Recent content by Meir Achuz
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Undergrad The Electric Displacement, ##\mathbf D##
In Gaussian units, which I use, ##\mathbf E##=q##\mathbf r##/r^3 & ##\mathbf D=\mathbf E+4\pi\mathbf P##.- Meir Achuz
- Post #3
- Forum: Electromagnetism
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Undergrad Small question about constantly accelerating charges
I meant applying his equivalence principle to EM radiation.- Meir Achuz
- Post #7
- Forum: Electromagnetism
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Undergrad Small question about constantly accelerating charges
The papers I have seen do not mention whether the antenna is accelerating or not. My feeling is that AE never mentioned EM when he stated the equivalence principle, and died drying to combine Relativity and EM.- Meir Achuz
- Post #5
- Forum: Electromagnetism
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High School Electric Fields inside Conductors & Gauss' Law
We derive Gauss's law from Coulomb's law for a single point charge. We start with the surface integral, $$ \oint {\bf dA}\cdot{\bf E}=q \oint{\bf d A}\cdot\frac{{\bf r}}{r^3}, $$ of the normal component of ##{\bf E}## over a closed surface surrounding the point charge. The vector...- Meir Achuz
- Post #8
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
Thanks for your interest, but I guess we are at an impasse. The quote was something like, “with all the new math being applied to my theory, I hardly understand it any more myself.”- Meir Achuz
- Post #19
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
I apologize. I shouldn't have used that word in a technical discussion thread. The point was to show by the insert where taking 'self energy' too seriously can lead.- Meir Achuz
- Post #18
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
It was a joke, but read the insert. I appreciate that you have expended time and knowledge on my post, which I had thought was straightforward. I certainly didn't mean to bring Einstein into it. We have some agreement, but I will comment on some things: 1. You wrote,"So in principle, we can...- Meir Achuz
- Post #15
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
Of course, I mistyped. It should have been, it IS there by absence. I did write, "This PDF shows that a point charge in classical electromagnetism has no 'self energy'." That's because there is no self energy term in the sum of charges. Thank you for pointing it out. Since the continuous...- Meir Achuz
- Post #12
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
This is getting silly. Neither of us will be convinced, but you keep putting up half truths, half wrong. I will try again. You neglect what you don't want. Jackson's equations 1.47, 1.48, 1.49, 1..50 clearly show there is no i=j term. For some reason, he says it in words for Eq,. (.51). You...- Meir Achuz
- Post #9
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
Don't ignore the footnote, which I have attached. Jackson points out that infinitesimal charge is mathematical and NOT PHYSICALLY POSSIBLE, The point here is that to define E, even a small charge can polarize the source of E, making the force equation bilinear. It is completely different for...- Meir Achuz
- Post #7
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
I thought you would recognize Griffiths. Actually, the shoe is on the other foot. Can you cite a textbook reference that justifies and agrees for an electron in the case where its charge is infinitesimal??- Meir Achuz
- Post #5
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
"Chapter2 Electrostatics so,ifyouhavesetthereferencepointatinfinity, W=QV(r)." You added the word "infinitesimal". "W= 1/ 8π\\epsilon_0 sum n i=1 n j=i qiqj/rij (2.41) (wemuststillavoidi=j,ofcourse)."- Meir Achuz
- Post #3
- Forum: Electromagnetism
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Undergrad Does a Point Charge in Classical Electromagnetism Possess Self Energy?
This PDF shows that a point charge in classical electromagnetism has no 'self energy'.- Meir Achuz
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- Replies: 20
- Forum: Electromagnetism
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High School What is the difference between B and H?
What a weird response- Meir Achuz
- Post #15
- Forum: Electromagnetism
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High School Understanding Newton's Third Law and the Net Force on Objects
Reading this thread, I see why students always get a third law question wrong.- Meir Achuz
- Post #10
- Forum: Mechanics