Revista Mexicana de Física E

Electromagnetic fields with symmetry

Gerardo Francisco Torres del Castillo — 2024-07-01

We show that if an electromagnetic field is invariant under translations or rotations, three of the six components of the field can be expressed in terms of a (gauge-invariant) scalar potential which is also invariant under these transformations. This scalar potential appears in the constant of motion associated with this symmetry for a charged test particle in this field. We also show that the Cartesian components of the electromagnetic field can be combined to form two SO(2, 1) vectors

Perturbations of planetary orbit parameters due to decreasing in stellar mass and the expansion of the universe from a classical approach

Juan D. Fonseca — 2024-07-01

In this analysis we found the disturbances caused by the decrease in stellar mass and the expansion of the universe, to three fundamental parameters that represented the stability of a planetary orbit: the period, the semi-major axis and the eccentricity. First, by assuming much greater the mass of the star than the planetary, the star-planet interaction is reduced to a single-body problem with origin of reference system lying in the greater mass; and, through the mathematical formalism of the central forces, the variations of the three orbital parameters to be considered were obtained. As a result, the variations corresponding to the period and semi-major axis have been characterized in their mathematical structure by the terms that describe each phenomenon; namely, ξ ∼ 2.16 × 10−21 for the case of Sun, and ̈α/α ∼ 3 × 10−36 concerning the decrease in stellar mass and the expansion of the universe, respectively. In the case of eccentricity, it is shown that this parameter is an invariant quantity under the disturbances produced by these two cosmological phenomena.

Visualization of non-linear continuous wave dispersion effects on fiber grating with spreadsheets in online learning

Sabarudiin — 2024-07-01

Spreadsheet software is a practical and straightforward computing and graphics tool. The use of Spreadsheets can reduce the risk of practicum in class and can be used remotely. This research presents a simple way to build a physics simulation based on mathematical equations in spreadsheet software. The simulation aims to visualize the effect of non-linear continuous wave dispersion on fiber gratings. Simulations can visualize different modes. The mathematical equations in fiber optics for non-linear effects are quite complex. Visualization can assist students in interpreting mathematical equations and making connections between theoretical and experimental modeling.

Measuring student mathematical representation abilities in physics on heat and temperature topic: Learning mode and gender

Dewi Fairuz Zulaikha — 2024-07-01

This research examined an in-depth analysis of students' MRAP: (1) the students’ MRAP score in each sub-topic (temperature, expansion, heat, heat transfer); (2) the students’ MRAP score in terms of learning mode (online and offline); (3) the students’ MRAP level based on gender. The study used the survey method as a quantitative approach. The study sample consisted of 260 grade 11 students from three public senior high schools in Yogyakarta, Indonesia, with low, medium, and high ability levels. The Mann-Whitney U test was performed to determine if there was a statistically significant difference in the pupils' test results by learning mode and gender. The study’s findings concluded that the students’ scores in each sub-topic of temperature, expansion, heat, and heat transfer are 67.66; 63.67; 56.86; and 60.43; respectively. There are significant differences in students’ mathematical representation abilities in physics between students learning modes (offline and online learning. At the same time there are no significant differences in students’ mathematical representation abilities in physics between males and females.

Modeling damped spring vibration using python to train students' critical thinking and scientific reasoning

Semiono Raharjo — 2024-07-01

Programming has been carried out to model the vibration of a mass spring system with no damping and with damping variations using Python programming language coding. This research aims to simulate the simple harmonic vibration of a mass spring (without damping) and the vibration of a damped mass spring. The programming is designed after formulating the equations of motion of damped mass spring vibrations that behave as second-order differential equations and analyzing the numerical formulation of the Feynman-Newton algorithm arrangement. The method used is experimentation using python to simulate the vibration of the spring. Simulation by varying the damping constant (c = 0, c < √4mk, c = √4mk, and c > √4mk). The simulation results show various vibration graphs, namely simple harmonic vibration, under damped vibration, critically damped vibration, and over damped vibration. The shape of the vibration graph is influenced by the mass, spring constant, and damping constant. The greater the damping constant, the less the maximum speed of vibration. This research has succeeded in visualizing the simple harmonic vibration of a massless spring (without damping) and the vibration of a damped massless spring. This modeling can help the physics learning process in high school in understanding the concept of spring vibration to obtain critical reasoning in accordance with physical phenomena. Modeling of damped spring vibrations using Python can be used as a physics learning media on vibration material to train scientific and critical reasoning skills, and as a learning innovation because it is a new thing where the curriculum and high school learning in Indonesia are not used to being delivered.

Aparato para realizar experimentos de Fluorescencia de Rayos X y de pérdida de energía de partículas α en un laboratorio de Física a nivel licenciatura

Juan Antonio Mendoza-Flores — 2024-07-01

Se describen el diseño y el funcionamiento de un dispositivo para realizar experimentos de espectrometrías de rayos X y de partículas cargadas, en un laboratorio avanzado de enseñanza de Física, a nivel licenciatura. Se presentan dos experimentos que pueden llevarse a cabo en seis sesiones de tres horas, cada uno. La primera práctica se refiere a la medición de probabilidades de transiciones radiativas de vacantes con fluorescencia de rayos X, usando la radiación γ producida por una fuente de ²⁴¹Am para inducir la emisión de rayos X K de elementos lantanoides. En el segundo experimento se mide el espesor de una muestra delgada de un polímero, mediante la pérdida de energía de partículas α emitidas por una fuente triple de ²³⁹Pu-²⁴¹Am-²⁴⁴Cm al atravesar el blanco. Con esto, los alumnos reciben una introducción a las técnicas de vacío, manejo de fuentes radiactivas, detectores de radiación ionizante y electrónica nuclear, así como también se muestra la importancia del cálculo de incertidumbres y errores experimentales.

The design and operation of a device for conducting X-ray and charged particle spectrometry experiments in an advanced Physics teaching laboratory at the undergraduate level are described. Two experiments are presented that can be carried out in six sessions of three hours each. The first practice concerns the measurement of probabilities of radiative transitions of vacancies with X-ray fluorescence, using the γ radiation produced by a ²⁴¹Am source to induce the emission of K X-rays from lanthanoid elements. In the second experiment, the thickness of a thin sample of a polymer is measured through the energy lost by α particles emitted by a ²³⁹Pu-²⁴¹Am-²⁴⁴Cm triple source when passing through the target. With this, students receive an introduction to vacuum techniques, radioactive sources handling, ionizing radiation detectors, and nuclear electronics, as well as the importance of evaluating experimental uncertainties and errors.

An introduction to semi-automated matrix element computation in particle physics

Aman Desai — 2024-07-01

This paper presents a semi-automated method to compute matrix elements at the Leading Order and the Next-to-Leading Order in the ABC model of particle physics. The ABC model consists of three scalar particles and they interact only when all three particles are present in the interaction. In the Next-to-Leading Order calculations, one often has to deal with ultraviolet divergences. Some of the techniques such as Wick’s rotation, Feynman parameterisation, and dimensional regularization which are useful in Next-to-Leading Order computations are presented by applying them on the ABC model calculations and also implemented in python based programs using Computer Algebra System.

Interaction in the classroom based on typologies of experiments and mathematization in physics teaching

Olga Lucía Castiblanco Abril — 2024-07-01

Changing the traditional approach to experimentation in science teaching poses a significant challenge. This research discusses the characterization of physics experiments, not solely based on the topics they cover, or the materials used in their setups, but rather in terms of the opportunities they offer to enhance classroom interaction and, consequently, contribute to the development of scientific thinking skills. This study is an action-research intervention in the classroom, involving four groups of undergraduate physics students from a public university in Bogotá, Colombia. This process allowed us to categorize experiment typologies, including discrepant, homemade, illustrative, research-based, recreational, crucial, mental, and virtual experiments. The most relevant data were derived from students’ productions and researchers’ reports after each class. Through content analysis techniques, we were able to categorize the information and derive insights into the richness that each experiment typology brings to classroom interactions. The results reveal shifts in the perception of the role of new teachers, who are no longer seen as mere possessors and transmitters of truth. They now comprehend strategies for effectively engaging students as the class progresses, fostering the exchange of ideas, reflections, debates, and questions among students themselves, their peers, and the teacher.

Materia, espacio, tiempo y campos: una reflexión sobre los conceptos fundamentales de la física clásica

Miguel Ángel Ocampo — 2024-07-01

Se presenta una reflexión sobre los conceptos de materia, espacio, tiempo y campos, sobre los que se fundamentan las descripciones de la física clásica. Se enfatizan el papel de la experiencia humana para su consolidación y la importancia de observar su establecimiento bajo una idea de concomitancia; la comprensión de dichos conceptos requiere reconocer que son inseparables y complementarios.

A reflection on the concepts of matter, space, time and fields, on which the descriptions of classical physics are based, is presented. The role of human experience for its consolidation and the importance of observing its establishment under an idea of concomitance are emphasized; understanding these concepts requires recognizing that they are inseparable and complementary.

Physical reality

Jesús Valdés-Hernández — 2024-07-01

The principle of non-locality, or the existence of systems of particles with properties that relate them even at great distances, are called entangled systems and defy the intuition that requires all relationships to be described by means of energy exchange or by material links, quantum physics presents non-locality as a consequence of objects being described by a single wave function and as such unless they decohere (losses its nonphysical link), the relationship remains, and each cannot be understood separately. Recently, there have been many technological models that can produce entangled systems. In addition to the examples that submicroscopic physics can illustrate, the simplest is spontaneous parametric fluorescence, which requires a laser and a parametric crystal that has allowed very elaborate experiments to be carried out and shows the relevance of quantum physics and the limitations of our perception. The examples described here have emerged over the years as attempts to make this concept more acceptable and try to guide the imagination to situations where these types of phenomena can be plausible and point to human perception with the duality of bringing us closer to the appreciation of nature, but at the same time, it is the main limitation to appreciate and understand nature. The relevance of this concept was recognized with the Nobel Prize 2022 in physics, and it can be summarized as the Proof of the Bell inequality using anecdotes from a Nobel non-recipient.

Charged particle reflection in a magnetic mirror

Luis Ángel Fernández — 2024-07-01

We study the reflection of electrons in a magnetic field mirror. It is a field with a gradient from a lowest value B₀ to a largest one B_m. With this purpose, Montecarlo simulations are made. We use a number of 5,000 particles with random pitch angles. The frequency distribution of these random values follows a Gaussian distribution centered at \theta = 0 and with standard deviation \sigma. Various values of \sigma and also different values of the B₀ /B_m ratio are used in the simulations. The simulations show that \sigma has an important influence on the confinement of charged particles, for the different B₀ /B_m ratios here studied. However, the percent of reflected particles differs from a B₀ /B_m ratio to another in the whole range of \sigma, although for \sigma = 10 the differences between different ratios are small (<5%). The number of reflected particles increases very rapidly with \sigma, in the range of 10° to 40^°. For the \sigma range from 20^° to 40^°, the percent of reflected particles is \leq 20% larger for B₀ /B_m = 0.10 than for the 0.55 ratio.

A variational approach to ground state energy estimation in relativistic quantum systems

Felan Amal — 2024-07-01

The variational method in quantum mechanics plays a crucial role in estimating upper bound values of eigenenergies, particularly in the efficient determination of ground state energies. This paper introduces a formalism for the calculation of ground state energies in relativistic quantum systems employing the variational method. The proposed approach is applied to specific physical systems, allowing us to evaluate its effectiveness. Furthermore, we compare the results obtained through this method with existing literature, shedding light on its accuracy and applicability in the context of relativistic quantum systems.

Gravity train of variable mass

Yuji Kajiyama — 2024-07-01

The gravity train is a virtual vehicle that travels in a tunnel across Earth, and its motion due to only gravity is a simple harmonic oscillator. It can run at a constant velocity by appropriately exhausting fuel. In this case, the train obeys the equation of motion for a variable mass system. We discuss the mass and energy reduction of the gravity train during travel and find the optimal conditions for economical travel. This study is suitable for university students in physics classes.

The propagator of the inverted Caldirola-Kanai Oscillator

Umpon Jairuk — 2024-07-01

In this paper, we will derive the propagators for an inverted Caldirola-Kanai oscillator by the Feynman path integral, the Schwinger method, and the Dodonov method. In Feynman path inte-gral, the propagator can be calculated from the functional integrals while in the Schwinger method the propagator can be obtained from basic operator algebra and elementary integrations. In Dodonov method, the propagator can be derived from the application of the integrals of the motion of quantum systems. Furthermore, the connection between these methods is also discussed.

Calibración de la unidad de medida inercial de un dispositivo móvil

C. D. Tobar — 2024-07-01

En este artículo se propone un método para la calibración del acelerómetro y del giróscopo de una unidad de medida inercial (UMI), el cual se basa en muestras de señales de aceleración, velocidad, y orientación. La calibración de cada uno de los dos componentes de la UMI requiere estimar nueve parámetros; tres asociados a errores de no ortogonalidad entre los ejes coordenados, otros tres derivados del sesgo del instrumento en las tres direcciones espaciales, y los tres restantes corresponden a las diferencias de los ejes coordenados en cuanto a sus factores de conversión entre valores medidos y unidades físicas. El procedimiento propuesto, el cual encuentra cada vector de nueve parámetros utilizando un algoritmo de optimización basado en el principio de los mínimos cuadrados, se aplicó a un teléfono móvil Samsung Galaxy A32.

This paper proposes a method for the calibration of the accelerometer and gyroscope of an inertial measurement unit (IMU), which is based on samples of acceleration, velocity, and orientation signals. The calibration of each of the two components of the IMU requires the estimation of nine parameters; three associated with non-orthogonality errors between the coordinate axes, three others derived from the bias of the instrument in the three spatial directions, and the remaining three correspond to the differences of the coordinate axes in terms of their conversion factors between measured values and physical units. The proposed procedure, which finds each nine-parameter vector using an optimization algorithm based on the principle of least squares, was applied to a Samsung Galaxy A32 cell phone.

Aspectos básicos de Supergravedad N=1 (D=4)

Justiniano Lorenzo Díaz Cruz — 2024-07-01

En este trabajo revisamos brevemente supergravedad N = 1 en cuatro dimensiones (D = 4), también llamada supergravedad pura, donde la acción es invariante bajo transformaciones de norma y de supersimetría global. Nuestro propósito es alentar a los estudiantes de licenciatura a estudiar la teoría de supergravedad, en particular presentando la demostración explícita de estas invarianzas.

In this work we briefly review N = 1 supergravity in four dimensions (D = 4), also known as pure supergravity, where the action is invariant under gauge and global supersymmetry transformations. Our purpose is to encourage undergraduate students to study the theory of supergravity, in particular by presenting the explicit demonstrations of these invariances.

An experiment for the study of projectile motion

Milan Kovačević — 2024-07-01

The classic demonstration experiment of the motion of a point mass thrown at an angle to the horizon is studied. Several measurements of the range of a projectile launched sphere are carried out and compared with the results that were obtained by an analytical approach. The sphere’s motion can be treated as two independent movements, a linear uniform movement in the horizontal direction and a uniformly accelerated motion in the vertical direction. The value of launching velocity obtained by kinematics is compared with those predicted by the law of mechanical energy conservation. The conclusion is that the model of a frictionless sliding sphere is far from explaining the experimental result. The model could be improved proposing that the sphere rolls without sliding (pure rolling) on the platform including the rotational kinetic energy. Finally, the fact that the sphere does not settle completely on the launch rail was considered using an effective radius of rotation. Observed from the three proposed models, the last one is the closest to the obtained experimental value. These activities can also improve students’ understanding of the concept of projectile motion.

Mathematica para entender la aritmética del color

Pablo Moreira — 2024-07-01

El trabajo propone una manera visual de entender la aritmética del color usando el software Mathematica y las leyes de Grassmann. El uso de Mathematica permite visualizar estas leyes de una manera que sería difícil . La representación vectorial de las leyes de Grassmann es una herramienta valiosa para la docencia y el aprendizaje de la teoría del color, debido que permite a los estudiantes comprender cómo funciona la aritmética del color de una manera intuitiva.
La metodología propuesta utiliza Mathematica para crear una representación visual de las leyes de Grassmann. Comprender los conceptos matemáticos involucrados, permite que mediante el uso de software como Mathematica puede hacer que la aritmética del color sea más fácil de entender y usar.

The work proposes a visual way to understand color arithmetic using the Mathematica software and the Grassmann laws. The use of Mathematica allows to visualize these laws in a way that would be difficult to do otherwise.
The vector representation of the Grassmann laws is a valuable tool for teaching and learning color theory, as it allows students to understand how color arithmetic works in an intuitive way.

The proposed methodology uses Mathematica to create a visual representation of the Grassmann laws. Understanding the mathematical concepts involved allows the use of software such as Mathematica to make color arithmetic easier to understand and use.

Simulation of Gaussian wave packets used to illustrate elementary quantum mechanics scenarios

F. Guzmán-Cajica — 2024-07-01

In this paper we numerically solve the time dependent Schrödinger equation for scenarios using wave packets. These examples include the free wave packet, which we use to show the difference between group and phase velocities, the packet in a harmonic oscillator potential with non-trivial initial conditions in one and two dimensions, which is compared with their classical analogs to show how Ehrenfest theorem holds. We also include simulations of the diffraction through the single and double slit potentials, the refraction with a step potential and the dispersion by a central potential. The aim of this paper is to illustrate with simulations, nowadays easy to implement, scenarios that can help explaining the basics of the wave-particle duality.