Re: Diffusion coefficients

Dr. George Booth wrote:

>After watching the fish in the tank for awhile, I decided the probe
>was not the best idea.  The fishes lateral lines are very sensitive to
>electric fields and they were apparently aligning themselves to the
>field: they were all leaning toward the probe no matter what their
>orientation.  A very strange effect, indeed.  To counter this, I ordered
>some titanium wire from Edmund Scientific and ran a loop around the
>top of the tank just below the water surface.  This completely cured
>the fishes tendency to lean.

I think you have made a profound discovery. I myself have always wanted a
way to control the random movements of fish in a tank.

Have you perhaps conducted any experiments using multiple electrodes
connected to computer controlled synchronous low frequency sinewave
oscillators. With careful selection of the signal phases and electrode
placements it should be possible to choerograph the movements of the fish
to be somewhat akin to Olympic synchronized swiming performances, kind of a
piscene ballet. Imagine the possibilities. With judicious application of
high potentials at the opportune moments, no doubt some of the creatures
could even be coaxed into breif periods of emersed activity.

I have in my youth personally experimented with this. Our experiments were
aimed at methods of removing fish from ponds. Because I was not encumbered
by an electrical engineering degree at the time and was unfettered by
professional responsibilities, we did not limit ourselves to 12 volts for
any reasons of safety. The technique consisted of holding a metal rod in a
rubber masonary glove, and connecting the rod to a 115 volt RMS low
impedence sine wave generator running at 60 Hertz and operated by the
Tennessee Valley Authority. The return side of the generator was connected
to earth ground. After connection of the power supply, the rod was inserted
into the water. However, unlike your alignment observation, the fish
appeared to be very confused by the alternating current and tended to
remain where they were at the commencement of the experiment. After removal
of the experimental apparatus, the confusion persisted for several seconds.
It is obvious that the frequency we utilized in our experiments was too
high, thereby preventing the field alignment phenomena you observed.

Your brilliant experiment has caused me to rethink this issue. No doubt the
key to piscene ballet lies somewhere between the 0 hertz experiments you
conducted and the 60 Hz experiments conducted by our research team (me and
my brothers). I propose investigation to determine the optimal frequencies,
voltages, and field electrode placement for piscene ballet be conducted
along with your plant nutrient diffusion experiments. No doubt, it should
be possible to acheive superior plant growth and perhaps develop a
contender for the 2000 Olympic synchronized swimming event. After all, fish
are known to be able to go without breathing air underwater much longer
than young women (thereby earning big points from the judges), and they
don't get athletes foot in the pool shower.


In hot and humid (to us) Southern California