Physics

This document contains supplementary material for the article with the same title that appeared in American Journal of Physics in 2019

At large research universities in the USA, introductory physics labs are often run by graduate student teaching assistants (TAs). Thus, efforts to reform introductory labs should address the need for effective and relevant TA professional development. We developed and implemented a research-based professional development program that focuses on preparing TAs to effectively support inquiry-based learning in the lab. We identify positive effects by examining three possible ways in which the professional development might have impacted TAs and their work. First, we examine lab TAs' written reflections to understand the effect of the program on TAs' ways of thinking about student learning. Second, we observe and categorize TA-student interactions in the lab in order to investigate whether TA behaviors are changing after the professional development. Third, we examine students' attitudes toward experimental science and present one example case in which students' attitudes improve for those TAs who `buy in' to the professional development. Our results suggest lab TA professional development may have a tangible positive impact on TA performance and student learning.

It has become increasingly common for high-school students to see media reports on the importance of quantum mechanics in the development of next-generation industries such as drug development and secure communication, but few of them have been exposed to fundamental quantum mechanical concepts in a meaningful classroom activity. In order to bridge this gap, we design and test a low-cost 20-minute demonstration of the Bell test, which is used in several entanglement-based quantum key distribution protocols. The demonstration introduces ideas such as the quantum state, quantum measurement, spin quantization, cryptography, and entanglement; all without using concepts beyond the 9th grade of the Chilean high-school curriculum. The demonstration can serve to promote early exposure of the future adopters and developers of quantum technology with its conceptual building blocks, and also to educate the general public about the importance of quantum mechanics in modern industry

In 2015 the first observation of gravitational waves marked a breakthrough in astrophysics, and in technological research and development. The discovery of a gravitational-wave signal from the collision of two black holes, a billion light-years away, received considerable interest from the media and public. We describe the development of a purpose-built exhibit explaining this new area of research to a general audience. The core element of the exhibit is a working Michelson interferometer: a scaled-down version of the key technology used in gravitational-wave detectors. The Michelson interferometer is integrated into a hands-on exhibit, which allows for user interaction and simulated gravitational-wave observations. An interactive display provides a self-guided explanation of gravitational-wave related topics through video, animation, images and text. We detail the hardware and software used to create the exhibit, and discuss two installation variants: an independent learning experience in a museum setting (the Thinktank Birmingham Science Museum), and a science-festival with the presence of expert guides (the 2017 Royal Society Summer Science Exhibition). We assess audience reception in these two settings, describe the improvements we have made given this information, and discuss future public-engagement projects resulting from this work. The exhibit is found to be effective in communicating the new and unfamiliar field of gravitational-wave research to general audiences. An accompanying website provides parts lists and information for others to build their own version of this exhibit.

Although online education has become a viable and major component of higher education in many fields, its employment in engineering disciplines has been limited. COVID-19 pandemic compelled the global and abrupt conversion of conventional face-to-face instruction to the online format. The negative impact of such sudden change is undeniable. Urgent and careful planning is needed to mitigate pandemic negative effects on engineering education, especially for vulnerable, disadvantaged, and underrepresented students who have to deal with additional challenges (e.g. digital equity gap). To enhance engineering online instruction during the pandemic era, we conducted an observational study at California State University, Long Beach (a minority-serving institution). 110 faculty and 627 students from six engineering departments participated in our surveys and answered quantitative and qualitative questions to highlight the challenges they experienced during the online instruction in Spring 2020. In this work, we present the results of these surveys in detail and propose solutions to address the identified issues including logistical, technical, learning/teaching challenges, assessment methods, and hands-on training. As the pandemic continues, sharing these results with other educators can help with more effective planning and choice of best practices to improve the online engineering education during COVID-19 and beyond.

An update is given on the exoplanet research collaboration between Nielsen (a marketing research company), Brigham Young University, and NZ universities with the National University of Singapore, which has been expanded to include a community college in the US. Key achievements from the past year are outlined, including density estimates for HD 209458 and Kepler 1 from radial velocity and transit fits. A comparison between the WinFitter optimizer and other techniques is outlined, showing that WinFitter estimated statistical errors are essentially in line (bar a scaling proportion) with those estimated via Markov Chain Monte Carlo techniques.

A bicycle wheel that was initially spinning freely was placed in contact with a rough surface and a digital film was made of its motion. Using Tracker software for video analysis, we obtained the velocity vectors for several points on the wheel, in the frame of reference of the laboratory as well as in a relative frame of reference having as its origin the wheel`s center of mass. The velocity of the wheel`s point of contact with the floor was also determined obtaining then a complete picture of the kinematic state of the wheel in both frames of reference. An empirical approach of this sort to problems in mechanics can contribute to overcoming the considerable difficulties they entail.

The development of systems for the deterministic transfer of two-dimensional (2D) materials have undoubtedly contributed to a great advance in the 2D materials research. In fact, they have made it possible to fabricate van der Waals heterostructures and 2D materials-based devices with complex architectures. Nonetheless, as far as we know, the amount of papers in the literature providing enough details to reproduce these systems by other research groups is very scarce in the literature. Moreover, these systems typically require the use of expensive optical and mechanical components hampering their applicability in research groups with low budget. Here we demonstrate how a deterministic placement system for 2D materials set up with full capabilities can be implemented under 900 Eur which can be easily implemented in low budget labs and educational labs.

We present a question bank consisting of over 250 multiple-choice and true-false questions covering a broad range of material typically taught in an introductory undergraduate course in numerical analysis or scientific computing. The questions are ideal for polling students during lectures by means of a student response system that uses clicker remotes or smartphones running a suitable app. We describe our experiences implementing these clicker questions in a recent class and provide evidence of their effectiveness in terms of testing students' prior knowledge, gauging understanding of new material, increasing participation, and especially improving student satisfaction. Our conclusions are supported by a mid-semester student survey as well as anecdotal observations. The question bank has been released as an open-access educational resource under a Creative Commons license (BY-NC-SA) for free use by the mathematics community.

Raised menisci around small discs positioned to pull up a water-air interface provide a well controllable experimental setup capable of reproducing much of the rich phenomenology of gravitational lensing (or microlensing events) by n -body clusters. Results are shown for single, binary and triple mass lenses. The scheme represents a versatile testbench for the (astro)physics of general relativity's gravitational lens effects, including high multiplicity imaging of extended sources.