physics

Special relativity aces time trial

Alexandra Witze

‘Time dilation’ predicted by Einstein confirmed by lithium ion experiment.

Article

Science language Wanted Alive: Through the dialectical/dialogical lens of Vygotsky and the Bakhtin circle

Wolff-Michael Roth

Over the past two decades, science educators increasingly have become interested in the role of language in the learning of science and have drawn on the work of Bakhtin, among others, for understanding the dialogical nature of knowledge in a sociocultural framework. However, the nature of language and its relation to thinking have not substantially changed and, in many ways, are incommensurable with the cultural–historical, materialist dialectical underpinning of the original framing of the sociocultural and dialogical approaches in the theories of L. S. Vygotsky and M. M. Bakhtin and his circle (e.g., V. N. Vološinov). Most importantly, currently available analyses of science classroom talk do not appear to exhibit sufficient appreciation of the fact that words, statements, and language are living phenomena, that is, they inherently change in speaking. In this paper, I begin by working out the premise that language is a living phenomenon that changes in use. I then present two key insights on language-in-use that derive from the works of Vygotsky and the Bakhtin circle, which are used to develop a theoretical and methodological frame. These key insights and the theoretical aspects of this paper are exemplified with materials from a concept mapping session in a 12th-grade physics course. The proposed model has considerable implications for theorizing the relation between classroom talk and formal written genres of expression, and gives rise to many new research questions.

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The evolution of classroom physics knowledge in relation to certainty and uncertainty

Andrée Tiberghien, David Cross, Gérard Sensevy

This paper deals with the joint construction of knowledge by the teacher and the students in a physics classroom. It is focused on the status of epistemic certainty/uncertainty of knowledge. The same element of knowledge can be introduced as possible and thus uncertain and then evolve towards a status of epistemic certainty; the status of other elements can do the reverse. The evolution of a certainty/uncertainty status reflects the evolution of the shared knowledge in the classroom. The study of this evolution is based on a previous analysis of the evolution of knowledge in a classroom during a teaching sequence of mechanics at grade 10. From this analysis two notions were selected and the evolution of the elements of knowledge associated was analyzed in terms of epistemic certainty/uncertainty. The results show how the emergence of new epistemic questions depends on the nature and status of student’s prior knowledge; in other terms, new epistemic uncertainty emerges from epistemic certainty.

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Narratives of Science Outreach in Elite Contexts of Academic Science

David R. Johnson, Elaine Howard Ecklund, Anne E. Lincoln

Using data from interviews with 133 physicists and biologists working at elite research universities in the United States, we analyze narratives of outreach. We identify discipline-specific barriers to outreach and gender-specific rationales for commitment. Physicists view outreach as outside of the scientific role and a possible threat to reputation. Biologists assign greater value to outreach, but their perceptions of the public inhibit commitment. Finally, women are more likely than men to participate in outreach, a commitment that often results in peer-based informal sanctions. The study reveals how the cultural properties of disciplines, including the status of women, shape the meaning and experience of science outreach.

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