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Dec 1977

Volume 45, Issue 12, pp. 1139-1239

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From the Compton effect to quarks and asymptotic freedom

Richard Wilson

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1139

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Jesse DuMond’s first major experiments on the broadening of the x‐ray line from Compton scattering of x rays showed the electron momenta in atoms and solids. Using electron scattering, momenta of nucleons in nuclei have been measured. Using electron or muon scattering by protons, momenta of quarks in the proton can be determined. These are all related physical processes.
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13.60.Fz Elastic and Compton scattering
14.65.-q Quarks
01.60.+q Biographies, tributes, personal notes, and obituaries
21.60.Cs Shell model

Benjamin Franklin as experimental philosopher

Samuel Devons

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1148

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The incomparable Benjamin Franklin, man of innumerable parts, pioneer of countless enterprises, set the stamp of his whole inimitable personality on all his works. A singular combination of pragmatism and idealism, of the practical and the philosophical, informed and inspired alike his business, his politics, his personal life, his experiments, and his science. Franklin’s contributions to science, and his electricity in particular, are here presented as illustrative of the exceptional talent and unique personality of this foremost experimental philosopher.
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01.65.+g History of science
01.60.+q Biographies, tributes, personal notes, and obituaries
03.50.De Classical electromagnetism, Maxwell equations

The Fizeau effect: Theory, experiment, and Zeeman’s measurements

I. Lerche

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1154 | Cited 5 times

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We have reconciled the apparent differences between the many theoretical formulas proposed over the years which purport to account for the speed of light in a moving medium being different from in a stationary medium. The majority of the differences arise from an imprecise definition, or use, of wavelength. A few of the formulas proposed are wrong and the errors are illustrated. We then appraise the basic experimental setup designed to measure the Fizeau effect pointing out the fundamental physical limitations inherent in the experiment and describing the sources of random experimental error. (There are always possible systematic errors about which we can say, or do, little.) In the light of the above analyses, we then consider the accuracy of the experiments reported by Zeeman—who is nearly always quoted as having performed the decisive experiments on the dispersive term in the Fizeau coeficient. We show that the minimum errors in his experiments are sufficient to rule out his capability for distinguishing experimentally between the competing formulas of Fresnel and Lorentz for the Fizeau effect; and, besides, the flow pattern Zeeman used was highly turbulent while the theory is known only for laminar flow. We suggest that the dispersive term in the Fizeau coefficient has not yet been accurately measured and we urge repetition of the experiment.
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03.30.+p Special relativity
42.25.Bs Wave propagation, transmission and absorption
42.25.Dd Wave propagation in random media

Views of the universe over cosmological time spans

J. K. Lawrence

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1164

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We consider an Earth observer’s view of the universe as it would appear at various stages of its evolution. This is calculated numerically from the relativistic Friedmann universe models and is presented in the form of Hubble plots of red shift versus distance for distant galaxies. Trajectories of particular galaxies followed through time are also shown. In the case of a closed universe, the results are particularly complex and interesting.
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04.20.-q Classical general relativity
98.80.-k Cosmology

Evolution of the black‐body spectrum in the Friedmann universe

James H. Cooke

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1168 | Cited 2 times

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A fully rigorous, but simple, derivation of the evolution of an initially black‐body spectrum in the closed Friedmann universe is given. Some authors have assumed that, strictly speaking, one cannot speak of thermal equilibrium of the radiation, since it is in a changing gravitational background. This is shown to be incorrect, and a simple analogy of vibrations on an expanding circle of string illustrates the reason. It is possible to define a very natural dimensionless equilibrium constant. Finally, the problem of finding the electromagnetic eigenmodes is solved efficiently with differential forms.
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04.20.-q Classical general relativity
04.30.-w Gravitational waves

Riemann curvature tensor and closed geodesic paths

Ralph E. Morganstern

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1173 | Cited 1 time

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It is shown how standard treatments of the change in a vector Δξi under parallel transport about a closed path in Riemannian spacetime lead to erroneous results if a complete circuit is made rather than just half a circuit followed by antisymmetrization. In fact a nonzero change in the vector is obtained upon returning to the initial point via the reversed path. The error in these treatments is shown to involve several aspects of the law of transplantation for a vector and the idea of path reversal in curved spaces.
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04.20.-q Classical general relativity
02.40.Ky Riemannian geometries

The career oriented pretechnical physics project

Walt Elliott

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1176

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A career oriented pretechnical physics curriculum was successfully tested in four Dallas high schools during the school year 1973–74. The curriculum consists of a set of minicourses from which students tailor a physics course to meet their personal interests, needs, and abilities. Although designed for self‐pacing, the minicourses appear suitable for lock‐step instructional modes. The experimenal minicourse students indicated that they liked physics better, preferred minicourse instruction to traditional instruction, were more positive in valuing their performance in learning physics, and exhibited physics knowledge comparable to that of the control group. Those schools using the minicourses experienced exciting gains in physics enrollments.
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01.40.Di Course design and evaluation
01.40.G- Curricula and evaluation

Mathematical statistics in student physics laboratories

Henryk Szydlowski

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1180

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Problems related to the modernization of the experimental procedure are considered based on the author’s experience as head of the physics majors’ laboratory. The curriculum for our freshmen has been modified to include, in the first semester, a lecture course and blackboard exercises in measurement theory largely comprising elements of mathematical statistics. Wortk in the physics laboratory during the second and third semesters has been made to include, to a much higher degree than hitherto, the elements of mathematical statistics. Statistical methods of measurement designing and experimental results evaluation are applied. As a rule, standard deviations as well as correlation and regression factors are determined, and the testing of statistical hypotheses is required. Conclusions from the experience gained are discussed briefly.
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01.50.Qb Laboratory course design, organization, and evaluation
06.20.-f Metrology
02.50.-r Probability theory, stochastic processes, and statistics

Derivation of noise formulas using Campbell’s theorem

E. Mathieson

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1184

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Campbell’s theorem evaluates the mean‐square fluctuation in the output of a system whose input is subject to a random succession of equal strength impulses. It is pointed out that this important theorem may be conveniently employed as the basis for a brief discussion of electrical noise in an undergraduate physics course. Practical formulas are derived to describe certain shot‐noise situations. By using a specific conduction model, it is shown how Campbell’s theorem may also be applied to obtain thermal‐noise formulas.
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72.70.+m Noise processes and phenomena
84.30.Bv Circuit theory
85.90.+h Other topics in electronic and magnetic devices and microelectronics (restricted to new topics in section 85)

Group velocity in crystal optics

D. F. Nelson

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1187

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We show, contrary to developments in prominent optics texts, that the assumption of a single‐frequency wave does not eliminate the effect of frequency dispersion upon the energy transport (group) velocity nor upon the energy density.
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83.10.Ff Continuum mechanics
42.25.Lc Birefringence

On the unambiguity of stationary perturbation theory

Willem M. de Muynck

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1191 | Cited 1 time

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The relation is obtained between the solution of the stationary perturbation problem for which the unperturbed states ‖ En 〉 and the perturbed states ‖ Wn 〉 obey the relation 〈 Wn ‖ En 〉 = 1, and the solution in case this requirement is not made. This is done in all orders of the perturbation theory. It is shown that the influence of the requirement amounts to a normalization factor which is not merely a phase factor.
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03.65.-w Quantum mechanics

A physical explanation of the gyroscope effect

P. L. Edwards

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1194 | Cited 3 times

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A force applied perpendicular to a point on the axis of a rotating gyroscope does not cause the point of application, unless it happens to be the center of gravity, to move in the direction of the force, as might be expected, but at approximately 90° to it. We show that this effect can be understood physically by considering the rotation of two equal masses mounted on a frame of negligible mass. It is also noted that the mathematical simplifications made in the study of rigid‐body motion often tend to obscure what is happening physically.
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45.05.+x General theory of classical mechanics of discrete systems

Some plasma physics experiments on electrical conductivity and similarity laws

J. T. Pytlinski and I. Alexeff

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1196 | Cited 1 time

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Two elementary experiments treating plasma electrical conductivity and similarity laws are described. Plasma is generated by means of commercially available gas tubes. Basic electronic equipment of low cost, available in most laboratories, is used. The experiments are especially suitable for an introductory course in plasma physics.
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01.50.Pa Laboratory experiments and apparatus
52.80.Dy Low-field and Townsend discharges
52.25.Fi Transport properties

Classical and quantum spreading of position probability

J. E. G. Farina

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1200 | Cited 3 times

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If Δxt is the standard deviation of the position probability distribution at time t of a particle moving freely in one dimension, and Δv is the standard deviation of its velocity distribution, it is shown for a suitable choice of time origin that (Δxt)2 =  (Δx0)2 +  (Δv)2t2 whether the particle is moving classically or quantum mechanically. The quantum‐mechanical proof is shown to exactly parallel that in the classical case. In the classical case, the correlation coefficient between the velocity and position distributions is shown to tend to −1 as t → −∞, to increase steadily with time, and to become +1 as t → +∞. A quantum‐mechanical analog of this result is also proved.
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45.05.+x General theory of classical mechanics of discrete systems
03.65.-w Quantum mechanics

Concept of temperature without the zeroth law

Dipankar Home

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1203 | Cited 1 time

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The present article consists of two parts: (1) criticism of the zeroth law, and (2) development of thermodynamics dispensing with the zeroth law. Two main criticisms of the zeroth law are (a) it is not an independent law of thermodynamics, and (b) it does not furnish even a qualitative objective definition of temperature. It is, therefore, asserted that the concept of temperature must not be introduced before the second law. How the second law can be used to give a complete objective definition of temperature consistent with the zeroth law is then discussed.
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05.70.-a Thermodynamics

Humanistic physics: A course using paraphysical topics to illustrate the scientific method

Michael K. Garrity

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1206

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Community‐interest short courses in physics can be developed to increase awareness of the methods and principles of science despite the reluctance of the general public to explore the unfamiliar. Humanistic physics uses topics chosen from neuroscience and the study of the paranormal, as well as demonstrations and lectures given by informed individuals from other disciplines, to cultivate an appreciation for the power as well as the limit of the scientific method when applied to the synergistic nature of man and his reaction with his environment.
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01.75.+m Science and society
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Comment on ’’Are the Lorentz transformations kinematically consistent?’’

Nancy Hicks

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1210

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Abstract Unavailable
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03.30.+p Special relativity

Author’s reply

Wallace Kantor

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1210

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Abstract Unavailable
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03.30.+p Special relativity

Doppler effect in special relativity theory

B. L. Rawat

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1211

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Abstract Unavailable
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03.30.+p Special relativity

The velocity of a pulse on a string

John M. Wessner

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1212

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Abstract Unavailable
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83.10.Ff Continuum mechanics
41.20.Jb Electromagnetic wave propagation; radiowave propagation

A laboratory determination of the total decay energy for electron‐capture process from inner bremsstrahlung spectrum

H. Sanjeeviah, S. Gopal, and B. Sanjeevaiah

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1214

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Abstract Unavailable
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01.50.Pa Laboratory experiments and apparatus
23.40.-s β decay; double β decay; electron and muon capture

The mean radius in Kepler’s third law

John E. Prussing

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1216

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Abstract Unavailable
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45.05.+x General theory of classical mechanics of discrete systems

Mass velocity dependence without the momentum principle

Michel Nicola

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1218

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Abstract Unavailable
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03.30.+p Special relativity

The equivalence principle and quantum mechanics

C. J. Eliezer and P. G. Leach

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1218 | Cited 3 times

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Abstract Unavailable
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45.05.+x General theory of classical mechanics of discrete systems
03.65.-w Quantum mechanics

More parallax without pain

Joe L. Ferguson

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1221

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Abstract Unavailable
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01.50.Pa Laboratory experiments and apparatus
06.30.Bp Spatial dimensions (e.g., position, lengths, volume, angles, and displacements)

Comment on the unit perfection requirement in PSI

Robert D. Young and Charles P. Frahm

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1222

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Abstract Unavailable
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01.40.G- Curricula and evaluation

Degree of polarization in reflection

R. Simon and V. Srinivasan

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1223

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Abstract Unavailable
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03.50.De Classical electromagnetism, Maxwell equations
41.20.Jb Electromagnetic wave propagation; radiowave propagation

On the deductive and inductive nature of Newton’s gravitation law

Budh Ram

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1223 | Cited 1 time

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Abstract Unavailable
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01.65.+g History of science
95.10.Ce Celestial mechanics (including n-body problems)

The relativistic transformation of the energy and momentum of a gas

M. G. Calkin and M. H. Jericho

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1224 | Cited 1 time

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Abstract Unavailable
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03.30.+p Special relativity
05.20.-y Classical statistical mechanics

Some comments on the ’’axiomatic’’ formulation of the first law of thermodynamics

Joseph de Heer

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1225 | Cited 1 time

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Abstract Unavailable
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05.70.-a Thermodynamics

On momentum operators

Prakash Chand and R. Casanova

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1226 | Cited 1 time

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Abstract Unavailable
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03.65.-w Quantum mechanics

The classical Doppler effect and intuition

Herman Erlichson

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1227

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Abstract Unavailable
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01.40.G- Curricula and evaluation
83.10.Ff Continuum mechanics

Stellar aberration and the hodograph for the Kepler problem

Peter D. Noerdlinger

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1229

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Abstract Unavailable
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98.10.+z Stellar dynamics and kinematics
95.10.-a Fundamental astronomy

Erratum: ’’An elementary derivation of the perturbation equations of celestial mechanics’’

Joseph A. Burns

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1230 | Cited 4 times

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Abstract Unavailable
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99.10.Cd Errata
45.05.+x General theory of classical mechanics of discrete systems

Erratum: ’’An interesting exactly soluble one‐dimensional Hartree problem’’

L. L. Foldy

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1230 | Cited 1 time

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Abstract Unavailable
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99.10.Cd Errata
03.65.-w Quantum mechanics

Erratum: ’’Hartree‐Fock approximation for the one‐dimensional helium atom’’

Y. Nogami, M. Vallières, and W. van Dijk

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1231 | Cited 2 times

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Abstract Unavailable
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99.10.Cd Errata
03.65.-w Quantum mechanics
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Acoustical and ballistic derivations of the Lorentz transformation

Carl A. Zapffe

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1232

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Abstract Unavailable
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03.30.+p Special relativity
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Very low frequency oscillator

Lee Gray

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1234

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Abstract Unavailable
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01.50.My Demonstration experiments and apparatus
85.40.-e Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology
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Essential Relativity: Special, General, and Cosmological

Wolfgang Rindler, Author and Hans C. Ohanian

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1235

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Abstract Unavailable
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01.30.mp Textbooks for undergraduates
03.30.+p Special relativity
04.20.-q Classical general relativity

How to Buy and Use Minicomputers and Microcomputers

William Barden, Author and Robert F. Tinker

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1236

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Abstract Unavailable
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01.30.Ee Monographs and collections
01.50.ht Instructional computer use
07.05.-t Computers in experimental physics

Microcomputer Primer

Mitchell Waite, Author, Michael Pardee, Author, and Robert F. Tinker

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1237

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Abstract Unavailable
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01.30.Ee Monographs and collections
01.50.ht Instructional computer use
07.05.-t Computers in experimental physics
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The Key to the Universe (film)

BBC Producer, WTTW Producer, and John Kogut

American Journal of Physics -- December 1977 -- Volume 45, Issue 12, pp. 1238

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Abstract Unavailable
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01.50.F- Audio and visual aids
11.10.-z Field theory
98.80.Ft Origin, formation, and abundances of the elements
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