8,623 research outputs found
Potentiality and Contradiction in Quantum Mechanics
Following J.-Y.B\'eziau in his pioneer work on non-standard interpretations
of the traditional square of opposition, we have applied the abstract structure
of the square to study the relation of opposition between states in
superposition in orthodox quantum mechanics in \cite{are14}. Our conclusion was
that such states are \ita{contraries} (\ita{i.e.} both can be false, but both
cannot be true), contradicting previous analyzes that have led to different
results, such as those claiming that those states represent \ita{contradictory}
properties (\ita{i. e.} they must have opposite truth values). In this chapter
we bring the issue once again into the center of the stage, but now discussing
the metaphysical presuppositions which underlie each kind of analysis and which
lead to each kind of result, discussing in particular the idea that
superpositions represent potential contradictions. We shall argue that the
analysis according to which states in superposition are contrary rather than
contradictory is still more plausible
Axiomatization and Models of Scientific Theories
In this paper we discuss two approaches to the axiomatization of scien- tific theories in the context of the so called semantic approach, according to which (roughly) a theory can be seen as a class of models. The two approaches are associated respectively to Suppes’ and to da Costa and Chuaqui’s works. We argue that theories can be developed both in a way more akin to the usual mathematical practice (Suppes), in an informal set theoretical environment, writing the set theoretical predicate in the language of set theory itself or, more rigorously (da Costa and Chuaqui), by employing formal languages that help us in writing the postulates to define a class of structures. Both approaches are called internal, for we work within a mathematical framework, here taken to be first-order ZFC. We contrast these approaches with an external one, here discussed briefly. We argue that each one has its strong and weak points, whose discussion is relevant for the philosophical foundations of science
Does weak discernibility determine metaphysics?
Two entities are weakly discernible when an irreflexive and symmetric relation holds between them. That weak discernibility holds in quantum mechanics is fairly uncontroversial nowadays. The ontological consequences of weak discernibility, however, are far from clear. Part of the literature seems to imply that weak discernibility points to a definite metaphysics to quantum mechanics. In this paper we shall discuss the metaphysical contribution of weak discernibility to quantum mechanics and argue that, contrary to part of current literature, it does not provide for a fully naturalistic determination of metaphysics. Underdetermination of the metaphysics still plagues the way of the naturalist
Does Entropic Gravity Bound The Masses Of The Photon And Graviton?
If the information transfer between test particle and holographic screen in entropic gravity respects both the uncertainty principle and causality, a lower limit on the number of bits in the universe relative to its mass may be derived. Furthermore, these limits indicate particles that putatively travel at the speed of light -- the photon and/or graviton -- have a non-zero mass m≥10−68 kg. This result is found to be in excellent agreement with current experimental mass bounds on the graviton and photon, suggesting that entropic gravity may be the result of a (recent) softly-broken local symmetry. Stronger bounds emerge from consideration of ultradense matter such as neutron stars, yielding limits of m≥10−48−10−50 kg, barely within the experimental photon range and outside that of the graviton. We find that for black holes these criteria cannot be satisfied, and suggest some possible implications of this result
(1+1)-Dimensional Entropic Gravity
We consider the formulation of entropic gravity in two spacetime dimensions. The usual gravitational force law is derived even in the absence of area, as normally required by the holographic principle. A special feature of this perspective concerns the nature of temperature and entropy defined at a point. We argue that the constancy of the gravitational force in one spatial dimension implies the information contained at each point in space is an internal degree of freedom on the manifold, and furthermore is a universal constant, contrary to previous assertions that entropic gravity in one spatial dimension is ill-defined. We give some heuristic arguments for gravitation and information transfer constraints within this framework, thus adding weight to the contention that spacetime and gravitation might be emergent phenomena
Identical particles in quantum mechanics: favouring the Received View
The so-called Received View (RV) on quantum non-individuality states, basically, that quantum particles are not individuals. It has received an amount of criticism in the recent literature, most of it concerning the relation between the RV and the relation of identity. In this chapter we carefully characterise a family of concepts involved in clarifying the view, indicating how the very idea of failure of identity, commonly used to define the RV, may be understood. By doing so, we hope to dissipate some misunderstandings about the RV, which shall also be seen as evidence of its tenability
Identical particles in quantum mechanics: favouring the Received View
The so-called Received View (RV) on quantum non-individuality states, basically, that quantum particles are not individuals. It has received an amount of criticism in the recent literature, most of it concerning the relation between the RV and the relation of identity. In this chapter we carefully characterise a family of concepts involved in clarifying the view, indicating how the very idea of failure of identity, commonly used to define the RV, may be understood. By doing so, we hope to dissipate some misunderstandings about the RV, which shall also be seen as evidence of its tenability
The roads to non-individuals (and how not to read their maps)
Ever since its beginnings, standard quantum mechanics has been associated
with a metaphysical view according to which the theory deals with
non-individual objects, i.e., objects deprived of individuality in some sense
of the term. We shall examine the grounds of the claim according to which
quantum mechanics is so closely connected with a metaphysics of
non-individuals. In particular, we discuss the attempts to learn the required
`metaphysical lessons' required by quantum mechanics coming from four distinct
roads: from the formalism of the theory, treating separately the case of the
physics and the underlying logic; from the ontology of the theory, understood
as the furniture of the world according to the theory; and, at last, we analyze
whether a metaphysics of non-individuals is indispensable from a purely
metaphysical point of view. We argue that neither non-individuality nor
individuality is not to be found imposed on us in any of these levels so that
it should be seen as a metaphysical addition to the theory, rather than as a
lesson from it.Comment: Forthcoming in J. R. B. Arenhart, R. W. Arroyo (eds.), Non-Reflexive
Logics, Non-Individuals, and the Philosophy of Quantum Mechanics: Essays in
Honour of the Philosophy of D\'ecio Krause, Springer, Synthese Library 476,
https://doi.org/10.1007/978-3-031-31840-5_
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