Recent content by t_evans

I think it was precisely clear by what both I and vanhees said - energy time uncertainty relates to the length or time scale by which the state exists - not some arbitary time by which the state evolves by - in this Hyperphysics has a needless ambigious implementation of time-energy uncertainty...

I'm aware that this is going off topic from the very meritable discussion on the scientific method, but it's one of my favorite points and relates to the initial question. [/ end off topic apology] A really nice thing is to look at this whole exercise the other way around. Normally...

A good thing to consider is where the harmonic oscillator potential comes from - fundamentally it comes from taking a taylor expansion about an equilibrium (thus harmonic). According to Zee's book this is also true in QFT. The point is, \omega, is not some arbitary frequency - it relates to the...

Yeah, I can see it could be more stable if the step size were smaller. It would especially make sense if the potential was a slower in q than in p. The thing is, for most introductory examples, computation time isn't really a problem so you can take /epsilon to be really small and do more steps...

Hi Kulimer, It looks to me like your doing classical rather than quantum mechanics. But anyway, basically the equations you've got there are just expanding the derivatives in Hamilton's equations in a finite difference approximation. Anyway, the way to solve all such problems is iteratively...

Hi, Yes, sorry, I did mean linear momentum. Spin onto angular momentum would be something entirely different, although interesting quantity in it's own right. I've not heard the Higgs mechanism described in that way before, but then I don't know a great deal about it. Interesting. Just...

Disclaimer: If this is the wrong place for this, I apologise, this probably comes somewhere between QM, Atomic, Linear algebra and a spoonful of Quantum chemistry for good measure. Anyway, for a group of non interacting (mean field) electrons, moving in a potential generated by nuclei and...

Hi Cygnet, Helicity is (strictly speaking) the projection of the spin onto the direction of momentum. So, h = s \cdot \hat{p} Now in the case of a spin 1/2 particle, s can be \pm 1/2 , so the helicity can be either value. There are two limiting cases of interest, firstly the non...