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Easiest Ball lightning Yet
Matt Crowley

Is your town full of rednecks and hippies? Do you get dull stares when you ask around town for "carbon fiber veil"? Of course, carbon fiber veil is probably the best material yet discovered with which to create microwave oven ball lightning, but the harsh reality is that carbon veil is still a somewhat exotic material to obtain. I got my supply from Boeing Surplus in Kent, Washington, which is only about 20 minutes south of where I live here in Seattle. About 20 minutes north of me is one of the nation's best suppliers of composite materials: Fiberlay. Unfortunately, Boeing Surplus does not regularly carry carbon fiber veil, and they are not set up for mail order operations as far as I know. Fortunately, Fiberlay does have a mail order service. But what if you are really impatient, like me, and want to make ball lightning RIGHT NOW? Well you are in luck, for one can make ball lightning in the old microwave oven using steel wool. So even if your home town is full of gun racks and Birkenstocks, you can still experience the miracle of cutting-edge plasma physics!

First, let me cover the basics for all those readers who have never seen or created ball lightning in the microwave oven. There are numerous materials and shape configurations that have been used to create this effect. I have tried the following: carbon fiber veil (the very best), carbon arc welding rods, graphite mechanical pencil "leads," carbon fiber from woven cloth, carbon fiber tubes, graphite powder, burning candles, charred toothpicks, aluminum foils and sheets, copper foil, copper wire, copper scouring pads, solder, and steel wool. Of all of these, only carbon fiber veil and steel wool work consistently. This is why I am writing this essay; you can find all kinds of methods and materials with which to create ball lightning all over the Internet, but of those I have tried only two work consistently. (For information on the King of Ball Lightning methods, google "Bigger, Better Balls.")

To create ball lightning using steel wool, you should use the finest steel wool available, which is 0000 (which everyone calls quadruple "aught," but which should be called quadruple "naught," for aught means "something" or "everything" whereas naught means "nothing" or "zero"). I have been able to make 000, or triple naught, steel wool work, but I suggest you stick with 0000. You will need a microwave oven with enough power to make this effect work. Opinions vary among researchers, but the consensus seems to be that at least 1000 watts is needed. Most new microwave ovens are at least this powerful, but some of the tiny ones may not be. What if you have an old oven and you don't know how powerful it is? If you check the back of the oven you may find a plate listing the serial number and other manufacturer data. Look for a number indicating the amount of current being drawn by the machine in amperes or "A." Multiplying this amperage by 120 volts will give you the wattage. But remember, this is the amount of power drawn by the machine, not the amount put out by the magnetron. My oven draws about 1700 watts but is only rated at 1250 watts. So the power drawn by the machine is really only a rough guide to its rated power. You may be able to find the power rating of an old machine simply by doing an Internet search on the brand name and model number. This method worked for me, although I am fastidious enough to have saved the owner's manual!

You will need a glass bowl to act as a "bell jar" to contain the ball lightning once it erupts from the steel wool. You can use any glass container, but I highly advise you to stick with brand-name Pyrex "bakeware" or at least glassware that is designed to hold food for baking in a conventional oven. Most second-hand stores have loads of glassware. The reason for using bakeware and not ornamental glass (fishbowls and the like) is heat. Once formed, the plasma has a tendency to get very hot very quickly. This brings us to the most important safety aspect of the whole demonstration: Once you have created the luminous ball, NEVER RUN THE OVEN FOR MORE THAN A FEW SECONDS. Note that a few seconds means like 2 or 3 seconds! I speak from experience when I tell you that glassware can and will shatter when exposed for any length of time to hot plasma. I can only conclude that plasma is a really good absorber of microwave energy because it gets so hot so quickly.

The last item you will need is some sort of heat resistant stand or block to elevate the steel wool off the floor of the oven. The easiest to use is probably a small ceramic ashtray. Second-hand stores have lots and lots of ashtrays. There are a couple of reasons for this seemingly trivial addition. First, you will get much better results in general if you remove the revolving glass platter and plastic lazy Susan bearing before the demo. This leaves a bare metal "floor" and you will either get no ignition or an arcing electrical discharge to the floor if you simply set the steel wool on the floor. Second, the floor, ceiling, and sides of the oven act as reflective surfaces for the microwave energy and make poor places to position things if you want them to get hot. Elevating anything off the floor gives it a much better chance to get hot. Also note that "stoneware" (such as small candle holders) is not the same as ceramic. Stick with white ceramic ashtrays or cups and avoid glazed stoneware and glass ashtrays.

So here we go: First, remove the revolving glass platter and lazy Susan bearing from your oven. Notice that this leaves a "trough" or circular depression between the center spindle and the outer corners of the oven floor. This is good, as it creates an air gap when bridged by the overturned bakeware bell jar. The air gap allows the strong acoustic buzzing of the plasma to escape under the glass. If you set the bakeware over the steel wool without leaving a gap, you will get a strong glass-on-metal buzzing or rattling sound that detracts from the elegant beauty of the demonstration.

Place the ashtray in the oven. It can either be right-side up or upside down. Upside down might work a little better because it is slightly more elevated and the walls of the ashtray will not obscure the sightlines to the steel wool.

Place a walnut-sized blob (2 cm in diameter) of 0000 steel wool in or on the ashtray. Cover with the overturned bakeware. Obviously the bakeware needs to fit over the ashtray. This is usually not a problem, but it is worth checking the fit when shopping at the second-hand store. Make sure the bakeware bridges the lazy Susan trough and creates an air gap.

Because very fine steel wool will ignite with just a match, you should have a glass or bowl of water handy to dunk glowing steel wool in after the demonstration. Don't just throw it in the garbage or recycle can!

Close the oven door and set the oven to full power. How much time you set it for does not really matter since we will only run it for a few seconds. Opening the door automatically shuts off the oven, so as soon as you push the Start button move your hand to the "open door" button.

Once you push the Start button, the effect should occur almost immediately. The steel wool should begin to glow red, then white, and then the plasma will jump up from the steel wool and "flow" around the underside of the glass container. The great temptation is to stare at this little miracle and just let the oven keep running. Again, DO NOT LET IT RUN FOR MORE THAN 2 OR 3 SECONDS!

Sometimes the steel wool will just glow red and not create a plasma. In this case, open the door and remove the glass bakeware using oven mitts. Dunk the glowing steel wool into water, and try again using a new sample of steel wool. You may have to reposition the sample as far as height or location is concerned because microwave ovens have "hotspots," where their energy is concentrated. Do not let the microwave run for more than a few seconds whether or not a plasma is created! Even without a plasma, empty glassware can get very hot very quickly. The good news is that in my experiments I get an ignition almost every time so you will probably not end up having to futz with moving the equipment around to get it to work.

As a side note, you may wonder where to set the hot glassware down after a successful demonstration. Because most people keep their microwave ovens in the kitchen, one good spot is on a burner of the stove. Formica countertops and wood and plastic cutting boards are not the best places to set down hot glassware. In a pinch, you can use the top of the microwave oven itself, as it is almost always metal, but this is no guarantee that the heat will not char or damage the enamel! Don't blame me: I warned you! You may end up having to break out the old "trivet," a metallic or ceramic holder designed to support hot bakeware.

Where do we go from here? I believe we are at a point where the materials and methods are now so refined that anyone can create ball lightning on demand. We are past the trial-and-error stage. The use of either carbon fiber veil (best) or steel wool (second best) avoids all the inconsistent futzing that goes on with toothpicks and candles and pencil leads and little metallic thingies.

I believe the next step is "doping" the plasma with metallic salts to create various colors. My own experiments thus far have been hit and miss, partly from an inability to easily obtain simple metallic salts. When I was a kid, I would often read children's science experiment books that would detail the wonders of creating colored fire in the fireplace by burning pine cones soaked in various metallic salt solutions. Inevitably, the books would say something to the effect of "just go down to the drugstore to buy your supplies." Having been a pharmacist for about 15 years, I am here to tell you PHARMACIES DO NOT CARRY METALLIC SALTS TO CREATE COLORED FIRE! Sadly, it is becoming difficult to obtain even safe, simple metallic salts at all. I am at a loss to give out an easy source for their supply.

I have been able to create an intensely yellow-colored plasma using common table salt (sodium chloride) and a beautiful lavender with potassium salts, but nothing repeatable enough for me to detail how someone else should do it. I suspect green plasmas can be created with copper salts. I look forward to seeing other people "take it to the next level."

<--- BACK TO BIGBALLS

Matt "The Tube" Crowley
October 6, 2004

 


 


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