Past observable dynamics of a continuously monitored qubit

Monitoring a quantum observable continuously in time produces a stochastic measurement record that noisily tracks the observable. For a classical process such noise may be reduced to recover an average signal by minimizing the mean squared error between the noisy record and a smooth dynamical estimate. We show that for a monitored qubit this usual procedure returns unusual results. While the record seems centered on the expectation value of the observable during causal generation, examining the collected past record reveals that it better approximates a moving-mean Gaussian stochastic process centered at a distinct (smoothed) observable estimate. We show that this shifted mean converges to the real part of a generalized weak value in the time-continuous limit without additional postselection. We verify that this smoothed estimate minimizes the mean squared error even for individual measurement realizations. We go on to show that if a second observable is weakly monitored concurrently, then that second record is consistent with the smoothed estimate of the second observable based solely on the information contained in the first observable record. Moreover, we show that such a smoothed estimate made from incomplete information can still outperform estimates made using full knowledge of the causal quantum state.Comment: 11 pages, 4 figure

Undecidability and the problem of outcomes in quantum measurements

We argue that it is fundamentally impossible to recover information about quantum superpositions when a system has interacted with a sufficiently large number of degrees of freedom of the environment. This is due to the fact that gravity imposes fundamental limitations on how accurate measurements can be. This leads to the notion of undecidability: there is no way to tell, due to fundamental limitations, if a quantum system evolved unitarily or suffered wavefunction collapse. This in turn provides a solution to the problem of outcomes in quantum measurement by providing a sharp criterion for defining when an event has taken place. We analyze in detail in examples two situations in which in principle one could recover information about quantum coherence: a) "revivals" of coherence in the interaction of a system with the environment and b) the measurement of global observables of the system plus apparatus plus environment. We show in the examples that the fundamental limitations due to gravity and quantum mechanics in measurement prevent both revivals from occurring and the measurement of global observables. It can therefore be argued that the emerging picture provides a complete resolution to the measurement problem in quantum mechanics.Comment: 14 pages, Latex, one figure, version to appear in Foundations of Physic

A single-world consistent interpretation of quantum mechanics from fundamental time and length uncertainties

Within ordinary ---unitary--- quantum mechanics there exist global protocols that allow to verify that no definite event ---an outcome to which a probability can be associated--- occurs. Instead, states that start in a coherent superposition over possible outcomes always remain as a superposition. We show that, when taking into account fundamental errors in measuring length and time intervals, that have been put forward as a consequence of a conjunction of quantum mechanical and general relativity arguments, there are instances in which such global protocols no longer allow to distinguish whether the state is in a superposition or not. All predictions become identical as if one of the outcomes occurs, with probability determined by the state. We use this as a criteria to define events, as put forward in the Montevideo Interpretation of Quantum Mechanics. We analyze in detail the occurrence of events in the paradigmatic case of a particle in a superposition of two different locations. We argue that our approach provides a consistent (C) single-world (S) picture of the universe, thus allowing an economical way out of the limitations imposed by a recent theorem by Frauchiger and Renner showing that having a self-consistent single-world description of the universe is incompatible with quantum theory. In fact, the main observation of this paper may be stated as follows: If quantum mechanics is extended to include gravitational effects to a QG theory, then QG, S, and C are satisfied.Comment: thoughts and comments more than welcom

Shellfishers’ organizations as agency to social transformation

En este artículo se analiza el proceso de transformación llevado a cabo por las mariscadoras a pie gallegas entre 1995 y 2002. El marisqueo a pie es una actividad tradicionalmente desarrollada por mujeres. La tesis fundamental que se defiende es que la organización de las mariscadoras fue decisiva en este proceso. La organización de las mujeres ha sido fundamental para transformar una actividad informal en una profesión regulada, con reconocimiento y protección. Estas mujeres, al organizarse, introdujeron modificaciones respecto al medio ambiente, las instituciones y sus comunidades. Ellas gestionaron los recursos naturales, desarrollaron el cultivo y ocuparon posiciones de responsabilidad dentro de las cofradías de pescadores.This paper attempts to analyze the process of transformation of shellfish gathering on foot in Galicia between 1995 and 2002. The shellfish gathering on foot is an activity that traditionally has been developed mainly by women. We emphasize in the article that the role of shellfishers’ organizations in this process has been decisive. Women’ organizations has been essential in this process to transformation of an informal activity into a regulated activity, which gave full recognition and protection to women shellfish gathers. Women, by establishing their own organisations, modified the dynamics of the social, institutional and natural systems of their local communities. They manage the resource, develop extensive shellfish farming, and join established male organisations and to assume positions of responsibility within the governing bodies of these organisations

Some notes on the concept of social imaginary

[Resumen]Han pasado suficientes años de uso del término “Imaginarios” para que intentemos una clarificación provisional de tal concepto. Se trata de aportar algunas precisiones sobre la cuestión de entender lo que hacemos, lo que nos rodea y por qué, necesariamente tenemos que enfrentarnos con los procesos múltiples de construcción de la realidad. En un primer apartado nos ocuparemos de las definiciones más espontáneas o inmediatas. El segundo párrafo lo dedicaremos a algunas definiciones inspiradas por el marxismo. En el tercer apartado dedicaremos algunas consideraciones a las que provienen de fuentes cercanas a la semántica y finalmente, en el cuarto, expondremos más ampliamente la que nosotros defendemos: una concepción sistémica y sociocibernética, que parte del análisis de la “complejidad” y de la decisión como selección de posibilidades. Utiliza como eje diferenciador el código comunicativo “relevancia/opacidad”.[Abstract]The term ‘Imaginary’ has been academically in use for many years, so is now possible to try a provisional clarification of its concept. If the question is to try understanding what we do, what is around us and why, we must face necessarily the multiple processes of construction of reality. In a first section, we are going to deal with the most spontaneous and immediate definitions. Secondly, we go further analyzing some Marxist definitions. Third, we put under consideration some definitions from Semantics, and finally, we end with a more extensive exposition of our own criteria: i.e.: a systemic and cybernetic approach, which departs from the analysis of ‘complexity’ and the taking of decisions as a way of selection among possibilities. We resort to the communicative code ‘relevance/opacity’ as our main axis of differentiation

Domesticating Violence: A Way to Refusing the Intergender Conflict

La violencia contra las mujeres ha sido referenciada bajo distintas denominaciones: «maltrato», «violencia doméstica», «machista», «de género», «terrorismo doméstico», etc. Estas distintas denominaciones han significado una ampliación o una reducción de los comportamientos que en cada momento se consideraban violentos. Este artículo analizará el camino conceptual por el que ha transitado la violencia sobre las mujeres, en el Estado español, a lo largo de las últimas décadas. A través de este proceso de reconstrucción nominal se observará un doble movimiento: primero se irá ampliando progresivamente el tipo de conductas que exceden lo socialmente admitido, para, posteriormente, encorsetarla como «violencia doméstica» o «violencia en los entornos familiares», lo que no hace sino ocultar que en las relaciones de dominación que mantienen los hombres sobre las mujeres radica la raíz del problema.Violence against women has been referred to by different names: «abuse», «domestic violence», «sexist violence», «gender violence», «domestic terrorism», etc. These denominations have pointed to an extension or a reduction of the behaviors that were considered to be violent in each particular period. This article will explore the conceptual changes which have taken place concerning violence against women in the Spanish State, over the last few decades. Through this process of nominal reconstruction a double movement can be observed: firstly, the type of conduct considered outside of the socially acceptable was progressively expanded, only later to restrict this behavior as «domestic violence» or «violence in family environments», all of which did nothing but hide the ultimate root of the problem: the domination of men over women

Questions for change: the social imaginaries of the changes in the basic references

El uso incesante de la palabra “cambio” por parte de muchos actores políticos para encubrir la ausencia casi total de proyectos de resolución de los problemas que afectan a los ciudadanos y de llegar a ocupar un poder del que previamente tienen que desalojar al actual ocupante, encierra una alusión cierta a lo que está ocurriendo en nuestras sociedades particulares y en un mundo globalizado. El cambio se está produciendo ya. Pero ¿en qué consiste? Utilizaremos la perspectiva sociocibernética de la Teoría de los Imaginarios Sociales para señalar les principales relevancias y opacidades de este complejo proceso. La principal metáfora que utilizaremos es la de la puerta. Estamos “saliendo” de un espacio y un tiempo y estamos “entrando” en otro distinto del que no tenemos mapas ni cronologías. Tratamos de abordar analíticamente los datos que podemos observar de ese proceso enmarcándolos en tres ámbitos que definiremos como el “marco de referencias”, el “marco de conceptos” y el “marco instrumental”. En este primer artículo nos ocuparemos en desentrañar las relevancias y las opacidades que se pueden observar en el material mediático trabajado, en relación a las “Referencias Básicas”. Seguirán otros dos que se ocuparán de las variaciones de “los conceptos” y “los instrumentos” utilizados en este complejo proceso de “estar saliendo” y “estar entrando”The incessant use of the word "change" by many political actors to cover up the almost total absence of projects to solve the problems that affect the citizens and to come to occupy a power from which they have previously to dislodge the current occupant, Contains a certain allusion to what is happening in our particular societies and in a globalized world. The change is already taking place. But what is it? We will use the socio-cybernetic perspective of the Theory of Social Imaginaries to point out the main relevance and opacity of this complex process. The main metaphor we will use is that of the door. We are "leaving" a space and a time and we are "entering" into another one that we do not have maps or chronologies. We try to analyze analytically the data that we can observe of this process framing them in three areas that we will define as the "frame of reference", the "framework of concepts" and the "instrumental framework". In this first article we will focus on unraveling the relevancies and opacities that can be observed in the media material worked, in relation to the "Basic References". Two more will follow to deal with variations of "concepts" and "tools" used in this complex process of "coming out" and "coming in"info:eu-repo/semantics/publishedVersio