Recent content by jf117

Thank you for your comment, @.Scott. It says a' depends on a and p in a way to be specified. Fine, as it is to be specified, I can live with that until a' is used. But then <σ⋅a> is calculated and the result depends on θ', which is the angle between a' and p. Perhaps knowing how that result...

I have never been able to fully grasp John Bell toy model for spin in his 1964 article. He starts with a particle with pure spin state p. There exists a hidden variable called λ with a probability distribution given by a uniform distribution over the hemisphere λ⋅p > 0. I guess this uniform...

Perhaps I could join in the request by re-defining it: could somebody give names and/or places actively researching spintronics? J

What is this "Merriam's relational view"? :confused: J

I agree. :approve: J

I'm not the same guy that "Perturbation" refers to. By the way, I perfectly understand your point, and I basically agree with you. But I think the spirit of the proposed topic was something like: "If, at the moment in history when it was introduced, we had discovered that Planck's constant...

In fact, any time an RPM is given it is meant that the rotatory motion is uniform, i.e. the angular velocity is a constant and , therefore, the angular acceleration is zero. Perhaps the problem meant to ask the centripetal acceleration? J

Actually, making \hbar that big would mean making the rest of the world (us) very small, not big. I agree with you that these are tricky arguments, but then the whole topic's theme is quite tricky. J

Could I have the exact reference for this "arno'ld's book", please? J

Well, it depends on what is meant by "sensing the outside world". Even a single cell continuously exchanges stuff with the external world, be it big macromolecules or small molecules. And a whole series of internal or external mechanisms arise due to this exchange. Isn't this kind of sensing...

An easy way of thinking to it is the exact opposite to the arguments used to prove that our world would be exclusively governed by classical laws if \hbar\rightarrow 0 . When Planck's constant becomes very big, then all physical laws will tend to become quantum laws. In such a case we would...

Do you mean: \sum_{v} |v\rangle\langle v| = 1? Or just | v \rangle \langle v|=1?

I don't understand what is wrong in assuming an ideal plate with no thickness along the z direction. We are using it to prepare the state for our particle. Thanks to this plate/slit system, which acts as a filter, we have, for all times immediately after t=0, partial localization for the y...

When we use the plate/slit for the system preparation we are in fact reducing the particle's state to certain, definite values. In our specific case, slit with a width along y, the initial position ket will be |x,y0,z+>, where x means anywhere along x, y0 means a single, specific value on y, and...

Sorry, I just got the sense of your reply now! What you are saying is that no measurement at all is made on the z (or x) component, because the slit width is only along y. We could therefore shift backward and forward the plate along z, or shift upward or downward the slit along x, and nothing...