Artículos con la etiqueta ‘teoría cuantica’

Kantian causality and quantum quarks: the compatibility between quantum mechanics and Kant’s phenomenal world

Por • 2 abr, 2014 • Category: Filosofía

El indeterminismo cuántico parece incompatible con la defensa de la causalidad que hace Kant en su Segunda Analogía. La interpretación de Copenhague de la mecánica cuántica también considera a esta teoría como evidencia, a favor del antirealismo. Este articulo defiende que la ley (trascendental) de la causalidad se aplica solamente al mundo en tanto que observable, y no a objetos hipotéticos (inobservables) como los quarks, detectables solo mediante aceleradores de altas energías. Tomar la constante de Planck y la velocidad de la luz como límites inferior y superior de la observabilidad nos ofrece un modo de interpretar los observables de la mecánica cuántica como empíricamente reales, incluso aunque estos sean trascendentalmente, es decir, preobservacionalmente, ideales.



Generalized Quantum Theory: Overview and Latest Developments

Por • 12 feb, 2012 • Category: Ciencia y tecnología

The main formal structures of Generalized Quantum Theory are summarized. Recent progress has sharpened some of the concepts, in particular the notion of an observable, the action of an observable on states (putting more emphasis on the role of proposition observables), and the concept of generalized entanglement. Furthermore, the active role of the observer in the structure of observables and the partitioning of systems is emphasized.



Sheaf Logic, Quantum Set Theory and the Interpretation of Quantum Mechanics

Por • 24 nov, 2011 • Category: Ciencia y tecnología

Based on the Sheaf Logic approach to set theoretic forcing, a hierarchy of Quantum Variable Sets is constructed, which generalizes and simplifies the analogous construction developed by Takeuti on boolean valued models of set theory. Over this model, two alternative proofs of Takeuti’s correspondence, between self adjoint operators and the real numbers of the model, are given. This approach results to be more constructive, showing a direct relation with the Gelfand representation theorem, and revealing also the importance of these results with respect to the interpretation of Quantum Mechanics in close connection with the Deutsch-Everett multiversal interpretation of quantum theory. Finally, it is shown how in this context the notion of genericity and the corresponding generic model theorem can help to explain the emergence of classicality in Quantum Mechanics also in close connection with the Deutsch-Everett perspective.



The quantum state cannot be interpreted statistically

Por • 23 nov, 2011 • Category: Opinion

Quantum states are the key mathematical objects in quantum theory. It is therefore surprising that physicists have been unable to agree on what a quantum state represents. There are at least two opposing schools of thought, each almost as old as quantum theory itself. One is that a pure state is a physical property of system, much like position and momentum in classical mechanics. Another is that even a pure state has only a statistical significance, akin to a probability distribution in statistical mechanics. Here we show that, given only very mild assumptions, the statistical interpretation of the quantum state is inconsistent with the predictions of quantum theory. This result holds even in the presence of small amounts of experimental noise, and is therefore amenable to experimental test using present or near-future technology. If the predictions of quantum theory are confirmed, such a test would show that distinct quantum states must correspond to physically distinct states of reality.



de Broglie waves as the “Bridge of Becoming” between quantum theory and relativity

Por • 17 jul, 2011 • Category: Ambiente

It is hypothesized that de Broglie’s ‘matter waves’ provide a dynamical basis for Minkowski spacetime in an antisubstantivalist or relational account. The relativity of simultaneity is seen as an effect of the de Broglie oscillation together with a basic relativity postulate, while the dispersion relation from finite rest mass gives rise to the differentiation of spatial and temporal axes. Thus spacetime is seen as not fundamental, but rather as emergent from the quantum level. A result by Solov’ev which demonstrates that time is not an applicable concept at the quantum level is adduced in support of this claim. Finally, it is noted that de Broglie waves can be seen as the “bridge of becoming” discussed by Elitzur and Dolev (2005).



Editorial note to “The beginning of the world from the point of view of quantum theory”

Por • 1 jun, 2011 • Category: Leyes

This is an editorial note to accompany reprinting as a Golden Oldie in the Journal of General Relativity and Gravitation of the famous note by Georges Lemaitre on the quantum birth of the universe, published in Nature in 1931. We explain why this short (457 words) article can be considered to be the true “Charter” of the modern Big Bang theory.



Paradoxical Decision-Making Explained By Quantum Theory

Por • 15 abr, 2011 • Category: sociologia

At the heart of the Ellsberg paradox are two different kinds of uncertainties. The first is a probability: the chance of picking a red ball versus picking a non-red ball, which we are told is 1/3. The second is an ambiguity: the chance of the non-red ball being black or yellow which is entirely uncertain. Conventional decision theory cannot easily handle both types of uncertainty. But various researchers in recent years have pointed out that quantum theory can cope with with both types and what’s more, can accurately model the patterns of answers that humans come up with.



Temperature Dependence of Protein Folding Deduced from Quantum Transition

Por • 25 feb, 2011 • Category: Leyes

A general formula on the rate-temperature dependence has been deduced which is in good accordance with experimental data. These temperature dependences are further analyzed in terms of torsion potential parameters.