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ALSO SEE: even better
balls
Bigger, Better Balls
June 23, 2004 I discovered the joys of
zapping strange things in the microwave oven some time ago. I progressed
to the Christmas ornament and pretty much stopped there. Somewhere along
the line, I had learned that whatever was being zapped needed to be
electrically conductive to produce that distinctive buzzing sound and
lightning-like glow. Because I had been
keenly interested in Kevlar, epoxy, fiberglass, and resin composite
technology for some time, I happened to have on hand a small amount of
carbon fiber. Most people are familiar with carbon fiber as a woven
fabric, usually in a cross-hatched weave. I knew that carbon was a
semiconductor, so I unwove a patch of the woven fabric and placed a number
of "tows" of carbon fiber in the microwave. Nothing much happened: Usually
I would get a tiny white burning glow from one end of the bundle of black
fibers. Just to be experimental and cover all bases, I decided to "nuke" a
sample of another kind of carbon fiber: carbon "veil."
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Even people familiar
with fiberglass and composite construction techniques may not be familiar
with veil. A veil is a nonwoven mat of fiber that is usually used as a
final, top fabric layer on top of heavier (usually woven) layers of
fabric. Perhaps the most common use of veil is in antistatic dryer sheets.
It is also being used in ground-cover sheets as synthetic mulch. Because
the fibers in veil are very fine and randomly oriented, it helps to create
an even texture for an even-surface finish. I got very lucky one day
while at Boeing
Surplus, which is located south of where I live here in Seattle. I got
a huge roll of the stuff for $100. Pricing out a similar quantity from
Fiberlay (also here in I nuked a small piece of
carbon veil and found that it ignited almost immediately. At this point, I
was simply placing whatever "target" on the revolving glass plate and
cooking it. I learned that carbon veil would "burn," but it simply did not
produce that great of a display. I set aside my microwave experimentation
for some time. A year or two later I
read an article in Fortean
Times about ball lightning. I had been interested in ball
lightning since reading about it in one of Phillip Klass's early books. He
had suggested that many UFO reports could actually be instances of people
who had seen ball lightning. One aspect of the story in Fortean Times that really caught my
attention was the suggestion that people could make their own ball
lightning in the microwave oven! I eagerly reviewed the websites listed,
but I did not try it myself for fear that I would damage my nuker.
Eventually I got a lucky break. I had seen Bill Beaty
demonstrate an FET-based charge-sensing device at a One should remove the
revolving glass plate and plastic "lazy Susan"-bearing support. This is
done for two reasons. One is to minimize the air currents disturbing the
target as it revolves. The other is that if one places an upturned glass
bowl on top of a flat glass plate, something of a seal is formed between
the glass plate and the bowl, which usually leads to a strong buzzing and
vibration of the glass bowl. I believe this is due to hot, expanding air
rushing out of the upturned bowl and simply the strong "buzzing" sound of
the plasma ball itself. You will note this strong glass-on-glass rattling
effect in one of the short videos that French investigator Jean-Louis
Naudin posted on his website (http://jnaudin.free.fr/).
With the revolving glass
plate and the lazy Susan bearing removed, you have a circular trough that
surrounds the center spindle. If you place the upturned bowl such that it
bridges this gap, you will have no nasty buzzing glass vibration.
I tried the candle
method several times. I found the flame would tend to extinguish as it
consumed the oxygen in the upturned bowl. If you let the plasma ball run
for more that just a second or two, the candle will start to melt and make
a real mess. Timing the burn-out of the toothpick with the live candle
flame was tricky. The websites that I had found through Bill's microwave
oven site all seemed to indicate that carbon or carbon ions were somehow
mysteriously responsible. Luckily, I recalled my previous carbon veil
experiments. Unlike my previous experiments, this time I simply covered
the carbon veil sample with the Pyrex bowl. WOW! THE BIG
BREAKTHROUGH! Ladies and gentlemen,
throw away your candles! Screw the toothpick! Once you discover how vastly
cleaner and easier the method of using carbon veil is over the medieval
candle and toothpicks, you will never go back. With carbon veil, there is
no fire or smoke to worry about, no melted wax, and no toothpick futzing.
Even methods using graphite rods such as those of Naudin are less elegant.
According to Naudin, both his graphite rod and aluminum baseplate need to
be of rather precise dimension, based on the wavelength of the microwave
being produced by the magneto. Working with tiny graphite rods can also be
frustrating due to their delicacy. First of all, why the
emphasis on veil as opposed to the more common woven fiber? I do not know
for sure why veil works better than plain fiber so the following comments
are simply theories of mine. For one thing, the individual fibers of veil
are significantly finer than those of regular woven fiber. I suspect they
act as better tinder for ignition because of their greater surface area. I
suspect that veil provides more individual cut edges for the electrical
charges to accumulate. Also, most nonwoven fabrics contain some sort of
"binder," which is an adhesive of sorts to keep the fibers together until
the final resin is added. Perhaps this binder burns more easily than pure
carbon and acts as some sort of initiator. In any event I have not
been able to duplicate the success of veil with ordinary carbon fiber. I
also got sidetracked for a while because I felt I needed an inert gas
environment for the carbon to do its thing. As it turns out, inert gas is
not needed at all! So for all those who
have never nuked anything stranger than a slice of pizza but who want to
see microwave oven ball lightning, here is exactly how to do
it:
1.
Obtain a patch of carbon veil. A square foot is
probably enough for about 50 or 60 experiments. You will probably have to
buy
it from a roll that is 36 or 48 inches wide. The best retail places to
obtain
this semiexotic stuff are marine supply stores. Many boating supply stores
sell
only small repair kits, and those are almost always fiberglass so you may
have
to shop around. Some hobby stores will sell composite supplies, as carbon
is
becoming more commonly used in radio-controlled aircraft. In larger
cities,
check the old Yellow Pages under "fiberglass." If you live in the boonies,
you
will probably end up having to buy the stuff via the Internet. As of this
writing, Fiberlay in
2.
Obtain a large Pyrex baking or measuring bowl.
Again,
you will find other brands, but I recommend genuine Pyrex because of its
greater temperature tolerance. Most second-hand stores have tons of used
glassware and cookware. 3.
Obtain a small ashtray to act as a container for
the
target sample of carbon veil. It should be small enough to fit inside the
Pyrex
bowl. Strangely, I have found this is actually a fairly necessary piece of
equipment.
If you lay the carbon sample flat on the base of the microwave oven, it
does
not seem to work. I assume that the sample needs some height to intersect
the
standing waves. If you can't find an ashtray small enough you can use a
ceramic
spoon. These are often used in Asian restaurants and are usually available
in
Asian markets or restaurant supply stores. 4.
Remove the revolving glass platter and lazy Susan
bearing from your nuker. 5.
Cut a 1inch by 2 inch rectangle of veil. I have
found
that there seems to be a minimum dimension needed for this to work. My
bare
minimum seems to be about 1 square inch, so I double this for a margin of
success.
6.
Fold, cut, or crease the sample such that it
stands up
a little. A simple fold in the middle will tend to snap back flat, so you
may
need to rub the two halves of the fold a bit to allow the crease to become
a
permanent fold. This gives you a small "tent" that will stand up.
Alternatively,
go crazy with scissors and origami. All you need to do is have it stand up
a bit..
You can also set the target piece so that an edge sticks out over the rim
of
the ashtray or spoon, but make sure the overhanging edge is not closer
than
about 1 cm to the upturned glass bowl to avoid any arcing from the carbon
to
the glass. Arcing can spoil the plasma creation and erode holes in the
glassware. 7.
Set the ashtray with the carbon target in the
trough
that the revolving glass plate occupied, and then place the Pyrex bowl
over the
ashtray. The ends of the Pyrex bowl should span the lazy Susan trough. All
you
really need is for an air gap to exist between the floor of the oven and
the
lip of the Pyrex bowl so that the Pyrex bowl does not buzz and rattle
while the
plasma is present. 8.
Adjust the nuker's power setting to maximum. To
be
honest, I have not tested whether or not the effect would occur with lower
power settings. I suspect it would not, because the lower power settings
are
really just pulses of full power interspersed with longer periods of no
power
in-between. I suspect that any plasma created would disappear as soon as
the
first off-power interval occurred. 9.
Adjust your power setting to maximum, then press
Start.
If you don't achieve
ignition,
you may need to use a larger piece of veil or position it differently in
the
ashtray. Having done this many times, however, I can happily report that
the plasma
effect is easily created and remarkably tolerant of small changes.
I have tried wadding up
the
target into balls, but I have never gotten this to work. Again, it may
have
something to do with the exposed surface area or sharply defined edges. As
far
as two-dimensional shapes of the target, I have tried only squares and
triangles. My sense is that any more-or-less flat shape would do, as long
as it
is not lying flat on the base of the nuker or the ashtray.
Before I learned that
one
does not need an inert gas for the ball-lightning effect to work, I had
tried
both argon and helium as "shielding gasses." Sadly, I did not get a "neon
light" effect from either of these two inert gasses. I have tried doping
the
bowl with a slurry of salt granules and water. This seems to produce a
much
brighter and more yellow plasma ball. A few final thoughts:
The carbon
veil method is so much cleaner
than
the candle/toothpick method, and so little carbon veil seems to be
consumed
that for me it adds a new sense of wonder to the effect. As soon as the
veil
ignites and a plasma "sprite" jumps upward, the carbon stops burning. I do
not
have the electrical engineering background to explain why this happens. My
guess would be that the plasma absorbs microwave energy better than the
veil in
the same way that food containing water gets hotter than the plate or bowl
it
is in. One problem with the candle method is that the candle flame
continues to
burn while the plasma is active. This tends to obscure the fact that the
candle
is really only needed to initiate the effect, not to sustain it. This
"initiation" is demonstrated beautifully with carbon veil. Another candle
shortcoming is sputtering. Often with the candle method, the flame will
start a
plasma several times before it initiates a sustained plasma. I believe
this is
because of air turbulence inside the bowl that tends to blow the candle
flame
around. With carbon veil, you never have turbulence issues. You also do
not
have to clean away soot and crud created by the candle flame.
I also find it
interesting
that the carbon veil does not actually burn in the same way as if you lit
it on
fire with a flame. The "ignition" seems to produce little if any smoke,
and the
"flame" is usually white and not yellow-orange as in a conventional flame.
The
"ash" that results is grayish and extremely delicate, so clearly some sort
of
chemical and physical change has taken place. Amazingly, one can get
numerous
ignitions off the same carbon sample! Today I have gotten at least 30
ignitions
from a typical 1 inch-by-2 inch patch! But remember, you must let the bowl
and
ashtray cool down between consecutive ignitions. This quality alone shows
its
superiority over the candle method! I hope I have
contributed in
a positive way to the ball-lightning-at-home world. My guess is that this
method will prove itself superior in due time and that candle burning will
become
a thing of the past. After having
figuring out how to consistently create plasmas in the microwave oven I am
currently working on ways to "dope" either the carbon or the glassware to
produce different-colored plasmas. More: Easiest BL Yet My
thanks
to Bill Beaty for technical assistance and for posting this article on his
website.
Matt "The Tube" June 23, 2004 |