Showing papers on "Quantum capacity published in 1985"

Analysis of Quantum Probability Theory. I

Abstract: This paper is a continuation of Van Aken (1985). It details a proposal to deal with difficulties encountered there. This proposal is nothing less than an interpretation of the whole of quantum probability theory. Such an interpretation has to prove itself in a number of areas, and I’ll have room to sketch only a few of its advantages here. One of these is that it sidesteps quantum logic. That is: the operations of “negation” and “conjunction” defined in Section 1 will nor be treated as genuine logical operations, despite the existence of certain analogies with logic. In fact, once I’ve established (in Section 8) that state reduction is a probabilistic concept, the definitions given for these operations in Section 1 will show that they can be defined entirely in probabilistic terms, so that these are probabilistic (rather than logical) operations. A second advantage will be that it puts a stop to the “spooky” production of determinate values through measurement. There are two well-known ways of doing so. First, one can challenge the logical laws needed to arrive at the conclusion that this sort of thing happens. This drastic measure entails replacing classical logic with some new quantum logic, a step I’ve foresworn. Second, one can postulate determinate, pre-measurement values. Then one runs into difficulties of the Kochen-Specker variety, which force one to de-Occamize the theory rather severely, or to abandon simple, functional relationships strongly suggested by the formalism, or both. In Part I, I argued against this sort of approach under the label ‘the first-order thesis’. Now, in Part II, I’ll present a third way to stop the “spookiness”. This is to grant physicists the surface form of their ascriptions of values to observables, while interpreting them so as to show that this surface is deeply misleading. Properly construed, an observable isn’t the sort of thing that ever has a determinate value not even ufer measurement. So observables aren’t properly understood as quantities