A prototype of a large tunable Fabry–Pérot interferometer for solar spectroscopy

Large Fabry-Pérot Interferometers (FPIs) are used in a variety of astronomical instrumentation, including spectro-polarimeters for 4 m class solar telescopes. In this work we comprehensively characterize the cavity of a prototype 150 mm FPI, sporting a novel, fully symmetric design. Of particular interest, we define a new method to properly assess the gravity effects on the interferometer's cavity when the system is used in either the vertical or horizontal configuration, both typical of solar observations. We show that the symmetric design very effectively limits the combined effects of pre-load and gravity forces to only a few nm over a 120 mm diameter illuminated surface, with gravity contributing ~2 nm peak-to-valley (~0.3 nm rms) in either configuration. We confirm a variation of the tilt between the plates of the interferometer during the spectral scan, which can be mitigated with appropriate corrections to the spacing commands. Finally, we show that the dynamical response of the new system fully satisfies typical operational scenarios. We conclude that large, fully symmetric FPIs can be safely used within solar instrumentation in both, horizontal and vertical position, with the latter better suited to limiting the overall volume occupied by such an instrument

Studies of stellar oscillations using a Fabry-Perot spectrometer

Imperial Users onl

Feeling and thought in collective action on social issues: Toward a systems perspective

Theories of action have tended to view it—and its basis in thought and feeling—as static, discrete, mechanistic, and decontextualized. Moreover, studies of action have tended to be fragmented in academic silos. The consequences of these problems include a lack of cumulative and contextualized theory-building, and an inability to recognize emergent, dynamic, and non-linear causality, especially across levels of analysis. We argue that such problems could be partly alleviated with increased engagement with a meta-theoretical perspective that has long been advocated for in psychology—the systems approach. In this view, thought, feeling, motivation, action, and context can be viewed as co-evolving, inextricably linked, systems of systems. We illustrate the need for and benefit of this approach in the domain of collective action on social issues. We conclude that systems perspectives allow more contextualized, generalizable, conceptually rich, and applied directions for research in this domain

The Evolutionary Psychology of War: Offense and Defense in the Adapted Mind

The study of warfare from an evolutionary perspective has expanded rapidly over the last couple of decades. However, it has tended to focus on the ancestral origins, prevalence, and instruments of war rather than adaptationist analyses of its underlying psychology. I argue that our evolved coalitional psychology may contain a set of distinct evolved heuristics designed specifically for offensive and defensive coalitional aggression. Data from two survey experiments are presented, in which subjects were given scenarios depicting offensive or defensive aggression and were told to make decisions, for example, regarding their willingness to participate in the conflict, their opinions of others who did not choose to participate, and their expectations benefit. The results indicate that humans do indeed distinguish readily between these two domains and that their willingness to participate, as well as their emotional responses toward others, is highly contingent upon this informational cue in adaptively relevant ways. In addition, and consistent with parental investment theory, data reveal a range of sex differences in attitudes toward coalitional aggression in the two conflict domains. Beyond the study of warfare, this project has implications for our understanding of the relationship between individual behavior and group dynamics, as well as for our understanding of the mechanisms by which the psychological framing of political events can lead to important social outcomes

Cues of control modulate the ascription of object ownership

Knowing whether an object is owned and by whom is essential to avoid costly conflicts. We hypothesize that everyday interactions around objects are influenced by a minimal sense of object ownership grounded on respect of possession. In particular, we hypothesize that tracking object ownership can be influenced by any cue that predicts the establishment of individual physical control over objects. To test this hypothesis we used an indirect method to determine whether visual cues of physical control like spatial proximity to an object, temporal priority in seeing it, and touching it influence this minimal sense of object ownership. In Experiment 1 participants were shown a neutral object located on a table, in the reaching space of one of two characters. In Experiment 2 one character found the object first; then another character appeared and saw the object. In Experiments 3 and 4, spatial proximity, temporal priority, and touch are pitted against each other to assess their relative weight. After having seen the scenes, participants were required to judge the sensibility of sen- tences in which ownership of the object was ascribed to one of the two characters. Responses were faster when the objects were located in the reaching space of the characterto whom ownership was ascribed in the sentence and when ownership was ascribed to the character who finds the object first. When contrasting the relevant cues, results indicate that touch is stronger than temporal priority in modulating the ascription of object ownership. However, all these effects were also influenced by contextual social cues like the gender of both characters and participants, the presence of a third-party observer, and the co-presence of characters. Consistent with our hypothesis, our results provide evidence that many different cues of physical control influence the ascription of ownership in daily social contexts

Excavating the Foundations: Cognitive Adaptations for Multiple Moral Domains

Do humans have cognitive adaptations for detecting violations of rules in multiple moral domains? Previous research using the Wason Selection Task has provided evidence for domain-specific mechanisms for detecting violations of social exchange and hazard precaution rules. The present study investigates whether similar evidence can be found for mechanisms for detecting violations of rules relating to soliciting aid, maintaining coalitions, and navigating hierarchies. Participants (n = 887) completed one of seven Wason Selection Tasks—five sociomoral tasks (exchange, hazard, aid, coalition, and submission) and two controls (descriptive and general deontic). Participants also completed the short form Moral Foundations Questionnaire (MFQ) as a self- report measure of five corresponding sets of moral values. The study found that, as predicted, performance on all five sociomoral tasks was significantly better than performance on the two control tasks. However, there was no relationship between task perfor- mance and corresponding moral values. These results provide initial evidence for cognitive adaptations for detecting violations of rules relating to providing aid, maintaining coalitions, and submitting to authority. We outline how future research might provide additional tests of this theory, and thereby further extend our understanding of the foundations of human sociomoral reasoning

Speaking their language – Development of a multilingual decision-support tool for communicating invasive species risks to decision makers and stakeholders

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