The paper explores the fundamental physical principles of quantum mechanics (in fact, quantum field theory) that limit the bit rate for long distances and examines the assumption used in this exploration that losses can be ignored. Propagation of photons in optical fibers is modelled using methods of quantum electrodynamics. We define the “photon duration” as the standard deviation of the photon arrival time; we find its asymptotics for long distances and then obtain the main result of the paper: the linear (...) dependence of photon duration on the distance when losses can be ignored. This effect puts the limit to joint increasing of the photon flux and the distance from the source and it has consequences for quantum communication. Once quantum communication develops into a real technology (including essential decrease of losses in optical fibres), it would be appealing to engineers to increase both the photon flux and the distance. And here our “photon flux/distance effect” has to be taken into account. This effect also may set an additional constraint to the performance of a loophole free test of Bell’s type—to close jointly the detection and locality loopholes. (shrink)

People increasingly access news through ‘new’, algorithmic intermediaries such as search engines or aggregators rather than the ‘old’ (i. e., traditional), journalistic intermediaries. As algorithmic intermediaries do not adhere to journalistic standards, their trustworthiness comes into question. With this study, we (1) summarize the differences between journalistic and algorithmic intermediaries as found in previous literature; (2) conduct a cross-media comparison of information credibility and intermediary trustworthiness; and (3) examine how key predictors (such as modality, reputation, source attribution, and prior experience) (...) affect the trustworthiness and credibility assessments. Results from a quasi-experimental online survey (n = 485) confirm that recipients assess journalistic intermediaries more positively than algorithmic intermediaries and audio more positively than text intermediaries. Furthermore, we found reputation and information credibility to be the most important predictors of intermediary trustworthiness, while general media trust is the most important predictor of information credibility. Implications and directions for future research are discussed. (shrink)

This paper sheds further light on the contextual boundaries in the relationship between high-performance work practices and employee wellbeing. In particular, we analyze whether this relationship is moderated by health-oriented leadership behavior which describes the extent to which leaders value, are aware of, and protect their followers’ health at work. Our analyses are based on employee data from Germany, covering two points in time. Findings show positive associations between HPWPs and happiness-related and health-related wellbeing outcomes. The positive relationship between HPWPs (...) and employee wellbeing is weaker the more employees experience leadership behavior in terms of staff care. Thus, our results provide further evidence for a substitutive or compensatory effect between HRM and leadership. (shrink)

In order to explore the quantifiability and formalizability of uncertainty a wide range of uncertainties are investigated. They are summarized under eight main categories: factual, possibilistic, metadoxastic, agential, interactive, value, structural, and linguistic uncertainty. This includes both classical uncertainty and the uncertainties commonly called great, deep, or radical. For five of the eight types of uncertainty, both quantitative and non-quantitative formalizations are meaningful and available. For one of them (interactive uncertainty), only non-quantitative formalizations seem to be meaningful, and for two (...) (agential and structural uncertainty) neither quantitative nor non-quantitative formalization seems to be a useful approach. (shrink)

The safety conception of knowledge holds that a belief constitutes knowledge iff relevantly similar beliefs—its epistemic counterparts—are true. It promises an instructive account of why certain general principles of knowledge hold. We focus on two such principles that anyone should endorse: the closure principle that knowledge is downward closed under competent conjunction elimination, and the counter-closure principle that knowledge is upward closed under competent conjunction introduction. We argue that anyone endorsing the former must also endorse the latter on pains of (...) an unacceptable form of bootstrapping. We devise new formal models to identify necessary and sufficient conditions for these principles to hold on conceptions that construe knowledge in terms of true counterparts. These conditions state that counterparts of premise and conclusion beliefs are coordinated in certain ways whenever these beliefs stand in the relevant inferential relations. We show that the safety conception faces insuperable problems vindicating these coordination principles, because its epistemic counterpart relation is symmetric. We conclude that it thus proves unable to account for minimal closure properties of knowledge. More generally, our formal results establish parameters within which any conception must operate that construes knowledge in terms of true counterparts. (shrink)

In the most common approaches to belief dynamics, states of belief are represented by sets that are closed under logical consequence. In an alternative approach, they are represented by non-closed belief bases. This representation has attractive properties not shared by closed representations. Most importantly, it can account for repeated belief changes that have not yet been satisfactorily accounted for in the closed approach.

This is a reply to a comment by Kåre Letrud [Letrud, Kåre. 2019. “The Gordian Knot of Demarcation: Tying Up Some Loose Ends.” International Studies in the Philosophy of Science 32 : 3–11. doi:10...

Available methods such as technology assessment and risk analysis have failed to predict the effects of technological choices. We need to give up the futile predictive ambitions of previous approaches and instead base decisions on systematic studies of alternative future developments. It will then be necessary to cope with mere possibility arguments, i.e., arguments in which a conclusion is drawn from a mere possibility that a course of action may have certain consequences. A five-step procedure is proposed for the assessment (...) of such arguments. It includes a search for mere possibility arguments pointing in different directions, a scientific evaluation that may lead to the specification or refutation of some of these arguments, two symmetry tests, evaluation of the seriousness of the arguments in terms of novelty, spatio-temporal unlimitedness and interference with complex systems, and hypothetical retrospection that aims at finding a course of action that will be defensible in retrospect. (shrink)

The outcome set of a belief change operator is the set of outcomes that can be obtained with it. Axiomatic characterizations are reported for the outcome sets of the standard AGM contraction operators and eight types of base-generated contraction. These results throw new light on the properties of some of these operators.

Several attempts have been made to transfer the concept of informed consent from medical and research ethics to dealing with affected groups in other areas such as engineering, land use planning, and business management. It is argued that these attempts are unsuccessful since the concept of informed consent is inadequate for situations in which groups of affected persons are dealt with collectively (rather than individually, as in clinical medicine). There are several reasons for this. The affected groups from which informed (...) consent is sought cannot be identified with sufficient precision. Informed consent is associated with individual veto power, but it does not appear realistic to give veto power to all individuals who are affected for instance by an engineering project. Most importantly, the concept of informed consent puts focus on the public’s acceptance of ready-made proposals rather than on its participation in the decision-making process as a whole, which includes the development of alternatives for the decision. Therefore, the concept of informed consent is not applicable to a company’s relations with groups and collectives. It may, however, be applicable to a company’s relations with individual persons such as customers and employees. (shrink)

Science is praxis relevant to the extent that it guides goal-directed action by telling us how to act in order to achieve the goals. Investigations aiming at high praxis relevance are performed in various disciplines under names such as clinical trials, evaluation research, intervention research and social experiments. In this contribution, the notion of (direct) praxis relevance is delineated, and it is distinguished from related properties of science such as those of being applied and being practically useful in a wider (...) sense. Recommendations for the achievement of praxis relevance are offered in the form of five principles: the prerogative of direct experiments, minimized theory-induced uncertainty, multiple approximations, causal chain decomposition and successive improvements. (shrink)

Theoria, Volume 88, Issue 1, Page 3-7, February 2022.