also of 
Conway, SC   29528              variety in unity.
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