Bob,

Now regarding your second comment. I agree with your drawing of an analogy between protective measurements on a single system (assumed to remain in the initial state throughout) and tomographic measurements on an ensemble of identically prepared systems. There’s certainly a formal similarity here: we’re trading impulsive single measurements…[Read more]

Dear Bob,

Many thanks for your comments.

First, let me reply to your suggestion that a “FAPP” solution may well be acceptable. I’m happy with FAPP solutions to most problems, even some foundational ones. But I’m not sure that protective measurement falls into that category. As mentioned in my reply to Shan above, in protective measurement we’re…[Read more]

Hi Matt,

Thanks for the clarification. But I’m not sure if the conclusion from the reality of one expectation value to all expectation values is so straightforward. Suppose I identify “reality” with “can be measured.” So the first expectation value would be real because I was able to measure it (somehow). But if I cannot subsequently measure any…[Read more]

Hi Shan,

Thank you for your comments. Here are my responses.

First of all, in your paper you say that measurability of an unknown quantum state is a condition for the reality of the wave function that is “too stringent to be true.” But it was precisely this condition (albeit with reference to an unknown eigenstate of the Hamiltonian) that the…[Read more]