Thought experiments analogous to those discussed by Landau and Peierls are studied in the framework of a manifestly covariant relativistic quantum theory. It is shown that momentum and energy can be arbitrarily well defined, and that the drifts induced by measurement in the positions and times of occurrence of events remain within the (stable) spread of the wave packet in space-time. The structure of the Newton-Wigner position operator is studied in this framework, and it is shown that an analogous (...) time operator can be constructed which satisfies the canonical commutation relation with the energy E but does not commute (due to the presence of a time drift term) with the momentum p. The resulting commutation relation is used as a mathematical basis for the derivation of the Landau-Peierls relation Δt Δp≳ħ/c. (shrink)

Nucleation and motion of kink pairs on partial dislocations are examined by elasticity theory for materials with a high Peierls stress. Two approaches are used: one considers the change in average stacking-fault energy due to alloying elements and the other considers the change in local SFE due to a nearby solute atom. Both approaches highlight the role of SFE on kink nucleation, propagation and annihilation and both furnish strain rate as a function of stress, temperature and SFE. Model predictions (...) are compared with yield stress data for two systems: firstly, an intermetallic, MoSi 2 , which softens for alloying elements that decrease the SFE and hardens for Re additions that increase the SFE; secondly, a ceramic oxide, MgO-Al 2 O 3 spinel, which softens with increasing addition of excess alumina and at the same time exhibits a decrease in SFE. The average SFE approach agrees qualitatively with the data while quantitative agreement is obtained with the local SFE approach. The possibility is considered that the model applies to other materials, such as TiAl, HfV 2 and Fe 3 Al, which show softening with certain alloying additions. One requirement is that the dislocations are dissociated more than a few atomic distances; otherwise kink nucleation occurs on the perfect dislocation . Hence the model does not apply to materials such as bcc metals which only have a core dissociation. Normal hardening effects of solutes from size and modulus misfits are additive with any softening effects from a decrease in SFE and so may mask the latter, as occurs for W additions to MoSi 2. (shrink)

Since Bentley's attack upon the Greek letters of Euripides and Phalaris, scholarship has been inclined to look with suspicion upon other similar compositions, which have for the most part lain under a cloud of doubt. This attitude of doubt was certainly to be found in the scholarship of last century, though there has been a tendency of late years to attempt to restore certain of these groups of letters to their original position as genuine productions of the writers whom they (...) claim as their authors. Such has been the case with Plato's letters; such also is the case with those of M. Junius Brutus, the tyrannicide. Condemned last century by both Westermann and Marcks, they found in Rühl a clever and successful advocate, who stoutly refuted these attacks. His task was rendered less difficult, in that Marcks, who alone adduced arguments to support his thesis, had not gone deeply into his subject, and his reasoning, therefore, was superficial. But the subversion of Marcks' arguments did not of itself establish the authenticity of the letters, and the positive reasoning of Rühl was hardly less deficient than Marcks'. A fresh examination of these letters, therefore, may be pardoned, if the conclusions differ from those of Rühl. (shrink)

A Study of the sources of a Plutarchan Life may be excused on two grounds: first, a knowledge of the sources is important for a critical evaluation of the Life's historical worth; and second, such a study is instructive for the understanding of Plutarch's methods of composition, which, in its turn, helps considerably in the historical evaluation. For this second object the Titus is particularly well suited, since the problem, owing to the survival in large part of his main source, (...) is infinitely simpler than in many of the other Lives, and it is on these grounds that the present study seeks to justify itself. (shrink)

It is argued that behavior analysis is an actual or potential axiomatic system based upon the schedules of reinforcement which are behavioral, causative laws. Gödel proved that all axiomatic systems are complete or consistent, but not both at the same time. The point is made that behavior analysis is an incomplete, consistent system. The system's incompleteness is compensated for by the concept of the behavioral repertoire which, although in part lying outside of the axiomatic core of behavior analysis, both extends (...) and strengthens it. (shrink)

The thesis of this article is that there has never been any ground for the controversy between the doctrine of free will and determinism, that it is based upon a misapprehension, that the two assertions are entirely consistent, that one of them strictly implies the other, that they have been opposed only because of our natural want of the analytical imagination. In so saying I do not tamper with the meaning of either phrase. That would be unpardonable. I mean free (...) will in the natural and usual sense, in the fullest, the most absolute sense in which for the purposes of the personal and moral life the term is ever employed. I mean it as implying responsibility, merit and demerit, guilt and desert. I mean it as implying, after an act has been performed, that one " could have done otherwise " than one did. I mean it as conveying these things also, not in any subtly modified sense but in exactly the sense in which we conceive them in life and in law and in ethics. These two doctrines have been opposed because we have not realised that free will can be analysed without being destroyed, and that determinism is merely a feature of the analysis of it. And if we are tempted to take refuge in the thought of an "ultimate ", an "innermost" liberty that eludes the analysis, then we have implied a deterministic basis and constitution for this liberty as well. For such a basis and constitution lie in the idea of liberty. -/- The thesis is not, like that of Green or Bradley, that the contending opinions are reconciled if we adopt a certain metaphysic of the ego, as that it is timeless, and identifies itself with a desire by a " timeless act". This is to say that the two are irreconcilable, as they are popularly supposed to be, except by a theory that delivers us from the conflict by taking us out of time. Our view on the contrary is that from the natural and temporal point of view itself there never was any need of a reconciliation but only of a comprehension of the meaning of terms. (The metaphysical nature of the self and its identity through time is a problem for all who confront memory, anticipation, etc.; it has no peculiar difficulties arising from the present problem.) -/- I am not maintaining that determinism is true; only that it is true insofar as we have free will. That we are free in willing is, broadly speaking, a fact of experience. That broad fact is more assured than any philosophical analysis. It is therefore surer than the deterministic analysis of it, entirely adequate as that in the end appears to be. But it is not here affirmed that there are no small exceptions, no slight undetermined swervings, no ingredient of absolute chance. All that is here said is that such absence of determination, if and so far as it exists, is no gain to freedom, but sheer loss of it; no advantage to the moral life, but blank subtraction from it. -- When I speak below of "the indeterminist" I mean the libertarian indeterminist, that is, him who believes in free will and holds that it involves indetermination. (shrink)

R. E. Heinaman; XI*—Communion of Forms, Proceedings of the Aristotelian Society, Volume 83, Issue 1, 1 June 1983, Pages 175–190, https://doi.org/10.1093/aristot.

Open peer commentary on the article “The Circular Conditions of Second-order Science Sporadically Illustrated with Agent-based Experiments at the Roots of Observation” by Manfred Füllsack. Upshot: I follow the general tenor of Füllsack’s target article but I have some basic reservations as to the utilization of the thermodynamics involved.

Objective: To identify factors that predict physicians’ intent to comply with the American Medical Association’s ethical guidelines on gifts from the pharmaceutical industry.Methods: A survey was designed and mailed in June 2004 to a random sample of 850 physicians in Florida, USA, excluding physicians with inactive licences, incomplete addresses, addresses in other states and pretest participants. Factor analysis extracted six factors: attitude towards following the guidelines, subjective norms , facilitating conditions , profession-specific precedents , individual-specific precedents and intent. Multivariate regression (...) modelling was conducted.Results: Surveys were received from 213 physicians representing all specialties, with a net response rate of 25.5%. 62% of respondents were aware of the guidelines; 50% had read them. 48% thought that following the guidelines would increase physicians’ credibility and professional image; 68% agreed that it was important to do so. Intent to comply was positively associated with attitude, subjective norms, facilitators and sponsorship of continuing medical education events, while individual-specific precedents had a negative relationship with intent to comply. Predictors of intent were attitude, subjective norms, the interaction term , sponsorship of CME events and individual-specific precedents.Conclusions: Physicians are more likely to follow the AMA guidelines if they have positive attitudes towards the guidelines, greater subjective norms, fewer expectations of CME sponsorship and fewer individual-specific precedents. Physicians believing that important individuals or organisations expect them to comply with the guidelines are more likely to express intent, despite having fewer beliefs that positive outcomes would result through compliance. (shrink)

DNA profiling and databasing are now commonplace. A body of state and federal legislation enables the establishment and operation of profile databases for law-enforcement purposes. Enabling legislation is usually specific about who, or what evidence, may be profiled for a database. It may be less specific or silent on the issue of specimen retention following profiling and databasing.

Recent authors have raised objections to the counterfactual interpretation of the Aharonov-Bergmann-Lebowitz rule of time-symmetrised quantum theory. I distinguish between two different readings of the ABL rule, counterfactual and non-counterfactual, and confirm that TSQT advocate L. Vaidman is employing the counterfactual reading to which these authors object. Vaidman has responded to the objections by proposing a new kind of time-symmetrised counterfactual, which he has defined in two different ways. It is argued that neither definition succeeds in overcoming the objections, except (...) in a limited special case previously noted by Cohen and Hiley. In addition, a connection is made between TSQT and Price's concept of 'advanced action', which further supports the special case discussed. (shrink)