A Non-Probabilistic Model of Relativised Predictability in Physics

Little effort has been devoted to studying generalised notions or models of (un)predictability, yet is an important concept throughout physics and plays a central role in quantum information theory, where key results rely on the supposed inherent unpredictability of measurement outcomes. In this paper we continue the programme started in [1] developing a general, non-probabilistic model of (un)predictability in physics. We present a more refined model that is capable of studying different degrees of "relativised" unpredictability. This model is based on the ability for an agent, acting via uniform, effective means, to predict correctly and reproducibly the outcome of an experiment using finite information extracted from the environment. We use this model to study further the degree of unpredictability certified by different quantum phenomena, showing that quantum complementarity guarantees a form of relativised unpredictability that is weaker than that guaranteed by Kochen-Specker-type value indefiniteness. We exemplify further the difference between certification by complementarity and value indefiniteness by showing that, unlike value indefiniteness, complementarity is compatible with the production of computable sequences of bits.Comment: 10 page

Classical, quantum and biological randomness as relative unpredictability

International audienceWe propose the thesis that randomness is unpredictability with respect to an intended theory and measurement. From this point view we briefly discuss various forms of randomness that physics, mathematics and computing science have proposed. Computing science allows to discuss unpredictability in an abstract, yet very expressive way, which yields useful hierarchies of randomness and may help to relate its various forms in natural sciences. Finally we discuss biological randomness — its peculiar nature and role in ontogenesis and in evolutionary dynamics (phylogenesis). Randomness in biology has a positive character as it contributes to the organisms' and populations' structural stability by adaptation and diversity. Abstract We propose the thesis that randomness is unpredictability with respect to an intended theory and measurement. From this point view we briefly discuss various forms of randomness that physics, mathematics and computing science have proposed. Computing science allows to discuss unpredictability in an abstract, yet very expressive way, which yields useful hierarchies of randomness and may help to relate its various forms in natural sciences. Finally we discuss biological randomness—its peculiar nature and role in ontogenesis and in evolutionary dynamics (phylogenesis). Randomness in biology has a positive character as it contributes to the organisms' and populations' structural stability by adaptation and diversity

Natural Language Syntax Complies with the Free-Energy Principle

Natural language syntax yields an unbounded array of hierarchically structured expressions. We claim that these are used in the service of active inference in accord with the free-energy principle (FEP). While conceptual advances alongside modelling and simulation work have attempted to connect speech segmentation and linguistic communication with the FEP, we extend this program to the underlying computations responsible for generating syntactic objects. We argue that recently proposed principles of economy in language design - such as "minimal search" criteria from theoretical syntax - adhere to the FEP. This affords a greater degree of explanatory power to the FEP - with respect to higher language functions - and offers linguistics a grounding in first principles with respect to computability. We show how both tree-geometric depth and a Kolmogorov complexity estimate (recruiting a Lempel-Ziv compression algorithm) can be used to accurately predict legal operations on syntactic workspaces, directly in line with formulations of variational free energy minimization. This is used to motivate a general principle of language design that we term Turing-Chomsky Compression (TCC). We use TCC to align concerns of linguists with the normative account of self-organization furnished by the FEP, by marshalling evidence from theoretical linguistics and psycholinguistics to ground core principles of efficient syntactic computation within active inference

Philosophical aspects of chaos: definitions in mathematics, unpredictability, and the observational equivalence of deterministic and indeterministic descriptions

This dissertation is about some of the most important philosophical aspects of chaos research, a famous recent mathematical area of research about deterministic yet unpredictable and irregular, or even random behaviour. It consists of three parts. First, as a basis for the dissertation, I examine notions of unpredictability in ergodic theory, and I ask what they tell us about the justification and formulation of mathematical definitions. The main account of the actual practice of justifying mathematical definitions is Lakatos's account on proof-generated definitions. By investigating notions of unpredictability in ergodic theory, I present two previously unidentified but common ways of justifying definitions. Furthermore, I criticise Lakatos's account as being limited: it does not acknowledge the interrelationships between the different kinds of justification, and it ignores the fact that various kinds of justification - not only proof-generation - are important. Second, unpredictability is a central theme in chaos research, and it is widely claimed that chaotic systems exhibit a kind of unpredictability which is specific to chaos. However, I argue that the existing answers to the question "What is the unpredictability specific to chaos?" are wrong. I then go on to propose a novel answer, viz. the unpredictability specific to chaos is that for predicting any event all sufficiently past events are approximately probabilistically irrelevant. Third, given that chaotic systems are strongly unpredictable, one is led to ask: are deterministic and indeterministic descriptions observationally equivalent, i.e., do they give the same predictions? I treat this question for measure-theoretic deterministic systems and stochastic processes, both of which are ubiquitous in science. I discuss and formalise the notion of observational equivalence. By proving results in ergodic theory, I first show that for many measure-preserving deterministic descriptions there is an observationally equivalent indeterministic description, and that for all indeterministic descriptions there is an observationally equivalent deterministic description. I go on to show that strongly chaotic systems are even observationally equivalent to some of the most random stochastic processes encountered in science. For instance, strongly chaotic systems give the same predictions at every observation level as Markov processes or semi-Markov processes. All this illustrates that even kinds of deterministic and indeterministic descriptions which, intuitively, seem to give very different predictions are observationally equivalent. Finally, I criticise the claims in the previous philosophical literature on observational equivalence

The conceptual structure of product semantic models

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 21/09/1999.The study is concerned with the conceptual structure and content of the framework for characterising user-product interaction, proposed under the title – ‘Product Semantics’. The sources for the critique of design, from which the framework is derived, are identified and analysed, and the substantive theoretical and methodological content given initial consideration in terms of the deployment of the central concept of ‘meaning’, and the principal theoretical approaches adopted in the analysis of meaning and semantic concepts generally. The commitment to a cognitive and experiential approach to user-interaction is established and the concepts central to the framework, and requiring more detailed analysis, are identified. The core of the study consists in an analysis of the sequence of concepts and contexts that are chiefly used in the theoretical articulation of the framework, including - function, affordance, categorisation, artefacts, meaning and expression - of which the concept of affordance is central to the structure. On the basis of the initial consideration of the structure and content of the scheme, and in the light of the analysis of concepts, the explanatory structure of the framework is established. It is argued that the core commitment to an experiential and cognitive account, and the form of the explanatory structure, are jointly incompatible with the conceptual content of the framework, particularly in respect of the pivotal role of the concept of affordance. Proposals are advanced for an alternative interpretation which addresses the central issues of consistency and coherence, and which suggests an alternative approach to the conceptual characterisation of the framework and the form of the explanatory hierarchy. The implications of the framework, and the proposed alternative interpretation, are considered in respect of their application in shaping approaches to the development of design theory and methodology, and the experiential aspect of semantics and cognition

Quantitative analysis of urban morphology: Exploring ethnic urban formations and structure in the city of İzmir

Thesis (Doctoral)--Izmir Institute of Technology, City and Regional Planning, Izmir, 2009Includes bibliographical references (leaves: 128-150)Text in English; Abstract: Turkish and Englishxii, 381 leavesUrban design and planning have been mainly involved in forming and structuring our cities. In order to understand this form and structure, various methods and tools of analyses have been developed in urban morphology. Spatial analysis is of basic need within planning and one of the essential tools for anyone who wants to investigate space. Spatial analyses are also useful tools on the way to a deeper understanding of the city itself. The aim of this thesis is to develop a theoretical framework and quantitative methodology for modeling urban form and structure, in order to better understand the complexity inherent in urban environments and to generate and improve relevant knowledge for urban design and planning. Space syntax is a set of techniques for the analysis of spatial configurations of all kinds, especially where spatial configuration seems to be a significant aspect of human affairs, as it is in buildings and cities. Space Syntax is unique as an analysis tool since it allows us to objectively measure the street network configuration. To explore the geometrical features of urban form, a geometric model is utilized and a typological analysis approach will be used for the basic element of the fabric: .the building block., Quantitative measures obtained from these syntactic and geometric approaches, their relationships and interdependencies are analyzed and explored. An integrated set of measures is identified. Case studies in Izmir are selected for testing the methodology to be developed. Methodology development is concentrated on five ethnic districts at the late-Ottoman period. These are also known as the Greek, Jewish, Armenian, European and Turkish quarters of the city. By analyzing the urban form and structure of these districts, a new integrated quantitative methodology for analysis of urban morphology is presented. Keywords: Urban Morphology, Urban Analysis, Space Syntax, Urban Pattern, Izmi