On Sun, 3 Jun 2007, Michel Jullian wrote: > Only they are not filamentary in the monopolar drift area (most of their > path),
Says who? I hope you're not suggesting that, since theory predicts that they spread around, therefore they DO spread around, and no experimental verification is needed? > they spread around more or less evenly because they repell each other. Again: who as OBSERVED that they spread around as you say? My personal observations of actual ion flows shows that filament-shaped flows are common when potentials are below a certain high threshold. Threadlike streams of Electric Wind http://amasci.com/weird/unusual/airthred.html I initially found this very confusing, since self-repelling particles should fly outwards in all directions. How are these filament-shaped flows even possible? I know of two effects which could lead to narrow flows. First, when material is forced to flow through a fluid environment, sometimes the flow pattern of individual particles is not stable, and narrow jets spontaneously arise. Example: a descending cloud of volcanic particles sometimes forms a narrow ground-hugging sheet which flows at immense velocity. This is the origin of pyroclastic surges. Or more common: a descending group of rain drops moves together and flows faster than individual drops otherwise would fall, forming a "rain shaft." And rising hot air from a cigarette will become a very narrow vertical jet. In these cases the group of moving particles is dragging the air along with them, so the individual particles experience reduced air friction, and a self-organized flow structure with a particular diameter is created. Of course where charged particles are concerned, these "jet forming" forces would have to dominate over the particles' self-repulsion. If ion density was too high, the narrow jets would not appear. (((((((((((((((((( ( ( ( ( (O) ) ) ) ) ))))))))))))))))))) William J. Beaty SCIENCE HOBBYIST website billb at amasci com http://amasci.com EE/programmer/sci-exhibits amateur science, hobby projects, sci fair Seattle, WA 425-222-5066 unusual phenomena, tesla coils, weird sci

