Paul Teller

Quantum mechanics : an empiricist view

Part 1 Determinism and inderterminism in classical perspective: determinism indeterminism and probability. Part 2 How the phenomena demand quantum theory: the empirical basis of quantum theory new probability models and their logic. Part 3 Mathematical foundations: the basic theory of quantum mechanics composite systems, interaction, and measurement. Part 4 Questions of interpretation: critique of the standard interpretation modal interpretation of quantum mechanics EPR - when is a correlation not a mystery? the problem of identical particles indentical particles - individuation and modality.

Particle Labels and the Theory of Indistinguishable Particles in Quantum Mechanics

We extend the work of French and Redhead [1988] further examining the relation of quantum statistics to the assumption that quantum entities have the sort of identity generally assumed for physical objects, more specifically an identity which makes them susceptible to being thought of as conceptually individuatable and labelable even though they cannot be experimentally distinguished. We also further examine the relation of such hypothesized identity of quantum entities to the Principle of the Identity of Indiscernibles. We conclude that although such an assumption of identity is consistent with the facts of quantum statistics, methodological considerations show that we should take quantum entities to be entirely unindividuatable, in the way suggested by a Fock space description.

Particles, particle labels, and quanta : the toll of unacknowledged metaphysics

The practice of describing multiparticle quantum systems in terms of labeled particles indicates that we think of quantum entities as individuatable. The labels, together with particle indistinguishability, create the need for symmetrization or antisymmetrization (or, in principle, higher-order symmetries), which in turn results in “surplus formal structure” in the formalism, formal structure which corresponds to nothing in the real world. We argue that these facts show quanta to be unindividuatable entities, things in principle incapable of supporting labels, and so things which support no factual difference_if two of them are thought of as being switched. When thinking of the metaphysics of quanta, we should eschew the misleading labels of the tensor product Hilbert space formalism and prefer the ontologically more faithful description of the Fock space formalism. This conception eliminates puzzles about the quantum statistics of bosons.

Conditionalization, Observation, and Change of Preference

I take bayesianism to be the doctrine which maintains that (i) a set of reasonable beliefs can be represented by a probability function defined over sentences or propositions, and that (ii) reasonable changes of belief can be represented by a process called conditionalization. Bayesians have produced several ingenious arguments in support of (i); but the equally important second condition they often seem to take completely for granted. My main aim is to fill this gap in those bayesian positions which characterize reasonable belief directly as a probability function. Thus, what follows applies equally to the bayesian personalists’ views which characterize reasonable belief as having subjective sources and to views such as that of Carnap which attempt to explicitly define a function which characterizes the degree of belief it would be objectively reasonable for an idealized rational agent to have in a given proposition in stated circumstances. Many frequentist views are also classifiable as bayesian, and I will briefly discuss the justification of condition (ii) from the point of view of a frequency interpretation of probability or reasonable degree of belief. Two other topics will also come up along the way: the connection between change of belief and change of preference, and the connection between conditionalization and observation.

Substance, Relations, and Arguments About the Nature of Space-Time'

A machine and process are disclosed for assembling a plurality of semiconductor devices having heat sinks initially united in a common strip. A track is provided for allowing a heat sink strip to be sequentially transported through a plurality of assembly stations. A magazine is provided for dispensing heat sink strips to the track. The strip is advanced by fingers engaging regularly recurring apertures in the strip. The heat sink strip is first burred and then a solder preform is stamped onto the strip at spaced intervals overlying the burrs. Lead carrying headers are fed into association with spaced foot portions of the strip. A dispenser feeds a solder ball to a window in each header. A forming and pick up mechanism positions sub-assemblies including semiconductive elements and internal connectors on the heat sink strip overlying the solder preforms.

How We Dapple the World

This essay endorses the conclusion of Sklar’s “Dappled Theories in a Uniform World” that he announces in his abstract, that notwithstanding recent attacks foundational theories are universal in their scope. But Sklar’s rejection of a “pluralist ontology” is questioned. It is concluded that so called “foundational” and “phenomenological” theories are on a much more equal footing as sources of knowledge than Sklar would allow, that “giving an ontology” generally involves dealing in idealizations, and that a transfigured “ficitonalism” provides an (in many respects) better model of scientific knowledge than the model of “foundational truths.”

Quantum Physics, the Identity of Indiscernibles, and Some Unanswered Questions

A series of papers in Philosophy of Science have debated whether quantum physics shows there to be something wrong with Leibnizs principle that things which agree in all their properties and relations are identical. To begin with, I think we can learn something by considering an example somewhat different from the one on which the previous authors have focused. You and I hold the two ends of a rope and at the same moment each of us gives his respective end a little shake. This produces two waves which travel away from each of us, merge in the middle in a single bump, pass through each other, and continue on down the rope:

Algebraic constraints on hidden variables

In the contemporary discussion of hidden variable interpretations of quantum mechanics, much attention has been paid to the “no hidden variable” proof contained in an important paper of Kochen and Specker. It is a little noticed fact that Bell published a proof of the same result the preceding year, in his well-known 1966 article, where it is modestly described as a corollary to Gleasons theorem. We want to bring out the great simplicity of Bells formulation of this result and to show how it can be extended in certain respects.

The Law‐Idealization

There are few, perhaps no known, exact, true, general laws. Some of the work of generalization is carried by ceteris paribus generalizations. I suggest that many models continue such work in more complex form, with the idea of ceteris paribus conditions thought of as extended to more general conditions of application. I use the term regularity guide to refer collectively to cp‐generalizations and such regularity‐purveying models. Laws in the traditional sense can then be thought of as idealizations, which idealize away from the conditions of application of regularity guides. If we keep clearly in mind the status of laws as such idealizations, problems surrounding traditional topics—such as lawlikeness, corresponding counterfactuals and modality—no longer look to be intractable.

“Saving the Phenomena” Today

Bogen and Woodward argued the indirect connection between data and theory in terms of their conception of “phenomena.” I outline and elaborate on their presentation. To illuminate the connection with contemporary thinking in terms of models, I distinguish between phenomena tokens, representations of which can be identified with data models, and phenomena types that can be identified with relatively low-lying models or aspects of models in the model hierarchy. Throughout I stress the role of idealization in these considerations.