AAPT Logo
AJP Logo
 
   
 

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

Mar 1990

Volume 58, Issue 3, pp. 199-287

back to top
RSS Feeds

Guest Comment: A broader role for books

Ralph Baierlein

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 199

Full Text: | Download PDF

Abstract Unavailable
Show PACS
01.30.mp Textbooks for undergraduates
back to top
RSS Feeds

Resource Letter MD‐1: Maxwell’s demon

Harvey S. Leff and Andrew F. Rex

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 201

Full Text: | Download PDF

Show Abstract
This Resource Letter provides a comprehensive guide to the voluminous literature that has developed around Maxwell’s demon, and offers a perspective on issues for which the hypothetical character Maxwell introduced over 120 years ago has inspired continuing research and debate. The code (E) indicates elementary level or general interest material useful to persons just learning the field; (I) indicates intermediate level or somewhat specialized material; and (A) indicates advanced or highly specialized material. No accompanying AAPT reprint book will be available, because an extensive reprint collection (Ref. 29) edited by the authors will be published separately.
Show PACS
01.30.Rr Surveys and tutorial papers; resource letters
05.90.+m Other topics in statistical physics, thermodynamics, and nonlinear dynamical systems (restricted to new topics in section 05)

Feynman’s proof of the Maxwell equations

Freeman J. Dyson

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 209 | Cited 14 times

Full Text: | Download PDF

Show Abstract
Feynman’s proof of the Maxwell equations, discovered in 1948 but never published, is here put on record, together with some editorial comments to put the proof into its historical context.
Show PACS
03.50.De Classical electromagnetism, Maxwell equations

Nitrogen temperature superconducting ring experiment

Fuhan Liu, Rochelle R. Tucker, and Peter Heller

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 211

Full Text: | Download PDF

Show Abstract
A student experiment is described for studying persistent currents in a commercially obtained ring of the ‘‘123’’ superconducting material at liquid‐nitrogen temperature. The currents are easily detected with a standard analog Hall probe. From observations extended over a 3‐week period, an upper limit on the possible resistance of one such ring was set at about 2×10−16 Ω. For the rings studied, the induced current saturated at about 2 A as the applied flux change was increased. An ac technique for checking the continuity of the superconducting path around the ring is also described. These experiments provide an interesting supplement for topics in first‐year electricity and magnetism. The effects are striking and easily discussed at an introductory level. For example, the current induced by turning the ring over in the Earth’s field is readily seen.
Show PACS
01.50.Pa Laboratory experiments and apparatus
74.70.-b Superconducting materials other than cuprates

The American Physical Society: A survey of its first 50 years

Melba Phillips

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 219 | Cited 1 time

Full Text: | Download PDF

Show Abstract
As the distinct scientific professions arose in the 19th century, the need for professional societies was felt. Spurred by the momentous discoveries of its last decade (x rays, radioactivity, the electron), the American Physical Society was organized in 1899. The initiative was taken by Arthur Gordon Webster; Rowland and Michelson, the most prestigious physicists in the country, accepted positions as president and vice president. The chief and almost exclusive concern of APS was the encouragement of research in pure physics. This single‐minded behavior resulted in the formation of other societies of physicists: the Optical Society of America in 1916, the Acoustical Society of America and the Society of Rheologists in 1929, and the American Association of Physics Teachers in 1930, with talk of associations for applied physics and mathematical physics. That fragmentation coupled with the financial difficulties of the APS led to the formation of the American Institute of Physics in 1931. AIP played a more active role during the war years than did APS, but after the war the Physical Society grew rapidly. Its 50th anniversary celebration, held at Harvard, was characterized by optimism despite the existence of many new problems.
Show PACS
01.10.Hx Physics organizational activities
01.65.+g History of science

Application of the variational method to one‐dimensional infinite wells with internal cxn potentials

David Keeports

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 230

Full Text: | Download PDF

Show Abstract
The variational method is applied to the problem of a cxn potential within an infinite one‐dimensional well. Approximate ground‐ and excited‐state wavefunctions are constructed as linear combinations of two‐term even and odd polynomials. Comparisons are made between calculated approximate wavefunctions and energies, and results predicted from perturbation theory and from the behavior of related systems.
Show PACS
03.65.Ge Solutions of wave equations: bound states

The physics of fly casting

John M. Robson

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 234 | Cited 2 times

Full Text: | Download PDF

Show Abstract
The physics of the forward motion of the flyline during a fly cast is discussed, and a computer model of this motion is proposed which reproduces the main features of this part of the cast.
Show PACS
45.05.+x General theory of classical mechanics of discrete systems

Second law: Sears–Kestin statement and Clausius inequality

W. Muschik

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 241

Full Text: | Download PDF

Show Abstract
The Sears–Kestin statement represents a formulation of the second law of thermodynamics, restricted to adiabatic processes, which links equilibrium states and which is cyclic in the work variables (generalized displacements). Two conditions, formulated as axioms, are specified which, together with the Sears–Kestin statement, are necessary and sufficient to derive the Clausius inequality. Because these two additional axioms relate to reversible processes and to compound systems—general items not affecting the second law—the status of the Sears–Kestin statement among all the formulations of the second law is strengthened.
Show PACS
05.70.-a Thermodynamics

Do darker objects really cool faster?

Richard A. Bartels

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 244

Full Text: | Download PDF

Show Abstract
A common laboratory experiment in radiative heat transfer involves measuring the cooling rate of two water‐filled metal cans, one can left unpainted and the other painted black. The shiny unpainted can cools more slowly, and the student can be led to the incorrect conclusion that bodies that are poor emitters (good reflectors) of light are also poor emitters of heat. A variation of this experiment was done with the shiny unpainted can replaced by one painted white. The experiment still compares a good and poor reflector of light, but in this case there is essentially no difference in cooling rates. These results are explained and are discussed in terms of other phenomena involving radiative heat transfer.
Show PACS
44.40.+a Thermal radiation

The fighter pilot’s egg

Dale W. Fry

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 248

Full Text: | Download PDF

Show Abstract
Of common interest to fighter pilots is what maneuver should be flown to accomplish a 360° heading change in the least time. Among the infinite possibilities, analytic expressions for a very commonly used maneuver, a roughly circular planar turn that accomplishes the required heading change, are derived and examined under four realistic assumptions. Contrary to common belief, the time to complete the stated heading change turns out to be independent of the inclination of the plane of the turn.
Show PACS
45.05.+x General theory of classical mechanics of discrete systems

Cameron–Martin–Wiener expansions and one‐electron quantum transport

L. Radzihovsky and S. Nettel

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 252

Full Text: | Download PDF

Show Abstract
In 1946 Cameron and Martin concluded a paper [‘‘The orthogonal development of non‐linear functionals in series of Fourier–Hermite functionals,’’ Ann. Math. 48, 385–392 (1947)] by saying: ‘‘This paper opens up the whole set of techniques of Orthogonal Developments...for use...in the study of non‐linear functionals... .’’ Here, the Cameron–Martin–Wiener expansion is developed with mathematics familiar to physicists, and its use is illustrated and applied to a quantum theory of electron transport.
Show PACS
72.10.Bg General formulation of transport theory
02.30.Sa Functional analysis

An approximate image solution method for the electrostatic quadrupole lens

James Cederberg, Richard Thomas, and David Bartz

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 257

Full Text: | Download PDF

Show Abstract
While no simple image method exists that yields an exact solution for the potential around the parallel conducting cylinders of a quadrupole electrostatic lens, we have found that using two line image charges in each cylinder makes an excellent approximation. Graphs are presented of the equipotentials and contours of electric field squared for different rod spacing.
Show PACS
41.20.Cv Electrostatics; Poisson and Laplace equations, boundary-value problems
41.20.Gz Magnetostatics; magnetic shielding, magnetic induction, boundary-value problems

Lise Meitner’s escape from Germany

Ruth Lewin Sime

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 262

Full Text: | Download PDF

Show Abstract
Lise Meitner (1878–1968) achieved prominence as a nuclear physicist in Germany; although of Jewish origin, her Austrian citizenship exempted her from Nazi racial laws until the annexation of Austria in 1938 precipitated her dismissal. Forbidden to emigrate, she narrowly escaped to the Netherlands with the help of concerned friends in the international physics community.
Show PACS
01.60.+q Biographies, tributes, personal notes, and obituaries

Random multiplicative processes: An elementary tutorial

S. Redner

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 267 | Cited 9 times

Full Text: | Download PDF

Show Abstract
An elementary discussion of the statistical properties of the product of N independent random variables is given. The motivation is to emphasize the essential differences between the asymptotic N→∞ behavior of a random product and the asymptotic behavior of a sum of random variables—a random additive process. For this latter process, it is widely appreciated that the asymptotic behavior of the sum and its distribution is provided by the central limit theorem. However, no such universal principle exists for a random multiplicative process. In this case, the ratio between the average value of the product 〈P〉 and the most probable value Pmp diverges exponentially in N as N→∞. Within a continuum approximation, the classical log‐normal form is often invoked to describe the distribution of the product. It is shown, however, that the log‐normal provides a poor approximation for the asymptotic behavior of the average value and, also, for the higher moments of the product. A procedure for computing the correct leading asymptotic behavior of the moments is outlined. The implications of these results for simulations of random multiplicative processes are also discussed. For such a simulation, the numerically observed ‘‘average’’ value of the product is of the order of Pmp, and it is only when the simulation is large enough to sample a finite fraction of all the states in the system that a monotonic crossover to the true average value 〈P〉 occurs. An idealized, but quantitative account for this crossover is provided.
Show PACS
02.50.Ey Stochastic processes
05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion
01.30.Rr Surveys and tutorial papers; resource letters

Comment on ‘‘Newton’s Principia and the external gravitational field of a spherically symmetric mass distribution,’’ by R. Weinstock [Am. J. Phys. 52, 883–890 (1984)]

Herman Erlichson

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 274

Full Text: | Download PDF

Abstract Unavailable
Show PACS
01.65.+g History of science
45.05.+x General theory of classical mechanics of discrete systems

Strong shielding due to an electromagnetically thin metal sheet

P. Rochon and N. Gauthier

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 276

Full Text: | Download PDF

Abstract Unavailable
Show PACS
41.20.Gz Magnetostatics; magnetic shielding, magnetic induction, boundary-value problems
back to top
RSS Feeds

Simulating ideal self‐induction

Lance Breger and Ronald E. Jodoin

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 278

Full Text: | Download PDF

Abstract Unavailable
Show PACS
01.50.My Demonstration experiments and apparatus
41.20.Gz Magnetostatics; magnetic shielding, magnetic induction, boundary-value problems
84.30.Le Amplifiers
84.32.Hh Inductors and coils; wiring

Rotating liquid mirror

Richard E. Berg

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 280

Full Text: | Download PDF

Abstract Unavailable
Show PACS
01.50.My Demonstration experiments and apparatus
42.15.Eq Optical system design
42.79.Bh Lenses, prisms and mirrors
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
47.32.Ef Rotating and swirling flows
back to top
RSS Feeds

POST‐USE REVIEW: Introduction to Elementary Particles

David Griffiths, Author and Gerald W. Intemann

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 282

Full Text: | Download PDF

Abstract Unavailable
Show PACS
01.30.mp Textbooks for undergraduates
11.90.+t Other topics in general theory of fields and particles (restricted to new topics in section 11)
12.90.+b Miscellaneous theoretical ideas and models (restricted to new topics in section 12)

The Path of No Resistance

Bruce Schechter, Author and Anil Khurana

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 283

Full Text: | Download PDF

Abstract Unavailable
Show PACS
01.30.Ee Monographs and collections
74.70.-b Superconducting materials other than cuprates
74.25.-q Properties of superconductors
74.20.Mn Nonconventional mechanisms
74.20.Rp Pairing symmetries (other than s-wave)

Newton’s Dream

Marcia Sweet Stayer, Editor and Ravi Ravindra

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 285

Full Text: | Download PDF

Abstract Unavailable
Show PACS
01.30.Ee Monographs and collections
01.65.+g History of science

The New Physics

Paul Davies, Editor and Freeman J. Dyson

American Journal of Physics -- March 1990 -- Volume 58, Issue 3, pp. 286

Full Text: | Download PDF

Abstract Unavailable
Show PACS
01.30.Ee Monographs and collections
04.90.+e Other topics in general relativity and gravitation (restricted to new topics in section 04)
12.90.+b Miscellaneous theoretical ideas and models (restricted to new topics in section 12)
98.90.+s Other topics on stellar systems; interstellar medium; galactic and extragalactic objects and systems; the Universe (restricted to new topics in section 98)
Close

Your Recent History Recent History Help

Recently Viewed

  1. Henry Cavendish, Johann von Soldner, and the deflection of light
  2. Wormholes in spacetime and their use for interstellar travel: A tool for teaching general relativity
  3. Learning from computers about physics teaching
  4. Resource Letter FR‐1: Fractals
  5. The date and time of the vernal equinox: A graphical representation of the Gregorian calendar

AAPT on:

close