223 research outputs found
Il glossario TECT: uno strumento lessicale per la schedatura della pittura parietale
No full textl volume raccoglie i contributi della Giornata di studio tenutasi a Padova il 20 marzo 2014 dal titolo "La pittura frammentaria di età romana. Metodi di catalogazione e studio dei reperti", organizzata con l'obiettivo prioritario di presentare ad un pubblico di specialisti le prime fasi del progetto TECT, il cui nome deriva dall'abbreviazione del termine latino tectorium (intonaco), sviluppato al fine di creare una banca dati delle pitture parietali di età romana rinvenute in Italia settentrionale.
La "filosofia" del database TECT viene esplicitata nel volume, non solo tramite la presentazione della scheda, ideata nell'ambito del progetto con lo scopo di sistematizzare le evidenze archeologiche (A. Didonè, G. Salvo), ma anche attraverso la proposta di un glossario - pensato per uniformare la descrizione delle testimonianze pittoriche e per facilitarne la ricerca - le cui fasi di elaborazione vengono illustrate in questi atti (R. Helg, A. Malgieri)
The surprising rolling spool: librational motion and failure of the pure rolling condition
No full textIn a previous work (Onorato P, Malgieri M, Mascheretti P and De Ambrosis A 2014 The surprising rolling spool: experiments and theory from mechanics to phase transitions Eur. J. Phys. 35 055011) an asymmetric rolling spool (ARS) was investigated as a simple model for a second-order phase transition. Here, we deepen the study of this system to address critical aspects related both to the characteristic of the oscillatory anharmonic motion and to the role of friction forces in determining it. The experimental data show that for largely asymmetric bodies the rolling condition is not reliably fulfilled because the intensity of the friction force goes below the needed value to ensure rolling
without slipping
Experiments and models about the force between permanent magnets: Asymptotic analysis of a difficult problem
No full textWe propose a simple experiment, which allows students to explore quantitatively the magnetic interaction between neodymium cylindrical magnets. The experiment employs a precision digital balance, two screws with known thread pitch and two transparent tubes to measure the repulsive force between two magnets as a function of their distance. Different measurements are performed, focusing on the behavior of the interaction force at short and long distances and the role of the magnets' aspect ratio. We discuss the comparison between theoretical expectations resulting from conceptually simple approximate models and experimental results. The experiments employ inexpensive materials and address a relevant topic in the physics curriculum. Thus, they are appropriate for the undergraduate physics laboratory, for advanced high school students, and in the context of teacher education and in-service training to enhance students' knowledge of magnetism
Modeling and Representing Conceptual Change in the Learning of Successive Theories: The Case of the Classical-Quantum Transition
No full textMost educational literature on conceptual change concerns the process by which introductory students acquire scientific knowledge. However, with modern developments in science and technology, the social significance of learning successive theories is steadily increasing, thus opening new areas of interest to discipline-based education research, e.g., quantum logic, quantum information, and communication. Here, we present an initial proposal for modeling the transition from the understanding of a theory to the understanding of its successor and explore its generative potential by applying it to a concrete case—the classical-quantum transition in physics. In pursue of such task, we make coordinated use of contributions from research not only on conceptual change in education, but also on the history and philosophy of science, on the teaching and learning of quantum mechanics, and on mathematics education. By means of analytical instruments developed for characterizing conceptual trajectories at different representational levels, we review empirical literature in the search for the connections between theory change and cognitive demands. The analysis shows a rich landscape of changes and new challenges that are absent in the traditionally considered cases of conceptual change. In order to fully disclose the educational potential of the analysis, we visualize categorical changes by means of dynamic frames, identifying recognizable patterns that answer to students’ need of comparability between the older and the new paradigm. Finally, we show how the frame representation can be used to suggest pattern-dependent strategies to promote the understanding of the new content, and may work as a guide to curricular design
Teaching the heat transfer law using a stochastic toy model
No full textIn this paper we present a simple stochastic toy model playable with dice, coins and tokens, meant to represent the system composed of a conducting bar between two heat reservoirs. The toy model is meant to be used in the context of a computational approach to teaching thermal physics to undergraduates, and allows one to highlight step by step the mechanism by which deterministic differential equations for macroscopic quantities can arise from underlying microscopic processes which are inherently random. Since this mechanism crucially requires the passage to the thermodynamic limit, in order to test it on their own students are required to code and perform numerical simulations of the toy model system with an increasingly large number of elements. From the point of view of training students with programming skills, the toy model offers a suitable ground for an early activity, since the simulation of a game they can actually perform is expected to produce less cognitive load than the simulation of more abstract problems and equations, allowing students to concentrate on learning the basics of programming
Recent Progress on the Sum over Paths Approach in Quantum Mechanics Education
No full textIn this paper, we present an overview of recent developments in the Feynman sum over paths approach for teaching introductory quantum mechanics to high school students and university undergraduates. A turning point in recent research is identified in the clarification of the distinction between the time-dependent and time-independent approaches, and it is shown how the adoption of the latter has allowed new educational reconstructions to proceed much farther beyond what had previously been achieved. It is argued that sum over paths has now reached full maturity as an educational reconstruction of quantum physics and offers several advantages with respect to other approaches in terms of leading students to develop consistent mental models of quantum phenomena, achieving better conceptual understanding and a higher degree of longitudinal integration of knowledge
Bubble: Experimenting with Feynman’s sum over paths approach in the secondary school
No full textWe discuss a teaching experiment on the introduction of elements of quantum physics already at the level of the fourth year of high school (17–18 years old students) using Feynman’s sum over paths approach. More precisely, the educational sequence is constructed on the juxtaposition of the wave and quantum theories of light, and it constitutes an attempt to anticipate the current status of the past, secular debate on the nature of light to young students, while providing them with a unifying perspective on different approaches, models and theories which are encountered in high school. The experimentation is part of the research on quantum physics education in secondary school conducted by the Physics Education group in Pavia, and it was developed by the author as a thesis work in the context of the IDIFO-6 Master coordinated by the University of Udine. The focus of the work is on the gradual introduction of innovative elements in the traditional high school didactics. Analysis of the experimentation data shows very rich and complex patterns, allowing to identify activities which may be more productive for students and to uncover weak points and student’s difficulties
Investigating the beliefs of experts on teaching quantum physics at secondary schools: key concepts, topics, and fundamentals
No full textGeoGebra simulations for Feynman’s sum over paths approach
No full textWe present a collection of interactive simulations meant to complement the educational approach to quantum physics in high school developed since 2013 by the physics education research group at the University of Pavia. The collection, organized as a “book” within the online repository GeoGebra Tube is intended primarily for being used by physics teachers wishing to deepen their understanding of Feynman’s sum over paths approach. The simulations represent several problems of physical interest, and aim at clarifying different aspects of Feynman’s model. The collection has been used as an educational tool in the context of the IDIFO-6 Master
coordinated by the University of Udine, and encouraging indications have been collected. In particular, the use of an open-source software which is very widely known and used in the community of teachers may encourage them to produce their own example simulations, or make easier for them to modify the existing ones according to their preferences and needs
Measuring the hydrogen Balmer series and Rydberg’s constant with a homemade spectrophotometer
No full textIn a recent paper (Amrani 2014 Eur. J. Phys. 35 045001), the author presented two different methods to measure the wavelength of visible lines of Balmer series from the hydrogen atomic spectrum and estimate the value of Rydberg’s constant with an error difference of a few tenths of a per cent. Here we discuss how low cost spectrometers, based on the use of either transmission or reflection diffraction gratings coupled with a commercial digital camera, can be employed with the same aim. The Rydberg’s constant values obtained with our pectrometers are R = 1.096 ± 0.007 × 107 m−1 for the transmission grating spectrometer and R = 1.094 ± 0.005 × 107 m−1 for the reflection spectrometer, with a difference of less than 0.30% from the accepted value of 1.097 373 × 107 m−1
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