Lucky Event Research Articles

Crystal chemistry criteria of the existence of spin liquids on the kagome lattice

The structural-magnetic models of 25 antiferromagnetic kagome cuprates similar to herbertsmithite (ZnCu3(OH)6Cl2)—a perspective spin liquid—have been calculated and analyzed. Main correlations between the structure and magnetic properties of these compounds were revealed. It has been demonstrated that, in all AFM kagome cuprates, including herbertsmithite, there exists the competition between the exchange interaction and the antisymmetric anisotropic exchange one (the Dzyaloshinskii–Moriya interaction), as magnetic ions are not linked to the center of inversion in the kagome lattice. This competition is strengthened in all the kagome AFM, except herbertsmithite, by one more type of the anisotropy (duality) of the third in length J3 magnetic couplings (strong J3(J12) next-to-nearest-neighbor couplings in linear chains along the triangle edges and very weak FM or AFM J3(J d) couplings along the hexagon diagonals). The above couplings are crystallographically identical, but are divided to two types of different in strength magnetic interactions. The existence of duality of J3 couplings originated from the structure of the kagome lattice itself. Only combined contributions of dual J3 couplings with anisotropic Dzyaloshinskii–Moriya interactions are capable to suppress frustration of kagome antiferromagnetics. It has been demonstrated that the possibility of elimination of such a duality in herbertsmithite, which made it a spin liquid, constitutes a rare lucky event in the kagome system. Three crystal chemistry criteria of the existence of spin liquids on the kagome lattice have been identified: first, the presence of frustrated kagome lattices with strong dominant antiferromagnetic nearest-neighbor J1 couplings competing only with each other in small triangles; second, magnetic isolation of these frustrated kagome lattices; and third, the absence of duality of the third in length J3 magnetic couplings.

Lucky Events and the Need for Uniqueness.

This study shows that people are likely to consider themselves special after experiencing lucky events, which increases the motivation for self-enhancement, consequently prompting them to deviate from majority-endorsed options and express a need for uniqueness. Prior luck-related research has primarily explored the effects of perceived luck on superstition or the illusion of control. The present study explored whether incidental luck affects consumers' motivation to conform or stand out, specifically people's tendency to diverge from others by choosing minority-endorsed options. The results from three experiments supported the proposed hypotheses in this study. Experiment 1 revealed that a lucky event arouses people's need for uniqueness. Experiment 2 demonstrated that when people experience a lucky event and perceive that luck favors them after making a downward comparison, they consider themselves special and prefer minority-endorsed options. Experiment 3 revealed that self-enhancement is a mediator in the effect of lucky events on the need for uniqueness-seeking behavior. The findings of this research not only provide additional insight into the behavioral consequences of lucky events but also extend the understanding of uniqueness-seeking behavior.

A New Crater Near InSight: Implications for Seismic Impact Detectability on Mars

AbstractA new 1.5 m diameter impact crater was discovered on Mars only ~40 km from the InSight lander. Context camera images constrained its formation between 21 February and 6 April 2019; follow‐up High Resolution Imaging Science Experiment images resolved the crater. During this time period, three seismic events were identified in InSight data. We derive expected seismic signal characteristics and use them to evaluate each of the seismic events. However, none of them can definitively be associated with this source. Atmospheric perturbations are generally expected to be generated during impacts; however, in this case, no signal could be identified as related to the known impact. Using scaling relationships based on the terrestrial and lunar analogs and numerical modeling, we predict the amplitude, peak frequency, and duration of the seismic signal that would have emanated from this impact. The predicted amplitude falls near the lowest levels of the measured seismometer noise for the predicted frequency. Hence, it is not surprising this impact event was not positively identified in the seismic data. Finding this crater was a lucky event as its formation this close to InSight has a probability of only ~0.2, and the odds of capturing it in before and after images are extremely low. We revisit impact‐seismic discriminators in light of real experience with a seismometer on the Martian surface. Using measured noise of the instrument, we revise our previous prediction of seismic impact detections downward, from ~a few to tens, to just ~2 per Earth year, still with an order of magnitude uncertainty.

THE LUCK IN “TALENT VERSUS LUCK” MODELING

This paper further investigates the Talent versus Luck (TvL) model described by [Pluchino et al. Talent versus luck: The role of randomness in success and failure, Adv. Complex Syst. 21 (2018) 1850014] which models the relationship between ‘talent’ and ‘luck’ on the impact of an individuals career. It is shown that the model is very sensitive to both random sampling and the choice of value for the input parameters. Running the model repeatedly with the same set of input parameters gives a range of output values of over 50% of the mean value. The sensitivity of the inputs of the model is analyzed using a variance-based approach based upon generating Sobol sequences of quasi-random numbers. When using the model to look at the talent associated with an individual who has the maximum capital over a model run it has been shown that the choice for the standard deviation of the talent distribution contributes to 67% of the model variability. When investigating the maximum amount of capital returned by the model the probability of a lucky event at any given epoch has the largest impact on the model, almost three times more than any other individual parameter. Consequently, during the analysis of the model results one must keep in mind the impact that only small changes in the input parameters can have on the model output.

A THEORY OF DEFLATION: CAN EXPECTATIONS BE INFLUENCED BY A CENTRAL BANK?

This paper examines how to reverse deflation to inflation. Once deflation takes root, it is not easy to reverse because of the zero lower bound in nominal interest rates. My model indicates that there are two steady states where both inflation/deflation (i.e., changes in prices) and real activity (i.e., quantities) remain unchanged: that is, there are inflationary and deflationary steady states. The model indicates that, to switch a deflationary steady state to an inflationary steady state, a central bank needs to influence the time preference rates of the government and the representative household. It is not easy, however, to do so, and the best way of switching deflation to inflation may be to wait for a lucky event (i.e., an exogenous shock).

Collective nostalgia: A group-level emotion that confers unique benefits on the group.

This research established collective nostalgia as a group-level emotion and ascertained the benefits it confers on the group. In Study 1, participants who reflected on a nostalgic event they had experienced together with ingroup members (collective nostalgia) evaluated the ingroup more positively and reported stronger intentions to approach (and not avoid) ingroup members than those who recalled a nostalgic event they had experienced individually (personal nostalgia), those who reflected on a lucky event they had experienced together with ingroup members (collective positive), and those who did not recall an event (no recall). In Study 2, collective (vs. personal) nostalgia strengthened behavioral intentions to support the ingroup more so than did recalling an ordinary collective (vs. personal) event. Increased collective self-esteem mediated this effect. In Study 3, collective nostalgia (compared with recall of an ordinary collective event) led participants to sacrifice money in order to punish a transgression perpetrated against an ingroup member. This effect of collective nostalgia was more pronounced when social identification was high (compared with low). Finally, in Study 4, collective nostalgia converged toward the group average (i.e., was socially shared) when participants thought of themselves in terms of their group membership. The findings underscore the viability of studying nostalgia at multiple levels of analysis and highlight the significance of collective nostalgia for understanding group-level attitudes, global action tendencies, specific behavioral intentions, and behavior.

DECONVOLVING X-RAY SPECTRAL VARIABILITY COMPONENTS IN THE SEYFERT 1.5 NGC 3227

We present the variability analysis of a 100 ks XMM-Newton observation of the Seyfert 1.5 active galaxy NGC 3227. The observation found NGC 3227 in a period where its hard power-law component displayed remarkably little long-term variability. This lucky event allows us to observe clearly a soft spectral component undergoing a large-amplitude but slow flux variation. Using combined spectral and timing analysis we isolate two independent variable continuum components and characterize their behavior as a function of timescale. Rapid and coherent variations throughout the 0.2-10 keV band reveal a spectrally hard (photon index ~ 1.7-1.8) power law, dominating the observed variability on timescales of 30 ks and shorter. Another component produces coherent fluctuations in 0.2-2 keV range and is much softer (photon index ~ 3); it dominates the observed variability on timescales greater than 30 ks. Both components are viewed through the same absorbers identified in the time-averaged spectrum. The combined spectral and timing analysis breaks the degeneracy between models for the soft excess: it is consistent with a power-law or thermal Comptonized component, but not with a blackbody or an ionized reflection component. We demonstrate that the rapid variability in NGC 3227 is intrinsic to continuum-emitting components and is not an effect of variable absorption.

When Is A Belief True Because Of Luck?

Many epistemologists are attracted to the claim that knowledge possession excludes luck. Virtue epistemologists attempt to clarify this idea by holding that knowledge requires apt belief: belief that is true because of an agent's epistemic virtues, and not because of luck. Thinking about aptness may have the potential to make progress on important questions in epistemology, but first we must possess an adequate account of when a belief is true because of luck. Existing treatments of aptness assume a simple and natural view of luck attribution, according to which the success of a performance is attributable to luck if one of the principal causes of the success is a lucky event. I show that this view is false, and should be replaced. This has major implications for virtue‐theoretic accounts of knowledge, as well as the role of luck in epistemology more generally.

A Meteorite Falls on Ice

Primitive meteorites provide a glimpse into the early history of our solar system, but some of the most primitive meteorites are also rarely found on Earth. In his Perspective, Grossman explains why the fall of the Tagish Lake meteorite on 18 January 2000 in British Columbia, Canada, was a lucky event for meteorite researchers. The first analysis of the meteorite is reported by Brown et al. Well-preserved organic matter in the meteorite provides a unique opportunity to study the nature and origin of organic matter that may have accreted on early Earth and played a role in the origin of life.

Lucky Events and Beliefs in Luck: Paradoxical Effects on Confidence and Risk-Taking

The effects of a lucky event and irrational beliefs about luck were examined. In two experiments, some subjects experienced a lucky event, whereas others did not. All subjects then completed an unrelated decision task rated their confidence, and placed a bet. The effects of a lucky experience depended substantially on individual beliefs concerning the causal properties of luck. After the lucky event, those who believed in luck (i.e., thought of luck as a stable, personal attribute) were more confident and bet more, whereas those who did not believe in luck (i.e., thought luck was random) were less confident and bet less. A third experiment identified analogous effects using multiple-choice test questions that included a monetary penalty for errors. Increased expectations following initial luck were interpreted in terms of a lucky streak effect, whereas the paradoxical decrease in expectancy was viewed as an instance of the gamblers' fallacy.

MONTE CARLO TECHNIQUE FOR SIMULATION OF HIGH ENERGY ELECTRONS

A Monte Carlo (MC) technique useful for calculation of the high energy tail of the distribution function (d.f) is proposed. The well known MC technique for simulation in rarely visited region splits the real history of the particle, that has entered in this region, in N subhystories with weights 1/N. But the lucky event for entering must be waited to happen during the simulation. A presentation of the d.f is found here, which allows, knowing the d.f in the low (common) energy region, to simulate only high energy events. This technique can be used for example when gate current in submicrometer MOS devices is calculated.

An Epidemiological Study of Diphtheria in a remote New Zealand Community

1. The incidence produced during 1926 by two epidemics of diphtheria, in a remote and unsalted country district, was equivalent to 30 years of the London endemic morbidity.2. The cases arose in two distinct groups. An autumn outbreak with a definite concentration of infection on the school age, and probably disseminated by droplet infection, followed by an epidemic in the succeeding spring which was more severe, probably milk-borne, and in which the frequency of cases was higher among infants and adults than school children.3. The effect of a long drive over bad roads caused a deterioration of the diluted toxin which was used for a Schick test investigation. The use of this toxin led at first to false conclusions regarding the immunity of the children, since it only caused reactions in the most susceptible members of the community.4. As a result of retesting with a fully potent toxin it was estimated that the figure of 40 per cent. susceptible which was found with the weak toxin would have been about 80, if full strength toxin had been used.5. The attempt to immunise actively those children who had reacted to the weak Schick toxin was found to have failed in 72 per cent. of a group which was retested 7 months later. The prophylactic course was identical with one which had succeeded in inducing Schick immunity, within 4 months, in 100 per cent. of the susceptible children in the Dunedin orphanages.6. The slow rate of immunisation at Kaitangata is attributed to two causes, (a) the low original herd immunity of the district, (b) the selection by the weak toxin of only the most sensitive reactors which were almost certainly the most “unresponsive” members of the total Schick positive population.7. By a comparison of the rate of response to a small dose of toxin-anti-toxin mixture, in those positive Schick reactors (a) who had, and (b) who had not, received previous prophylactic injections, it was shown that the principle of “primary and secondary” antigenic stimuli held good for human subjects, as well as for experimental animals.8. Careful examination of the known data led to the conclusion that the air-borne autumn epidemic had increased the herd immunity of the population, in spite of the fact that the subsequent milk-borne spring outbreak produced as high a morbidity and a more severe type of diphtheria.9. The practical lessons which may be learnt from this study are: (a) That unless a special buffered diluent is used, the toxin used for Schick testing must be freshly diluted near the place where it is to be used, (b) Active immunisation of remote unsalted communities against diphtheria requires more time, and more intensive courses of prophylactic, than areas where diphtheria has been endemic for some years, (c) In such places with a low original herd immunity, it is essential, even more than in endemic centres, never to omit retesting those who have been inoculated, in order to be certain that any attempt made to induce active immunity to diphtheria may be successful. (d) Estimations of the relative efficiency of diphtheria prophylactics, which are based on the rapidity with which samples of children become immune, are worthless unless all the observations have been made in the same environment on groups having the same original herd immunity, (e) An immunity, good enough to withstand droplet infection in a day school environment, may be broken down by massive doses of diphtheria bacilli in milk.10. The study of outbreaks of disease in communities which are not too large to prevent a complete supervision of the whole population and environment, enable one to visualise imaginary mechanisms of infection very much more easily than in large populous areas, where so many more factors have to be left unexamined, or remain unsuspected. The hypotheses, perhaps better termed surmises, which the facts suggest, are only intended to be purely tentative and temporary. Their practical value is that they indicate to the investigator a plan of campaign and suggest what to look for, in the lucky event of his ever again meeting with a similar combination of circumstances. In epidemiology in general, as illustrated by this particular instance, opportunities arise and pass, often never to recur, and much is missed, or left undone that might have been done, if only the knowledge and hints gained during the passage of the epidemic itself had been known before its advent.