Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>
Greg, all,
Yes, I've tried the carbon-veil-in-the-microwave oven demo, as you describe it. I did it with just a burning match sitting on an upturned tumbler and I got the same type of spherical plasmoid that you de- scribed. In my case it would usually float upward and as it reached the top, it would float around and burn the surface of the plastic "ceiling" of the interior of the oven until I turned off the microwave. I would agree. That's the closest thing to what's described as BL as anything that I know of.
David Rieben
----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx> To: <tesla@xxxxxxxxxx> Sent: Thursday, June 23, 2005 3:09 AM Subject: Re: Ball Lightning in a different lab
Original poster: Greg Leyh <lod@xxxxxxxxxxx>
Haven't heard of any ball lightning anecdotes here at SLAC, although the accelerator here uses microwaves to accelerate the beam rather than direct high voltage, such as from a Van De Graff.
However one of the tenured professors here mentions that he witnessed a ball lightning event during a t-storm back in his teens, while living in the country.
Still the best pseudo-stable plasmoid event I've seen is Bill Beaty's carbon-veil-in-the-microwave demonstration. The generated plasma balls appear to be about 3cm in diameter, and stay coherent while moving horizontally or vertically within the oven. Their movement appears to be guided mostly by air convection in the oven. Revealing the physics behind these carbon-veil plasmoids could produce better theories for ball lightning, IMO.
-GL
Original poster: "S&JY" <youngsters@xxxxxxxxxxxxxxx>
[snip]
"The accidental formation of ball lightning has been observed about once per year for the past decade inside building 985 at Hill AF Missile Radiographic Facility, Utah. (my note: It's a huge X-ray facility for X-raying the first stage of ICBMs to detect propellant cracks, etc.) The volleyball-size fireballs drop out of the space adjacent to the high voltage supply of the 25 Mev linear accelerator.
The ball of blue fire floats down to the floor, rolls around randomly and then rises again to the power-supply area where it dissipates without detectable damage. Despite troubleshooting, no explanation can be found for this occurrence."
Greg Leyh - ever heard of that happening where you work?