Recent content by haushofer

  1. haushofer

    Physics/math: how much knowledge does a high school teacher need?

    I have a feeling my question was not properly formulated. Let me rephrase it: How much surplus knowledge does a teacher need to be considered a good teacher? One reason I'm asking this is because in Dutch teacher's educations more and more time is spend on pedagogy and didactics, at the cost...
  2. haushofer

    Physics/math: how much knowledge does a high school teacher need?

    Dear all, as some of you may know I'm a math/physics teacher at a teachers education in Holland, where we prepare teachers at pre-university level high school. We focus mainly on teachers who are already licensed to teach in the first three years of pre-university high school ("2nd degree")...
  3. haushofer

    Undergrad Ramsauer and Townsend effect: history and explanation

    I found this historical overview, https://www.jstor.org/stable/27757746 -never mind the request, I can read it online
  4. haushofer

    Undergrad Ramsauer and Townsend effect: history and explanation

    Dear all, I'm writing an article about the didactics of teaching quantum physics, and in particular the phenomenon of resonant transmission, as discovered by Ramsauer and Townsend in 1920. The phenomenon was used in a Dutch physics exam in 2023, and in it the question states "To explain the...
  5. haushofer

    High School Gravitons/Gravity passing through objects

    It turns out that in certain limits the gravitational field acts similarly to an electromagnetic field and has a "magnetic component". The Newtonian theory of gravity you learn at high school resembles the "electric" part of that limit, so this may sound unfamiliar. See...
  6. haushofer

    Undergrad Why is gravity a fictitious force?

    I don't think so, but I have to think about this a bit more. My gut reaction would be that this is similar to the question whether electrostatics with the Coulomb force can be recasted as spacetime curvature (since electric charge doesn't equal inertial mass), and I'm pretty sure it can't...
  7. haushofer

    Undergrad Why is gravity a fictitious force?

    I don't see that clear distinction between "interactions" and "spacetime curvature"; Fierz-Pauli is an interactive description of GR, and Newton-Cartan theory describes Newtonian gravity as spacetime curvature.
  8. haushofer

    Undergrad Why is gravity a fictitious force?

    My 2 cents: a fictitious force is due to your (accelerating) frame of reference; there is no interaction involved (if you don't subscribe to Mach's principle, that is). Gravity, although having the mentioned properties of fictitious forces (proportional to mass and frame-dependent), does involve...
  9. haushofer

    Graduate Sidney Coleman's opinion on interpretation in his Dirac lecture

    It's comparable to the time where the geocentric and heliocentric models both successfully explained planetary orbits. It was only in accepting the heliocentric model that modern cosmology could develop. From this modern standpoint the heliocentric model of course is to be preferred. Sometimes...
  10. haushofer

    Advice on visiting CERN?

    My advice: don't mention the war or supersymmetry.
  11. haushofer

    Undergrad ##r-##independent angular momentum in quantum mechanics

    Intuitively: if r and v point in the same or opposite direction, L is zero. So only movement in the direction perpendicular to r contributes to L. Those are the angles. By the way, this is also what makes the l=0 states of e.g. hydrogen clasically difficult to understand: it involves movement...
  12. haushofer

    Undergrad 2nd order ODE's, variation of parameters and the notorious constraint

    Yes, that's a gread addition. It leaves me with the final question: are all constraints one can impose consistent? And how can we check that? Working everything out for other constraints leaves us in general with second order derivatives and the coefficients themselves, giving the same problem...
  13. haushofer

    Undergrad 2nd order ODE's, variation of parameters and the notorious constraint

    Yes, thanks a lot, you're absolutely right. Reading your post I redid the calculation and indeed was missing a factor of p(x) which makes all the difference! I had a strong feeling pW=const. should play a role, but couldn't see it of course. You saved my day! I've seen quite some texts on this...
  14. haushofer

    Undergrad 2nd order ODE's, variation of parameters and the notorious constraint

    I found the book: https://people.uncw.edu/hermanr/mat463/ODEBook/Book/ODE2.pdf
  15. haushofer

    Undergrad 2nd order ODE's, variation of parameters and the notorious constraint

    Hi folks, I decided to brush up my knowledge of Green's functions and Differential Equations, and came across this chapter, https://people.uncw.edu/hermanr/mat463/odebook/book/greens.pdf of some unknown book (if anybody recognizes it, I'd like to know the title). In 8.3 (page 265) the...