Hasil untuk "physics.ed-ph"

T. Clayton, R. Byrne

J. Dressman, R. Berardi, Lambros C. Dermentzoglou et al.

Jan M. Antosiewicz, J. McCammon, Michael K. Gilson

Gianluca Li Causi

In this work, I propose a way to help high school students and the general population understand quantum concepts by adopting a new inherently dual representation. Major difficulties in explaining to people the basic concepts of quantum mechanics reside in the apparent impossibility of representing quantum superposition with examples taken from everyday life. In this context, I propose a new pictorial paradigm that illustrates a number of quantum concepts by means of optical illusions, potentially without raising misconceptions. The method is based on "bistable reversible figures", which induce in the viewer a multistable perception, conveying a direct understanding of superposition, random collapse, and observer effect via a sensorial experience. I present the advantages and discuss the limitations of this analogy, and show how it extends to the concepts of complementarity and quantum entanglement, also helping to avoiding misconceptions in quantum teleportation. Finally, I also address quantum spin and quantum measurement by using different types of optical illusions.

Chris L. Lin

The reciprocal velocity force, $F(v)=\frac{C}{v}$, despite its theoretical and practical importance, is often neglected in mechanics courses. We use graphical methods to explain how such a force naturally arises from a device called a transmission, and discuss the kinematic consequences of this force. As an application, we discuss the role of this force for both internal combustion engines and electric vehicles.

Marcin Kościelecki, Piotr Nieżurawski

We present a few charge distributions for which the application of Gauss' law in its integral form, as typically outlined in standard textbooks, results in a contradiction. We identify the root cause of such contradictions and put forward a solution to resolve them.

Xiao-Ping Li, A. Gilmore, S. Caffarri et al.

The biochemical, biophysical, and physiological properties of the PsbS protein were studied in relation to mutations of two symmetry-related, lumen-exposed glutamate residues, Glu-122 and Glu-226. These two glutamates are targets for protonation during lumen acidification in excess light. Mutation of PsbS did not affect xanthophyll cycle pigment conversion or pool size. Plants containing PsbS mutations of both glutamates did not have any rapidly inducible nonphotochemical quenching (qE) and had similar chlorophyll fluorescence lifetime components as npq4-1, a psbS deletion mutant. The double mutant also lacked a characteristic leaf absorbance change at 535 nm (ΔA535), and PsbS from these plants did not bind dicyclohexylcarbodiimide (DCCD), a known inhibitor of qE. Mutation of only one of the glutamates had intermediate effects on qE, chlorophyll fluorescence lifetime component amplitudes, DCCD binding, and ΔA535. Little if any differences were observed comparing the two single mutants, suggesting that the glutamates are chemically and functionally equivalent. Based on these results a bifacial model for the functional interaction of PsbS with photosystem II is proposed. Furthermore, based on the extent of qE inhibition in the mutants, photochemical and nonphotochemical quenching processes of photosystem II were associated with distinct chlorophyll fluorescence life-time distribution components.

M. N. Tarabishy

Gyroscopic motion explanation in texts is relatively long and requires reasonable level of comfort with the mathematical tools used. On the other hand, popular explanation outside academic courses does not explain the phenomenon and only describes it leaving many to think that it is so weird that it defies physics. In this paper we offer a simplified and mathematically sound explanation that can be used in either setting.

T. Rabilloud, C. Adessi, A. Giraudel et al.

Membrane and nuclear proteins of poor solubility have been separated by high resolution two‐dimensional (2‐D) gel electrophoresis. Isoelectric focusing with immobilized pH gradients leads to severe quantitative losses of proteins in the resulting 2‐D map, although the resolution is usually high. Protein solubility could be improved by using denaturing solutions containing various detergents and chaotropes. Best results were obtained with a denaturing solution containing urea, thiourea, and detergents (both nonionic and zwitterionic). The usefulness of thiourea‐containing denaturing mixtures is shown for microsomal and nuclear proteins as well as for tubulin, a protein highly prone to aggregation.

Bree Barnett Dreyfuss, David Marasco

While AAPT and many other physics organizations have been introducing a series of effective practices around diversity and inclusion at the national level in recent years, it was wondered if these were being adopted at the local level. It is hoped that section members and Section Representatives will decide to further expand the actions of national leadership to make their own section meeting more inclusive. In order to assess if this was in fact the case, a survey on diversity practices that have been used the the national level and can be implemented at the section level was sent to AAPT's Section Reps mailing list in the spring of 2018, with a follow-up survey in winter 2020. Feedback in both cycles suggested that a guide for section leadership would be useful. The Northern California/Nevada section has made progress in implementing some of the effective practices from the national meetings into our local section meetings, we share these efforts in the hope that they assist our fellow sections.

Mirjana Pović

Africa has amazing potential due to natural (such as dark sky) and human resources for scientific research in astronomy and space science. At the same time, the continent is still facing many difficulties, and its countries are now recognising the importance of astronomy, space science and satellite technologies for improving some of their principal socio-economic challenges. The development of astronomy in Africa (including Ethiopia) has grown significantly over the past few years, and never before it was more possible to use astronomy for education, outreach, and development as it is now. However, much still remains to be done. This paper will summarise the recent developments in astronomy research and education in Africa and Ethiopia and will focus on how working together on the development of science and education can we fight poverty in the long term and increase our possibilities of attaining the United Nations Sustainable Development Goals in future for benefit of all.

Melanie Archipley, Hannah S. Dalgleish, Eva-Maria Ahrer et al.

Professional astronomy is historically not an environment of diverse identities. In recognizing that public outreach efforts affect career outcomes for young people, it is important to assess the demographics of those being reached and continually consider strategies for successfully engaging underrepresented groups. One such outreach event, the International Astronomical Youth Camp (IAYC), has a 50-year history and has reached ~1700 participants from around the world. We find that the IAYC is doing well in terms of gender (59% female, 4.7% non-binary at the most recent camp) and LGBT+ representation, whereas black and ethnic minorities are lacking. In this proceeding, we report the current landscape of demographics applying to and attending the IAYC; the efforts we are making to increase diversity amongst participants; the challenges we face; and our future plans to bridge these gaps, not only for the benefit of the camp but for society overall.

Rick Orij, J. Postmus, Alexander Ter Beek et al.

Mateo Dutra, Álvaro Suárez, Martín Monteiro et al.

While Bernoulli's equation is one of the most frequently mentioned topics in Physics literature and other means of dissemination, it is also one of the least understood. Oddly enough, in the wonderful book "Turning the world inside out" [1], Robert Ehrlich proposes a demonstration that consists of blowing a quarter dollar coin into a cup, incorrectly explained using Bernoulli's equation. In the present work, we have adapted the demonstration to show situations in which the coin jumps into the cup and others in which it does not, proving that the explanation based on Bernoulli's is flawed. Our demonstration is useful to tackle the common misconception, stemming from the incorrect use of Bernoulli's equation, that higher velocity invariably means lower pressure.

Andreas J. C. Woitzik

Quantum Information Processing is usually taught as an elective in the master's degree in physics. We argue that a basic understanding of Quantum Information Processing can already be achieved by high school juniors and seniors. Moreover, we explain why it is useful to teach Quantum Information at this level and describe a teaching unit which has already been tested in the classroom. We will hereby focus on didactical reductions and describe some physical basics.

C. López-Vázquez, A. Oehmen, C. M. Hooijmans et al.

E. Gianazza, P. Righetti

L. de Nooijer, T. Toyofuku, H. Kitazato

Jun Chen, Xiaozhong Qiu, Jun Ouyang et al.

Yang‐Hsiang Chan, Changfeng Wu, Fangmao Ye et al.