bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase Change on Reflection from Isotropic Dielectrics
Authors: Friedmann G. , Sandhu H. S.
Published: August 2005

Interpretation of the Fresnel equations regarding phase relationships of the reflected and transmitted light to the incident light is discussed. It is emphasized that confusion is avoided if care is exercised in relating vector diagrams to the signs of the equations.
A Note on Time-Reversal Invariance
Authors: Boya Luis J.
Published: August 2005

A simple argument is advanced which makes it plausible that time-reversal invariance holds universally. The argument is to define the physical Lorentz group as the minimal lineal group which carries any point into any other point in a certain invariant figure, which in the physical case has two sheets.
Optical Pumping Theory and Experiments
Authors: Benumof Reuben
Published: August 2005

The theory of several experiments involving optical pumping is presented in a simplified form. Vector methods are employed to discuss the hyperfine energy levels of an atom in a weak magnetic field, and, for the purposes of considering relaxation time, the system is assumed to have only two effective levels. The Breit-Rabi equation for the ground-state hyperfine Zeeman energy levels of an alkali atom is derived from the Schrödinger equation to facilitate the interpretation of the quadratic Zeeman effect. A number of suggestions for practical optical pumping experiments are made.
Anniversaries in 1965 of Interest to Physicists
Authors: Barr E. Scott
Published: August 2005

During the year 1965 there are major anniversaries of the birth or death of eleven men whose accomplishments and influence have been of importance to the development of physics. They are: Louis Agricola Bauer; Giambattista della Porta; William Rowan Hamilton; Heinrich Friedrich Emil Lenz; Ernest George Merritt; William Nicholson; Louis Carl Heinrich Friedrich Paschen; Heinrich Rubens; James Lewis Macie Smithson; William Watson; and Pieter Zeeman. Brief accounts of their achievements and lives are given here.
The Physical Meaning of Parseval's Theorem
Authors: Hughes Harold K.
Published: August 2005

Parseval published his theorem about trigonometric series 17 years before Fourier. This paper considers the question of priority and illustrates applications of Parseval's theorem in simple electrical circuits and in quantum mechanics.
Another Approach to the First-Year Physics Laboratory Course
Authors: Murty R. C.
Published: August 2005

A different approach to the first-year physics laboratory course, consisting of open laboratory sessions and practical examinations, is described. The responsiblity for the student's development is left much more in his own hands than is customary. The underlying philosophy of the course and its organization is discussed.
Graphical Representations of Magnetic Space Groups
Authors: Atoji Masao
Published: August 2005

Extensive graphical representations are shown for the magnetic Bravais lattices and for symmetry and antisymmetry operations in the magnetic (or two-color) space groups. With aids of these figures and newly introduced graphical symbols, symmetry characteristics of the magnetic space groups are discussed and some pertinent examples of the magnetic spin structure are cited.
Quantum-Mechanical Proof of the Second Law
Authors: Wannier Gregory H.
Published: August 2005

A proof of the second law of thermodynamics is given, starting from elementary quantum mechanics. The theorem proved states that, for a macroscopic body, the state of thermal equilibrium has a larger entropy than any other possible state which is subject to the same external constraints and has the same total energy.
Length of a Moving Rod
Authors: Sears Francis W.
Published: August 2005

The measurement of the length of a rod in motion relative to an observer, by means of light signals reflected from a mirror attached to one end of the rod, is represented graphically in a Brehme diagram. It is pointed out that although the calculations are based on nonsimultaneous clock readings, the coordinates of the ends of the rod are, in effect, determined simultaneously. Another method of finding the length is described, in which the coordinates of the ends of the rod are not observed simultaneously and which does not require the use of light signals or synchronized clocks.
Demonstrations of Waves on an Air Track
Authors: Howland L. Philip
Published: August 2005

Demonstrations of both traveling and standing waves in a uniform line of cars connected by springs on an air track are described, the crucial point being the special mass and damping necessary for the last car in the case of traveling waves. The theory of the motion of the cars under various circumstances pertaining to the demonstrations is presented, and procedural details are described. A scheme is outlined for using the wave demonstrations in an introductory course, and another, simple demonstration is mentioned. A demonstration of the localized mode associated with a light impurity car is described.
The Poynting Vector in Magnetohydrodynamics
Authors: Boldt Elihu
Published: August 2005

The propagation of electromagnetic energy arising from magnetohydrodynamic disturbances is described by a general Poynting vector, valid for perturbations of any magnitude. The Poynting vector associated with the solar wind is specified, and its magnitude is shown to be of the order of 6 μW/m2 at the orbit of earth.
Two Air-Supported Devices for Physics Laboratories and for Physics Demonstrations
Authors: Daw Harold A.
Published: August 2005

Two air-supported devices are described. One is an air-bearing gyroscope and the other a classical “nuclear” magnetic resonance apparatus using an air-bearing gyroscope.
An Undergraduate Laboratory Apparatus for Measuring e/m as a Function of Velocity. I
Authors: Bartlett A. A. , Correll Malcolm
Published: August 2005

The design and development of an apparatus for measuring e/m of β particles as a function of velocity is described. A 10 mCi source, such as 90Sr or 137Cs, is used to provide a range of high-speed electrons. A magnetic field-momentum selector and a crossed magnetic and electric field-velocity selector provide the elements of the experimental apparatus. The same magnetic field is used in both selectors and this field is provided by an inside-out electromagnet, which may be described as an iron pillbox with the energizing coil on the inside. The iron pillbox also serves as the vacuum chamber. The electrons are detected by a GM or solid-state counter. Provisions for measuring the magnetic and electric fields are described. The results obtained by use of the apparatus are given. Such results can be duplicated by students in one or two laboratory sessions of the normal three-hour length. A continuing program of development of experiments with the apparatus is described.
Gibbs vs Boltzmann Entropies
Authors: Jaynes E. T.
Published: August 2005

The status of the Gibbs and Boltzmann expressions for entropy has been a matter of some confusion in the literature. We show that: (1) the Gibbs H function yields the correct entropy as defined in phenomenological thermodynamics; (2) the Boltzmann H yields an “entropy” that is in error by a nonnegligible amount whenever interparticle forces affect thermodynamic properties; (3) Boltzmann's other interpretation of entropy, S = k log W, is consistent with the Gibbs H, and derivable from it; (4) the Boltzmann H theorem does not constitute a demonstration of the second law for dilute gases; (5) the dynamical invariance of the Gibbs H gives a simple proof of the second law for arbitrary interparticle forces; (6) the second law is a special case of a general requirement for any macroscopic process to be experimentally reproducible. Finally, the “anthropomorphic” nature of entropy, on both the statistical and phenomenological levels, is stressed.
Radioisotopes in Zone Refining—A Student Experiment
Authors: Mikhail S. Z.
Published: August 2005

Illustration of redistribution of impurities by zone-refining could be achieved by adding a colored, radioactive impurity to a bar of material and surveying the bar, before and after passing the zone, by a counting system. Stepwise details of the experiment are given. The main conclusions of the theory of zone-refining are summarized. Comparison between the experimental results and the theoretical predictions proved success of the zone-refining technique and demonstrated the advantage of using radioisotopes as a nondestructive means of analysis.
Brief Review of Lorentz-Covariant Scalar Theories of Gravitation
Authors: Harvey A. L.
Published: August 2005

An historical review of Lorentz-covariant scalar theories of gravitation is presented. Included are the theory of Poincaré, its presentation by Kottler, and its modification by Whitrow and Morduch; the first theory of Nordström, its modified form due to Bergmann, the modifications due to Whitrow and Morduch, and the field-theoretic approach of Thirring; the second theory of Nordström; and the theory of Kustaanheimo. The extent to which these theories can be said to be in accord with the experimental evidence concerning red shift, advance of the perihelion of Mercury, and deflection of light rays is discussed. It is found that except for red shift, there is, at best, poor agreement and, at worst, disagreement.
1965 Citations for Distinguished Service
Authors: Parker Vincent E.
Published: August 2005

The American Association of Physics Teachers annually cites some of its members for distinguished service to the teaching of physics. Three citations, prepared by Vincent E. Parker, Chairman of the Committee on Awards, were presented by President Edward U. Condon at the Annual Meeting of the Association on 30 January 1965.
Some Experiments on Statistical Distributions using a Multichannel Analyzer
Authors: Robinson Berol L.
Published: August 2005

A student experiment is outlined using a multichannel pulse-height analyzer, in multiscaler mode of operation, to make repeated observations of statistically distributed events. Experiments on the distribution of repeated counting observations, the distribution of intervals between (successive and scaled) events, and binomial distributions are described. In this way, hundreds of observations can be made and recorded in a short time; and the student may devote his laboratory period to the analysis of his own experimental data. One laboratory session provides time enough to investigate several sets of real experimental data, and thus experiments become practical which might not otherwise be considered.
Precision Compton-Effect Experiment
Authors: French Walter R.
Published: August 2005

A conceptually simple Compton-effect experiment is described which uses two Nal detectors and coincidence techniques to measure scattered photon and Compton electron energies as a function of the scattering angle. The results of the experiment agree well with the theoretical predictions for various scattering angles from 15° to 165°.
Low-Cost Fabry-Perot Interferometers
Authors: French A. P. , Smith J. H.
Published: August 2005

This article describes the construction and use of Fabry-Perot devices for use in elementary laboratories. The basic ingredients are microscope cover glasses and inexpensive plate glass. The devices provide moderate resolving power (̃104) at almost no cost.
The Geometrical Appearance of Large Objects Moving at Relativistic Speeds
Authors: Scott G. D. , Viner M. R.
Published: August 2005

The calculated geometrical appearance of objects moving at relativistic speeds and subtending large angles at the observer is illustrated by diagrams of a plane grid and perspective views of a group of boxes. In addition to the distortion of scales in the direction of motion, planes perpendicular to the motion appear as hyperboloids. Contrary to an impression which might be taken from some papers on the subject, the Lorentz contraction is visible under suitable conditions, in particular for observations approximately at right angles to the motion.
Connection between Macroscopic and Microscopic Transport Phenomena in Solid Conductors
Authors: Beaumont C. F. A.
Published: August 2005

An expression for the rate of production of entropy in a homogeneous solid conductor is obtained and in the process leads to a natural selection of current densities. It is shown that these current densities when written from the microscopic point of view give a system of equations satisfying Onsager's theorem, thus facilitating a comparison between microscopic and macroscopic transport phenomena.
Asymptotic Behavior of Scattered Waves
Authors: Roskies Ralph
Published: August 2005

The relation between the Fourier transform of a scattered wave and its asymptotic behavior at large distances from the scatterer is derived rigorously, and generalized to spaces of arbitrary dimension. Using this result, a simple derivation of the partial-wave expansion is given. Also a concise representation for the Laplacian on a sphere in n dimensions is obtained.
An Interference Fringe Photometer
Authors: French A. P. , King J. G. , Cronin D. J.
Published: August 2005

The paper describes the construction and use of a simple photometer consisting of a small photoconductive cell mounted so that it can be moved smoothly across an interference fringe system. The detector width is about 0.005 in. The photoconductive current is measured with a commercial electrometer or with a simple transistorized amplifier. Intensity distributions as measured with the photometer are shown for single, double and triple slits, and for a straight edge. The paper also describes the use of the photometer to illustrate the principle of Michelson's stellar interferometer, by making measurements of the visibility of double-slit fringes as a function of the width of the light source.
Enumerating Near Neighbors
Authors: Wood Van E.
Published: August 2005

An elementary method is described for enumerating near neighbors of an ion in a composite lattice where the ion positions are determined by symmetry. The method is illustrated by examples.
Position of Lanthanum in the Periodic Table
Authors: Hamilton David C.
Published: August 2005

In a widely-used version of the periodic table, lanthanum is classed in the same column with scandium and yttrium. However, in a number of respects lutetium resembles scandium and yttrium more closely than lanthanum does. Hence the periodic table should be modified so that scandium, yttrium, and lutetium are in the same column.
New Approach to Special Relativity
Authors: Weinstock Robert
Published: August 2005

A development of the theory of special relativity is based on a principle of relativity for inertial frames as applied to mechanical phenomena only. The Lorentz-transformation equations and the familiar mass-variation formula are deduced from the observation that mass does vary with speed; but in these the speed of light c is everywhere replaced by a universal speed k—namely, the speed at which the mass of any particle must become infinite—which arises as a consequence of the assumptions. The experimental result that the free-space speed of light with respect to the earth is equal to k then implies the same free-space speed of light with respect to every inertial frame—the usual starting point of the theory.
Streamline Functions for Potential Flow in Axial Symmetry
Authors: Zaslavsky Dan , Kirkham Don
Published: August 2005

A general solution for the differential equation for the stream function in axial symmetric flow is derived. It is shown how the general form of the stream function is related to the solution for the potential function and a table of functions is given by use of which equations for the stream function may be written down if the potential function is known and vice versa. By use of the table a stream-function pattern is worked out from a known potential function. The tabulated functions satisy “Cauchy-Riemann-type” of relations for axial symmetry.
Galileo, Yesterday and Today
Authors: Seeger Raymond J.
Published: August 2005

Looking at souvenirs from Galileo, physicists often wonder, “Who was the real Galileo?” What was his place in science? in philosophy? in history? in public affairs? A brief review is made here of the nature of historical evidence and its applicability to two famous Galileo incidents: the swinging lamp of Pisa and the leaning tower of Pisa. Some attention is given also to the question of historical myth, particularly in the case of Galileo. The author emphasizes Galileo's contributions to modern physics rather than his indebtedness to ancient philosophy. Galileo is first considered as a public figure; on the one hand, as a prominent person and, on the other hand, as a propagandist for the Copernican theory and for a phenomenological outlook. Galileo is regarded as a person, with particular concern for the “inevitability” of the celebrated Galileo case. The author, however, deals with Galileo as a physicist. His scientific approach is examined in terms of his experiential viewpoint, of his own behavior as an observer and a measurer, and of his role as a mathematical physicist, with particular interest in his use of models. Finally, Galileo's contributions to dynamics are reviewed: namely, his growing understanding of the first law of motion and his inklings as to the second law, with respect to acceleration but even more important with reference to role of the medium, as well as the relation of the projectile and tidal phenomena to Newton's first two corollaries. The author concludes that Galileo, the physicist, can rightly be regarded as the founder of dynamics.
Statistical Experiment for a General Science Laboratory
Authors: Russell Allan M.
Published: August 2005

An experiment is described in which students of general science make many independent measurements of resistance and perform a statistical analysis on the accumulated data. The results are compared with the normal distribution curve. The values of various precision indices are determined and the significance of such statistical facts examined. Mention is made of the need for a similar kind of experiment that would use multifactorial analysis and correlation techniques.
Maxwellian Interpretation of the Laplacian
Authors: McDonald J. E.
Published: August 2005

In many physical relationships involving the Laplacian of a function, it proves useful to interpret the Laplacian as a measure of the local anomaly of that function. This little used, but often very illuminating interpretation, due originally to Maxwell, is illustrated with a number of examples drawn from mathematical physics.
Approach to Equilibrium
Authors: Heims Steve P.
Published: August 2005

The time-dependent behavior of an isolated system consisting of many spins in a solid lattice is studied. An interaction of the form Bjkσjxσkx is assumed between any pair (j, k) of spins. The system is treated without making any approximations; it is one of the few many-body systems whose time-evolution can be treated exactly. The behavior is fully determined by the initial density matrix and the distribution of values Bjk. By considering a variety of distributions for the Bjk, and a variety of initial density matrices, one finds cases (initial random phasing and particular continuous spectra) where the system relaxes monotonically to a metastable equilibrium; in other cases (coherent initial state or nearest-neighbor coupling only) the system oscillates indefinitely without relaxation; in still other cases (initial random phasing and N → ∞) the system relaxes in an oscillatory way to the metastable equilibrium.
Asymptotic Direction of Arrival of Charged Particles in the Earth's Magnetic Field
Authors: Lanza Giovanni
Published: August 2005

The motion of charged particles in the earth's magnetic field has been investigated. Attention has been given to the motion in the equatorial plane. It is shown how, from the knowledge of the angle of arrival, particle species and energy, for a value of the impact parameter, the asymptotic direction of arrival can be calculated in closed form. The results of calculations are shown in Figure 4.
Formulation of Quantum Mechanical Perturbation Theory
Authors: Roberts Edwin M.
Published: August 2005

A new expression is found for the perturbation energy, with the principle feature that it is in remainder form. The remainder is first applied or manipulated to obtain the familiar infinite series of perturbation theory. Secondly, an iterative procedure for solving the Schrödinger equation is proposed. It is shown, by making use of the remainder, that this procedure leads to results equivalent, in the small perturbation limit, to the results of perturbation theory.
Deductions from a Kinematic Principle of Relativity
Authors: Drake Eric
Published: August 2005

The principle of relativity applied to purely length-time considerations is shown to lead rigorously to either the Lorentz or the Galilean transformations, but to no other. No reference is made to properties of light or of mass. The derivation itself leads to the appearance of an invariant and ultimate speed k as a constant of integration.
Evolution of Masers and Lasers
Authors: Lengyel Bela A.
Published: August 2005

The art of masers and lasers is founded on Einstein's discovery of stimulated emission. This discovery led to a search for methods for establishing population inversion in a suitable material and hence to the construction of a radiation amplifier. In 1954 Townes and his students constructed the first microwave amplifier and oscillator based on the stimulated emission principle. Three-level solid masers followed quickly and speculations began on extending the art into the optical region. The first ruby laser was built in 1960 by Maiman. It was quickly followed by the four-level lasers of Sorokin and Stevenson and the He-Ne laser of Javan. Large scale search for additional laser materials and more effective laser techniques began in 1961. This fascinating and frantic effort is still in progress. Its highlights are briefly described.
Kelvin and Caratheodory—A Reconciliation
Authors: Zemansky Mark W.
Published: August 2005

In conventional thermodynamics, the two most important consequences of the second law of thermodynamics, namely, the existence of an absolute temperature scale and the existence of an entropy function are deduced from the Kelvin-Planck statement or its equivalent, the Clausius statement, with the aid of the Carnot engine and Carnot refrigerator. In the Caratheodory method, a new statement of the second law is made; the Carnot cycle is dispensed with and purely analytical methods are used to derive the absolute temperature and the entropy. It is shown in this paper how the analytic methods of Caratheodory may be used without replacing the traditional statements of the second law by a new axiom. Both the Caratheodory statement of the second law and the Caratheodory theorem on Pfaffian differential forms are unnecessary.
Linear Momentum of Quasistatic Electromagnetic Fields
Authors: Calkin M. G.
Published: August 2005

It is shown that the net mechanical impulse one must exert to change one static system of currents and charges slowly into another such system is independent of the method used, and is given by the change in ΣqiAT(xi,t), where AT(xi,t) is the transverse vector potential, evaluated at the position xi of the charge qi. The linear momentum stored in a quasistatic electromagnetic field is thus given by ΣqiAT(xi,t). These considerations show that it is possible to give the transverse vector potential AT of a static system a physical meaning. Namely, that AT(x) is the net mechanical impulse one must exert to bring a unit point charge slowly from infinity to the point x.
Currents Induced by Moving Charges
Authors: Sirkis Murray D. , Holonyak Nick
Published: August 2005

This note demonstrates how the principle of conservation of energy can be used to derive in a simple and correct way the Shockley-Ramo equation for currents induced by charged particles in electronic devices. The simplest form of this equation occurs for a charge q which moves with speed v between two plane-parallel electrodes separated by a distance d. For this case the induced current I is given by I = qv/d. A one-dimensional example, for which the calculations are quite simple, is considered in detail by the energy method.
Autocorrelation Spectroscopy
Authors: Bartling Judd Q.
Published: August 2005

Partial coherence theory is used to describe Fourier spectroscopy. It is shown that the resolving power is of the form rm/aλ with the value of a depending upon the coherence time of the radiation. The effect of spatial coherence upon the experiment is considered as well as the continuous variation of the delay time. No effects of data processing are considered.
Carnot Cycle Diagrams
Authors: Kalantar A. H.
Published: August 2005

A number of interesting sketches of the Carnot cycle (operated as a heat engine and with an ideal gas as the working substance) are presented. Heat and work are used as the coordinates in addition to several thermodynamic variables (P, V, T, E, H, S, G, and A). The teaching value of such diagrams is stressed as some characteristics of the diagrams are pointed out.
Resource Letter PP-2 on Plasma Physics: Waves and Radiation Processes in Plasmas
Authors: Bekefi G. , Brown Sanborn C.
Published: August 2005

Prepared at the request of the AAPT Committee on Resource Letters; supported by a grant from the National Science Foundation.

This is one of a series of Resource Letters on different topics, intended to guide college physicists to some of the literature and other teaching aids that may help them improve course contents in specified fields of physics. No Resource Letter is meant to be exhaustive and complete; in time there may be more than one letter on some of the main subjects of interest. Comments and suggestions concerning the content and arrangement of letters as well as suggestions for future topics will be welcomed. Please send such communications to Professor Arnold Arons, Chairman Resource Letter Committee, Department of Physics, Amherst College, Amherst, Massachusetts.

Notation: The letter E after the item number means that the reference should be mainly useful for elementary courses. In view of the complexity of the subject, elementary will normally imply junior courses. The letter I indicates intermediate (senior and first-year graduates) and A indicates advanced (second-year graduates and students beginning research in plasma physics).

Additional copies: Available from American Institute of Physics, 335 East 45 Street, New York, New York 10017. When ordering, request Resource Letter PP-2 and enclose a stamped return envelope.
Direct Integration of Time-Dependent Maxwell Equations
Authors: Unz H.
Published: August 2005

Maxwell's equations for time-dependent fields are integrated directly by using the scalar-vector analog of Green's theorem and the Dirac delta function. The fields are expressed in terms of volume and surface integrals over the time varying sources. For the particular case of harmonic time variation, the results agree with previous solutions.
Method for Displaying Lines of Force in an Electrostatic Field
Authors: Cavanagh P.
Published: August 2005

The concept of magnetic lines of force usually has been substantiated by an appropriate demonstration of the arrangement of iron filings around a magnet. In the corresponding case of electric field, demonstrations have been difficult to make. This article describes a method which overcomes the difficulties and, with simple equipment and materials, illustrates three-dimensionally electric lines of force in fields of fairly low intensity.
Maxwell—Out of Newton, Coulomb, and Einstein
Authors: Tessman Jack R.
Published: August 2005

The electromagnetic field of an accelerating charge is obtained starting with (1) Coulomb's law in extended form (a stationary source charge exerts a Coulombic force on an arbitrarily moving test charge), (2) the special relativity transformation relations for coordinates and forces, (3) charge conservation, (4) Newton's third law, and (5) the assumption that electric effects are transmitted with the velocity c. This method can also be used to investigate the fields of hypothetical “charges” obeying a “Coulomb law” F = q1q2/rn, where n is different from 2.
Electrons, Photons, and Students
Authors: Portis Alan M.
Published: August 2005

The Robert A. Millikan Lecture Award is made annually to a physicist chosen by a special committee of the American Association of Physics Teachers because of his creative and imaginative contributions to the teaching of physics. The lecturer selected is one whom the Association wishes to honor at the Summer Meeting in the same way that it honors the Oersted Medalist at the time of the Annual Meeting. The award is made possible through the annual support of of Prentice-Hall, Inc.; the first award was made in 1964.

The recipient of this award for 1966 is Alan M. Portis, Professor of Physics at the University of California at Berkeley.

The four-year development of the Berkeley Physics Laboratory is described starting from its inception in the Summer of 1962. Reasons for the special attention given to electrons and photons are presented. The use of student groups in the laboratory trials is discussed. The wide response to the laboratory is analyzed. Finally, modifications currently being made in the Laboratory by the Berkeley Physics faculty are presented and discussed.
Electric Analog Network for Quantum Mechanics
Authors: Cowan E. W.
Published: August 2005

An electric network is presented in which the energy density is distributed in three-dimensional space in the same fashion as the probability density waves for a spinless particle in any given potential field. The network is of interest in that it can be easily realized physically.
Visualizing Statistical Thermodynamics: The Boltzmann Distribution Model
Authors: Sussman M. V.
Published: August 2005

Entropy change, work and heat effects, temperature, distribution functions, Brownian movement, and other elementary concepts of statistical thermodynamics can be visually demonstrated with a mechanical device that simulates some of the microscopic thermodynamic behavior of a nonatomic ideal gas.
Quantum Fact and Fiction. II
Authors: Landé Alfred
Published: August 2005

Electron diffraction was shown in Part I to be due to the quantum-mechanical activity of the diffractor rather than to a fictional wave-picture manifestation of the diffracted particles. Part II aims at eliminating further fictional elements, most of them based on inconsistency of interpretation. The controversy between the extremist views of Schrödinger and Born, either frequency resonance or quantum jumps, is removed by showing that consistency compels one to admit both to occur simultaneously. Attempts at saving duality and other fictions are criticized, such as the contention that (1) “duality is a fact” seen in the contrast of obvious particle effects and not so obvious particle effects, (2) that particles are material and waves are expectations by observing subjects, (3) that statistical law means the end of the sharp separation between subject and object, (4) that Heisenberg's empirical rule for the uncertainty of prediction means indeterminacy of existence. It is pointed out that quantum mechanics can be derived as a necessary consequence of general nonquantal postulates, known from deterministic mechanics, but applied now to the construction of a probabilistic schema of connection between events.
Kruskal Space and the Uniformly Accelerated Frame
Authors: Rindler W.
Published: August 2005

The striking formal similarities between the diagram of Kruskal space in general relativity and that of the uniformly accelerated rigid rod in special relativity are shown to be the result of certain physical similarities.
A Radiation Torque Experiment
Authors: Allen P. J.
Published: August 2005

The torque exerted by circularly polarized radiation can be demonstrated and measured in a simple microwave motor experiment. A small electric dipole, delicately suspended in a circular waveguide, continuously rotates under the torque influence of an incident circularly polarized wave of low power. A component of the wave energy scattered from the dipole experiences a natural downshift in frequency equal to twice the dipole rotation frequency. This intrinsic change in wave energy completely accounts for the power extracted from the wave in turning the dipole against damping forces. The experiment is a macroscopic model of a rotational mechanism through which spectral shifts can arise in nature, and appears to be analogous to the rotational Raman effect with linear molecules. Since the interaction between wave and dipole is reversible, the energy (frequency) of an interacting circularly polarized wave is increased whenever the direction of rotation of the scattering dipole opposes the torque of the wave. Through this mechanism, energy can be transferred from one circularly polarized wave to a second of higher frequency but of less intensity. This corresponds to the generation of an anti-Stokes line.
Anniversaries in 1966 of Interest to Physicists
Authors: Barr E. Scott
Published: August 2005

During the year 1966 there are major anniversaries of the birth or death of nine men whose accomplishments and influence have been of importance to the development of physics. They are: John Dalton, Gottfried Wilhelm von Leibniz, John Leslie, Dayton Clarence Miller, Lewis Morris Rutherfurd, Joseph Sauveur, Charles Mahon Stanhope, John Wallis, and William Hyde Wollaston. Brief accounts of their lives and achievements are given here.
Conservation of Angular Momentum
Authors: Podolsky Boris
Published: August 2005

Two usual methods of proving the Law of Conservation of Angular Momentum lead to discrepant results. It is shown that the two methods deal with different definitions of angular momentum. When the definitions agree, the discrepancy disappears.
Precision High-Resolution Mössbauer Spectrometer
Authors: Nussbaum Rudi H. , Gerstenfeld Floyd , Richardson James K.
Published: August 2005

The design, construction, and performance of a low-cost precision and high-resolution constant-velocity Mössbauer spectrometer, based on a micometer leadscrew drive, is described. Natural linewidth of 0.19 mm/sec has been obtained for the inner two lines of the six-line Fe-hyperfine spectrum.
Uncertainty Principle and Normal Operators
Authors: Bersohn Malcolm
Published: August 2005

The expression for the uncertainty principle applied to normal operators is derived. This treatment includes Hermitian operators as a special case.
Use of Langmuir Probes for Low-Density Plasma Diagnostics
Authors: Mawardi O. K.
Published: August 2005

A review is given for the theory of operation of the single and double Langmuir probe. The method of using the double Langmuir probe for the purpose of measuring the temperature and density of electrons in a plasma is described. In the remaining part of this paper, a laboratory experiment using Langmuir probes is suggested and sample calculations pertaining to such an experiment have been given.
Cesium-Diode Thermionic Converter for Laboratory Experiments
Authors: Meyerand Russell G. , Bullis Robert H.
Published: August 2005

A cesium-diode thermionic converter suitable for laboratory instruction is described. The construction of this converter employs only simple glass-blowing techniques so that it can be easily fabricated in a moderately, well-equipped physics laboratory. The use of kovar-to-glass seals and lead-glass sections has been completely eliminated, and the use of oxide glass-to-metal seals has been minimized in the construction of the converter, thereby significantly reducing the probability of cesium attack in seal areas which would seriously limit the useful lifetime of the device. Many interesting and instructive experiments involving thermionic power generation, arc-mode or ignited operation, spectroscopic studies, ion production on high work function surfaces, and the determination of converter current-voltage characteristics can be conducted with this device.
Graphing Self-Absorption Curves with Ordinary Gamma-Ray Absorption Data
Authors: Rabinoff Carter V. , Boekelheide Irving
Published: August 2005

Ordinary experimental gamma-ray absorption data can be graphed to closely approximate the theoretical self-absorption curves of W. R. Dixon. To do so emphasizes the point of Dixon's work for the student and gives additional insight into the nature of absorption. A method for accomplishing this is described.
Dynamic Consequences of Intermolecular Attraction in Gases
Authors: Thoburn W. C.
Published: August 2005

The effects of intermolecular attractions on molecular trajectories in gases are discussed. It is shown that the observed modification of pressure cannot be accounted for by any reduction in molecular speeds or by mere alterations in direction of motion. Reduced impact frequencies are shown to come about by time delay in curved trajectories. The pressure modifying term in Van der Waals' equation is derived. The approximations are recognized, and collateral evidences for the interpretation are presented.
Quantum Theory of the Forced Harmonic Oscillator
Authors: Gilbey D. M. , Goodman F. O.
Published: August 2005

A unified treatment by the methods of the operator mechanics is given of the quantum theory of the harmonic oscillator subjected to an applied force which is a given, but arbitrary, function of time. Few of the results are new, and most have appeared before scattered among papers devoted to a variety of topics and using a variety of mathematical techniques. Emphasis is placed on numerical methods for the evaluation of the relevant transition probabilities, and on the equality, under certain conditions, of the classical and quantum values of the average energy transfer to an oscillator by an impressed force. Generating functions for the transition probabilities are derived. Some numerical results are presented for illustration.
Potential Scattering
Authors: Tang K. T.
Published: August 2005

The well-known expression of the scattering amplitude is rederived from the integral representation. The exact equivalence between the integral and differential formulation is explicitly demonstrated.
Approaching the Square Root of Two
Authors: Forbes Stephen H.
Published: August 2005

An empirical approach to the problem of generating the members of the class of all right triangles whose legs differ by one unit gives rise to a sequence differing from that either of Osborne or of Kraitchik, The sequence derives from the continued fraction whose limit is 1+2 as compared with Kraitchik's 2. New sequences are possible when the legs differ by constants other than one.
Student Experiment on Coriolis Force
Authors: Hegarty John C.
Published: August 2005

A simple experiment is described in which measurements may be made of the trajectory of a of a particle moving under the influence of the Coriolis force; these measurements in turn provide experimental verification of certain elementary features of the motion.
Do-It-Yourself Knudsen Gauge
Authors: Block B. , Moore R. D. , Roos P.
Published: August 2005

A Knudsen Gauge, suitable to be designed and built by sophomores, is described. This experiment gives an example of a theory (molecular transport of momentum) which has an easily seen breakdown, namely the finite size of molecules. The students verify the idea of molecular momentum transport and then use the deviations of the experimental results at high pressures from their simple theory to give them a measurement of molecular collision cross sections.
Multiple Transforms for Mathematical Physics Courses
Authors: Slinn W. G. N.
Published: August 2005

Multiple transforms are used to solve five partial differential equations subject to boundary and initial conditions. The simplifications over single transforms that result are: the reduction of the original equation and boundary relations to a single algebraic equation, the removal of singularities in the transformed time plane (s plane) which do not originate from the physics of the problem and finally, the necessity for quoting a solution to an ordinary differential equation is removed. Because of these advantages, it is apparent that more attention should be paid to the method in mathematical physics courses.
Development of Vector Analysis from Quaternions
Authors: Stephenson Reginald J.
Published: August 2005

About the middle of last century, there were invented several forms of multiple algebra, some of which are extensively used today in mathematical physics. The two types discussed here are quaternions, a quadruple algebra, and vector analysis, a triple algebra. The notations and forms of analysis used in the two systems are contrasted, using for each their representation of scalar and vector products and of Gauss's, Stokes's and Green's theorems. Maxwell made use of the vector part of quaternions in his Treatise on Electricity, and it was largely due to this that Gibbs came to invent his form of vector analysis. By 1890, about fifty years after the invention of quaternions, it became apparent that Gibbs's vector analysis was being used in place of quaternions, and this gave rise to a heated controversy in the pages of Nature. In the seventy years since this controversy, it is apparent that Gibbs's work and point of view have been completely vindicated.
“Vectors Versus Quaternions”—The Letters in Nature
Authors: Bork Alfred M.
Published: August 2005

A facet of the development of electromagnetic theory was the choice of a proper notation. This seemingly minor problem generated a large dispute from about 1880 to 1900, reaching a climax in a series of letters in Nature arguing about the relative merits of the quaternion formulation, due to Hamilton and supported by Tait, and the newer vector analysis of Gibbs and Heaviside. This quarrel was carried on at a violent level in many letters in Nature.
Electromagnetic Mass of the Classical Electron
Authors: Zink J. W.
Published: August 2005

The difference between the electrostatic mass of the classical electron m0, and the electrodynamic mass (4/3)m0, has caused a considerable amount of confusion because the theory of relativity seems to predict that, in the limit of small velocities, the two masses should be the same. It is shown that within the structure of relativity the two masses should not necessarily be the same. The nature of each of the two masses is brought out.
Research Topic for Small Colleges: Thermoluminescence
Authors: Crawford Julian A.
Published: August 2005

A somewhat neglected area of research in the optical properties of solids is the study of thermoluminescence. The experimental method is to measure the temperature variation of the fluorescence which results from warming a sample in the dark after excitation by some form of radiation at low temperatures. Its usefulness lies in the information it furnishes concerning defect and impurity energy levels in the band gap in semiconductors and insulators. The experimental results when combined with supplementary data (obtained with the same equipment), yield information concerning the energy distribution of trapping levels and luminescent centers in the material. The relatively small investment required for experimental equipment, the very large range of potential materials for study, and the fact that comparatively little is being done in this field all combine to make thermoluminescence a good possibility for solid-state research in the smaller colleges.
Demonstration of the Buildup and Decay of Radioactivity
Authors: Ruby Lawrence
Published: August 2005

A simple apparatus is described which serves to demonstrate both the buildup and decay of radioactivity. The buildup is observed by, in effect, periodically sampling the radioactivity during activation. The sampling is effected by mounting Ag foil on a wheel which rotates it alternately between a neutron source and a beta detector.
Development of a Ruby Laser System as an Undergraduate Project
Authors: Anderson O. T. , Bedesem M. P.
Published: August 2005

The construction of a pulsed ruby laser and output measuring devices, built as a two-year undergraduate student project, is outlined. By using a silvered glass cavity with a linear flash-tube, thresholds as low as 180 J were obtained, and an energy output in excess of 0.20 J was observed at an input of 650 J. Emphasizing design and construction at all stages as opposed to acquisition of ready-made components, an attempt was made to use as many locally available parts as possible.
Study of the Simple Harmonic Oscillator by means of F-Center Absorption
Authors: Turner Thomas J.
Published: August 2005

An experiment is described which enables the student to study a simple harmonic oscillator as it changes from classical behavior to that which must be described quantum mechanically. The oscillator is the F center in KCl. A configuration coordinate diagram is used to show that the width of the center's optical absorption is proportional to the amplitude of oscillation of the ions surrounding the center. The width of the optical absorption is measured from 300 to 20°K, effectively giving the amplitude of oscillation over this temperature range. Below 50°K the amplitude does not change, indicating the zero-point oscillation. The results can be described by an expression for the amplitude as a function of temperature which is deduced from the correspondence principle.
Spectroscopy and Thermochemistry: Electronic Energy Relationships between Molecules and their Fragments
Authors: Innes K. Keith
Published: August 2005

It is suggested that an electronic energy-level diagram that includes a molecule and some of its possible dissociation products on a single scale is a useful summary of widely scattered experimental results. Since such diagrams seem to be rare in both the original and the textbook literature, four illustrations are offered. These consist of some lower energy levels available to the respective atomic combinations: 2Na, 2N+O, 2H+C+O, and 4H+4C+2N.
Introductory Physics Experiments using a Digital Computer
Authors: Ahearne John F.
Published: August 2005

The basic physics course at the United States Air Force Academy now includes an experiment using the Burroughs B-5500 Computer. The general procedure is outlined and three completed experiments discussed.
Educational Assistance Provided by the United States Atomic Energy Commission
Authors: Parker Vincent E.
Published: August 2005

The Atomic Energy Act of 1946, with its later amendments, directed the Atomic Energy Commission (AEC) to conduct research, development, and training in the field iof atomic energy. These activities were initially retained within the national laboratories and other AEC sites because the major portion of nuclear technology was classified. As declassification proceeded, the AEC started an intensive program of educational assistance activities in order to help the academic community develop its own nuclear education capabilities. These activities were supported by cooperative programs at the national laboratories. The assistance described consists of providing teachers and other scientists with opportunities to up-date their scientific knowledge, to conduct research, to participate in institutes, to obtain specialized training; providing graduate and postdoctoral fellowships, and research opportunities to students. It further provides support for special schools offering nuclear eduational opportunities too specialized for colleges and universities; and provides scientific lectures and funds for specialized equipment to nonprofit educational institutions.

The national program is described briefly. Special emphasis is given to those programs operated by the Oak Ridge Institute of Nuclear Studies.