Re: Somewhat off topic. Neon gas tubes..

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: William Beaty <billb@xxxxxxxxxx>

On Tue, 4 Oct 2005, Tesla list wrote:

> Original poster: stork <stork@xxxxxxxxxxxxxxxxxxx>
>
> Bill
>
> I believe you're talking about repolarization during the T wave and
> it's a current related thing.

Yep.  One of the researchers who discovered this effect was killed by
experimenting on himself.  There's an old SciAm article about this stuff.
Apparently you can apply pulses of quite small current to your chest which
will advance or retard your heartbeat by one cycle.  If you do a graph of
pulse height verus phase with respect to heartbeat, you end up plotting
concentric circles.  What happens when you adjust the pulse phase and
height to explore the points in the center of the bullseye graph?  That's
the center of the lethal time window, the portal that leads to a fractal
world.  It kills you.  But it also shows that the "lethal window" requires
a current pulse of a certain height.  Your heart is like a tempered glass
bottle which can be flung against the floor without damage.  But it
shatters if tapped gently just once, in just the right way.

Years ago for a science exhibit I was planning on creating a heart muscle
made of an array of LM555 timers with LEDs.  Each 555 would trigger it's
neighbors, but would also self-trigger at a slower rate.  That way we
could see the waves which cross the muscle.  A faster 555 would be the
pacemaker node which controls the normal beating.  By poking at the array
we could trigger the tail-chasing pinwheel patterns which damp out
quickly.  Lethal fibrillation occurs whenever one of those pinwheels
surrounds the major vessles.  Unplug a few 555s in the middle of the array
to simulate scar tissue.  Lethal pinwheel patterns are also stablized
by such dead areas.  An engineer at Physio Controls says that these
phenomena can be viewed directly, by using voltage-sensitive dyes on
living heart muscle surfaces.



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William J. Beaty                            SCIENCE HOBBYIST website
billb at amasci com                         http://amasci.com
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Seattle, WA  206-789-0775    unusual phenomena, tesla coils, weird sci