scholarly journals Causation does not explain contextuality

Quantum ◽  
2018 ◽  
Vol 2 ◽  
pp. 63 ◽  
Author(s):  
Sally Shrapnel ◽  
Fabio Costa
Keyword(s):  
Quantum Mechanics ◽  
Causal Structure ◽  
Quantum Correlations ◽  
Global Constraints ◽  
Local Constraints ◽  
The Past ◽  
Interpretations Of Quantum Mechanics ◽  
The World ◽  
Non Local ◽  
Initial States

Realist interpretations of quantum mechanics presuppose the existence of elements of reality that are independent of the actions used to reveal them. Such a view is challenged by several no-go theorems that show quantum correlations cannot be explained by non-contextual ontological models, where physical properties are assumed to exist prior to and independently of the act of measurement. However, all such contextuality proofs assume a traditional notion of causal structure, where causal influence flows from past to future according to ordinary dynamical laws. This leaves open the question of whether the apparent contextuality of quantum mechanics is simply the signature of some exotic causal structure, where the future might affect the past or distant systems might get correlated due to non-local constraints. Here we show that quantum predictions require a deeper form of contextuality: even allowing for arbitrary causal structure, no model can explain quantum correlations from non-contextual ontological properties of the world, be they initial states, dynamical laws, or global constraints.

Quantum mechanics, interpretation of

2018 ◽  
Author(s):  
Allen Stairs
Keyword(s):  
Quantum Mechanics ◽  
Microscopic Level ◽  
Quantum States ◽  
Quantum Mechanical ◽  
Quantum Superposition ◽  
Ordinary Objects ◽  
Making Sense ◽  
Interpretations Of Quantum Mechanics ◽  
The World

Quantum mechanics developed in the early part of the twentieth century in response to the discovery that energy is quantized, that is, comes in discrete units. At the microscopic level this leads to odd phenomena: light displays particle-like characteristics and particles such as electrons produce wave-like interference patterns. At the level of ordinary objects such effects are usually not evident, but this generalization is subject to striking exceptions and puzzling ambiguities. The fundamental quantum mechanical puzzle is ’superposition of states’. Quantum states can be added together in a manner that recalls the superposition of waves, but the effects of quantum superposition show up only probabilistically in the statistics of many measurements. The details suggest that the world is indefinite in odd ways; for example, that things may not always have well-defined positions or momenta or energies. However, if we accept this conclusion, we have difficulty making sense of such straightforward facts as that measurements have definite results. Interpretations of quantum mechanics are, in one way or another, attempts to understand the superposition of quantum states. The range of interpretations stretches from the metaphysically daring to the seemingly innocuous. But, so far, no single interpretation has commanded anything like universal agreement.

scholarly journals Relativistic independence bounds nonlocality

2019 ◽  
Vol 5 (4) ◽  
pp. eaav8370 ◽  
Author(s):  
Avishy Carmi ◽  
Eliahu Cohen
Keyword(s):  
Quantum Mechanics ◽  
Quantum Correlations ◽  
Physical Principle ◽  
Quantum Nonlocality ◽  
Measuring Instruments ◽  
Uncertainty Relations ◽  
The Past ◽  
Nonlocal Correlations

If nature allowed nonlocal correlations other than those predicted by quantum mechanics, would that contradict some physical principle? Various approaches have been put forward in the past two decades in an attempt to single out quantum nonlocality. However, none of them can explain the set of quantum correlations arising in the simplest scenarios. Here, it is shown that generalized uncertainty relations, as well as a specific notion of locality, give rise to both familiar and new characterizations of quantum correlations. In particular, we identify a condition, relativistic independence, which states that uncertainty relations are local in the sense that they cannot be influenced by other experimenters’ choices of measuring instruments. We prove that theories with nonlocal correlations stronger than the quantum ones do not satisfy this notion of locality, and therefore, they either violate the underlying generalized uncertainty relations or allow experimenters to nonlocally tamper with the uncertainty relations of their peers.

Reforming French Culture

2017 ◽  
Author(s):  
George Hoffmann
Keyword(s):  
Sixteenth Century ◽  
Sense Of Belonging ◽  
Old Regime ◽  
Self Presentation ◽  
The Past ◽  
Diasporic Identity ◽  
The World ◽  
French Culture ◽  
Political Effect ◽  
Non Local

Satire has recently re-emerged as a potent political tool, but it has played many different roles in the past. French reformers waged massive satire campaigns in the sixteenth century to little or no political effect and, even, to their own disadvantage. Satiric forms nevertheless flourished because they fulfilled a devotional purpose. By portraying themselves as lonely travelers passing through the strange and exotic lands of Catholic custom, French reformers found a way to flesh out imaginatively the Pauline injunction to live in the world but not as part of it. The spiritual alienation cultivated in satiric literature allowed reformers to fashion themselves, after Calvin’s recommendation, as pilgrims in this world and confessional foreigners in their home country. At the same time, these satires’ self-presentation and their modes of address implied a reformed audience constituted by those who “got the joke.” The new communion entailed in laughing at Catholic excesses, modeled upon the reformed theological concept of “communication,” imagined a pan-European community held together by a non-local sense of belonging. Thus, French reformers embraced a diasporic identity well in advance of their actual emigration to the New World. But, more surprising still, the attitude of looking at one’s own culture through the eyes of an estranged traveler spread beyond reformed milieus to become a staple of French culture more generally. Through Montaigne, the ploy of acting the outsider in one’s homeland would become one of the signature devices of the Enlightenment’s challenge to the world of the Old Regime.

scholarly journals Exploring the limits of no backwards in time signalling

Quantum ◽  
2019 ◽  
Vol 3 ◽  
pp. 211 ◽  
Author(s):  
Yelena Guryanova ◽  
Ralph Silva ◽  
Anthony J. Short ◽  
Paul Skrzypczyk ◽  
Nicolas Brunner ◽  
...  
Keyword(s):  
Quantum Theory ◽  
Causal Structure ◽  
Spatial Correlations ◽  
The Past ◽  
The Future ◽  
Non Local ◽  
Model Independent

We present an operational and model-independent framework to investigate the concept of no-backwards-in-time signalling. We define no-backwards-in-time signalling conditions, closely related to the spatial no-signalling conditions. These allow for theoretical possibilities in which the future affects the past, nevertheless without signalling backwards in time. This is analogous to non-local but no-signalling spatial correlations. Furthermore, our results shed new light on situations with indefinite causal structure and their connection to quantum theory.

scholarly journals The Operational Choi–Jamiołkowski Isomorphism

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1063 ◽  
Author(s):  
Emily Adlam
Keyword(s):  
Quantum Mechanics ◽  
Causal Structure ◽  
Temporal Correlations ◽  
Fundamental Object ◽  
Generalized Probabilistic Theories ◽  
Operational Theory ◽  
Local Correlations ◽  
Non Local ◽  
Operational Formulation ◽  
Probabilistic Theories

In this article, I use an operational formulation of the Choi–Jamiołkowski isomorphism to explore an approach to quantum mechanics in which the state is not the fundamental object. I first situate this project in the context of generalized probabilistic theories and argue that this framework may be understood as a means of drawing conclusions about the intratheoretic causal structure of quantum mechanics which are independent of any specific ontological picture. I then give an operational formulation of the Choi–Jamiołkowski isomorphism and show that, in an operational theory which exhibits this isomorphism, several features of the theory which are usually regarded as properties of the quantum state can be derived from constraints on non-local correlations. This demonstrates that there is no need to postulate states to be the bearers of these properties, since they can be understood as consequences of a fundamental equivalence between multipartite and temporal correlations.

COMPLEMENTARY HISTORIES AND COLLAPSE INTO THE PAST IN STANDARD QUANTUM MECHANICS

1999 ◽  
Vol 13 (20) ◽  
pp. 2629-2636
Author(s):  
YURI F. ORLOV
Keyword(s):  
Quantum Mechanics ◽  
Quantum States ◽  
Standard Quantum ◽  
Quantum Formalism ◽  
The Past ◽  
Interpretations Of Quantum Mechanics ◽  
Single State ◽  
Standard Formalism ◽  
Faster Than Light

It follows from the standard quantum formalism that in the time between any two noncommuting measurements there are two quantum states of the same system representing two complementary, forward and backward histories, histories that may be observed in two complementary experiments. It follows from this in turn that all interpretations of quantum mechanics based on the idea of a single state between measurements should be rejected. The non-existence of a faster-than-light nonlocality and of paradoxes in EPR-type experiments1 can be proved in the frame of the standard formalism when the reality of backward histories is taken into account.

A basic introduction to image processing using NIH-Image as a model

1994 ◽  
Vol 52 ◽  
pp. 392-393
Author(s):  
John Mansfield
Keyword(s):  
Image Processing ◽  
Digital Image ◽  
Image Acquisition ◽  
Digital Instrument ◽  
Novice User ◽  
Nih Image ◽  
The Past ◽  
Digital World ◽  
The World ◽  
Instrument Control

Advances in camera technology and digital instrument control have meant that in modern microscopy, the image that was, in the past, typically recorded on a piece of film is now recorded directly into a computer. The transfer of the analog image seen in the microscope to the digitized picture in the computer does not mean, however, that the problems associated with recording images, analyzing them, and preparing them for publication, have all miraculously been solved. The steps involved in the recording an image to film remain largely intact in the digital world. The image is recorded, prepared for measurement in some way, analyzed, and then prepared for presentation.Digital image acquisition schemes are largely the realm of the microscope manufacturers, however, there are also a multitude of “homemade” acquisition systems in microscope laboratories around the world. It is not the mission of this tutorial to deal with the various acquisition systems, but rather to introduce the novice user to rudimentary image processing and measurement.

On the Symbolism of Rain in A Farewell to Arms

2018 ◽  
Keyword(s):  
Research Tool ◽  
The Past ◽  
The World ◽  
Farewell To Arms

This paper critically analyzes the symbolic use of rain in A Farewell to Arms (1929). The researcher has applied the Sapir-Whorf Hypothesis as a research tool for the analysis of the text. This hypothesis argues that the languages spoken by a person determine how one observes this world and that the peculiarities encoded in each language are all different from one another. It affirms that speakers of different languages reflect the world in pretty different ways. Hemingway’s symbolic use of rain in A Farewell to Arms (1929) is denotative, connotative, and ironical. The narrator and protagonist, Frederick Henry symbolically embodies his own perceptions about the world around him. He time and again talks about rain when something embarrassing is about to ensue like disease, injury, arrest, retreat, defeat, escape, and even death. Secondly, Hemingway has connotatively used rain as a cleansing agent for washing the past memories out of his mind. Finally, the author has ironically used rain as a symbol when Henry insists on his love with Catherine Barkley while the latter being afraid of the rain finds herself dead in it.

The Event Universe

2015 ◽  
Author(s):  
Leemon B. McHenry
Keyword(s):  
Electromagnetic Field ◽  
Quantum Mechanics ◽  
Common Sense ◽  
Physical Theory ◽  
Alfred North Whitehead ◽  
Bertrand Russell ◽  
Theory Of Relativity ◽  
The World ◽  
Modern Physics ◽  
Linguistic Methods

What kinds of things are events? Battles, explosions, accidents, crashes, rock concerts would be typical examples of events and these would be reinforced in the way we speak about the world. Events or actions function linguistically as verbs and adverbs. Philosophers following Aristotle have claimed that events are dependent on substances such as physical objects and persons. But with the advances of modern physics, some philosophers and physicists have argued that events are the basic entities of reality and what we perceive as physical bodies are just very long events spread out in space-time. In other words, everything turns out to be events. This view, no doubt, radically revises our ordinary common sense view of reality, but as our event theorists argue common sense is out of touch with advancing science. In The Event Universe: The Revisionary Metaphysics of Alfred North Whitehead, Leemon McHenry argues that Whitehead's metaphysics provides a more adequate basis for achieving a unification of physical theory than a traditional substance metaphysics. He investigates the influence of Maxwell's electromagnetic field, Einstein's theory of relativity and quantum mechanics on the development of the ontology of events and compares Whitehead’s theory to his contemporaries, C. D. Broad and Bertrand Russell, as well as another key proponent of this theory, W. V. Quine. In this manner, McHenry defends the naturalized and speculative approach to metaphysics as opposed to analytical and linguistic methods that arose in the 20th century.

Profilometry. Using Corneo-scleral topography for scleral lens fitting

The Eye ◽  
2019 ◽  
Vol 21 (128) ◽  
pp. 19-22
Author(s):  
Gregory DeNaeyer
Keyword(s):  
Ocular Surface ◽  
World Wide ◽  
Contact Lenses ◽  
The Past ◽  
The World ◽  
The Future ◽  
The Way

The world-wide use of scleral contact lenses has dramatically increased over the past 10 year and has changed the way that we manage patients with corneal irregularity. Successfully fitting them can be challenging especially for eyes that have significant asymmetries of the cornea or sclera. The future of scleral lens fitting is utilizing corneo-scleral topography to accurately measure the anterior ocular surface and then using software to design lenses that identically match the scleral surface and evenly vault the cornea. This process allows the practitioner to efficiently fit a customized scleral lens that successfully provides the patient with comfortable wear and improved vision.

Sign in / Sign up

Export Citation Format

Share Document