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Threadlike streams of electric wind




I put some photos on page describing those narrow streams of ionized air
I've been playing with:

http://www.eskimo.com/~billb/weird/unusual/airthred.html


The strangest part of this phenomena is the apparent speed of the air
streams. With a VDG machine as a power supply, tiny spots on my
fingernails can easily create an air stream which punches a tiny hole in
the dry ice fog from 10" away. Yet when I then flap my hand back and
forth as fast as possible, the little spot on the fog moves in synch with
my hand motion!

I estimate my hand's peak speed to be 4 m/s, so the speed of the air
stream has to be lots more than 10x higher, otherwise a time lag in the
movements of the dot would be easily seen. But it seems impossible to me
that a stream of air 1mm in dia. could have a velocity of hundreds of KPH.

Perhaps the apparent high velocity is actually from e-fields redirecting
the air flow? So, as my hand moves, the e-field distorts, and the long
stream of charged air is dragged sideways, yet the moving air in the
stream itself does not have such a huge velocity? (But when I blow hard
on the air stream via a soda straw, the stream is not disrupted, and this
suggests to me that the stream DOES have a huge velocity.)

I've used the edges of paper "conductors" to punch large circles and
triangles in the fog from 12" away (see the GIFs), but I haven't tried
writing "PHYSICS" yet. :)

Materials:
- Electrostatic power supply (at least 5KV)
- Tray of water sitting on insulator
- chips of dry ice
- dark paper (submerged in the water for contrast)

Procedure:

Drop several CO2 chips in the tray so that a thin layer of fog forms.

Charge the tray with respect to ground.

Move your hand slowly over the fog, keeping your hand a few inches above
it. You'll see small mysterious furrows being carved in the fog by
the invisible, narrow threads of "electric wind"

If your hands are extremely clean (no sharp microscopic defects), then
instead try waving a torn bit of paper over the mist. The sharp paper
fibers seem to generate these "threads" of charged air fairly well.
If humidity is very low, then perhaps the paper should be made moist.

Wave your hand fast, and the spots in the mist follow your hand motions.

Form a "thread", then wave a charged object near it. The spot in the
mist moves, indicating that the "thread" is being deflected.

Use a soda straw to blow hard across a "thread". The corresponding spot
in the mist will move only a small amount!

Drop some short (1cm) pieces of hair onto the charged water surface.
They will stand on end, emit "threads" upwards, and narrow flows of
entrained mist will be seen to project upwards from the fog layer.

((((((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))))
William J. Beaty SCIENCE HOBBYIST website
billb@eskimo.com www.eskimo.com/~billb
EE/programmer/sci-exhibits science projects, tesla, weird science
Seattle, WA 206-781-3320 freenrg-L taoshum-L vortex-L webhead-L