*Your attachment shows how to establish the HUP, not why there is a spread in momentum. Classically, energy and momentum are related by a simple formula. So if one wants to prepare a system in some specific momentum, one needs to control the energy of the particle. Presumably, this can never be done precisely; hence we get the spread. Is this not a sufficient explanation for the spread? AG*
*As far as the HUP is concerned the cause of spread in momentum is that the spread in conjugate position must be finite, and vice versa. * *Are all the momenta in the spread, eigenvalues of the momentum operato*r*? AG* *Yes. But they have different probabilities of being found when measured. Brent* *But if one always gets a spread, how can any particular momentum in the spread be measured? AG * *You can't choose which value you get measuring a random variable. You just measure momentum and you get a certain value. Then you repeat the experiment and you get a different value. You repeat this a thousand times and you can plot the distribution function of momenta and measure the spread. Brent* *Presumably, if it's momentum that's being measured, and one always measures eigenvalues, why is the spread larger on "imprecise" measuring devices, as opposed to undefined "ideal" measurements? And what is an ideal measurement? AG * -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/3a542bc7-15a9-4652-a7ce-a717343a6c67n%40googlegroups.com.
