Hemeroteca del mes julio, 2015

To Teach Modal Logic: An Opinionated Survey

Por • 26 jul, 2015 • Category: Ciencia y tecnología

I aim to promote an alternative agenda for teaching modal logic chiefly inspired by the relationships between modal logic and philosophy. The guiding idea for this proposal is a reappraisal of the interest of modal logic in philosophy, which do not stem mainly from mathematical issues, but which is motivated by central problems of philosophy and language. I will point out some themes to start elaborating a guide for a more comprehensive approach to teach modal logic, and consider the contributions of dual-process theories in cognitive science, in order to explore a pedagogical framework for the proposed point of view.



General en Jefe Vladimir Padrino López: El proyecto de Hugo Chávez

Por • 26 jul, 2015 • Category: Nacionales

El ministro de Defensa, General en Jefe Vladimir Patrino López, aseguró este sábado que la Fuerza Armada Nacional Bolivariana está unida detrás del presidente Nicolás Maduro y del proyecto bolivariano de Hugo Chávez.



Daniel Estulin: Venezuela debe invertir en infraestructura

Por • 26 jul, 2015 • Category: Nacionales

El conferencista, escritor e investigador Daniel Estulin expresó que la única manera que tiene un país para salir de la crisis es invertir en infraestructura para las futuras generaciones



«El reto de ser una Venezuela diversificada»

Por • 26 jul, 2015 • Category: Nacionales

La industrialización de los hidrocarburos solo ha sido un enunciado sin llevarlo a cabo.



«Voto nulo en Venezuela»

Por • 26 jul, 2015 • Category: Nacionales

En Venezuela están creciendo los electores desencantados de la clase política que gobierna y que se le opone.



Zurück zu Kant”

Por • 26 jul, 2015 • Category: Opinion

Considering history of philosophy as a whole, the two main traditions of thought from the 20th century (analytic and phenomenological hermeneutic) can be regarded as being variants of one same fundamental turn. This systematic relation is connected to a common historical root. To highlight it implies to review the ideas that are deeply in the basis of the historiography of the German thought in the 19th century. Beyond names, problems and theses that may appear to haveat first sight no relationship whatsoever, we can notice a continuous unitary development that has not yet received all the attention it deserves. In this movement, Adolf Trendelenburg stands out, once the beginners of both the above mentioned traditions and of Neokantianism (Frege, Brentano, Dilthey and Cohen) received a decisive impulse from his reflections. Síntesis en inglés y el texto en castellano



Quantum Dynamical Relativity and the Nature of Spacetime

Por • 26 jul, 2015 • Category: Educacion

Einstein’s special theory of relativity starts with assumptions about how observations conducted in relatively moving inertial frames must compare. From these assumptions, conclusions can be drawn regarding the laws of physics in any one frame. Can we do the reverse, that is, build the correct physics entirely from considerations within a single frame and infer therefrom the results of measurements in moving frames? Can we, in this project, supply the «elementary foundations» that Einstein found lacking in his own theory, thereby converting special relativity from (in Einstein’s terminology) a «principle» theory to a «constructive» one?



Violation of Invariance of Measurement for GDP Growth Rate and its Consequences

Por • 26 jul, 2015 • Category: Economía

The aim here is to address the origins of sustainability for the real growth rate in the United States. For over a century of observations on the real GDP per capita of the United States a sustainable two percent growth rate has been observed. To find an explanation for this observation I consider the impact of utility preferences and the effect of mobility of labor \& capital on every provided measurement. Mobility of labor results in heterogenous rates of increase in prices which is called Baumol’s cost disease phenomenon. Heterogeneous rates of inflation then make it impossible to define an invariant measure for the real growth rate. Paradoxical and ambiguous results already have been observed when different measurements provided by the World Bank have been compared with the ones from the central banks. Such ambiguity is currently being discussed in economy. I define a toy model for caring out measurements in order to state that this ambiguity can be very significant.



The Temporal Logic of two dimensional Minkowski spacetime is decidable

Por • 26 jul, 2015 • Category: Crítica

We consider Minkowski spacetime, the set of all point-events of spacetime under the relation of causal accessibility. That is, x can access y if an electromagnetic or (slower than light) mechanical signal could be sent from x to y . We use Prior’s tense language of F and P representing causal accessibility and its converse relation. We consider two versions, one where the accessibility relation is reflexive and one where it is irreflexive. In either case, it is not known if the logic is decidable or even axiomatisable and this has been an open problem for decades. We make a small step forward by proving, for the case where the accessibility relation is irreflexive, that the set of valid formulas over two-dimensional Minkowski spacetime is decidable; decidability for the reflexive case follows from this. The complexity of either problem is EXPTIME at worst.



How observers create reality

Por • 25 jul, 2015 • Category: Filosofía

Wheeler proposed that repeated acts of observation give rise to the reality that we observe, but offered no detailed mechanism for this. Here this creative process is accounted for on the basis of the idea that nature has a deep technological aspect that evolves as a result of selection processes that act upon observers making use of the technologies. This leads to the conclusion that our universe is the product of agencies that use these evolved technologies to suit particular purposes.