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Gaussian statics law
On Wed, 14 Mar 2007 09:09:27 -0800, Tom Donaly
wrote: Different texts have Maxwell's equations in different order. What text did you get this from? Becker has it (in Gaussian CGS units) as div D = 4\pi\rho (where the backslash indicates multiplication, and D and rho have the usual meanings. You can add the 't' if you want to, but it's unnecessary. Also, since you're dealing in 3 dimensions, why not indicate them as in E(x,y,z), or E(x,y,z,t) (if the time means something to you)? I tend to write equations in LaTeX form as most people I exchange emails with mathematical equations use that for formatting mathematics. Here, \pi represents the greek letter pi, and \rho is the greek letter rho. I used x to represent a spatial 3-vector. I could have written it as (x,y,z) but I did not think this shorthand would cause any confusion given the context. The difference between E and D is not important here. If you use D, then \rho must be interpreted as the so-called "free" charge density. However, the fundamental field is E, and if you use it the \rho must be interpreted as the _full_ charge density. The relationship between E and D can be very complex and may well depend upon the strength of the applied field E. For simple materials a linear relationship is usually assumed, e.g., D = \epsilon E, where \epsilon is the dielectric constant of the medium. Also even here in this linear relationship, \epsilon need not be a scalar (a number). It could be a tensor (a 3x3 matrix), in which case D and E would not have the same direction. --John |
Gaussian statics law
On Mar 13, 6:33 pm, Richard Clark wrote:
On 13 Mar 2007 22:15:37 GMT, (John E. Davis) wrote: I do not understand your comment. Hi John, It was rather explicit. To have disputed Dave's assertion with additional material that substantiated him, makes for a rather strange reading of Feynman. .. You can bow out once again, of course, and become a martyr instead. Or you can indulge us with a dialog with Art. I would think this comment applied equally to Dave. Derek |
Gaussian statics law
John E. Davis wrote:
On Wed, 14 Mar 2007 09:09:27 -0800, Tom Donaly wrote: Different texts have Maxwell's equations in different order. What text did you get this from? Becker has it (in Gaussian CGS units) as div D = 4\pi\rho (where the backslash indicates multiplication, and D and rho have the usual meanings. You can add the 't' if you want to, but it's unnecessary. Also, since you're dealing in 3 dimensions, why not indicate them as in E(x,y,z), or E(x,y,z,t) (if the time means something to you)? I tend to write equations in LaTeX form as most people I exchange emails with mathematical equations use that for formatting mathematics. Here, \pi represents the greek letter pi, and \rho is the greek letter rho. I used x to represent a spatial 3-vector. I could have written it as (x,y,z) but I did not think this shorthand would cause any confusion given the context. The difference between E and D is not important here. If you use D, then \rho must be interpreted as the so-called "free" charge density. However, the fundamental field is E, and if you use it the \rho must be interpreted as the _full_ charge density. The relationship between E and D can be very complex and may well depend upon the strength of the applied field E. For simple materials a linear relationship is usually assumed, e.g., D = \epsilon E, where \epsilon is the dielectric constant of the medium. Also even here in this linear relationship, \epsilon need not be a scalar (a number). It could be a tensor (a 3x3 matrix), in which case D and E would not have the same direction. --John Thanks for explaining that, John. I am unfamiliar with the conventions of LaTex, obviously (I get my information from books that are generally older than I am, and I'm not young). I don't have any problem with Gauss' law being used in a non-static context. It applies, regardless. That's as far as I go in agreeing with Art, though, since I can't understand the rest of his theory, at all (but might if I could turn off the left side of my brain - maybe). 73, Tom Donaly, KA6RUH |
Gaussian statics law
On 14 Mar, 12:40, "Tom Donaly" wrote:
John E. Davis wrote: On Wed, 14 Mar 2007 09:09:27 -0800, Tom Donaly wrote: Different texts have Maxwell's equations in different order. What text did you get this from? Becker has it (in Gaussian CGS units) as div D = 4\pi\rho (where the backslash indicates multiplication, and D and rho have the usual meanings. You can add the 't' if you want to, but it's unnecessary. Also, since you're dealing in 3 dimensions, why not indicate them as in E(x,y,z), or E(x,y,z,t) (if the time means something to you)? I tend to write equations in LaTeX form as most people I exchange emails with mathematical equations use that for formatting mathematics. Here, \pi represents the greek letter pi, and \rho is the greek letter rho. I used x to represent a spatial 3-vector. I could have written it as (x,y,z) but I did not think this shorthand would cause any confusion given the context. The difference between E and D is not important here. If you use D, then \rho must be interpreted as the so-called "free" charge density. However, the fundamental field is E, and if you use it the \rho must be interpreted as the _full_ charge density. The relationship between E and D can be very complex and may well depend upon the strength of the applied field E. For simple materials a linear relationship is usually assumed, e.g., D = \epsilon E, where \epsilon is the dielectric constant of the medium. Also even here in this linear relationship, \epsilon need not be a scalar (a number). It could be a tensor (a 3x3 matrix), in which case D and E would not have the same direction. --John Thanks for explaining that, John. I am unfamiliar with the conventions of LaTex, obviously (I get my information from books that are generally older than I am, and I'm not young). I don't have any problem with Gauss' law being used in a non-static context. It applies, regardless. That's as far as I go in agreeing with Art, though, since I can't understand the rest of his theory, at all (but might if I could turn off the left side of my brain - maybe). 73, Tom Donaly, KA6RUH- Hide quoted text - - Show quoted text - Tom, don,t worry about it! A poster has stated it was invented years ago. I haven,t found it in any of my books so perhaps he will tell you where you can look at it. I assume my patent will now be turned down when it is pointed out where the Gaussian antennas can be seen. When he describes it it to you then it should be much easier for you to understand the logic behind it and to determine whether it is all a todo about nothing. As for me I think the subject can be said as proven, albiet over 100 years or more ago and the whole subject started by that blithering idiot, sycopath and all those other phrases can now seen as closed. I will hang around a bit to see what I could have been if only I had been born 100 or 200 years ago where somebody said I will have all the manufacturers knocking on my door. Maybe that inventor of the gaussian array left me a morsel on the cutting room floor which I can exploit and which I can reveal after the existing Gaussian presence is revealed by the poster. But that still leaves the question why haven't ham radio users not picked up the slack and tried them? Maybe it is the 'not invented in my town' thinking and where their heads still rest in the sand. I also have this other invention that I want.............no, I have learned my lesson I will take it to my grave that would be so much easier. Art The Englishman |
Gaussian statics law
"Derek" wrote in message ups.com... On Mar 13, 6:33 pm, Richard Clark wrote: On 13 Mar 2007 22:15:37 GMT, (John E. Davis) wrote: I do not understand your comment. Hi John, It was rather explicit. To have disputed Dave's assertion with additional material that substantiated him, makes for a rather strange reading of Feynman. . You can bow out once again, of course, and become a martyr instead. Or you can indulge us with a dialog with Art. I would think this comment applied equally to Dave. Derek i like the post that points out the unnecessary t in the Gauss's law equation... well done. sri i didn't state that myself, but i have had better things to do than try to argue with art. |
Gaussian statics law
On 14 Mar 2007 13:26:46 -0700, "art" wrote:
But that still leaves the question why haven't ham radio users not picked up the slack and tried them? Hi Art, That was done an hundred years ago, and people found better ways. 73's Richard Clark, KB7QHC |
Gaussian statics law
On Mar 14, 2:39 pm, "Dave" wrote:
i like the post that points out the unnecessary t in the Gauss's law equation... well done. sri i didn't state that myself, but i have had better things to do than try to argue with art. As I remember it you were arguing with John. Derek |
Gaussian statics law
"Derek" wrote in message ups.com... On Mar 14, 2:39 pm, "Dave" wrote: i like the post that points out the unnecessary t in the Gauss's law equation... well done. sri i didn't state that myself, but i have had better things to do than try to argue with art. As I remember it you were arguing with John. Derek i was probably arguing with a couple of them... all the blabbering looks the same after a while. |
Gaussian statics law
On Mar 9, 2:11 pm, John Smith I wrote:
Cecil Moore wrote: wrote: EM waves depart when energy is applied, not particles. Quantum Electrodynamics tells us that EM waves consist of photons which are particles. -- 73, Cecil, w5dxp.com So, which is the real question: 1) Why do waves act like particles? --OR-- 2) Why do particles act like waves? JS --http://assemblywizard.tekcities.com When a field is traveling at/near the speed of light it has mass(acts as a particle) slower and it is a wave. EM lives on the hairy edge of both worlds. vAt least thats what my Phd girlfriend told me once. Who knows though, she was pretty weird. JIMMIE |
Gaussian statics law
JIMMIE wrote:
... When a field is traveling at/near the speed of light it has mass(acts as a particle) slower and it is a wave. EM lives on the hairy edge of both worlds. vAt least thats what my Phd girlfriend told me once. Who knows though, she was pretty weird. JIMMIE Yes. Just thinking about this one aspect can keep me up for hours from a restful sleep ... :( Regards, JS -- http://assemblywizard.tekcities.com |
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