7,169 research outputs found
Duality and ontology
A ‘duality’ is a formal mapping between the spaces of solutions of two empirically equivalent theories. In recent times, dualities have been found to be pervasive in string theory and quantum field theory. Naïvely interpreted, duality-related theories appear to make very different ontological claims about the world—differing in e.g. space-time structure, fundamental ontology, and mereological structure. In light of this, duality-related theories raise questions familiar from discussions of underdetermination in the philosophy of science: in the presence of dual theories, what is one to say about the ontology of the world? In this paper, we undertake a comprehensive and non-technical survey of the landscape of possible ontological interpretations of duality-related theories. We provide a significantly enriched and clarified taxonomy of options—several of which are novel to the literature
The Strange Nature of Quantum Perception: To See a Photon, One Must _Be_ a Photon
This paper takes as its point of departure recent research into the possibility that human beings can perceive single photons. In order to appreciate what quantum perception may entail, we first explore several of the leading interpretations of quantum mechanics, then consider an alternative view based on the ontological phenomenology of Maurice Merleau-Ponty and Martin Heidegger. Next, the philosophical analysis is brought into sharper focus by employing a perceptual model, the Necker cube, augmented by the topology of the Klein bottle. This paves the way for addressing in greater depth the paper’s central question: Just what would it take to observe the quantum reality of the photon? In formulating an answer, we examine the nature of scientific objectivity itself, along with the paradoxical properties of light. The conclusion reached is that quantum perception requires a new kind of observation, one in which the observer of the photon adopts a concretely self-reflexive observational posture that brings her into close ontological relationship with the observed
The ontology of Bohmian mechanics
The paper points out that the modern formulation of Bohm's quantum theory
known as Bohmian mechanics is committed only to particles' positions and a law
of motion. We explain how this view can avoid the open questions that the
traditional view faces according to which Bohm's theory is committed to a
wave-function that is a physical entity over and above the particles, although
it is defined on configuration space instead of three-dimensional space. We
then enquire into the status of the law of motion, elaborating on how the main
philosophical options to ground a law of motion, namely Humeanism and
dispositionalism, can be applied to Bohmian mechanics. In conclusion, we sketch
out how these options apply to primitive ontology approaches to quantum
mechanics in general
Realism and the wave-function
Realism -- the idea that the concepts in physical theories refer to 'things'
existing in the real world -- is introduced as a tool to analyze the status of
the wave-function. Although the physical entities are recognized by the
existence of invariant quantities, examples from classical and quantum physics
suggest that not all the theoretical terms refer to the entities: some terms
refer to properties of the entities, and some terms have only an epistemic
function. In particular, it is argued that the wave-function may be written in
terms of classical non-referring and epistemic terms. The implications for
realist interpretations of quantum mechanics and on the teaching of quantum
physics are examined.Comment: No figure
Realism about the Wave Function
A century after the discovery of quantum mechanics, the meaning of quantum
mechanics still remains elusive. This is largely due to the puzzling nature of
the wave function, the central object in quantum mechanics. If we are realists
about quantum mechanics, how should we understand the wave function? What does
it represent? What is its physical meaning? Answering these questions would
improve our understanding of what it means to be a realist about quantum
mechanics. In this survey article, I review and compare several realist
interpretations of the wave function. They fall into three categories:
ontological interpretations, nomological interpretations, and the \emph{sui
generis} interpretation. For simplicity, I will focus on non-relativistic
quantum mechanics.Comment: Penultimate version for Philosophy Compas
The physics and metaphysics of primitive stuff
The paper sets out a primitive ontology of the natural world in terms of
primitive stuff, that is, stuff that has as such no physical properties at all,
but that is not a bare substratum either, being individuated by metrical
relations. We focus on quantum physics and employ identity-based Bohmian
mechanics to illustrate this view, but point out that it applies all over
physics. Properties then enter into the picture exclusively through the role
that they play for the dynamics of the primitive stuff. We show that such
properties can be local (classical mechanics), as well as holistic (quantum
mechanics), and discuss two metaphysical options to conceive them, namely
Humeanism and modal realism in the guise of dispositionalism
Brentanian Continua
Brentano’s theory of continuity is based on his account of boundaries. The core idea of the theory is that boundaries and coincidences thereof belong to the essence of continua. Brentano is confident that he developed a full-fledged, boundary-based, theory of continuity1; and scholars often concur: whether or not they accept Brentano’s take on continua they consider it a clear contender. My impression, on the contrary, is that, although it is infused with invaluable insights, several aspects of Brentano’s account of continuity remain inchoate. To be clear, the theory of boundaries on which it relies, as well as the account of ontological dependence that Brentano develops alongside his theory of boundaries, constitute splendid achievements. However, the passage from the theory of boundaries to the account of continuity is rather sketchy. This paper pinpoints some chief problems raised by this transition, and proposes some solutions to them which, if not always faithful to the letter of Brentano’s account of continua, are I believe faithful to its spirit.
§1 presents Brentano’s critique of the mathematical account of the continuous. §2 introduces Brentano’s positive account of continua. §3 raises three worries about Brentano’s account of continuity. §4 proposes a Neo-Brentanian approach to continua that handles these worries
Quantum Mechanics as Classical Physics
Here I explore a novel no-collapse interpretation of quantum mechanics which
combines aspects of two familiar and well-developed alternatives, Bohmian
mechanics and the many-worlds interpretation. Despite reproducing the empirical
predictions of quantum mechanics, the theory looks surprisingly classical. All
there is at the fundamental level are particles interacting via Newtonian
forces. There is no wave function. However, there are many worlds.Comment: 25 page
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