Kriesel and Wittgenstein

Georg Kreisel (15 September 1923 - 1 March 2015) was a formidable mathematical logician during a formative period when the subject was becoming a sophisticated field at the crossing of mathematics and logic. Both with his technical sophistication for his time and his dialectical engagement with mandates, aspirations and goals, he inspired wide-ranging investigation in the metamathematics of constructivity, proof theory and generalized recursion theory. Kreisel's mathematics and interactions with colleagues and students have been memorably described in Kreiseliana ([Odifreddi, 1996]). At a different level of interpersonal conceptual interaction, Kreisel during his life time had extended engagement with two celebrated logicians, the mathematical Kurt Gödel and the philosophical Ludwig Wittgenstein. About Gödel, with modern mathematical logic palpably emanating from his work, Kreisel has reflected and written over a wide mathematical landscape. About Wittgenstein on the other hand, with an early personal connection established Kreisel would return as if with an anxiety of influence to their ways of thinking about logic and mathematics, ever in a sort of dialectic interplay. In what follows we draw this out through his published essays—and one letter—both to elicit aspects of influence in his own terms and to set out a picture of Kreisel's evolving thinking about logic and mathematics in comparative relief.Accepted manuscrip

String Phenomenology: Past, Present and Future Perspectives

The observation of a scalar resonance at the LHC, compatible with perturbative electroweak symmetry breaking, reinforces the Standard Model parameterisation of all subatomic data. The logarithmic evolution of the SM gauge and matter parameters suggests that this parameterisation remains viable up to the Planck scale, where gravitational effects are of comparable strength. String theory provides a perturbatively consistent scheme to explore how the parameters of the Standard Model may be determined from a theory of quantum gravity. The free fermionic heterotic string models provide concrete examples of exact string solutions that reproduce the spectrum of the Minimal Supersymmetric Standard Model. Contemporary studies entail the development of methods to classify large classes of models. This led to the discovery of exophobic heterotic-string vacua and the observation of spinor-vector duality, which provides an insight to the global structure of the space of (2,0) heterotic-string vacua. Future directions entail the study of the role of the massive string states in these models and their incorporation in cosmological scenarios. A complementary direction is the formulation of quantum gravity from the principle of manifest phase space duality and the equivalence postulate of quantum mechanics, which suggest that space is compact. The compactness of space, which implies intrinsic regularisation, may be tightly related to the intrinsic finite length scale, implied by string phenomenology.Comment: 35 pages. No figures. To appear in the special volume edited by Gerald Cleaver on "Particle Physics and Quantum Gravity Implications for Cosmology". Based on talk presented at the 2012 CERN Summer Institute on String Phenomenolog

From theoretical foundation to analytical application by 3D solid representations of open public spaces

Tese de Doutoramento em Arquitetura, com a especialização em Teoria e Prática do Projeto apresentada na Faculdade de Arquitetura da Universidade de Lisboa para obtenção do grau de Doutor.Num meio construido sobre-edificado contemporâneo, reconheceu-se a sua parte não edificada, o Vazio Arquitetónico-Urbano, como um elemento gradiente e estrutural, que contribui para as suas qualidades formais e funcionais. Baseado nas referências do urbanismo, arquitetura e geografia humana, e com o fim de analisar o Espaço Aberto Público, este estudo propõe, defina e captura o fenómeno do Vazio Arquitetónico-Urbano - Vazio UrbArq. Começando com uma abordagem teórica mais ampla a partir da qual o Vazio UrbArq é conceptualizado, desenvolve-se um método de representação do domínio do negativo do ambiente construído, objetivando-o em novas representações sólidas 3D (Convex, Solid and Fragmented Voids) e combinando-os com as representações do campo visual já existentes (Isovist and Viewsheds). Esses modelos de representação são usados para capturar os atributos de Espaços Públicos Abertos, abordando as suas propriedades mensuráveis, que estão posteriormente relacionadas com os usos espaciais como expressões das qualidades dos espaços urbanos. As expressões de qualidade são inferidas através da análise fenomenológica in-situ e da observação natural, a partir das quais foram estabelecidas correlações preliminares entre as propriedades quantitativas e qualidades dos Espaços Públicos Abertos. Combinando metodologias qualitativas e quantitativas, a investigação utiliza a representação sólida 3D e investiga o papel do Vazio UrbArch na geração de atributos e qualidades de Espaços Públicos Abertos na zona ribeirinha de Lisboa. Para esse efeito: a) Introduziu-se o conceito de vazio como base inspiradora e teórica da pesquisa (capítulo 2); B) Definiu-se o foco da pesquisa - Vazio UrbArch (capítulo 3); C) Desenvolveram-se os modelos de representação de Espaços Públicos Abertos abordando o foco do Vazio UrbArch (capítulo 4); D) Definiram-se os atributos específicos dos Espaços Públicos Abertos para serem abordados (capítulo 5); Aplicou-se a metodologia a partir da qual se estabeleceu a correlação entre atributos, propriedades qualitativas e qualidades espaciais (capítulo 6).ABSTRACT: In the nowadays tightly built environment we recognize the unbuilt part of urban-architectural space as its gradient and structural element, which influences its formal and functional qualities. Based on the references of urbanism, architecture and human geography and in order to analyse Open Public Spaces through the prism of its unbuilt part, the study proposes, defines and captures the notion of urban-architectural emptiness – UrbArch Emptiness. It starts from a theoretical analysis of emptiness wherefrom the UrbArch Emptiness was conceptualised. It further develops a way to represent the realm of the negative of built environment by objectifying it into novel 3D solid representations (Convex, Solid and Fragmented Voids) which are combined with already existing View field representations (Isovist and Viewsheds) and applied on case study of Lisbon Riverside. These representation models are used for capturing attributes of Open Public Spaces by approaching their measurable properties which are further related to spatial experiences and usages as expressions of spatial qualities. The expressions of qualities are inferred through first person in-situ phenomenological analysis and natural observation wherefrom correlations between Open Public Spaces’ quantitative properties and qualities were preliminarily established. Combining qualitative and quantitative methodologies, the research takes the 3D solid representation and investigates the role of UrbArch Emptiness in generating qualities of Open Public Spaces in Lisbon riverside. To do so research: a) Introduces the concept of Emptiness as inspirational and theoretical basis of research (chapter 2); b) Defines objectified focus of research – UrbArch Emptiness (chapter 3); c) Develops models for Open Public Spaces representation and analysis based on UrbArch Emptiness (chapter 4); d) Defines specific Open Public Spaces’ attributes to be approached (chapter 5); Applies the methodology wherefrom correlations between attributes, qualitative properties and spatial qualities are preliminarily established (chapter 6).N/

Art installation of conic sea and peculiar angels and its affordances

Installations attempt to expose everyday space by depicting an environment that appears normal yet has been altered in perceptibly unexpected ways. Such environments are typically designed to re-orient participants, giving them the feeling of stepping out of conventional reality, with the goal of creating a lingering heightened perception of one’s normal environs. A video art installation entitled Conic Sea and Peculiar Angels was created with the intent to inveigle participants into exploring an unwonted environment. The main artistic properties used to entice exploration will be reviewed. With emphasis on these specific properties influential artists and their work will be expounded upon. Ecological Psychology, a theoretical framework most closely associated with the seminal writings of J.J. Gibson, was used to critically evaluate this installation. A key theoretical construct in this framework is the concept of an affordance. An affordance is a property of the immediate environment taken with reference to a perceiver. Such relational properties enable a range of activities that may or may not be utilized by the inhabitants of an environment. The artistic properties used by artists can be related to affordances in Ecological Psychology, as are they both mechanisms to entice exploration. Based on personal observation and reflection, as well as on the works of relevant artists, the affordances that enable exploration of this installation are proposed and discussed. The installation mounted and view on three separate occasions. The researcher observed and documented the audiences’ responses that showed a desire to explore. It was found that the artistic properties in Conic Sea and Peculiar Angels afforded participants to explore