4
$\begingroup$

With regard to the recent arXiv article:

J. D. Shelton, Eddy Current Model of Ball Lightening
http://arxiv.org/abs/1102.1224

I wonder if this is a reasonable explanation of ball lightening, or if there is such an explanation. The paper is somewhat technical and E&M is one of my worst subjects.

Please feel free to edit this question to one better suited, or if you don't have the rep, add a comment suggesting changes.

Improve this question
$\endgroup$
  • 2
    $\begingroup$ I would suspect any glowing gas-like stuff of being plasma. Just from the abstract I suspect the paper is about suggesting a mechanism for confining and conserving the plasma; which is rather less obvious. $\endgroup$ – dmckee --- ex-moderator kitten Feb 11 '11 at 3:57
  • 1
    $\begingroup$ Mr. Shelton seems to have solved some other hard problems, like dark matter and time travel... $\endgroup$ – user68 Feb 11 '11 at 9:06
  • 1
    $\begingroup$ I actually had thought that ball lightning as plasma was something that was established awhile ago. Curious. $\endgroup$ – Brian Knoblauch Feb 11 '11 at 15:29
  • $\begingroup$ One of the reasons I found the above paper interesting is because it delved into the topic of currents parallel to the magnetic field inside of helical fields. This was mentioned in the book that led me to the explanation of why the space physicists were wrong about the heliopause. See physics.stackexchange.com/questions/3957 $\endgroup$ – Carl Brannen Feb 12 '11 at 0:38
6
$\begingroup$

Ball lightning could definitely be some atmospheric pressure plasma phenomenon. You can make a pretty impressive ball plasma by discharging a kilojoule-scale capacitor bank into a bucket of salt water. Check out Free-Floating Atmospheric Pressure Ball Plasma. In most of those pictures they're using a copper sulfate solution, but that's not essential (sodium chloride also works). These ones only last a (significant) fraction of a second, but I'm sure if you made a larger one (e.g. by a lightning strike), they could last longer.

BTW, this was the subject of a killer science fair project: http://www.youtube.com/watch?v=SE6sbaNsKoc

Improve this answer
$\endgroup$
1
$\begingroup$

It's not a plasma. Couldn't be. When I saw one over a decade ago, it went straight through my glass window (which would insulate a plasmoid). The glass did slow it down to a walking-pace though, which was quite eery. Also, it had a sulfuric smell and was absorbed by my CRT tv, didn't even damage the thing... just turned it off.

http://pastebin.com/S12k4ZFv

Improve this answer
$\endgroup$
  • 3
    $\begingroup$ why would glass insulate a plasmoid? Link? From encyclopedic physics knowledge I know plasma can trap magnetic fields and carry them along. If it reaches the glass the magnetic field would pass ( momentum conservation of the field) and regenerate the plasma after the glass given enough energy, imo. $\endgroup$ – anna v Oct 3 '13 at 6:32
  • 1
    $\begingroup$ Anecdotes don't make for good answers. $\endgroup$ – Brandon Enright Sep 30 '15 at 4:10
0
$\begingroup$

I think that "magnetophosphenes" like those produced by transcranial magnetic stimulation, are more likely--ie a strong fluctuating magnetic field produced by nearby lightning strikes causes visual hallucination in the occipital cortex (visual region). These are reproducible using TMS but other mechanisms like plasmas are possible. Transcranial stimulability of phosphenes by long lightning electromagnetic pulses Authors: J. Peer, A. Kendl

Improve this answer
$\endgroup$
  • $\begingroup$ Just what I'm looking for, +1, when I get my voting rights back. $\endgroup$ – Carl Brannen Feb 11 '11 at 4:16
  • 3
    $\begingroup$ But there are videos of ball lightning so it cannot be only in the head: youtube.com/watch?v=D4vV3KxQ16c for example. Ever since meeting soliton solutions to differential equations I have been wondering if ball lightening are the effect of such a solution:a high self sustained em field. $\endgroup$ – anna v Feb 11 '11 at 6:33
  • $\begingroup$ Whoa, what happened to your voting rights @Carl? $\endgroup$ – user346 Feb 11 '11 at 7:17
  • 2
    $\begingroup$ I thought there was documented evidence on burns resulting from contact with ball lightning? That would be difficult to reconcile with it being an induced optical effect. $\endgroup$ – Brian Knoblauch Feb 11 '11 at 15:28
  • $\begingroup$ @anna v Well there are videos of UFOs too anna. Some are faked, some are of other things. There likely are freak situations when real plasmas are created, but very few. $\endgroup$ – Gordon Feb 11 '11 at 20:07
0
$\begingroup$

From my reading not all descriptions of "ball lightning" could be plasma. Plasma can't last for minutes hovering and/or passing through solid objects.

A free standing ball of plasma for a few seconds in the air sounds pretty reasonable though.

Improve this answer
$\endgroup$
0
$\begingroup$

This is a qualitative explanation of plasma behavior in a plasma ball given by the famous theoretical physicist Boris Kadomtsev in his book "Dynamics and Information":

The whole picture, despite its complexity,  can be qualitatively easily understood from a physical point of view. Of course, theoretically much easier to imagine   absolutely symmetrical glow discharge between the inner and outer electrodes, but such a discharge is unstable: due to the heating of the gas and  lowering its local density with a corresponding decrease  electrical resistivity it is more profitable to flow through relatively narrow channels - tubes. The discharge breaks down into plasma cords. Being lighter, these cords float up under Archimedes force. And the interaction of cords with gas flows and between themselves leads to the formation of complicatedly organized picture of "snakes", resembling the mythological head of the Gorgon Medusa. One can also understand why the ends of each "snake" form "cat paws". If the conductivity of the electrodes is low, then directly opposite to tht end of discharge tube surface charge density becomes less and the end of the "snake" with opposite charge conveniently split  and run from point to point, collecting surface  charge.

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.