Recent content by phoenix3

To say that, while not measured along ##\vec r_2## the spin is in a superposition state of being spin-up and spin-down at each individual point in time is not only incorrrect, its meaningless.

The entire expression evaluates to ##cos(\theta)## and indicates that ##cos(\theta)## is in fact a net result of spin-up and spin-down during any non-zero interval of time ##\delta t##, whereas at any single 'point' in time it is either spin-up xor spin-down.

It does wrk: it gives it spin-down probability as ##sin^2(\frac{\theta}{2})##

to include 'time' into consideration. One can't pretend time is irrelevant.

This is technically incorrect. A spin-1/2 system has a spin magnitude of , with its projection on any axis being . yes i know, but it only ever 'measured' to be ##\frac {\hbar}{2}##

Respectfully, DrClaude, that still doesn't explain where any error is, either in my math or in my interpretation of it. Besides, as long as the math correctly predicts the probability, where's the harm in having an interpretation of it that is non-mysterious?

Here is my workings out: $$$$ If a particle's spin of magnitude ##\frac {\hbar}{2}## is prepared along direction ##\vec r_1## and subsequently its spin is measured along direction ##\vec r_2 ## at an angle ##\vec \theta ## to ##\vec r_1##, the probability of its being found "spin up" along is...