30,961 research outputs found
On Vague Computers
Vagueness is something everyone is familiar with. In fact, most people think
that vagueness is closely related to language and exists only there. However,
vagueness is a property of the physical world. Quantum computers harness
superposition and entanglement to perform their computational tasks. Both
superposition and entanglement are vague processes. Thus quantum computers,
which process exact data without "exploiting" vagueness, are actually vague
computers
Quantum objects are vague objects
[FIRST PARAGRAPHS]
Is vagueness a feature of the world or merely of our representations
of the world? Of course, one might respond to this question by asserting
that insofar as our knowledge of the world is mediated by our
representations of it, any attribution of vagueness must attach to the latter.
However, this is to trivialize the issue: even granted the point that all
knowledge is representational, the question can be re-posed by asking
whether vague features of our representations are ultimately eliminable or
not. It is the answer to this question which distinguishes those who believe
that vagueness is essentially epistemic from those who believe that it is,
equally essentially, ontic. The eliminability of vague features according to
the epistemic view can be expressed in terms of the supervenience of
āvaguely described factsā on āprecisely describable factsā:
If two possible situations are alike as precisely described in terms of
physical measurements, for example, then they are alike as vaguely
described with words like āthinā. It may therefore be concluded that the facts
themselves are not vague, for all the facts supervene on precisely
describable facts. (Williamson 1994, p. 248; see also pp. 201-
204)
It is the putative vagueness of certain identity statements in
particular that has been the central focus of claims that there is vagueness
āinā the world (Parfit 1984, pp. 238-241; Kripke 1972, p. 345 n. 18). Thus,
it may be vague as to who is identical to whom after a brain-swap, to give
a much discussed example. Such claims have been dealt a forceful blow
by the famous Evans-Salmon argument which runs as follows: suppose for
reductio that it is indeterminate whether a = b. Then b definitely possesses
the property that it is indeterminate whether it is identical with a, but a
definitely does not possess this property since it is surely not
indeterminate whether a=a. Therefore, by Leibnizās Law, it cannot be the
case that a=b and so the identity cannot be indeterminate (Evans 1978;
Salmon 1982)
Some Worlds of Quantum Theory
This paper assesses the Everettian approach to the measurement problem,
especially the version of that approach advocated by Simon Saunders and David
Wallace. I emphasise conceptual, indeed metaphysical, aspects rather than
technical ones; but I include an introductory exposition of decoherence. In
particular, I discuss whether -- as these authors maintain -- it is acceptable
to have no precise definition of 'branch' (in the Everettian kind of sense).Comment: 42 pages, no figures: a pdf file. A version of this paper will appear
in a CTNS/Vatican Observatory volume on Quantum Theory and Divine Action, ed.
Robert Russell et a
Imperfect identity
Questions of identity over time are often hard to answer. A long
tradition has it that such questions are somehow soft: they have no unique,
determinate answer, and disagreements about them are merely verbal. I
argue that this claim is not the truism it is taken to be. Depending on how
it is understood, it turns out either to be false or to presuppose a highly
contentious metaphysical claim
Semantic categories underlying the meaning of āplaceā
This paper analyses the semantics of natural language expressions that are associated with the intuitive notion of āplaceā. We note that the nature of such terms is highly contested, and suggest that this arises from two main considerations: 1) there are a number of logically
distinct categories of place expression, which are not always clearly distinguished in discourse about āplaceā; 2) the many non-substantive place count nouns (such as āplaceā, āregionā, āareaā, etc.) employed in natural
language are highly ambiguous. With respect to consideration 1), we propose that place-related expressions
should be classified into the following distinct logical types: a) āplace-likeā count nouns (further subdivided into abstract, spatial and substantive varieties), b) proper names of āplace-likeā objects, c) locative property phrases, and d) definite descriptions of āplace-likeā objects. We outline possible formal representations for each of these. To address consideration 2), we examine meanings, connotations and ambiguities of the English vocabulary of abstract and generic place count nouns, and identify underlying elements of meaning, which explain both
similarities and differences in the sense and usage of the various terms
Drawing Boundaries
In āOn Drawing Lines on a Mapā (1995), I suggested that the different ways we have of drawing lines on maps open up a new perspective on ontology, resting on a distinction between two sorts of boundaries: fiat and bona fide. āFiatā means, roughly: human-demarcation-induced. āBona fideā means, again roughly: a boundary constituted by some real physical discontinuity. I presented a general typology of boundaries based on this opposition and showed how it generates a corresponding typology of the different sorts of objects which boundaries determine or demarcate. In this paper, I describe how the theory of fiat boundaries has evolved since 1995, how it has been applied in areas such as property law and political geography, and how it is being used in contemporary work in formal and applied ontology, especially within the framework of Basic Formal Ontology
Fuzzy Bigraphs: An Exercise in Fuzzy Communicating Agents
Bigraphs and their algebra is a model of concurrency. Fuzzy bigraphs are a
generalization of birgraphs intended to be a model of concurrency that
incorporates vagueness. More specifically, this model assumes that agents are
similar, communication is not perfect, and, in general, everything is or
happens to some degree.Comment: 11 pages, 3 figure
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