Recent content by haushofer

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

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...

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...

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...

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.

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...

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...

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

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...

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...

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...

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

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...

If I understand you correctly: wouldn't that mean that your version of the Kruskal metric still has a coordinate singularity at r=2M? So no, that doesn't seem right.

Ah, the one book, from the one author. My favourite.