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| bio | website | |
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| location | ||
| age | ||
| visits | member for | 1 year, 1 month |
| seen | 2 hours ago | |
| stats | profile views | 130 |
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Dec 12 |
comment |
Why doesn't the dark matter halo co-rotate with the luminous disk? Makes sense. Yet something appears to act differentially on stars (compared with dark matter) so that the stars cluster nearer to the center. My thought was that they just form there. |
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Dec 12 |
comment |
Why doesn't the dark matter halo co-rotate with the luminous disk? Is it the case that 1) gas interacts readily and so clusters at the center, 2) stars form from the gas, and hence also cluster there, 3) dark matter doesn't interact and stays far out? I ask because of this 2006 report which showed both stars and dark matter separating from gas in a galactic collision, indicating stars interact similarly to dark matter (?): news.discovery.com/space/… |
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Dec 11 |
comment |
What happens to orbits at small radii in general relativity? $a$ is a distance that is proportional to the angular momentum $l$ per unit mass $m$ of the test body: $a=(l/m)/c$. This stuff is quite interesting, thanks! |
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Dec 10 |
comment |
Conservation of Charge and Method of Images I'm actually not sure; your answer is well above my level of understanding. (Color me jealous!) The question is a bit difficult to understand; I think I finally worked it out. |
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Dec 9 |
comment |
Conservation of Charge and Method of Images I don't think $q_{image}=-q_{external}$ in this geometry. Consider the case where the external charge is very far away compared to the sphere's radius: it won't take much image charge to balance the external charge's field. |
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Dec 9 |
answered | Conservation of Charge and Method of Images |
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Dec 9 |
comment |
Maxwell's Correction to Ampere's Law @ZAC: Re 2) I want to add that I am relying on superposition of sources: a) a set of fixed charges produces $\boldsymbol{E_l}$ (and crucially produces no magnetic fields), and b) a set of time-varying currents (with 0 charge density) somewhere off-stage produces the time varying $\boldsymbol{B}$ fields you specify, and hence $\boldsymbol{E_t}$. By superposition, you can add the two $\boldsymbol{E}$ fields to get the result. Superposition works because the equations are linear in the sources. |
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Dec 9 |
comment |
Maxwell's Correction to Ampere's Law @ZAC: Ah, I think I understand your question a bit better now. 1) Yes, there's only one $\boldsymbol{E}$ in the equations; it's not different from one to the next. 2) You can decompose that field into "divergence-less" ($\boldsymbol{E_t}$, aka transverse) and "curl-less" ($\boldsymbol{E_l}$ aka longitudinal or irrotational) components, $\boldsymbol{E=E_t+E_l}$; the transverse element is zeroed by the divergence operator of Gauss law, and the irrotational element is zeroed out by the curl in Faraday's law. 3) Yes, it's possible to have exactly the same V function in the two cases. |
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Dec 9 |
comment |
Conservation of Energy in a Capacitor @VincentTjeng: No problem! You're welcome. |
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Dec 8 |
answered | Maxwell's Correction to Ampere's Law |
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Dec 8 |
answered | Conservation of Energy in a Capacitor |
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Dec 8 |
answered | Spin-orbit coupling constant for rubidium |
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Dec 8 |
revised |
Delta Dirac Charge Density question corrected volume integral |
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Dec 8 |
answered | Delta Dirac Charge Density question |
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Dec 6 |
awarded | Constituent |
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Dec 5 |
awarded | Talkative |
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Dec 1 |
revised |
Metal rod between a capacitor added analysis. |
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Nov 30 |
answered | Metal rod between a capacitor |
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Nov 30 |
comment |
electrostatic potential, analytic properties @molkee: You're welcome. |
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Nov 30 |
answered | electrostatic potential, analytic properties |
