Ball Lightning?

[JTM³]

Did anyone watch the national geographic channel special on lightning?

 

 

What did you guys think of the ball lightning part?

 

Was it all hype or could there be some new physics there?

 

 

 

From my other post in the General section. Sorry to put it here again but it hasn't gotten any replies and I'd really like to know....

 

 

 

 

Thanks for understanding

[bascule]

I doubt there's new physics involved... here's the Wikipedia take:

 

http://en.wikipedia.org/wiki/Ball_lightning

 

For a long time the phenomenon was treated as myth. Surveys have been taken of eyewitness accounts by at least 3000 people, and it has been photographed several times. There is as yet no widely accepted explanation.

 

Difficult features of the lightning include its persistence and its near-neutral buoyancy in air. In February 2006 Israeli scientists announced that they had created a short-lived effect using the same technology found in microwave ovens. More recently (June, 2006) researchers at the Max Planck Institute for Plasma Physics successfully recreated the phenomenon using a relatively simple water tank experiment. The experiment involves two electrodes placed in a small tank of salt water, with one electrode covered by a clay tube. A large current of over 60 amps was then run through the water for 150 milliseconds, vaporizing water inside the clay tube and causing a ball of plasma to appear above the tank for 0.3 seconds. Although the plasma glows brightly it was found to be quite cold, much like a neon tube.

 

A popular hypothesis is that ball lightning is a highly ionized plasma contained by self-generated magnetic fields: a plasmoid. This hypothesis is not initially credible. If the gas is highly ionized, and if it is near thermodynamic equilibrium, then it must be very hot. Since it must be in pressure equilibrium with the surrounding air, it will be much lighter and hence float up rapidly. Magnetic fields, if present, might provide the plasmoid's coherence, but will not reduce this buoyancy. In addition a hot plasma cannot persist for long, because of recombination and heat conduction.

 

There may, however, be some novel form of plasma for which the above arguments do not fully apply. For example, a plasma may be composed of negative and positive ions, rather than electrons and positive ions. In that case, the recombination may be rather slow even at ambient temperature. One such theory involves positively charged hydrogen and negatively charged nitrites (NO2–) and nitrates (NO3–). In this theory, the role of the ions as seeds for the condensation of water droplets is important.

[ecoli]

From my other post in the General section. Sorry to put it here again but it hasn't gotten any replies and I'd really like to know....

 

 

 

 

Thanks for understanding

 

This is probably what you're looking for.

http://www.newscientist.com/article.ns?id=dn9293