Principle Of Causality Research Articles

Why optimisation of a system of systems is both unattainable and unnecessary

The operational and managerial independence, geographic distribution, emergent behaviour, and evolutionary development that characterise a system of systems (SoS) also ensure that it is impossible to truly optimise it. However, using the concept of satisficing, we can declare that a 'good enough' solution is in fact, sufficient. Why are we all right with this potentially unsettling notion in the context of a system of systems? In part, due to the principle of finite causality introduced in this paper, stating no system outcome can have infinitely bad (or good) implications; thus, the outcome of any action or series of actions is finite in nature. This realisation further bolsters the acceptability of an inherently sub-optimal SoS. This paper explores the notions of why optimisation of a SoS is both: 1) unattainable based on its inherent characteristics and associated systems principles; and 2) unnecessary in practice.

Causalidade e teoria quântica

O desenvolvimento da teoria quântica, na primeira metade do século passado, acendeu um debate acalorado entre filósofos e físicos sobre a natureza das leis físicas e, em especial, sobre a validade do princípio de causalidade. Tendo em vista a teoria de Planck sobre a radiação, a interpretação probabilista de Max Born, as relações de incerteza de Heisenberg e o princípio de complementaridade de Bohr, muitos físicos colocaram em dúvida a causalidade clássica, cuja legitimidade parecia a princípio não mais estar assegurada no domínio quântico. O objetivo deste artigo é apresentar e discutir as diferentes posições em torno desse debate. Serão analisados, além dos argumentos levantados pelos intérpretes de Copenhague, aqueles sustentados por neopositivistas e neokantianos. Procuraremos mostrar que, a despeito dos antagonismos filosóficos, a posição adotada por Schlick nesse debate parece estar mais próxima de Cassirer do que de seu colaborador Reichenbach.

Complex modulus estimation respecting causality: Application to viscoelastic bars

The identification of linear visco-elasticity models mostly focuses on the real and imaginary parts of the Young’s modulus. Many methods have been proposed in the past to identify these material model parameters from experiments. However, when these parameters are determined independently, they are likely to violate the principle of causality. The present work presents a method that accounts for the constraints of causality and positivity of dissipation rate. The proposed method is based on a finite set of n measured angular frequencies and complex moduli. It includes a noise reduction procedure and provides a rheological 2p + 1)-parameter model with p parameters which are obtained as the common positive zeros of a special class of rational functions, while the remaining parameters are obtained from a least squares fit. The level of refinement of the rheological model, expressed by p , is not an assumed value but a result of the method. The method is applied to an impact test with a Nylon bar specimen. In this case, data at the n = 29 lowest resonance frequencies resulted in a rheological model with 14 parameters (p = 6). The validity of the method is checked through supplementary experimental results at low frequencies.

Forms of Reflection, Imagination, and the Love of Wisdom

AbstractThis article reflects upon the relationship between philosophy and theology. It further considers the persisting relevance of the specifically Hellenic inheritance of philosophy as contemplation and the Delphic exhortation, “Know thyself!” It concludes with reflections upon the role of imagination in relation to the philosophical idea of God as the supreme and transcendent causal principle of the physical cosmos.

The superluminal limit as a consequence of the classical causality principle

The superluminal limit states that no physical object can overpass the velocity of the light in vacuum. This limit is usually considered a consequence of the special theory of relativity (STR). In contrast with the basic hypotheses chosen by Albert Einstein, many authors wrongly consider it a basic assumption of the STR. Here, we revise this limit by showing that it can be derived as a consequence of the classical causality principle without invoking any additional hypotheses. It will be demonstrated to hold true in any kind of medium even in those exhibiting either a phase or group velocity of the light greater than that of light in vacuum. The behavior of some neutral particles (e.g. neutrinos, photons) is shown to be fully consistent with this model. The validity of our discussion rests on the hypotheses of a gravitationless vacuum.

Gain functionalized core–shell nanoparticles: the way to selectively compensate absorptive losses

We experimentally demonstrate that gain materials properly encapsulated into the shell surrounding metal nanoparticles (NPs) are responsible for the modification of the overall plasmon response of engineered nanostructures. A comparison between designed systems based on functionalized core–shell NPs having different encapsulated dye molecules is presented. Experimental observations of Rayleigh scattering enhancement, accompanied by an increase of transmission as a function of gain, reveal striking optical loss compensation effects. Fluorescence lifetime measurements demonstrate a quenching of dye photoluminescence in functionalized core–shell NP samples with respect to pure dye solutions, confirming the strong resonant coupling occurring between the gain medium and gold NPs. Experimental evidence of a selective modification of the gain functionalized core–shell Au NP extinction curve is found, in good agreement with the results of a simplified theoretical model. The model verifies the causality principle through Kramers–Kronig dispersion relations for the investigated gain functionalized plasmonic nanostructure.

Effects of inhomogeneity on the causal entropic prediction ofΛ

The causal entropic principle aims to predict the unexpectedly small value of the cosmological constant Lambda using a weighting by entropy increase on causal diamonds. The original work assumed a purely isotropic and homogeneous cosmology. But even the level of inhomogeneity observed in our universe forces reconsideration of certain arguments about entropy production. In particular, we must consider an ensemble of causal diamonds associated with one cosmology, and we can no longer immediately discard entropy production in the far future of the universe. Depending on our choices for a probability measure and our treatment of black hole evaporation, the prediction for Lambda may be left intact or dramatically altered.

The principle of causality in acoustic double-negative media

We discuss double negative acoustic media with various types of dispersion. The absence of dispersion leads to violation of the causality principle. No strong absorption occurs and there is no violation of the principle of causality in a dispersive medium with resonant response.

TRENTOOL: A Matlab open source toolbox to analyse information flow in time series data with transfer entropy

BackgroundTransfer entropy (TE) is a measure for the detection of directed interactions. Transfer entropy is an information theoretic implementation of Wiener's principle of observational causality. It offers an approach to the detection of neuronal interactions that is free of an explicit model of the interactions. Hence, it offers the power to analyze linear and nonlinear interactions alike. This allows for example the comprehensive analysis of directed interactions in neural networks at various levels of description. Here we present the open-source MATLAB toolbox TRENTOOL that allows the user to handle the considerable complexity of this measure and to validate the obtained results using non-parametrical statistical testing. We demonstrate the use of the toolbox and the performance of the algorithm on simulated data with nonlinear (quadratic) coupling and on local field potentials (LFP) recorded from the retina and the optic tectum of the turtle (Pseudemys scripta elegans) where a neuronal one-way connection is likely present.ResultsIn simulated data TE detected information flow in the simulated direction reliably with false positives not exceeding the rates expected under the null hypothesis. In the LFP data we found directed interactions from the retina to the tectum, despite the complicated signal transformations between these stages. No false positive interactions in the reverse directions were detected.ConclusionsTRENTOOL is an implementation of transfer entropy and mutual information analysis that aims to support the user in the application of this information theoretic measure. TRENTOOL is implemented as a MATLAB toolbox and available under an open source license (GPL v3). For the use with neural data TRENTOOL seamlessly integrates with the popular FieldTrip toolbox.

Bound on genuine multipartite correlations from the principle of information causality

Quantum mechanics is not the unique no-signaling theory which is endowed with stronger-than-classical correlations, and there exists a broad class of no-signaling theories allowing even stronger-than-quantum correlations. The principle of information causality has been suggested to distinguish quantum theory from these nonphysical theories, together with an elegant information-theoretic proof of the quantum bound of two-particle correlations. In this work, we extend this to genuine $N$-particle correlations that cannot be reduced to mixtures of states in which a smaller number of particles are entangled. We first express Svetlichny's inequality in terms of multipartite no-signaling boxes, then prove that the strongest genuine multipartite correlations lead to the maximal violation of information causality. The maximal genuine multipartite correlations under the constraint of information causality is found to be equal to the quantum mechanical bound. This result consolidates information causality as a physical principle defining the possible correlations allowed by nature, and provides intriguing insights into the limits of genuine multipartite correlations in quantum theory.

Bound on genuine multipartite correlations from the principle of information causality

Quantum mechanics is not the unique no-signaling theory which is endowed with stronger-than-classical correlations, and there exists a broad class of no-signaling theories allowing even stronger-th...

Information causality from an entropic and a probabilistic perspective

The information causality principle is a generalisation of the no-signalling principle which implies some of the known restrictions on quantum correlations. But despite its clear physical motivation, information causality is formulated in terms of a rather specialised game and figure of merit. We explore different perspectives on information causality, discussing the probability of success as the figure of merit, a relation between information causality and the non-local `inner-product game', and the derivation of a quadratic bound for these games. We then examine an entropic formulation of information causality with which one can obtain the same results, arguably in a simpler fashion.

On the Consistency of Constraints in Matter Field Theories

We consider how the principles of causality and equivalence restrict the background in which matter field theories are defined; those constraints develop in restrictions for these matter field theories: the simplest matter field theory aside, all other less simple matter field theories are too complex therefore resulting to be inconsistent in general instances.

Comparison of pseudo‐random binary sequence and square‐wave transient controlled‐source electromagnetic data over the Peon gas discovery, Norway

ABSTRACTWe discuss the problem of source control in controlled‐source electromagnetic (CSEM) surveying and compare and contrast equal energy transient square‐wave and transient pseudo‐random binary sequence source signatures for the same towed‐streamer electromagnetic survey line over the Peon gasfield in the Norwegian sector of the North Sea. The received response of the transient square‐wave data was 11 dB greater than that of the pseudo‐random binary sequence data, due to diffusive attenuation of higher frequencies present in the more broadband pseudo‐random binary sequence signature. Deconvolution of the pseudo‐random binary sequence data recovers the total impulse response function, increases the signal‐to‐noise ratio by 32.6 dB and separates most of the air wave from the earth impulse response by the causality principle. The recovered impulse responses have more detailed information in the frequency domain than the transient square‐wave data. The pseudo‐random binary sequence data were acquired with a 10 Hz source bit rate but contain no information about the Peon gasfield at frequencies above 2 Hz. The bit rate could have been reduced to 4 Hz, increasing the signal energy below 2 Hz by 150% and thus, potentially, increasing the signal‐to‐noise ratio by a further 4 dB.Because the total earth impulse response can be recovered from the broad‐bandwidth pseudo‐random binary sequence data, further time‐domain processing may be applied, including correlated noise removal, which can increase the signal‐to‐noise ratio by as much as 20 dB, and air wave removal using the causality principle. The information in the arrival time of the peak of the earth response provides the potential for traveltime to resistivity mapping to provide a starting model for inversion.

Causes of Behavioral Processes: An Interview with Mario A. Bunge

Mario A. Bunge is one of the most prominent philosophers and humanists of our time. His vast record of publications has covered, among others, epistemology, ontology, ethics, philosophy of natural and social sciences, philosophy of technology, and philosophy of mind. A topic that intersects many of these areas and is recurrent in Bunge’s work is causality. His analyses of the causal principle, and the redefinition of determinism into near-determinism have been applied to different philosophical issues that range from the causal role of neuronal functioning to the laws of social phenomena. Bunge has criticized functionalism, cognitivism, computationalism, behaviourism, and idealism in their attempt to explain human and non-human behaviour. This article results from an extensive interview held with Dr. Bunge in which we discussed a variety of conceptual issues related to the notions of causality and explanation in psychology.

Causas de los Procesos Comportamentales: Un diálogo con Mario Bunge

Mario A. Bunge is one of the most prominent philosophers and humanists of our time. His vast record of publications has covered, among others, epistemology, ontology, ethics, philosophy of natural and social sciences, philosophy of technology, and philosophy of mind. A topic that intersects many of these areas and is recurrent in Bunge’s work is causality. His analyses of the causal principle, and the redefinition of determinism into near-determinism have been applied to different philosophical issues that range from the causal role of neuronal functioning to the laws of social phenomena. Bunge has criticized functionalism, cognitivism, computationalism, behaviourism, and idealism in their attempt to explain human and non-human behaviour. This article results from an extensive interview held with Dr. Bunge in which we discussed a variety of conceptual issues related to the notions of causality and explanation in psychology.

Non-equilibrium pattern selection in particle sedimentation

In this paper, we explain some well known experimental observations in fluid solid interaction from a thermodynamic perspective. In particular we use the extremum of the rate of entropy production to establish the stability of specific patterns observed in single and multiparticle sedimentation in an infinite fluid and the sedimentation of spheres in the presence of walls. While these phenomena have been explained numerically, there is no known rigorous theoretical argument to establish the stability of the observed configurations. We provide a very convincing theoretical basis using entropy based arguments that are considered by several scientists as the underlying theme of nature, life and evolution. In the absence of many rigorous examples for the entropy production principle, our paper advances this argument and lends it much credibility. In addition to looking at the rate of entropy production, we also put forth a very plausible heuristic argument based on the thermal gradients in the systems being studied, which could be the underlying causal principle for many known patterns in nature.

Lasing in a gain slab as a consequence of the causality principle

Transmission of a semi-infinite light pulse through a slab of an gain medium is considered. It is demonstrated that, in the presence of lasing, the Fresnel formulas yield a finite field distribution violating the causality principle: lasing in the slab begins starts the moment at which the pulse front reaches the slab. A modification of the Fresnel approach providing for causality through adding time-diverging terms for description of the linear stage of lasing is proposed. The correctness of the proposed approach is proved by the comparison with the numerical solution of the system of Maxwell-Bloch equations. It is shown that fulfillment of lasing conditions does not contradict the causality principle.

Variational formulations of differential equations and asymmetric fractional embedding

Variational formulations for classical dissipative equations, namely friction and diffusion equations, are given by means of fractional derivatives. In this way, the solutions of those equations are exactly the extremal of some fractional Lagrangian actions. The formalism used is a generalization of the fractional embedding developed by Cresson [Fractional embedding of differential operators and Lagrangian systems, J. Math. Phys. 48 (2007) 033504], where the functional space has been split in two in order to take into account the asymmetry between left and right fractional derivatives. Moreover, this asymmetric fractional embedding is compatible with the least action principle and respects the physical causality principle.

Emilie du Châtelet on the Existence and Nature of God: An Examination of Her Arguments in Light of Their Sources

Many commentators have suggested that the metaphysical portions of Emilie du Châtelet's Institutions de physique are a mere retelling of Leibniz's views. I argue that a close reading of the text shows that du Châtelet's cosmological argument and discussion of God's nature contains both Lockean and Leibnizian elements. I discuss where she follows Locke in her arguments, what Leibnizian elements she brings in, and how this enables her to avoid some of the mistakes commonly attributed to Locke's formulation of the cosmological argument. I show that while du Châtelet accepts the causal principle ex nihilo nihil fit, she does not utilize Locke's stronger causal principle. I also discuss her use of the principle of sufficient reason in both improving the Lockean cosmological argument and in proving the attributes of God.