Threadlike streams of "Electric wind"
- Hairs emit these threads. If I hold the bare side of my arm above the
mist tray, I'll see just a few black spots where threads touch down.
If I turn my arm over so the hairy side faces down, a great many
furrows appear, maybe several hundred. Occasionally I see a very
"powerful" ion-thread, one which can extend itself more than 2ft, and
when the emitter is close to the mist, it makes a 10cm circle of
roiling disruption. These super-threads come from very thin pieces of
lint, far thinner than hair. Perhaps they are more conductive than
other fibers? Or perhaps they are simply sharper. STEEL-WOOL
WHISKERS AND CARBON FIBERS ACT AS 'SUPER THREAD" EMITTERS TOO.
- if I tap upon the HV wire with a finger, the furrow in the mist jerks
after a short delay, maybe .05sec for 13cm, that's five MPH (can't
- the smaller, weaker "air threads" seem to be much narrower than 1mm.
How can they move so fast without turbulence! Or does their
short time-delay response come from a sort of electrostatic "stretched
long rubber band" effect, where the air itself moves slower than the
waves which propagate along on the "band"?
- When I used a soda straw and blew upon a thread with all my might,
the dot in the mist only moved a little. The 5mm dot was changed to a
10mm x 30mm blotch. INCREDIBLY BIZARRE! The air blast either causes
the thread to spread out into a narrow fan, or it causes it to
vibrate at high speed so that the thread tip traces out an oblong
blotch in the mist. These threads are robust! Not at all like smoke,
they are more like carbon-fiber spiderwebs under high linear tension.
- If I interrupt the path of a "thread" by using a plastic pen, it
is deflected by the pen depending on the polarity of the pen's
surface charge. The plastic is damp, and I tried touching the tray
with a finger to alter the polarity of the pen's charge, and found
attraction or repulsion of the threads. When the plastic pen is
polarized to repel the threads, and the pen is brought near, the
thread is pushed farther and farther from its original path, then
it suddenly skips to the other side of the pen. If I "push" it with
the pen tip, it swerves very fast around the tip. Like pushing an
electron beam with a charged object in a vacuum chamber! But at 1-Atm
pressure on my kitchen table! Cool!
- Threads seem to curve towards the charged plate. If I rotate my hand,
the tracing of furrows in the mist are showing that the threads
don't extend straight out from my skin. Perhaps they follow the lines
of the electric field. (So if they could be made visible, they would
be like electrostatic iron filings?) However, they don't seem to
repel each other very much. I've seen two threads with 5mm spacing
between them, yet they were 15cm long. If they were highly charged,
they would repel apart. If they are ions, there must be both
polarities of ions involved, so that the charge of the thread is
very weak in relation to the charge on the metal tray.
- I've seen pairs of threads come from a fingernail top, extend down
about 10cm and apparantly follow the field lines, all the while
maintaining a distance from each other of about 1cm! They don't
seem to repel each other much.
- The "fingernail pair" of threads above, when I placed my finger so
the emitter-points faced upwards, still curved around 180deg to
loop downwards and impact on the mist layer below. But now the
separation between them grew to 4cm. Though invisible, I can almost
"see" them curving and separating while spewing upwards from my
fingernail, like two streams from an invisible fountain.
- some "threads" are up to 60cm long! Very strange to wiggle the
HV cable more than 2 feet away from the mist pool, yet see
the trace of a thread-tip moving in the mist. The longer ones seem
to fan out towards their far end, to maybe 1cm diameter.
- each stream seems to fall apart at a particular distance. They
are weaker near their tips, then they simply end. However, this
might be caused by my increasing the distance between the charged
plate and the sharp hairs. Increasing the distance might lower the
e-field at the electrode-tip and cause the thread to vanish entirely,
though it seems as if I am pulling the end of the thread away from the
fog-layer so that it's tip no
longer reaches the plate. [Must try making a thread-gun which sends
beam into zero-field space. Then explore the "thread tip" behavior.]
- I can't get a view of the streams by forcing them to flow across
the mist. They refuse. They always curve down to the plate and hit
it roughly at right angles.
- I briefly saw a VISIBLE air-thread. A piece of lint was standing on
end in the water on the charged plate. When I brought my hand above
it, a white "needle" appeared above the lint and extended vertically
to my hand as the air-thread sucked the mist along with it. Then the
lint aparently leaped upwards to my hand, wrecking the effect.
- I can see a tiny time-delay when I wiggle a long fingertip-thread, so
the speed of the effect might be around 10mph or so, not instantaneous
- A sewing needle does not generate an ion-thread, while most types of
fabric fibers or human hairs do. A single human eyelash, clamped with
a small alligator clip, works very well as an electrode. I suspect that
when using much larger electrodes, the cause of the threads is always a
tiny and very,
very sharp fiber or object adhering to the electrode (or, existing
surface defects.) Perhaps any surface-defects
are atomically sharp, and this is an example of "field emission;" of
charged-particle emission which does not require a hot filament.
Perhaps dull objects such as sewing needles can only generate
air-threads whenever much higher voltages are employed. From my
experiences with VandeGraaff machines, I find that sewing needles
will cause air-flows of much larger diameter. I've heard that
atomically-sharp tungsten needles can be formed by evaporating the tip
of a tungsten wire in burning acetylene. STEEL WOOL WHISKERS
MAKE POWERFUL AIR-FLOWS.
- I connected a microamp meter in series with the plate. It indicated
zero. When I let the other HV wire create one furrow in the mist,
the meter indicated zero UA. When I brought the cable close, so
there were maybe 50 to 70 furrows being drawn along the mist, the
meter started flickering, indicating approx. 0.5uA. These
ion-streams, if that's what they are, are each delivering an electric
current in the range of 10 nanoamperes or less. Jeeze. No wonder
nobody ever notices them.
- I can't see any effects from a 3/4" neodymium magnet. At 10nA,
the magnetism around each thread must be incredibly small.
- I searched for optical deflection caused by air density variations
in the threads, viewing them in darkness while backlit by a bare
flashlight bulb and by the spread-out light of a laser pointer with
its collimating lens removed. Nothing. They don't cast visible
shadows on a screen, and don't appear as little glass fibers when I
look down the beam of the laser. According to Charles Yost's
FOUCAULT MIRROR TEST camera setup, I expected them to cast shadows
and be directly viewable. Perhaps his threads are denser (higher
total current.) I did note that the chips of charged dry ice are
emitting columns of frost specks upwards (very visible in the
scattered light viewed looking towards the laser. Frost builds up on
the surface of the dry ice, stands on end because of the surface
charge, and the fragments occasionally detatch and float upwards
along the flux direction.)
- I guided an air-thread onto the tiny frost-forest on a chip of dry
ice. The frost needles jerked, then a small patch of them collapsed
and melted. Aha, the air-thread is transporting a jet of warm air
downwards into the chilled boundary layer. If I used a very tiny
air-thread, maybe I could use it as a "pencil", and melt my initials
into the frost. Tiny carbon-dioxide civilizations would see mysterious
writing form in their crops, as if by magic. Hmmmmmm. Crops!
- Fibers from extra-fine steel wool can be used to create air-threads.
A sewing needle didn't work well, it probably was not sharp enough.6/9
- A steel-wool fiber, when held within 3cm of the charged surface, began
oscillating at its resonant frequency, and appeared to blur out into a
fan shape. Possibly the jet of air at the tip of the fiber can propel
the fiber sideways, and the direction of the jet is altered by the
changing e-fields and by motion of the fiber, so it "thrusts" in a
pattern which causes the steel fiber vibrations to increase
(or sometimes to rotate, which moves the fiber in a small circle at
fairly high frequency. Self-organizing plasma-ion thruster!). 6/9
- Without the mist, I observed the water surface by bouncing fanned-out
laser light from it at a glancing angle and onto a white screen. The
air-thread from a steel wool fiber caused a dimple in the water which
created a bright spot in the patch of light on the screen. The same
air-thread caused a 5cm patch of roiling turbulence in the dry-ice
mist. The more usual, Feeble air-threads did not cause observable
dimples. It seems that the mist technique is far more sensitive than
direct viewing of the dimpled water surface. I wonder what the air-
threads will do to the colored banding of a soap bubble?
- I attempted to view possible shadows of air-threads by using
fanned-out laser light. Nothing. Yost had success, but he was using
a proper Scheliern Photography setup, and his air-threads had hundreds
of times higher current (approx 20uA).
- I noticed a "dotted line" pattern in one linear furrow in the mist
layer. As I moved my arm along, one particular thread-emitter seemed
to be "sputtering" at a continuous pulse rate of a few 10s of Hz.
Could be from one arm-hair discharging to an adjacent one? I bet that
if a carbon-fiber thread emitter was grounded through a relay or other
HV switch, the connection could be pulsed and this would pulse the
air-thread's velocity. A row of these devices, if swept broadside
across the mist, could act like a "ink-jet printer" and paint any
pattern across the mist. It should be easy to use an oscilloscope and
a pulsed air-thread to measure the air velocity within the thread. 6/13
- By gluing a 1cm carbon fiber to a small floating "island" of Al foil,
I was able to make one of the stronger threads visible. It launched
itself upwards from the mist layer, and appeard as a 7mm tall jet of
white mist with a very narrow dark core (about .5mm core dia.) The
entrained mist-jet was laminar for about 5cm, then turned turbulent
above this height. I couldn't see if the dark core also became
turbulent. At the tip of the fiber I could see streams of mist moving
inwards in 3D from all directions, as if the tip of the fiber was the
mouth of a tiny suction hose (like gasses surrounding a black hole!)
The high-speed vertical jet is very narrow, and barely interferes with
this contracting sphere of incoming air. The carbon fiber was covered
with water droplets, and the air-thread would vanish unless my hand
was held about 5cm above its tip. This is different than when the
fiber is supported above the water and aimed downwards: when aimed
upwards under mist, the tip voltage needs to be much larger. The mist
droplets must interfere with the e-fields at the tip. 6/14/98
- In the dark with a flashlight, sometimes I see dust motes floating in
the air between my hand and the mist. If I move an air-thread around
in the volume containing the dust mote, I can eventually score a "hit"
an the dust mote vanishes, no doubt yanked downwards at several meters
per second by the core of the air-thread. 6/14
- I tried to grab a "thread" with a hook cut from paper. The paper simply repels the threads. However, the mist was raked by a pattern of parallel threads, and the result resembles the details of the cut paper! I found that, sure enough, if I sweep a torn paper edge over the mist, it rakes a pattern across the mist which resembles the structure of the torn edge. The torn edge seems to launch a great many parallel air-threads downwards. I bet I could bend the paper into a shape, and see the shape appear in the mist. Or even write entire words using edge-on paper, then stamp them into the mist! 6/14
Fig. 4 A large number of separate threads are pouring downwards from the fiberous edge of this suspended triangular paper tube (held by grounded yellow cliplead). They punch a dark triangular slot in the mist below. Mist which approaches this slot is forced down into the water, resulting in a mist-free triangle. Dry ice chip to the left.
Fig. 5 Now the triangular paper tube is closer to the charged mist tray, and a floating chip of dry-ice is within the "slot" created by the rows of parallel air threads. The center of the triangular area fills with mist, but any mist droplets which meet the wall of air-threads are forced to meld with the water surface. (Some mist leaks out at the right.)
- The preceding suggestion does work. A paper triangular cylinder 4cm on a side, held about 25cm above the mist, created a fairly clean triangular shape in the mist. The triangular slot in the mist was about 2x larger than the paper shape which generated it. The edge of the paper had to be torn using a straightedge. Cut paper edges do not work, there are not enough stray fibers. I bet that serrated-edge dressmaker scissors would work though. The threads create a slot, and if there is no chip of floating dry ice inside the triangular slot, a dark, mist-free triangular shape is the result. 6/25
Fig. 6 An "air thread shoots upwards
- I briefly made a tornado. With a carbon fiber jutting up from the water about 1cm, and a 10cm grounded brass sphere suspended about 10cm above it, a turbulent cone-shaped mist flow erupted upwards from the vicinity of the fiber, with a spiral inwards flow in the surrounding mist at the water's surface. No spiral in the "tornado" itself, instead it looked like a V-shaped jet of smoke, apparantly shooting violently upwards from a (nonexistent) hole in the surface of the water. I wonder if the air-flow pattern at the fiber tip might look like a spiral galaxy (with a radio beam exiting up along the axis?) Add a weird howling sound, and the mist jet it would be identical to films that I've seen made of the lowest 10ft of a real tornado. -6/25