Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Toilet bowl physics ???



Those are interesting observations. I have not done the time dependent
experiment. I notice that when the contents of my razor are emptied into
a similar container, the small hair particles immediately spread across
the surface of the water. Seems to be uniform in density (surface hair
density!).

Sam


On Wed, 14 May 1997, LUDWIK KOWALSKI wrote:

Can you confirm the observation described below? Can you explain it?

I use an electric shaver (Philips) and empty it at once by throwing the
pieces of hair into a standard white porcelaine toilet bowl (from an
elevation of about one meter). The area of the toilet covered by water
is egg-shaped, nearly an ellipse (say a/b=2 and a=30 cm). The profile of
the bowl is more or less parabolic narrowing progeressivly toward the
bottom exit. There is no leak and ordinary clean water is still. I do
not think that these geometrical parameters are important.

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