ETlight
Chris Knight wrote:That leads to a discussion of field-shaping. I'd have to suggest a book on electrostatics from a university library. The shape of an electrode is indelibly linked to the field shape - cone, rod, toroid, sphere, etc.
Chris Knight wrote:That leads to a discussion of field-shaping. I'd have to suggest a book on electrostatics from a university library. The shape of an electrode is indelibly linked to the field shape - cone, rod, toroid, sphere, etc.
Good, I really do need to find something constructive to do with all these guitars....twigsnapper wrote: I know of one in particular who shares sand and songs with your Mr. Buffet. Watch for him in the future.
I'm right with you on that one...Watch Dr. Browns path very carefully. When he is powering up, another is saying " I have seen all I needed to see" and is shutting down.
Paul, this is not a puzzle for you. You already know the answer to this one.
Yes, I'm well aware. The question was how you change the field in-flight if the surface of your disc is conductive. A conductive surface distributes charge fairly evenly over the surface (though charge density alters in regions of high surface curvature). My point is that you cannot alter the shape of the surface in mid-flight, consequently you cannot change the shape of the field in mid-flight, though you can reduce or increase its gradient with variations in applied voltage.Chris Knight wrote:That leads to a discussion of field-shaping. I'd have to suggest a book on electrostatics from a university library. The shape of an electrode is indelibly linked to the field shape - cone, rod, toroid, sphere, etc.
Gewis wrote:Yes, I'm well aware. The question was how you change the field in-flight if the surface of your disc is conductive. A conductive surface distributes charge fairly evenly over the surface (though charge density alters in regions of high surface curvature). My point is that you cannot alter the shape of the surface in mid-flight, consequently you cannot change the shape of the field in mid-flight, though you can reduce or increase its gradient with variations in applied voltage.Chris Knight wrote:That leads to a discussion of field-shaping. I'd have to suggest a book on electrostatics from a university library. The shape of an electrode is indelibly linked to the field shape - cone, rod, toroid, sphere, etc.
So here is my question. With such a field, how do you do x and y axis movement instead of just z-axis? I.e. How do you change direction? That's why I asked the question about the composition of the disc. If the surface is not of uniform composition then you can have metal parts here and insulating parts there and you can have preferred direction of flight because you can change the directions of the electric field gradients. Is that what is going on? If not, and the surface is of uniform composition, what is the mechanism by which direction of travel is controlled?
I hope what I was trying to ask is clearer now.
EDIT: No, I don't think it was necessarily clearer, upon reading over again. Here's the link: disc shape does not change in flight. Thus field shape, based on the disc, will not change in flight. I hope that's the last of what I need.
Chris Knight wrote:Have you ever seen the plasma generators thet they sell at Spencer Gifts ? They come in various sized glass discs - 10" and 12", I think. There is a gradient from the center of the disc where the arc density is relatively high compared to the outer edge where is is relatively low.
If you can imagine applying that analogy to the tri-arcuate discs, while it's true that the shape of the disc may not be modified during flight, the field shape can be modified by altering not only the charge density on the canopy, but the location of the charge density.
Chris Knight wrote:Have you ever seen the plasma generators thet they sell at Spencer Gifts ? They come in various sized glass discs - 10" and 12", I think. There is a gradient from the center of the disc where the arc density is relatively high compared to the outer edge where is is relatively low.
If you can imagine applying that analogy to the tri-arcuate discs, while it's true that the shape of the disc may not be modified during flight, the field shape can be modified by altering not only the charge density on the canopy, but the location of the charge density.
And they will - in a static situation such as the distribution of charge on the ball of a Van de Graff generator. However, you're dealing several differences - the most obvious difference is that you are not dealing with a static situation. Not only are you dealing with the modification of the location and value of charge densities, but also the asymmetric nature of the configuration of the disc.Charge really likes to distribute itself as evenly as possible on conductive surfaces.
Andrew,Gewis wrote:And that brings back my other question. What is the disc material composition?
I would recommend Serway and Beichner's Physics for Scientists and Engineers. It either comes in a large hard-cover book or broken into several volumes soft-cover. If you get the soft-cover, look for Volume 2. This is a standard text for introductory E&M courses. (When I say introductory, I don't mean it isn't good, deep stuff.) Chapters are Electric Fields, Gauss's Law, Electric Potential, Capacitance and Dielectrics, Current and Resistance, Direct Current Circuits, Magnetic Fields, Magnetic Field Sources, Faraday's Law, Inductance, Alternating Current Circuits, and Electromagnetic Waves.ETernalightwithin wrote:There are a lot of them out there, Anyone of them you'd recommend?
ETlight
Gewis wrote:I would recommend Serway and Beichner's Physics for Scientists and Engineers. It either comes in a large hard-cover book or broken into several volumes soft-cover. If you get the soft-cover, look for Volume 2. This is a standard text for introductory E&M courses. (When I say introductory, I don't mean it isn't good, deep stuff.) Chapters are Electric Fields, Gauss's Law, Electric Potential, Capacitance and Dielectrics, Current and Resistance, Direct Current Circuits, Magnetic Fields, Magnetic Field Sources, Faraday's Law, Inductance, Alternating Current Circuits, and Electromagnetic Waves.ETernalightwithin wrote:There are a lot of them out there, Anyone of them you'd recommend?
ETlight
If you can follow that book and work the problems (Calculus 1 and 2 are prerequisites), then you should have a solid working knowledge of the principles here.
EDIT: I mean you can have a working knowledge of the behavior of electricity. The interaction of that with gravity isn't something covered anywhere.