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The limited time allocation for lectures in the classroom is an obstacle to presenting student-centered learning. This is one of the factors that prospective physics teacher students experience conceptual difficulties, especially in crystal structure material. So the purpose of this study was to determine the effectiveness of the problem flipped classroom learning model on understanding the concepts of prospective physics teacher students on crystal structure material. This study used a quasi-experimental method with a one-group pretest-posttest research design. The subjects of this study were 16 students who took solid-state physics courses. Data analysis techniques were carried out using normality tests, homogeneity tests, and pretest and posttest average difference tests. Then test the N-gain to see the increase in the pretest and posttest results and continue with the effect size test using the effect size. The instrument used was a test of mastery of the concept of crystal structure material. The results of the paired sample t-test analysis show that the Problem Based Flipped Classroom significantly influences learning outcomes with a t value of 11.439 with a significance of 0.000. Students' understanding of crystal structure material has increased with an N-Gain of 0.75, which is in the high category. This means that the pretest and posttest scores have a high increase. While the results of the effect size test obtained a score of d = 2.86, which means that learning with the Problem Based Flipped Classroom has a strong effect on student learning outcomes on crystal structure material.

This research is part of the integration of information and communication technologies (ICT) in the Moroccan education system, our objective being to evaluate the use of computer-assisted experimentation (CAEx) in learning to encourage the authorities of the Ministry of National Education, Vocational Training and Sports to adopt the CAEx program in the teaching and learning of physics so that it becomes compulsory for all high schools. To evaluate the impact of using CAEx in the study of free oscillations of an RLC circuit (a linear circuit containing an electrical resistor, an inductor, and a capacitor). A study was conducted with 40 Moroccan students in the second year of the scientific baccalaureate option life and earth sciences at the high school Abdellah Laroui in the city of Fez, as this work aims to highlight the effect of the use of CAEx on the learning of students. Using the methodology of pre-test and post-test with an experimental group (20 students) and a control group (20 students). The results of both groups are analyzed with IBM SPSS 21 statistical analysis software the results obtained from the post-test show that the average of the tests addressed to both control and experimental groups has a significant difference. In addition, non-directive and directive interviews were conducted with the students of the experimental group. Indeed, the content of the grid of open and closed questions was elaborated in agreement with the teachers of physical sciences of the high school Abdellah Laroui, concerning the use of CAEx in learning and to know the degree of satisfaction of the integration of CAEx in the study of free oscillations in an RLC circuit. In addition, the data were processed by Sphinx v5 software. This study showed that CAEx integration had a positive effect on student learning. It can be said that CAEx plays an important role in the grasp and assimilation of scientific concepts, and it represents a solution to make the student more attentive and serious. Computer Aided Instruction can develop a spirit of initiative in the learner.

The aim of this research is to take a fresh look at the physical science concepts that Year 3 students struggle with. In this work, the responses of over 8,000 middle-primary-aged students to a range of physics, space science and chemistry questions were evaluated. The questions covered a number of topics ranging from selecting and using simple measurement tools to changes of state. From the student responses, we were able to address the following questions: 'Which physical science concepts did the students find difficult?' and 'Are the identified concepts the same concepts that students struggled with in the past or have new difficulties emerged?'. From the responses, it was determined that difficult concepts for Year 3 included: bigger objects don't always weigh more than smaller objects; gases have mass and volume; and day and night is caused by the Earth spinning on its axis. We summarise these findings along with recommendations for the Year 3 classroom.

We experience (perceive, act upon and react to, and conceptualize) dynamical processes in nature as agentive. Expressed differently, we experience events as resulting from activities and interactions of "Forces of Nature" (such as wind, light, heat, fluids, electricity, substances, and motion) that are conceived of as powerful agents acting and interacting in physical environments. An example would be sunlight creating heat in the Earth's surface layers, and this heat using the atmosphere as a heat engine whose output are the winds on our planet. In the physics of dynamical systems, these forces are characterized in terms of intensive and extensive quantities (i.e., electric potential and electric charge in the case of electricity). The aspect of power is formalized with the help of a generalized energy principle and the rules relating power/energy to intensive and extensive physical quantities. Concrete processes depend upon properties of physical materials (in and through which forces are active) such as (thermal, electrical, etc.) capacity or conductivity. In this paper, we demonstrate how we can create "Embodied Simulations" and "Forces-of-Nature Theater" performances, where children act as forces such as water, heat, electricity, and motion. The embodied logic of the physical play teaches children about the logic of our explanations of physical processes.

There is growing awareness that established structures of higher education are often predicated on problematic assumptions about merit, excellence, and rigor. Doctoral qualifying exams, for example, are required to advance to candidacy in many Ph.D. programs despite decades of documented concerns about the implications of standard modes for student equity and well-being. As more Ph.D. programs move to reform these exams and candidacy requirements, it is important to understand how Ph.D. programs, as academic organizations, construct the significance of the qualifying exam. A sociocultural lens suggests qualifying exams and the learning that enables their passage are symbolic rituals that move doctoral students from legitimate peripheral participation toward full membership and belonging in academic communities of practice. We conducted a comparative case study to understand how two Ph.D. programs in the physical sciences that have reformed their candidacy requirements--one elite and one middle ranked but striving for respect--constructed the significance and purpose of their qualifying exam and the broader transition to candidacy. Our inquiry included the contexts and mechanisms that mediated student learning. Through interviews with faculty, staff, and students, we found that the Ph.D. programs' recognition of their status within their respective disciplines emerged as a crucial component in constructions about the significance of exams and candidacy. The middle-ranked Ph.D. program changed the exam and candidacy structure to reflect legitimate practices in their discipline. The elite Ph.D. program created multiple pathways toward candidacy to mitigate long-standing concerns about gender equity and student well-being. Despite the structural changes, the Ph.D. programs left intact cultural understandings of merit, excellence, and rigor that maintain inequity in doctoral socialization. Our findings suggest that researchers and practitioners should pay more attention to designing and implementing structures that facilitate faculty assessments of doctoral student learning.

In many introductory physics classes, diffraction of light is introduced first, then more advanced diffraction topics such as x-ray diffraction, Bragg's law, and crystallography are covered. Since using x-rays raises safety concerns and atomic spacing in a crystal is not easy to change, microwaves with macroscopic crystals have been used to study Bragg's law in the undergraduate laboratory. A number of scientific supply companies, including PASCO and 3B Scientific, sell 10-GHz microwave optics systems. However, using these systems within the parameters of the manufacturer's procedure for a Bragg diffraction lab poses some challenges. First, the receiver and transmitter must be manually positioned, making the data collection process slow. Second, the microwaves should be plane waves and the receiver should be located beyond the far-field limit. These 10-GHz microwave optics systems are low power, making them safe for lab use, but this limits the crystal size and working distance between the transmitter and receiver to under 1000 mm. The experimental setup suggested by the manufacturer separates the transmitter and receiver by about 10 wavelengths from the center of rotation. While the bells on the transmitter and receiver help with producing plane waves, it is expected that ideal conditions for Bragg's law are not completely fulfilled. Indeed, the experiment guide warns of errors up to 15% and unexplained peaks in the data.

Wildland fires have become a regular aspect of life for people living in the western United States. Wildfire smoke is now impacting air quality across the United States. Unprecedented wildfires have swept through Australia, Russia, and Portugal in the last few years. Like other natural disasters, wildland fires can have a devastating impact on communities that are directly in their paths. However, they also cast a much bigger footprint due to the smoke they release on a global scale. These smoke events can lead to health warnings, noticeable irritation to the lungs, and cancelled outdoor events. They have quickly become part of the life experience of many students around the world. Their connections to global climate change and environmental policy, juxtaposition as positive forces in ecosystem succession, and relationship to a wide variety of both simple and complex natural phenomena leave science teachers with an opportunity to frame myriad lessons within the context of wildfire. This article presents a series of such lessons, adaptable to various levels of physical or integrated science. This series of lessons was taught in 9th- and 10th-grade physical science classes with students who are regularly affected by intense wildfire smoke. The learning sequence would also be appropriate for general chemistry and physics courses and can be easily adapted to meet the academic level of the students. The lessons were adapted for online instruction in response to the COVID-19 pandemic.

Despite holding wide-ranging experiences with constant velocity and non-zero acceleration, students wrestling with physical science concepts struggle to demarcate the two distinct characteristics of motion. In fact, this prior experience and loose familiarity with associated terminology often act as an obstacle toward a deep and robust understanding of the distinction between velocity and acceleration foundational to meaningful learning of force and motion. Age-appropriate, decontextualized instruction serves to bypass these barriers as it engages students in analogous experiences divorced from science vocabulary that provide a concrete link for later science instruction.

This study investigates women's science identity development in physics and the physical sciences in higher education through a gender perspective. It arises from the real-life sociological issue of women's lower level of participation in physics and physical sciences in Ireland, where the gender gap is the highest of all science disciplines, according to the Higher Education Authority (HEA) reports of recent years. Twenty-nine undergraduate, graduate students, and postdoctoral researchers from four Dublin universities were interviewed to achieve an in-depth understanding of gender and science issues from their standpoints. The focus was on how they constitute their identities as a 'scientist' in relation to their gender. The result of this study illustrates a variety of possible science identity constitutions of women both from an individual and collective identity perspective. Understanding women's science identity development help brings a general view about developing a more welcoming and flexible science culture for individuals who think they do not fit well or who are left outside of the certain prevailing norms in the scientific climate. It also can allow seeking a way of challenging and changing the predominant culture and the prevailing masculine norms in doing science.

In the United States, research on beginning science teachers provides little guidance regarding empirical minimum levels of discipline-specific science coursework for sufficient subject matter knowledge to teach science. Accordingly, in this study we analyzed secondary physical science teachers' science coursework for subject matter knowledge (SMK) and resulting misconceptions of chemistry and physics concepts. Findings were compared with state-level science teacher certification policies. Participants had either: (a) completed a master's level teacher preparation program with an undergraduate degree in science, (b) completed an undergraduate teacher preparation program with a minor degree or more in science, or (c) were undergraduate students enrolled in science courses required for chemistry and physics teacher certification. We analyzed participants' transcripts for discipline-specific science coursework credit hours and GPAs and identified possible predictors of SMK predictors of the likelihood of passing chemistry and physics misconceptions tests. We categorized teachers' level of SMK and used multiple variable and logistic regressions (n = 212 participants; n = 109 chemistry and n = 103 physics). To identify teacher candidates' possible misconceptions, we analyzed chemistry (n = 97) and physics (n = 91) participants' item responses with the corresponding science credit hours and GPAs. With increasing numbers of credit hours teachers held fewer misconceptions. However, even with medium to high SMK levels, teachers still held misconceptions about chemical bonding, electromagnetism, and Newton's laws until they reached critical credit hour and GPA thresholds. Lastly, we provide recommendations for physical science teachers' programs of study and state-level teaching certification policies, using empirical minimum quantity and quality of chemistry, physics, and mathematics coursework.

Physics and physical science content are essential for many professional fields, and they are an important component of scientific literacy. Yet, students are commonly less engaged in physics learning at all levels. Funds of knowledge approaches to science instruction build upon learners' real-world experiences and interests in order to make science learning more relevant and engaging. This study investigates how college undergraduates' football experiences elicit physical science content knowledge with a larger goal of developing physical science instruction that better connects to learners. This exploratory interpretive study utilized individual interviews and a focus groups with 22 college students to elicit their ideas about a variety of common football contexts: kicking, pursuit, throwing, and football deflation. The analysis identified several physical science concepts elicited by particular football scenarios, particular football experiences that could be utilized in science instruction, and some misconceptions or points of confusion about physical science concepts. Implications for curricular development, teacher education, and research are provided.

We show how learning can be improved, beyond that shown in actively taught classrooms, by also transforming the homework using the principles of deliberate practice. We measure the impact of transforming the homework on student learning in a course that had already implemented an active approach to teaching in class. We compare performance on the same final exam in equivalent cohorts of students over three semesters of an introductory physics course: the first taught with traditional lectures and traditional homework, the second taught with active instruction coupled with traditional homework, and the last taught with both active instruction and transformed homework. We find students in the semester where both active teaching and transformed homework are used scored significantly higher on the final exam than the students taught actively but with traditional homework. This learning gain achieved by transforming the homework is comparable to that achieved by replacing traditional lectures with active teaching strategies in class. We further show the positive effects of transforming the homework on student learning through a shorter, controlled experiment. When everything but the homework implementation is controlled, students scored 5%-10% higher on a test of learning following transformed homework compared with traditional homework. This significant improvement to learning occurs despite students spending a similar amount of time on task. This study represents an initial step towards understanding how deliberate practice can be extended to improve pedagogy beyond what happens in the classroom to the out-of-class homework.

The National Academy of Science has published studies showing strong scientific evidence that global warming is caused by human consumption of fossil fuels, yet recent surveys have shown young adults in the U.S. are disengaged or disagree with this fact. Accordingly, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) published learning objectives to educate the world population on global warming and renewable energy by 2030. In this paper, we introduce a reflective writing activity physics educators can employ to foster a deeper understanding of global warming in introductory college physics and physical science courses, without overloading their teaching time.

Crystallography is a fascinating subject and an argument of great importance in the study of structure of matter and fundamental physics. Moreover, many characteristics of crystals, as well as other organic and inorganic substances, are analyzed with x-ray diffraction. In order to introduce at a basic level the above mentioned subjects, and also interference and diffraction of wave light, here we present some simple and new inexpensive optical experiments, analogous to the Laue diffraction of x-rays and electrons. We also propose an elementary geometric model to explain the two-dimensional pattern of diffractions by grating.

Many large-lecture introductory science courses for nonscience majors do not have a lab component and hence do not provide much opportunity for students to engage in the practice of science. I have developed a new instructional activity called Dorm Room Labs that enables students to conduct hands-on activities as homework (or dorm room work) to explore more deeply concepts covered in 100-level science courses. The labs focus on concepts relevant to many physical science courses and consist of no-cost or low-cost lab equipment or their smartphones, enabling their use in large-enrollment courses. Using qualitative research methods, I have found that these dorm room experiments have meaningful impact on the development of students' conceptual understanding of several important physics and space science topics. For example giving the students a magnet and compass (or using the student's own smartphone magnetometer) fosters the understanding of the structure of dipole magnetic fields. Dorm Room Labs help engage and motivate students to learn about the process and culture of science by having them "do" science.

This paper describes the results of a comparative study into the approaches used by science undergraduates when solving open-ended problems. This study adopted a pseudo-grounded theory framework to analyse six case studies, one from each of the science disciplines studied. The study involved 70 participants from 5 institutions solving open-ended problems using a think-aloud protocol. Analysis of the data identified a number of different approaches used by each subject group. Participants in psychology, pharmacy and sports rehabilitation used a greater number of novice-like approaches than participants in chemistry, physics and interdisciplinary science. The approaches used by physical science participants were very similar whereas those from pharmacy, sports rehabilitation and psychology were more varied and relied on students' ability to relate to a familiar context. Evaluation of the relative quality of solutions showed variation with discipline.

On graduation, teacher candidates (TCs) are typically underprepared to teach science, particularly physical science, whereas physics graduates frequently lack training in teaching or effective communication. In response, we created two models for interdisciplinary peer learning where TCs were paired with either graduate or undergraduate physics students. In both models, physics students teach TCs content knowledge relevant to a given area of either classical or quantum physics, which TCs then use to design and implement a short lesson for K-5 students. Overall, both models were successful, with the two sets of students reporting benefits in each case. Affordances for TCs included increased confidence to teach physical science and an appreciation for collaboration with experts. Physics students described increased awareness of the complexities of communicating science to general audiences and stronger community with their classmates. Students from both groups cited insufficient project time as a constraint, whereas physics students found it challenging to align their project and coursework. In moving away from traditional lecture, these interdisciplinary collaborations also benefitted us as instructors, giving us new perspectives on teaching. In light of our findings we propose improvements to these proof-of-concept models to enable their future scale-up and replication in other disciplines.

The concept of wave-particle duality in quantum theory is difficult to grasp because it attributes particle-like properties to classical waves and wave-like properties to classical particles. There seems to be an inconsistency involved with the notion that particle-like or wave-like attributes depend on how you look at an entity. The concept comes into more clear focus with the precise language of mathematics and with an experiment or demonstration of quantum interference that involves the scattering of photons by a single slit. After describing a photon as a quon, a quantum-sized entity, a precise description of the interference of quantum probability amplitudes allows determination of the photon wavelength by classical measurements of laboratory observations.

I report an innovation that provides a compelling demonstration of rocket propulsion, appropriate for students of physics and other physical sciences. An electrical spark is initiated from a distance to cause the deflagration of a combustible vapor mixed with air in a lightweight plastic bottle that is consequently propelled as a rocket by the release of combustion products, i.e., a "whoosh rocket." My recommendation is that the standard fuel for pedagogical whoosh demonstrations be isopropanol, and the recommended vessel is the 3.8-L high-density polyethylene (HDPE) bottle.

Background: Mentoring supports professional success in a myriad of fields; in the physical sciences, mentoring increases the retention of diverse groups of students. While physics education has made progress in classifying the availability and structural components related to mentoring programs, little is known about the qualitative nature of mentoring relationships. This article draws from frameworks in science identity and belongs to analyze the nature of relationships in the mentoring program offered by the Sundial Project at Arizona State University, which aims to help new students with diverse backgrounds succeed in physics and related majors. To provide insight into mentoring relationships, we analyze over 150 reports submitted by mentors and mentees in a near-peer mentoring program. Results: Mentoring groups enjoyed positive rapport and often remarked upon becoming friends. As such, mentoring relationships provided mentees with both psychosocial and academic support. Mentoring supported students to deal with a wide variety of topics, ranging from academic to personal, according to the needs of individual mentees. Moreover, outcomes of students in the mentoring program were favorable; the mean GPA of participating mentees was 3.49 for their first college semester. Conclusions: Mentors acted both as guides who shared information and as caring friends who providing psychosocial support, including normalizing struggle. These connections supported students to develop a sense of belonging and positive science identities.

For more than a century the notion of a pre-established harmony between the mathematical and physical sciences has played an important role not only in the rhetoric of mathematicians and theoretical physicists, but also as a doctrine guiding much of their research. Strongly mathematized branches of physics, such as the vortex theory of atoms popular in Victorian Britain, were not unknown in the nineteenth century, but it was only in the environment of fin-de-siècle Germany that the idea of a pre-established harmony really took off and became part of the mathematicians' ideology. Important historical figures were in this respect David Hilbert, Hermann Minkowski and, somewhat later, Albert Einstein. Roughly similar ideas can be found also among British theorists, among whom Arthur Eddington, Arthur Milne, and Paul Dirac are singled out. Although largely limited to the period 1870-1940, the paper also considers Max Tegmark's recent hypothesis of the universe (or multiverse) being a one-to-one reflection of mathematical structures.

Research shows that women are entering the field of physics at a faster rate than the field of chemistry through bachelor's and doctoral degrees. However, STEM studies primarily compare women to men or examine them as a single entity. Therefore, a paucity of research exists that examines what may differentiate women in certain critical and underrepresented fields of STEM education, such as the physical sciences. The focus of this study is to examine differences among women in chemistry in the physical sciences based on background demographics and motivational factors such as academic achievement and experiences ranging from secondary through postsecondary education. This study examines the following research question: "On average, do females who select chemistry as compared to physics doctoral programs differ in their reported personal motivations and background factors prior to entering the field?" This question is analyzed using variables in a logistic regression from the Project Crossover Survey data set through a subset of female physical science doctoral students and scientists (n = 1137). Results show that females who have higher secondary and postsecondary grades and positive experiences in postsecondary chemistry as well as negative postsecondary physics experiences are more likely to enter the field of chemistry as opposed to physics. Therefore, success and experiences in entry-level chemistry courses are critical for female entry into the field and should be further examined. Overall, analyses show that women should not be studied in comparison only to men or as a single entity; they should also be compared to one another to uncover what motivation and background variables influence them to enter a particular field.

Using the Sun to tell time is an ancient idea, but we can take advantage of modern technology to bring it into the 21st century for students in astronomy, physics, or physical science classes. We have employed smartphones, Google Earth, and 3D printing to find the moment of local noon at two widely separated locations. By reviewing GPS time-stamped photos from each place, we are able to illustrate that local noon is longitude-dependent and therefore explain the need for time zones.

This article describes an activity appropriate for middle or high school physics or physical science students. Rather than giving the answer to the question "How does a milliliter compare to a cubic centimeter?" the students develop a procedure for measuring volume by calculation and by displacement of water. Students share the data and use graphical analysis to determine how a milliliter compares to a cubic centimeter. This procedure can be adapted to other quantities. Concepts include measurement, volume, graphical analysis of data, and measurement units.

Mitochondria serve a wide range of functions within cells, most notably via their production of ATP. Although their morphology is commonly described as bean-like, mitochondria often form interconnected networks within cells that exhibit dynamic restructuring through a variety of physical changes. Further, though relationships between form and function in biology are well established, the extant toolkit for understanding mitochondrial morphology is limited. Here, we emphasize new and established methods for quantitatively describing mitochondrial networks, ranging from unweighted graph-theoretic representations to multi-scale approaches from applied topology, in particular persistent homology. We also show fundamental relationships between mitochondrial networks, mathematics, and physics, using ideas of graph planarity and statistical mechanics to better understand the full possible morphological space of mitochondrial network structures. Lastly, we provide suggestions for how examination of mitochondrial network form through the language of mathematics can inform biological understanding, and vice versa.

Noninvasive imaging of endogenous retinal fluorophores, including vitamin A derivatives, is vital to developing new treatments for retinal diseases. Here, we present a protocol for obtaining in vivo two-photon excited fluorescence images of the fundus in the human eye. We describe steps for laser characterization, system alignment, positioning human subjects, and data registration. We detail data processing and demonstrate analysis with example datasets. This technique allays safety concerns by allowing for the acquisition of informative images at low laser exposure. For complete details on the use and execution of this protocol, please refer to Bogusławski et al. (2022).1.

Among about a thousand objects obtained by the Science Museum from Stephen Hawking's office is a blackboard full of cartoons and puns, both childishly silly and deeply scientifically meaningful. This blackboard is now one of the Museum's most popular objects thanks to its playful imagery and perhaps also its perceived fragility. But it is also one of the objects that best illustrates the scientific life of Stephen Hawking and his generation, and more broadly, it is an exemplar of the social and material culture of the postmodern epoch of theoretical physics in the decades around the turn of the twenty-first century. In this article, the curator of the Hawking Collection explains the importance of this blackboard, first through an account of its unexpected trajectory to becoming the Hawking Collection's most charismatic object, followed by a discussion of the general historical role of blackboards: their iconography, material culture, and value as historical sources and how their conservation requirements contribute to their perceived value. The author then delves deeper into the specific content of this blackboard, showing how it constitutes a window into the highs and lows of a generation of physicists inspired by Hawking's work, as they attempted, and ultimately failed, to unify the two great theories of the twentieth century: general relativity and quantum mechanics. What we now call the superspace and supergravity blackboard is a microcosm of one of those moments in physics when theory broke away from what was empirically verifiable. The scribblings on the blackboard were collectively drawn by an up-and-coming generation of supersymmetry theorists. It immortalises the promising early years of supergravity, one of the hopeful candidates at the time for the long-wished-for Theory of Everything. Preserved in chalk are the seeds of one of the most brilliant theoretical discoveries of the turn of the century: what is now called the holographic principle. But also, seen with the benefit of hindsight, supersymmetric approaches seeded the identity crisis that theoretical physics is experiencing today, especially around the role of empirical anchoring of proposed fundamental theories. The contested status of the blackboard's content and its humorous, self-ironic style, make it a key piece of a unique zeitgeist of physics at the turn of the twenty-first century, which one could call the era of postmodern physics. In addition to its significance to the history of specific ideas, this paper also argues that the blackboard reflects the collective, social nature of theoretical research, while also inviting reflection on what constitutes success and failure in the physical sciences. [ABSTRACT FROM AUTHOR]

Physics-based and first-principles models pervade the engineering and physical sciences, allowing for the ability to model the dynamics of complex systems with a prescribed accuracy. The approximations used in deriving governing equations often result in discrepancies between the model and sensor-based measurements of the system, revealing the approximate nature of the equations and/or the signal-to-noise ratio of the sensor itself. In modern dynamical systems, such discrepancies between model and measurement can lead to poor quantification, often undermining the ability to produce accurate and precise control algorithms. We introduce a discrepancy modeling framework to identify the missing physics and resolve the model-measurement mismatch with two distinct approaches: (i) by learning a model for the evolution of systematic state-space residual, and (ii) by discovering a model for the deterministic dynamical error. Regardless of approach, a common suite of data-driven model discovery methods can be used. Specifically, we use four fundamentally different methods to demonstrate the mathematical implementations of discrepancy modeling: (i) the sparse identification of nonlinear dynamics, (ii) dynamic mode decomposition, (iii) Gaussian process regression, and (iv) neural networks. The choice of method depends on one's intent (e.g., mechanistic interpretability) for discrepancy modeling, sensor measurement characteristics (e.g., quantity, quality, resolution), and constraints imposed by practical applications (e.g., state- or dynamical-space operability). We demonstrate the utility and suitability for discrepancy modeling using the suite of data-driven modeling methods on four dynamical systems under varying signal-to-noise ratios. Finally, we emphasize structural shortcomings of each discrepancy modeling approach depending on error type. In summary, if the true dynamics are unknown (i.e., an imperfect model), one should learn a discrepancy model of the missing physics in the dynamical space. Yet, if the true dynamics are known yet model-measurement mismatch still exists, one should learn a discrepancy model in the state space. [ABSTRACT FROM AUTHOR]

This paper reviews the ecosystem of GATE, an open-source Monte Carlo toolkit for medical physics. Based on the shoulders of Geant4, the principal modules (geometry, physics, scorers) are described with brief descriptions of some key concepts (Volume, Actors, Digitizer). The main source code repositories are detailed together with the automated compilation and tests processes (Continuous Integration). We then described how the OpenGATE collaboration managed the collaborative development of about one hundred developers during almost 20 years. The impact of GATE on medical physics and cancer research is then summarized, and examples of a few key applications are given. Finally, future development perspectives are indicated.

DNA supercoils are generated in genome regulation processes such as transcription and replication and provide mechanical feedback to such processes. Under tension, a DNA supercoil can present a coexistence state of plectonemic and stretched phases. Experiments have revealed the dynamic behaviors of plectonemes, e.g., diffusion, nucleation, and hopping. To represent these dynamics with conformational changes, we demonstrated first the fast dynamics on the DNA to reach torque equilibrium within the plectonemic and stretched phases, and then identified the two-phase boundaries as collective slow variables to describe the essential dynamics. According to the timescale separation demonstrated here, we developed a two-phase model on the dynamics of DNA supercoiling, which can capture physiologically relevant events across timescales of several orders of magnitudes. In this model, we systematically characterized the slow dynamics between the two phases and compared the numerical results with those from the DNA polymer physics-based worm-like chain model. The supercoiling dynamics, including the nucleation, diffusion, and hopping of plectonemes, have been well represented and reproduced, using the two-phase dynamic model, at trivial computational costs. Our current developments, therefore, can be implemented to explore multiscale physical mechanisms of the DNA supercoiling-dependent physiological processes.

A new paradigm for data-driven, model-agnostic new physics searches at colliders is emerging, and aims to leverage recent breakthroughs in anomaly detection and machine learning. In order to develop and benchmark new anomaly detection methods within this framework, it is essential to have standard datasets. To this end, we have created the LHC Olympics 2020, a community challenge accompanied by a set of simulated collider events. Participants in these Olympics have developed their methods using an R&D dataset and then tested them on black boxes: datasets with an unknown anomaly (or not). Methods made use of modern machine learning tools and were based on unsupervised learning (autoencoders, generative adversarial networks, normalizing flows), weakly supervised learning, and semi-supervised learning. This paper will review the LHC Olympics 2020 challenge, including an overview of the competition, a description of methods deployed in the competition, lessons learned from the experience, and implications for data analyses with future datasets as well as future colliders.

Although physics does not often veer into financial concerns, it is an illuminating exercise to try estimating the value of a barren planet at market prices for dirt, rock, water, copper, aluminum, silver, gold, etc. Energy perspectives Physics "owns" energy (and space and time if we're being greedy), so energy and power domains offer rich opportunities for gaining new understanding. The thermodynamic consequences of this absurdity can also be examined, by which it is revealed that waste heat from all this energy production on Earth would rival climate change in a century and be 10 times worse a century after that, eventually boiling Earth's oceans in about 400 yr.[3] It can be tricky to convey to students that this is not a I prediction i of what I will i - or even I can i - happen, but a tool to understand I limits i to what is possible and what I cannot i transpire. [Extracted from the article]

In my context, such a class might be a general physics course for science majors (pre-calculus- or calculus-based) or an algebra-based, mostly conceptual survey course for non-science majors, with between 8 and 30 students per class. Homework assignments, reflections, surveys, and biweekly anonymous feedback from 2017 onward (excepting 2020) from general physics courses for science majors and for non-science majors indicate enhanced interest in physics, greater cognitive understanding of climate science basics, increased appreciation of the value of climate stories and justice issues, ability to think critically about proposed climate solutions, and, for the majority of students (in some classes greater than 80%), a desire to take meaningful action for climate justice. Today, I still teach the basic science of climate change as it aligns with physics topics in my general physics courses. [Extracted from the article]

The goal of immunotherapy is to mobilize the immune system to kill cancer cells. Immunotherapy is more effective and, in general, the prognosis is better, when more immune cells infiltrate the tumor. We explore the question of whether the spatial distribution rather than just the density of immune cells in the tumor is important in forecasting whether cancer recurs. After reviewing previous work on this issue, we introduce a novel application of maximum entropy to quantify the spatial distribution of discrete point-like objects. We apply our approach to B and T cells in images of tumor tissue taken from triple negative breast cancer patients. We find that the immune cells are more spatially dispersed in good clinical outcome (no recurrence of cancer within at least 5 years of diagnosis) compared to poor clinical outcome (recurrence within 3 years of diagnosis). Our results highlight the importance of spatial distribution of immune cells within tumors with regard to clinical outcome, and raise new questions on their role in cancer recurrence.

Even as the physical sciences have advanced and transformed, many of the community's needs and concerns have persisted. [ABSTRACT FROM AUTHOR]

The transverse momentum (pT) spectra of inclusively produced Λc+ baryons are measured via the exclusive decay channel Λc+→pK−π+ using the CMS detector at the LHC. Spectra are measured as a function of transverse momentum in proton-proton (pp) and lead-lead (PbPb) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The measurement is performed within the Λc+ rapidity interval |y|

The running of the top quark mass is experimentally investigated for the first time. The mass of the top quark in the modified minimal subtraction (MS‾) renormalization scheme is extracted from a comparison of the differential top quark-antiquark (tt¯) cross section as a function of the invariant mass of the tt¯ system to next-to-leading-order theoretical predictions. The differential cross section is determined at the parton level by means of a maximum-likelihood fit to distributions of final-state observables. The analysis is performed using tt¯ candidate events in the e± μ∓ channel in proton-proton collision data at a centre-of-mass energy of 13 TeV recorded by the CMS detector at the CERN LHC in 2016, corresponding to an integrated luminosity of 35.9fb−1. The extracted running is found to be compatible with the scale dependence predicted by the corresponding renormalization group equation. In this analysis, the running is probed up to a scale of the order of 1 TeV.

A search in an all-jet final state for new massive resonances decaying to W W , W Z , or Z Z boson pairs using a novel analysis method is presented. The analysis is performed on data corresponding to an integrated luminosity of 77.3 fb - 1 recorded with the CMS experiment at the LHC at a centre-of-mass energy of 13  Te . The search is focussed on potential narrow-width resonances with masses above 1.2  Te , where the decay products of each W or Z boson are expected to be collimated into a single, large-radius jet. The signal is extracted using a three-dimensional maximum likelihood fit of the two jet masses and the dijet invariant mass, yielding an improvement in sensitivity of up to 30% relative to previous search methods. No excess is observed above the estimated standard model background. In a heavy vector triplet model, spin-1 Z ' and W ' resonances with masses below 3.5 and 3.8   Te , respectively, are excluded at 95% confidence level. In a bulk graviton model, upper limits on cross sections are set between 27 and 0.2 fb for resonance masses between 1.2 and 5.2   Te , respectively. The limits presented in this paper are the best to date in the dijet final state.

A combination of four searches for new physics involving signatures with at least one photon and large missing transverse momentum, motivated by generalized models of gauge-mediated supersymmetry (SUSY) breaking, is presented. All searches make use of proton-proton collision data at s=13 TeV, which were recorded with the CMS detector at the LHC in 2016, and correspond to an integrated luminosity of 35.9 fb−1. Signatures with at least one photon and large missing transverse momentum are categorized into events with two isolated photons, events with a lepton and a photon, events with additional jets, and events with at least one high-energy photon. No excess of events is observed beyond expectations from standard model processes, and limits are set in the context of gauge-mediated SUSY. Compared to the individual searches, the combination extends the sensitivity to gauge-mediated SUSY in both electroweak and strong production scenarios by up to 100 GeV in neutralino and chargino masses, and yields the first CMS result combining various SUSY searches in events with photons at s=13 TeV.

A search for WW production from double-parton scattering processes using same-charge electron-muon and dimuon events is reported, based on proton-proton collision data collected at a center-of-mass energy of 13TeV. The analyzed data set corresponds to an integrated luminosity of 77.4fb-1, collected using the CMS detector at the LHC in 2016 and 2017. Multivariate classifiers are used to discriminate between the signal and the dominant background processes. A maximum likelihood fit is performed to extract the signal cross section. This leads to the first evidence for WW production via double-parton scattering, with a significance of 3.9 standard deviations. The measured inclusive cross section is 1.41±0.28(stat)±0.28(syst)pb.

Measurements of the cross sections for the production of single top quarks and antiquarks in the t channel, and their ratio, are presented for proton-proton collisions at a center-of-mass energy of 13 TeV. The data set used was recorded in 2016 by the CMS detector at the LHC and corresponds to an integrated luminosity of 35.9 fb−1. Events with one muon or electron are selected, and different categories of jet and b jet multiplicity and multivariate discriminators are applied to separate the signal from the background. The cross sections for the t-channel production of single top quarks and antiquarks are measured to be 130±1(stat)±19(syst)pb and 77±1(stat)±12(syst)pb, respectively, and their ratio is 1.68±0.02(stat)±0.05(syst). The results are in agreement with the predictions from the standard model.