Sind die klassische Mechanik und die spezielle Relativitätstheorie kommensurabel?

In its first part, this paper shows why a recently made attempt to reduce the special theory of relativity to Newtonian kinematics is bound to fail. In the second part, we propose a differentiated notion of incommensurability which enables us to amend the contention that the special theory of relatively and Newtonian kinematics are incommensurable.     

Models of Public Engagement: Nanoscientists’ Understandings of Science–Society Interactions

This paper explores how scientists perceive public engagement initiatives. By drawing on interviews with nanoscientists, it analyzes how researchers imagine science–society interactions in an early phase of technological development. More specifically, the paper inquires into the implicit framings of citizens, of scientists, and of the public in scientists’ discourses. It identifies four different models of how nanoscientists understand public engagement which are described as educational, paternalistic, elitist, and economistic. These models are contrasted with the dialog model of public engagement promoted by social scientists and policymakers. The paper asks if and in what ways participatory discourses and practices feed back into scientists’ understandings, thus co-producing public discourses and science.     

On Usnadze's volume illusion

Summary Contrary to what was expected, subjects overestimated the volume in heavier objects, when making estimations with no visual cues available (a positive volume illusion). This finding contradicts the result of Usnadze. He found, that the heavier of two spheres, equal in volume, was perceived as the smaller by most subjects, with their eyes closed.The stimuli used were spheres and cylinders of different weights and volumes. In four experiments, the subjects reported their volume ratings with the help of two direct scaling methods, magnitude estimation or ratio estimation. Lifting stimuli with one sphere in each hand gave, as a result, a difference between hands. This difference was interpreted to imply, that the subjects did not just follow a strategy to give higher volume estimates to heavier objects.The positive volume illusion phenomenon, that appeared in all four experiments, was affected by such sources of variation as time (trial number), and size-weight interaction, defined as a stimulus context variable. Neither a strategy which assumes that the subjects judge density instead of volume, nor any other sizeweight interaction model is effective in explaining the volume illusion. The search for such a model was suggested as a line for future research, though.

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Zusammenfassung Gegensatz zur Erwartung scheinen schwerere Versuchskörper größeres Volumen zu haben als die leichteren, wenn Vpn die Volumina vergleichen, ohne sie anzusehen (eine positive Volumtäuschung). Dieses Resultat stimmt nicht mit den Ergebnissen von Usnadze. Er fand, daß wenn man zwei verschieden schwere, im übrigen aber ganz gleichartige Körper mit geschlossenen Augen, bloß tastend, auf ihre Größe vergleicht, so erscheint der Schwere kleiner, der Leichtere größer.Die Versuchskörper waren Kugeln und Zylinder verschiedenen Gewichtes und Volumens. In vier Versuchen schätzen die Vpn das Volumen mit Hilfe von zwei direkten Schätzmethoden, Magnitudenschätzung (magnitude estimation) und Verhältnisschätzung (ratio estimation), jedoch ohne die Versuchskörper sehen zu dürfen. Das Heben der Versuchskörper mit einer Kugel in jeder Hand gab als Resultat einen Unterschied zwischen den Händen. Dieser Unterschied schien zu bedeuten, daß die Vpn nicht automatisch schweren Körpern ein größeres Volumen gaben.Die positive Volumtäuschung, die in allen vier Versuchen erschien, war durch solche Faktoren wie Zeit (Nummer der Vergleichsfälle), und Größe-Gewichtwechselwirkung, definiert in der Verschiedenheit der vorhandenen Versuchskörper, beeinflußt. Die Versuchsdaten stützen nicht die Hypothese, daß die Vpn versuchten die Dichte der Versuchskörper zu schätzen. Auch wurde kein brauchbares Modell für die Wechselwirkung gefunden um die Volumtäuschung zu illustrieren. Ein solches Modell wurde doch für zukünftige Forschung vorgeschlagen.

     

Effects of white noise and irrelevant information on speeded classification: A developmental study

The study examined how well subjects were able to ignore the presence of irrelevant stimulus information in noise and in silence, as a function of age. Children aged six and nine, and adults, performed speeded card-sorting tasks with one binary dimension relevant and zero or two dimensions irrelevant. The presence of irrelevant information interfered with performance, the magnitude of interference declining with age. The interfering effects of irrelevant information were greater when it was (relatively) more salient than when it was less salient, but there was no interaction between relative salience and the effects of noise. Noise (95 dB(A)) slowed down sorting performance of adult subjects in all conditions, it slightly improved the performance of nine-year-old children, and it improved the performance of six-year-old children significantly when irrelevant information was present. The effects of noise on attentional control are discussed, mainly with reference to inhibitory effects of noise on subvocal activity.     

Visual Power in Action: Digital Images and the Shaping of Medical Practices

The increasing presence of images in medicine is mostly understood as a visualization of medicine. In this view, physicians and researchers are strongly guided by the visual power of images. Ethnographic fieldwork and interviews with physicians and scientists working in radiology departments and magnetic resonance imaging units however, show that visual power is not always effective. Depending on a situation, physicians and scientists are guided more strongly either by the persuasiveness of an image's visual qualities or its scientific and sociomaterial qualities. Actors trust in images and perceive them as attractive and objective in certain situations, whereas in others they classify images as manipulated representations that are untrustworthy. It is either the visual power or the status of images as scientific and sociomaterial facts that shapes physicians' and researchers' actions. Depending on whether an image is used, for example, to make a diagnosis, to validate a research finding, to communicate with a patient, to prevent litigation, or to improve one's position in the professional field, it is either the visual power or the scientific and sociomaterial characteristics of an image that are more effective in shaping medical practices. Fieldwork and interviews with physicians and scientists show in which situations visual power is relevant (or not) for medical practices.     

Stress and happiness among adolescents with varying frequency of physical activity

The aim of this cross-sectional study was to investigate associations between physical activity, stress, and happiness, as well as possible sex and age differences on these variables in a survey of 1,508 adolescent pupils (13 to 18 yr.) in middle Norway. Adolescents who reported they participated in physical activity 2 to 3 times per week or more scored significantly lower on stress and higher on happiness than those who participated in physical activity 1 day per week or less. There was no significant difference on stress and happiness between those being physically active 2 or 3 times a week and those being active almost every day. There was no sex difference in physical activity frequency. Girls had higher mean scores on stress, and boys scored higher on happiness. Adolescents 15 to 16 years old showed higher stress scores than those 17 to 18 years old, but there were no significant differences between the different age groups when looking at happiness and physical activity. A statistically significant two-way interaction of sex by age was found on both stress and happiness.