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9,400
Partnerships For Physics Teaching Reform -- a crucial role for universities and colleges
physics.ed-ph
To meet National Standards recommended by the National Research Council for high school physics, inservice teachers must be integrated into the physics community. They must be empowered by access to resources of the physics community and by sustained support for their professional development. To that end, university a...
physics
9,401
Ideal Gas in a Finite Container
physics.ed-ph
The thermodynamics of an ideal gas enclosed in a box of volume a1 x a2 x a3 at temperature T is considered. The canonical partition function of the system is expressed in terms of complete elliptic integrals of the first kind, whose argument obeys a transcendental equation. For high and low temperatures we derive expli...
physics
9,402
A Elasticidade Relativista
physics.ed-ph
The purpose of this paper is to make clear the difference between rigid and undeformable bodies in Relativity. The error of confusing these two concepts has survived up to the present day treatises. We hope it will not persist in the XXI century treatises. The large majority of relativists do not know the formulae for ...
physics
9,403
Renormalizing Recitation Grades
physics.ed-ph
I discuss issue of how to adjust recitation grades given by different instructors in a large course, taking into account and correcting for differences in standards among the instructors, while preserving the effects of differences in average student performance among the recitation sections.
physics
9,404
Potential Momentum, Gauge Theory, and Electromagnetism in Introductory Physics
physics.ed-ph
If potential energy is the timelike component of a four-vector, then there must be a corresponding spacelike part which would logically be called the potential momentum. The potential four-momentum consisting of the potential momentum and the potential energy taken together is just the gauge field of the associated for...
physics
9,405
The Quantized Hall Effect. (Lab Tutorial. In German.)
physics.ed-ph
This paper is a lab tutorial (and a theory primer) for the integral quantum Hall effect experiment as conducted at Applied Solid State Physics, University of Bochum, Germany.
physics
9,406
Introduction to the Fock Quantization of the Maxwell Field
physics.ed-ph
In this article we give an introduction to the Fock quantization of the Maxwell field. At the classical level, we treat the theory in both the covariant and canonical phase space formalisms. The approach is general since we consider arbitrary (globally-hyperbolic) space-times. The Fock quantization is shown to be equiv...
physics
9,407
Aberration and Special Relativity
physics.ed-ph
Section 7 of Einstein's 1905 electrodynamics paper gives frequency-shift and aberration formulae that together describe an elongated ellipsoidal wavefront. A Lorentz contraction of this ellipsoid solves most (but not all) of the associated relativistic problems.
physics
9,408
Ruler-changes and Relative Velocity
physics.ed-ph
Simple signal-propagation effects make receding objects seem contracted and approaching objects seem elongated. These effects are theoretically photographable, and are proportional in strength to the frequency-change in the object's emitted light. In a one-dimensional version of the "barn-pole" experiment, a "moving" o...
physics
9,409
Some Remarks on the Question of Charge Densities in Stationary-Current-Carrying Conductors
physics.ed-ph
Recently, some discussions arose as to the definition of charge and the value of the density of charge in stationary-current-carrying conductors. We stress that the problem of charge definition comes from a misunderstanding of the usual definition. We provide some theoretical elements which suggest that positive and ne...
physics
9,410
Finite Rotations
physics.ed-ph
We present an elementary discussion of two basic properties of angular displacements, namely, the anticommutation of finite rotations and the commutation of infinitesimal rotations, and show how commutation is achieved as the angular displacements get smaller and smaller.
physics
9,411
Four-Spinor Reference Sheets
physics.ed-ph
Some facts about 4-spinors listed and discussed. None, well perhaps some, of the work is original. However, locating formulas in other places has proved a time-consuming process in which one must always worry that the formulas found in any given source assume the other metric (I use {-1,-1,-1,+1}) or assume some other ...
physics
9,412
Notes on Brownian motion and related phenomena
physics.ed-ph
In this article we explore the phenomena of nonequilibrium stochastic process starting from the phenomenological Brownian motion. The essential points are described in terms of Einstein's theory of Brownian motion and then the theory extended to Langevin and Fokker-Planck formalism. Then the theory is applied to barrie...
physics
9,413
Gauge Invariance and Canonical Variables
physics.ed-ph
We discuss some paradoxes arising due to the gauge-dependence of canonical variables in mechanics.
physics
9,414
Intrinsic Kinematics
physics.ed-ph
We show how some geometric elements of the path of a particle moving in a plane -- the osculating circle and its radius of curvature -- can be used to construct the parabolic trajectory of projectiles in motion under gravity.
physics
9,415
Difficult Problems Having Easy Solutions
physics.ed-ph
We discuss how a class of difficult kinematic problems can play an important role in an introductory course in stimulating students' reasoning on more complex physical situations. The problems presented here have an elementary analysis once certain symmetry features of the motion are revealed. We also explore some unex...
physics
9,416
Progetto per la costituzione del centro di divulgazione della cultura scientifica a Sesto Fiorentino
physics.ed-ph
Two Italian non-profit organizations (Set and Galea) are working together to realize a center (Cdcs) supported by the town administration of Sesto Fiorentino (a little town not far from Florence, Italy), for the divulgation of the scientific culture in the schools and among people. This is their project: the key idea i...
physics
9,417
Post-Gaussian variational method for quantum anharmonic oscillator
physics.ed-ph
Using the post-Gaussian trial functions, we calculate the variational solutions to the quantum-mechanical anharmonic oscillator. We evaluate not only the ground state but also some excited energies, and compare them with numerical results.
physics
9,418
Mecanica Clasica (Classical Mechanics)
physics.ed-ph
First Internet graduate course on Classical Mechanics in Spanish (Castellano). This is about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. English and Romanian versions are in (slow) progress and hopefully will be arXived. For a similar course on Quantum Mechan...
physics
9,419
Oscar's Physics Phaire: A Collection of Problems
physics.ed-ph
You will find here a number of (mostly) elementary physics problems dealing mainly with uniform motion kinematics. In preparing this collection I have tried to create original situations that could help bring motivation to an introductory course. You are welcome to suggest improvements and ... provide solutions!
physics
9,420
Classical Mechanics
physics.ed-ph
This is the English version of a friendly graduate course on Classical Mechanics, containing about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. For the Spanish version, see physics/9906066
physics
9,421
Regional Centres for Space Science and Technology Education (Affiliated to the United Nations)
physics.ed-ph
Education is a prerequisite to master the challenges of space science and technology. Efforts to understand and control space science and technology are necessarily intertwined with social expressions in the cultures where science and technology is carried out. The United Nations is leading an effort to establish regio...
physics
9,422
Making sense of Physics in the first year of study
physics.ed-ph
We address the question "How do students make sense of Physics from the point of view of constituting physics knowledge?". A phenomenographic study is described as a result of which we present six qualitatively different ways in which students experience the first year of Physics. The variation is analysed in terms of ...
physics
9,423
An elementary quantum mechanics calculation for the Casimir effect in one dimension
physics.ed-ph
We obtain the Casimir effect for the massless scalar field in one dimension based on the analogy between the quantum field and the continuum limit of an infinite set of coupled harmonical oscillators.
physics
9,424
Hydrogen atom in a spherical well: linear approximation
physics.ed-ph
We discuss the boundary effects on a quantum system by examining the problem of a hydrogen atom in a spherical well. By using an approximation method which is linear in energy we calculate the boundary corrections to the ground-state energy and wave function. We obtain the asymptotic dependence of the ground-state ener...
physics
9,425
In search of fundamental laws
physics.ed-ph
One of the main activities in science teaching, and in particular in Physics teaching, is not only the discussion of both modern problems and problems which solution is an urgent matter. It means that the picture of an active and alive science should be transmitted to the students, mainly to the College students. A cen...
physics
9,426
Compendium of vector analysis with applications to continuum mechanics
physics.ed-ph
1. Connection between integration and differentiation/ Gauss theorem. Coordinate-free definitions: gradient, divergence, curl. Stokes theorem. 2. Elements of continuum mechanics/ Continuity equation. Stress tensor. Euler equation. Hydrodynamics. Elasticity.
physics
9,427
Averages of static electric and magnetic fields over a spherical region: a derivation based on the mean-value theorem
physics.ed-ph
Submitted to "Notes and Discussions" in American Journal of Physics.
physics
9,428
The oscillations in the lossy medium
physics.ed-ph
The object of this laboratory work: to explore dependence mass point oscillatory motion parameters in the following cases: - without resistance (free oscillations); - the resistance force is proportional to the velocity vector; - the resistance force is proportional to the velocity squared. Used equipment: the ...
physics
9,429
Effective Field Theory for Pedestrians
physics.ed-ph
A pedagological introduction to effective field theory is presented.
physics
9,430
Elementary Quantum Mechanics
physics.ed-ph
This is the first graduate course on elementary quantum mechanics in Internet written in Romanian for the benefit of Romanian speaking students (Romania and Moldova). It is a translation (with corrections) of the Spanish version of the course (physics/9808031, English translation physics/0004072), which I did at the re...
physics
9,431
Revitalization of an undergraduate physics program
physics.ed-ph
This article describes the successful revitalization of an undergraduate physics program. The areas of curriculum development, undergraduate research experiences and advising and retention, to name a few, are emphasized in this interconnecting and systematic approach whereby each and every effort combines to get result...
physics
9,432
Lagrangians and Hamiltonians for High School Students
physics.ed-ph
A discussion of Lagrangian and Hamiltonian dynamics is presented at a level which should be suitable for advanced high school students. This is intended for those who wish to explore a version of mechanics beyond the usual Newtonian treatment in high schools, but yet who do not have advanced mathematical skills.
physics
9,433
Matching Conditions on Capillary Ripples: Polarization
physics.ed-ph
The matching conditions at the interface between two non-mixed fluids at rest are obtained directly using the equation of movement of the whole media. This is a non-usual point of view in hydrodynamics courses and our aim is to fix ideas about the intrinsic information contained in the matching conditions, on fluids in...
physics
9,434
Elementary Nonrelativistic Quantum Mechanics
physics.ed-ph
This is a graduate course on elementary quantum mechanics written for the benefit of undergraduate and graduate students. It is the English version of physics/0003106, which I did at the suggestion of several students from different countries. The topics included refer to the postulates of quantum mechanics, one-dimens...
physics
9,435
Classical Electrodynamics
physics.ed-ph
Excerpts are presented from a graduate course on Classical Electrodynamics held during the spring semester of 2000 at the Institute of Physics, Guanajuato State University, Mexico
physics
9,436
The Precessing Top
physics.ed-ph
I discuss the precession motion of a symmetrical top without the assumption that its precessional velocity is much smaller than its spin angular velocity. I derive the general formula for the precessional velocity in an elementary way and discuss the cases of slow and fast precessions.
physics
9,437
Coriolis force in Geophysics: an elementary introduction and examples
physics.ed-ph
We show how Geophysics may illustrate and thus improve classical Mechanics lectures concerning the study of Coriolis force effects. We are then interested in atmospheric as well as oceanic phenomena we are familiar with, and are for that reason of pedagogical and practical interest. Our aim is to model them in a very s...
physics
9,438
Compactification of the moduli space in symplectization and hidden symmetries of its boundary
physics.ed-ph
In this paper, we establish the compactification of the moduli space in symplectization and and studied the hidden symmetries of its boundary.
physics
9,439
A bubble theorem
physics.ed-ph
Proof of a simple mathematical inequality using elements of surface tension theory and ideal gas law to the formation and coalescence of bubbles.
physics
9,440
Mecanica Relacional: A proposito de uma resenha
physics.ed-ph
We present a critical analysis of what is called Relational Mechanics, as it has been presented in a book thus entitled, which has been recently reviewed in this journal.
physics
9,441
Adding Resistances and Capacitances in Introductory Electricity
physics.ed-ph
We propose a unified approach to addition of resistors and capacitors such that the formulae are always simply additive. This approach has the advantage of being consistent with the intuition of the students. To demonstrate our point of view, we re-work some well-known end-of-the-chapter textbook problems and propose s...
physics
9,442
Verifying the learning process in Physics
physics.ed-ph
The paper describes an automated evaluation system for the learning of general Physics. The system whose name is Test on Line (ToL) is based on a questions bank from which an appropriate software generates individual multi-issue questionnaires to be submitted through the web. ToL has been extensively experimented durin...
physics
9,443
Addition Laws in Introductory Physics
physics.ed-ph
We propose a unified approach to addition of some physical quantities (among which resistors and capacitors are the most well-known) that are usually encountered in introductory physics such that the formulae required to solve problems are always simply additive. This approach has the advantage of being consistent with...
physics
9,444
Lessons From the Physics-Education Reform Effort
physics.ed-ph
Several years ago I reported a survey (Hake 1998a,b,c) of pre/post test data for 62 introductory physics courses enrolling a total of 6542 students. The present article provides a summary of that survey and presents fourteen lessons from the physics-education reform effort that may assist the general upgrading of educa...
physics
9,445
Introducing Time Dependence into the Static Maxwell Equations
physics.ed-ph
Using to a minimum extent special relativity input, and relying on the Lorentz-force expression for the force acting on a charged particle in motion under the influence of electric (E) and magnetic (B) fields, the Maxwell curl equations are shown to follow from the covariance of the two Maxwell divergence equations ${\...
physics
9,446
Improving the effectiveness of introductory physics service courses: Bridging to engineering courses
physics.ed-ph
A simple model to help students see the connections between a physics course and their engineering major is described. "Bridging" had positive effects on performance, attitude, and motivation, as measured by grade analyses, surveys, and student and faculty comments. In addition to the improved performance, enrollment i...
physics
9,447
Direction dependency of extraordinary refraction index
physics.ed-ph
A simple experiment is presented that enables qualitative and quantitative measurement of the extraordinary refractive index direction dependency in an uniaxial nematic liquid crystal. Three liquid crystaline cells were designed in which elongated molecules of nematic liquid crystal align in directions which enable to ...
physics
9,448
An experience model for anyspeed motion
physics.ed-ph
Simple airtrack simulations, like those now possible with web-based 3D environments, can provide explorers of any age with experiential data sufficient to formulate their own models of motion. In particular, with a compressable spring, two gliders, a moving clock and two gate pairs with timers (pre and post collision),...
physics
9,449
Electromagnetic induction and damping - quantitative experiments using PC interface
physics.ed-ph
A bar magnet, attached to an oscillating system, passes through a coil periodically, generating a series of emf pulses. A novel method is described for the quantitative verification of Faraday's law which eliminates all errors associated with angular measurements, thereby revealing delicate features of the underlying m...
physics
9,450
Kinematics on oblique axes
physics.ed-ph
We solve a difficult problem involving velocity and acceleration components along oblique axes, and propose two problems of central force motion to be solved using oblique axes.
physics
9,451
Speed of light measurement using ping
physics.ed-ph
We report on a very simple and inexpensive method for determining the speed of an electrical wave in a transmission line. The method consists of analyzing the roundtrip time for ethernet packets between two computers. It involves minimal construction, straightforward mathematics and displays the usefulness of stochasti...
physics
9,452
A Hundred Years of Larmor Formula
physics.ed-ph
Sir Joseph LARMOR showed in 1897 that an oscillating electric charge emits radiation energy proportional to (acceleration)$^2$. At first sight,the result appears to be valid for arbitrary accelerations. But, perpetual uniform acceleration has been a case of nagging doubts, as radiation reaction vanishes and the equival...
physics
9,453
Expounding on physics -- A phenomenographic study of physicists talking of their physics
physics.ed-ph
Physicists and physics students have been studied with respect to the variation in ways they expound on their topic of research and a physics problem, respectively. A phenomenographic approach has been employed; six fourth-year physics students and ten teacher/researcher physicists at various stages of their careers ha...
physics
9,454
Can we derive the Lorentz force from Maxwell's equations?
physics.ed-ph
The Lorentz force can be obtained from Maxwell's equations in the Coulomb gauge provided that we assume that the electric portion of the force acted on a charge is known, and the magnetic component is perpendicular to the velocity of motion of the charged particle.
physics
9,455
Initial-amplitude dependence in weakly damped oscillators
physics.ed-ph
A pedagogically instructive experimental procedure is suggested for distinguishing between different damping terms in a weakly damped oscillator, which highclights the connection between non-linear damping and initial-amplitude dependence. The most common damping terms such as contact friction, air resistance, viscous ...
physics
9,456
Education Curricula of the Regional Centres for Space Science and Technology Education (Affiliated to the United Nations)
physics.ed-ph
Since 1988, the United Nations, through the Programme on Space Applications, is supporting the establishment and operation of regional Centres for Space Science and Technology Education in Africa, Asia and the Pacific, Latin America and the Caribbean, and Western Asia. Simultaneously, education curricula have been deve...
physics
9,457
Investigating Student Understanding of Quantum Mechanics: Spontaneous Models of Conductivity
physics.ed-ph
Students are taught several models of conductivity, both at the introductory and the advanced level. From early macroscopic models of current flow in circuits, through the discussion of microscopic particle descriptions of electrons flowing in an atomic lattice, to the development of microscopic non-localized band diag...
physics
9,458
Understanding and Affecting Student Reasoning About Sound Waves
physics.ed-ph
Student learning of sound waves can be helped through the creation of group-learning classroom materials whose development and design rely on explicit investigations into student understanding. We describe reasoning in terms of sets of resources, i.e. grouped building blocks of thinking that are commonly used in many d...
physics
9,459
The Object Coordination Class Applied to Wavepulses: Analysing Student Reasoning in Wave Physics
physics.ed-ph
Detailed investigations of student reasoning show that students approach the topic of wave physics using both event-like and object-like descriptions of wavepulses, but primarily focus on object properties in their reasoning. Student responses to interview and written questions are analysed using diSessa and Sherin's c...
physics
9,460
The Vocabulary of Introductory Physics and its Implications for Learning Physics
physics.ed-ph
We investigate studnets' use of words used in everyday language as well as in physics. We find students are more likely to identify and explain the meaning of the word as it is used in physics when they have become familiar with the associated physical variables.
physics
9,461
Model Analysis: Assessing the dynamics of student learning
physics.ed-ph
In this paper we present a method of modeling and analysis that permits the extraction and quantitative display of detailed information about the effects of instruction on a class's knowledge. The method relies on a congitive model that represents student thinking in terms of mental models. Students frequently fail to ...
physics
9,462
Epistemology mediating conceptual knowledge: Constraints on data accessible from interviews
physics.ed-ph
A student's epistemological stance (be it knowledge as memorized information, knowledge from authority, or knowledge as invented stuff) may constrain that student from reasoning in productive ways while also shaping the inferences a researcher can make about how that student reasons about a particular phenomenon. We di...
physics
9,463
The challenge of listening: The effect of researcher agenda on data collection and interpretation
physics.ed-ph
Even in the relatively favorable circumstances of an individual interview, accurate listening requires careful effort. Our research interests dictate which student statements we attend to during the interview, and which we consider to constitute data during later analysis. Explicit consideration of possible research ag...
physics
9,464
The challenge of changing deeply-held student beliefs about the relativity of simultaneity
physics.ed-ph
Previous research indicates that after standard instruction students at all academic levels often construct a conceptual framework in which the ideas of absolute simultaneity and the relativity of simultaneity co-exist. This article describes the development and assessment of instructional materials intended to improve...
physics
9,465
Student Resources in Quantum Mechanics, or Why Students Need Meta-resources
physics.ed-ph
We are trying to identify resources students are using to reason in quantum mechanics. In this process we realize students must have not only the right resources available but sophisticated for evaluating and controlling their thought processes. We will discuss examples from student interviews to illustrate our point.
physics
9,466
Making Sense of How Students Make Sense of Mechanical Waves
physics.ed-ph
We report on our study of student understanding of the physics of mechanical waves, specifically the propagation and superposition of simple wavepulses traveling on long, taut strings. We introduce the terms "particle pulses mental model" to describe the reasoning approach that students use to guide their thinking in w...
physics
9,467
Mathematical Tutorials in Introductory Physics
physics.ed-ph
Students in introductory calculus-based physics not only have difficulty understanding the fundamental physical concepts, they often have difficulty relating those concepts to the mathematics they have learned in math courses. This produces a barrier to their robust use of concepts in complex problem solving. As a part...
physics
9,468
Effectiveness of group interaction on conceptual standardized test performance
physics.ed-ph
We analyze the effectiveness of working in pairs on the Conceptual Survey of Electricity and Magnetism test in a calculus-based introductory physics course. The group performance shows large normalized gain and evidence for co-construction. We discuss the effect of pairing students with different individual achievement...
physics
9,469
Student understanding of time in special relativity: simultaneity and reference frames
physics.ed-ph
This article reports on an investigation of student understanding of the concept of time in special relativity. A series of research tasks are discussed that illustrate, step-by-step, how student reasoning of fundamental concepts of relativity was probed. The results indicate that after standard instruction students at...
physics
9,470
A Wind Tunnel in Your Classroom: The Design and Implementation of a Portable Wind Tunnel for Use in the Science Classroom
physics.ed-ph
This article describes a wind tunnel's ease of construction and its uses as a visualization tool that integrates concepts at the primary and secondary levels. An Appendix contains detailed building instructions. A web site (under construction) will provide sample lesson plans, visualization and application tips, animat...
physics
9,471
Limitations in predicting student performance on standardized tests
physics.ed-ph
The Maryland Physics Expectations Survey (MPEX) describes student attitudes and expectations toward learning, and might be used to predict normalized gains on tests such as the Force and Motion Concept Evaluation (FMCE). These predictions are incomplete, though, due to limitations of the standardized tests themselves. ...
physics
9,472
Listening to the coefficient of restitution and the gravitational acceleration of a bouncing ball
physics.ed-ph
We show that a well known method for measuring the coefficient of restitution of a bouncing ball can also be used to obtain the gravitational acceleration.
physics
9,473
The Nobel Prize in Physics 2002 for the observation of cosmic neutrinos
physics.ed-ph
A brief description of the work for which the first half of the Nobel prize for physics for the year 2002 is presented.
physics
9,474
Teaching with Physlets: Examples from Optics
physics.ed-ph
Physlets are scriptable Java applets that can be used for physics instruction. In this article we discuss the pedagogical foundations of Physlet use and provide a sample of Physlet-based exercises that could be used to teach optics.
physics
9,475
Wick Calculus
physics.ed-ph
In quantum field theory, physicists routinely use "normal ordering" of operators, which just amounts to shuffling all creation operators to the left. Potentially confusing, then, is the occurrence in the literature of normal-ordered functions, sometimes called "Wick transforms". We aim to introduce the reader to some b...
physics
9,476
Abstract Applets: a Method for Integrating Numerical Problem-Solving into the Undergraduate Physics Curriculum
physics.ed-ph
In upper-division undergraduate physics courses, it is desirable to give numerical problem-solving exercises integrated naturally into weekly problem sets. I explain a method for doing this that makes use of the built-in class structure of the Java programming language. I also supply a Java class library that can assis...
physics
9,477
A Note on Derivation of Rutherford Formula within Born Approximation
physics.ed-ph
It is shown in this paper that one does not need to use just exponential dumping factor when computing the Rutherford formula within Born approximation. Text, which is very simple, might be of interest for physics students as well as for physics teachers.
physics
9,478
Physical Science: A revitalization of the traditional course by avatars of Hollywood in the physics classroom
physics.ed-ph
National studies conducted over many years show that, while most Americans are interested in science and support federal funding of scientific research, the scientific literacy of the public is very low. Why this situation exists and who is responsible are not easy questions to answer. This paper describes a project ai...
physics
9,479
Brownian Motion: Theory and Experiment:: A simple Classroom Measurement of the Diffusion Coefficient
physics.ed-ph
Brownian motion is the perpetual irregular motion exhibited by small particles immersed in a fluid. Such random motion of the particles is produced by statistical fluctuations in the collisions they suffer with the molecules of the surrounding fluid. Brownian motion of particles in a fluid (like milk particles in water...
physics
9,480
Ex-nihilo II: Examination Syllabi and the Sequencing of Cosmology Education
physics.ed-ph
Cosmology education has become an integral part of modern physics courses. Directed by National Curricula, major UK examination boards have developed syllabi that contain explicit statements about the model of the Big Bang and the strong observational evidence that supports it. This work examines the similarities and d...
physics
9,481
Wave propagation in a chiral fluid: an undergraduate study
physics.ed-ph
We study the propagation of electromagnetic waves in a chiral fluid, where the molecules are described by a simplified version of the Kuhn coupled oscillator model. The eigenmodes of Maxwell's equations are circularly polarized waves. The application of a static magnetic field further leads to a magnetochiral term in t...
physics
9,482
Quantum Statistics: Is there an effective fermion repulsion or boson attraction?
physics.ed-ph
Physicists often claim that there is an effective repulsion between fermions, implied by the Pauli principle, and a corresponding effective attraction between bosons. We examine the origins of such exchange force ideas, the validity for them, and the areas where they are highly misleading. We propose that future explan...
physics
9,483
Visualizing the Mass and Width Spectrum of Unstable Particles
physics.ed-ph
Several graphical representations of the mass and width spectrum of unstable subatomic particles are presented. Such plots are useful tools for introducing students to the particle zoo and provide students an alternate way to organize conceptually what can seem like an overwhelming amount of data. In particular, such g...
physics
9,484
The Flex-Pendulum -- Basis for an Improved Timepiece
physics.ed-ph
A compound pendulum of simple geometry was built from a lightweight rod to which a pair of masses are clamped, one above and the other below the axis of rotation. By making the position of the upper mass variable, it was found that the characteristics of this pendulum can be altered dramatically. A theoretical model of...
physics
9,485
A comment on W. Greiner's "Quantum Mechanics -- An Introduction"
physics.ed-ph
It is pointed out that in Greiner's book, ``Quantum Mechanics --An Introduction,'' there is a confusion between the wavelength spectral function and the (angular) frequency spectral function in the derivation of the Wien's displacement law.
physics
9,486
Textos de física para professores e estudantes
physics.ed-ph
This is a series of short teaching papers dealing with specific topics in a standard first-year undergraduate Physics course. ----- Este texto comp\~oe-se de quatro pequenas notas -- independentes entre si -- em que se discutem alguns t\'opicos espec\'{\i}ficos de f\'{\i}sica para o segundo grau e o primeiro ano un...
physics
9,487
Classroom computer animations of relativistic objects
physics.ed-ph
This is a short note to announce the availability of some movies that may be useful in classroom discussions on the photographic appearance of objects moving at relativistic speeds. The images are based on special relativity with no account taken of (other than to ignore) the effects of doppler shifts, intensity shifts...
physics
9,488
Quaternions in University-Level Physics Considering Special Relativity
physics.ed-ph
As an expansion of complex numbers, the quaternions show close relations to numerous physically fundamental concepts. In spite of that, the didactic potential provided by quaternion interrelationships in formulating physical laws are hardly regarded in the current physics curriculum. In particular, many approaches emer...
physics
9,489
Complex functions as lumps of energy
physics.ed-ph
We present an application of the basic mathematical concept of complex functions as topological solitons, a most interesting area of research in physics. Such application of complex theory is virtually unknown outside the community of soliton researches.
physics
9,490
The Thomas Precession Factor in Spin-Orbit Interaction
physics.ed-ph
The origin of the Thomas factor 1/2 in the spin-orbit hamiltonian can be understood by considering the case of a classical electron moving in crossed electric and magnetic fields chosen such that the electric Coulomb force is balanced by the magnetic Lorentz force.
physics
9,491
The rules of coherence and other habits
physics.ed-ph
Physics and mathematics are difficult enough without the aditional burden of bad habits. In this article, we examine some helpful habits that tend to be underemphasized by many physics teachers (mainly because they seem so obvious!).
physics
9,492
Problems When Studying Holography (Probleme beim Erlernen der Holographie)
physics.ed-ph
Holography as a subject is neglected largely in current physics lessons and in school books. Even though this topic might be complex, it is applicable and viable in the world that we live in. Holography lends itself to further develop knowledge with regard to inference optics. However, misconceptions of students impede...
physics
9,493
A Newtonian pre-introduction to gravitational lenses
physics.ed-ph
Understanding the deflection of light by a massive deflector, as well as the associated gravitational lens phenomena, require the use of the theory of General Relativity. I consider here a classical approach, based on Newton's equation of motion for massive particles. These particles are emitted by a distant source and...
physics
9,494
Student Conceptions of Holography (Schuelervorstellungen zur Holographie)
physics.ed-ph
In a lesson on holography a tension is to be found between the ray model, the wave model, the phasor model and the particle model. Lessons depend on the previous experiences of the students, the intentions of the teacher as well as on other parameters and therefore provide a diversity in emphasis while explaining holog...
physics
9,495
What happened to modern physics?
physics.ed-ph
Relativity, Quantum Mechanics and Chaos theory are three of the most significant scientific advances of the 20th Century - each fundamentally changing our understanding of the physical universe. The authors ask why the UK National Curriculum in science almost entirely ignores them. Children and young people regularly c...
physics
9,496
A Didactic Approach to Linear Waves in the Ocean
physics.ed-ph
The general equations of motion for ocean dynamics are presented and the waves supported by the (inviscid, unforced) linearized system with respect to a state of rest are derived. The linearized dynamics sustains one zero frequency mode (called buoyancy mode) in which salinity and temperature rearrange in such a way th...
physics
9,497
Making sense of studying physics
physics.ed-ph
With an investigation into how students in a physics Master of science program make sense of their whole first year study experience in one of the years following a programme reform, we try to offer insights and advice to consider when involved in similar changes. We conclude and argue that by trying to support the stu...
physics
9,498
Learning-focuses in physics simulation learning situations
physics.ed-ph
This is a report on a qualitative study of students' learning where a physics computer simulation session is used to supplement lectures on the topic. Drawing on phenomenography as the analytical framework, the students' learning-focuses were analysed. The result is a description of four distinctly different learning-f...
physics
9,499
Expressing Maxwell's equations independently of the unit system
physics.ed-ph
A procedure to teach Electrodynamics independently of unit systems is presented and compared with some of those given in physics literature.
physics