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We discuss an investigation of student difficulties with the representation in which a Hermitian operator corresponding to a physical observable (e.g., the Hamiltonian operator corresponding to energy) is diagonal in the context of degenerate perturbation theory involving the Zeeman effect in the hydrogen atom. This investigation was carried out in advanced quantum mechanics courses by administering written free-response and multiple-choice questions and conducting individual interviews with students. We discuss the common student difficulties related to these concepts, knowledge of which can be useful for developing research-validated learning tools.

AAPT SM 21

Student difficulties with diagonal operators for degenerate perturbation theory

tutorials

degenerate perturbation theory

quantum mechanics

**Making Physics More Inclusive and Eliminating Exclusionary Practices in Physics**

As a gateway discipline to STEM majors and careers, physics plays a central role in deciding who does, and who doesn't, get to discover and pursue scientific careers. Technical and scientific professionals are rewarded with economic privilege and status which affords them both social and cultural power. Therefore, social justice will be realized only when the opportunity, and the choice, to excel in physics is open to all students. The culture and practices of the physics classroom reflect the culture of physics at large, which raises the question of how our professional physics communities can embrace, rather than inadvertently repel, a diverse group of academics that can help improve physics culture.  To this end, the 2021 Physics Education Research Conference will focus on defining inclusive spaces and practices. Additionally, we will explore strategies for eliminating exclusionary practices in our classrooms, research spaces, and professional organizations. We call on the community to propose sessions that will drive conversations related to these initiatives throughout PERC 2021.

Please download the full program [here. ](https://drive.google.com/file/d/1TRMC_SYJ3PUqXyP7sskA7LRSA8ow0eRE/view?usp=sharing)

PERC SM 21

August 4, 2021 - August 5, 2021 in a Virtual Conference Format

Making Physics More Inclusive and Eliminating Exclusionary Practices in Physics

poster

Join AAPT and Physics Educators worldwide in developing and strengthening your professional connections by attending the 2021 AAPT Virtual Summer Meeting. AAPT meetings are a great way to reflect on your teaching, recommit to best practices and re-energize your career with new research, products, and techniques.

Listen to internationally known plenary speakers, attend sessions, workshops, and special activities. Attending the virtual summer meeting is an excellent opportunity to share your expertise and learn from and network with leaders in the field.

Please log in with your AAPT account or register for the event if you haven't already.

If you are registered please note that you need to be logged in with your AAPT email / credentials in order to get access.

A large body of research supports the positive impact of interactive instruction on student learning. The mechanism for this increased student learning, however, is less well understood. We propose collaborative mechanistic reasoning as a possible mechanism for this enhanced learning. In this research, we analyze video episodes of small group work during weekly LA preparation sessions, using a discourse analysis framework developed by Russ et al. (2008) to identify elements of mechanistic reasoning. This framework allows us to identify episodes of high-level mechanistic reasoning in LA discussion. In our analysis, we are focused on the highest level of mechanistic reasoning, chaining. We will present analysis of an episode of collaborative chaining in terms of the mechanistic reasoning discourse analysis framework.


Collaborative mechanistic reasoning in a Learning Assistant preparation session

What role does experimental apparatus play as a semiotic resource and what do students do when the apparatus is replaced with a video of the same experiment?
In this talk, we will examine this question in the context of a quasi-experimental study where we examined how students developed scientific reasoning abilities using video-based experiments as compared to students who conducted the same experiments with physical apparatus.
In comparing the affordances and constraints of each environment (video-based experiments versus apparatus-based experiments) we discovered interesting patterns in students’ sense-making behaviors
a. When equipment was present, it served as a key semiotic resource in sense-making.
b. Students in the video-based condition also engaged in sense-making without equipment. When they did, their verbal sense-making was accompanied by extensive use of gesture.
We will present case studies from our research and discuss the broader implications for supporting students' sense-making in different contexts.

Sense-making by manipulating apparatus and using gesture

In a field that is known for being predominantly white and male, teachers have a greater than usual obligation and challenge to ensure students can see themselves as doers of physics. Starting from Gholdy Muhammad's Historical Responsive Literacy framework, the identity encounters were formed. Rather than a focus on "inspiring" students, students are exposed to a diverse group of physicists and physics students in both live and pre-recorded formats. The structure of the encounters and their impact on student identity will be discussed.

Identity Development though Diverse Encounters

Arkansas is primarily an agricultural economy with billions of dollars accrued through crop production. Because of this, agriculture should be represented in Arkansas classrooms and in national education as agronomy requires a broad range of STEM trained graduates. Teachers can introduce basic physics concepts such as fluid flow and thermodynamics using real world agricultural scenarios and in-class demonstrations such as measuring water amount in soil, to demonstrating the effect of water evaporation in irrigation systems (and the resultant cost of such). As a cross cutting concept, soybeans are cultivated to be used in the implementation of this lesson to determine water evaporation which includes discussion of soybean transpiration. The concepts and examples presented can easily be modified for any science classroom using locally used crops.

Teaching physics using agricultural concepts.

General, conceptual, and “Physics First” instructors are often isolated and left to either adapt advanced curricula or piece together resources. PEER Physics provides a robust NGSS-aligned curriculum and a community for teachers to connect and learn about implementing science and engineering practices. Students are immersed into the discipline of physics through anchoring phenomena that drive their curiosity while they make and defend claims. This evidence-based reasoning is supplemented with argumentation and consensus building where the whole class generates a set of broadly-applicable principles. Materials have been carefully developed and tested with input from practicing teachers, physics content and pedagogy experts, and instructional coaches. This unique collaborative effort has led to a physics program that is unlike anything else available for high school general and conceptual physics. In this presentation, we will share about our newly released open source Waves chapter, and the accompanying phenomenon, engineering design challenge, and 3D-assessment.


PEER Physics: Open Source Waves Unit

I have applied the syllabus of a First Year University Physics course toward Instructing High School Juniors in AP Physics C Mechanics and E&M (Calculus based). As these students are enrolled in Calculus I concurrently (have not yet fulfilled the pre-requisite), I must creatively teach them concepts and applications of differentiation, integration, and differential equations "on the fly." Rather than struggling, the students consistently rise to the occasion and attain success in understanding and mastering advanced topics not normally expected of High School students (e.g., I use imaginary exponentials to help them solve SHO problems with damping). I will present anecdotal evidence from Physics Faculty at the University associated with the High School that the students are not only superbly prepared, they "trounce the curve" and are encouraged to skip First Year Physics. I will also present AP Score distributions and Student evidence as to their satisfaction and enhanced confidence.

Pushing The Limit: Students Rising To The Challenge

Special Relativity is a critical issue in the teaching of physics in the Italian high school.
The theory does not show daily examples, thus preventing the possibility of structuring simply laboratory's experiences.

In this talk, we present the results of an experimentation regarding the teaching of Special Relativity.
The main innovation of our project consists of a mechanical instrument we use to explain Special Relativity. This tool is a big spacetime diagram in which each event on the grid can be moved along certain hyperbolas-shaped tracks, that represent the surface of constant interval.
Thus, one physically and mechanically performs Lorentz’s transformation by hands, exploring the effects of a change of the reference frame. Teachers and students can deal “by eye” with unusual phenomena as the loss of simultaneity, times dilation, lengths contraction, relativistic addition of velocities and Doppler’s effect which are the main topics of interest for High Schools.

Seeing Reality Through Einstein's Eyes: A Proposal for Special Relativity

Secondary school physics teachers often teach out-of-field, out-of-certification and are often the only physics teacher in their school. As a result, physics teachers lack support in developing pedagogical content knowledge. The Physics of Living Systems - Teacher (PoLS-T) network was established in 2020 to address salient challenges in secondary physics classrooms, within a community of practice of high school teachers and education researchers. In the year since its founding, the PoLS-T network has met on a monthly basis to discuss the needs of physics teachers, focusing on existing online resources they could leverage, and disseminating evidence -based best teaching practices. Due to the network’s membership, composed of both U.S.-based and international physics educators, the network has been a rich action-oriented community of practice. In our presentation, we will share key insights and future plans for the network, including the Monthly Speaker Series and other events.

The Physics of Living Systems Teachers (PoLS-T) Network

In a prior study, we investigated graduate student reasoning on a set of entropy-related conceptual tasks in a think-aloud format. The tasks involved entropy from microscopic and macroscopic perspectives, ideal gases, and a novel context involving a system with a dynamic string. In the current study, we conducted interviews with undergraduates using the same questionnaire. Most students were interviewed during the second half of their upper-division Thermal Physics course at the University of Colorado Boulder while two were upper-division undergraduates from other institutions with strong physics programs. We analyze the responses of the undergraduates to a section of the interview involving a novel system of a dynamic string waving in a bath of water and discuss the similarities and differences between the undergraduate and graduate students' responses. The responses from the two populations share many similarities with a few noteworthy exceptions. The undergraduates generally did not produce multiple macrostate classifications in the novel system, and some expressed a concern with what they perceived to be an infinite number of microstates---and thus infinite entropy---which was not a concern among the graduate students.

Comparing undergraduate and graduate student reasoning on conceptual entropy questionnaire

Students from two nearby high schools designed and configured a QuarkNet cosmic ray muon detectors to measure any changes in cosmic ray flux due to an inserted 0.1T magnetic field. The design included two separate methods to measure differences in muon path. We hypothesized that the neodymium magnetic field would vary muon flux in an offset detector array. Results will be presented.

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Student difficulties with diagonal operators for degenerate perturbation theory

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Collaborative mechanistic reasoning in a Learning Assistant preparation session

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Student difficulties identifying diagonal operators for degenerate perturbation theory