Recent content by keniwas

  1. K

    Angular Momentum the Full Operator Approach

    Excellent! Thank you for the references!
  2. K

    Angular Momentum the Full Operator Approach

    Greetings all, In going through an operator approach to deriving the rules of angular momentum I find myself asking a curious question. Is it possible to fully derive the Angular momentum algebra relying on only a minimal set of classical relations. That is to say, if we take the only...
  3. K

    Voltage Induced by slowing varying magnetic moment

    Excellent, it makes more sense now thanks. As for part B, I said slow enough would imply that the field varies slowly such that the current can be modeled as a steady current at any given point in time (hence why using the biot-savart law was valid). I think that even if the source were...
  4. K

    Voltage Induced by slowing varying magnetic moment

    Ok, so here is what I have now. From Biot-Savart Law I find the Btest(r) to be \vec{B}_{test}(r)=\frac{1}{c}\int_c I_{test} \frac{d\vec{l}\times\vec{r}}{|r|^3} Which allows me to place the integral form into the equation given in the problem, hence E(t)=\alpha\frac{1}{c}\int_c...
  5. K

    Voltage Induced by slowing varying magnetic moment

    So I have tried what you suggested but I seem to be missing a vital step... I started with Faradays law and reduced it via stokes theorem to the following \int_c \vec{E}\cdot d\vec{l} = -\frac{d}{dt}\int\int_s \vec{B}\cdot d\vec{a} which is the EMF and the magnetic flux (in integral...
  6. K

    Voltage Induced by slowing varying magnetic moment

    Great! thanks for the reply. I will try that and see how it goes. I am curious though what gave you the idea to do this? Why would one use a test current in this fashion?
  7. K

    Voltage Induced by slowing varying magnetic moment

    Homework Statement A small magnetic moment \vec{m}(t) fixed at position \vec{r} varies in a complicated way as a function of time. (a) Show that if the time variation is "slow enough", the voltage generated around an arbitrary loop of wire near the origin is E(t)=\alpha...
  8. K

    Between two powers of an integer there is a power of two

    Sorry, could you explain a little by what you mean that it applies to arbitrary integer sequences as well? I am not clear why we want the smallest member less than or equal to r?
  9. K

    Between two powers of an integer there is a power of two

    Hi Everyone, I am reading up on information theory, and every resource I have found on the topic which derives the form of entropy uses the following inequality as part of the proof. Let n be a fixed positive integer greater than 1. If r is an arbitrary positive integer, then the number...
  10. K

    Pulsed Point Dipole: Jackson's E&M Explained

    In Jackson's E&M book, he talks about using the following charge and current densities to demonstrate causality in the coulomb gauge. \rho (\vec{r},t)=\delta(x)\delta(y)\delta'(z)\delta(t) \vec{J}(\vec{r},t})=\delta(x)\delta(y)\delta(z)\delta'(t)\hat{z} since they represent a point dipole...
  11. K

    Is it possible to become an independent physicist?

    The days of basement physics are long gone, while there is no rule against such activity, it is in general very difficult to keep on top of new research without being in an academic environment (or a corporate research environment akin to Bell Labs... which was really academic at its core.)...
  12. K

    Find Best Astrophysics College for Florida High School Senior

    FSU is the cosmology and astrophysics center of Florida. In fact its the only one which has much active research on the topic. Though I guess I should ask what in astrophysics are you interested in? Also, if the reason you can't leave florida is becuase of $$, then you should try...
  13. K

    Is a 650 PGRE Score Enough for Top Graduate Programs in Particle Physics?

    I disagree with this, mainly becuase as I already said, most top universities don't think the GRE is a good metric to quaify their applicants. They only use it in cases when they have nothing else to go by. If you have supplemental material supporting your ability to research (like publications)...
  14. K

    Making it as a Theoretician - can it be done so late in the game ?

    I don't disagree with you completely on your first statement. It is true there is no real metric for measuring the future success of a student. It is certainly true that harvard isn't able to accept everyone who would fit the bill, the point was more to say that the majority of people who...
  15. K

    Making it as a Theoretician - can it be done so late in the game ?

    I have to disagree with you, the fact that it induced "Pain and agony" for you is a clear sign you were in the wrong field, or more generally in it for the wrong reason. I don't think there is any brainwashing going on at all, it is just a general consensus that most people who go into a...
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