Physics Commons^™

Dynamical Effects Of Partial Orderings In Physical Systems, Adam S. Landsberg, Eric J. Friedman

WM Keck Science Faculty Papers

We demonstrate that many physical systems possess an often overlooked property known as a partial-ordering structure. The detection and analysis of this special geometric property can be crucial for understanding a system's dynamical behavior. We review here the fundamental dynamical features common to all such systems, and describe how the partial ordering imposes interesting restrictions on their possible behavior. We show, for instance, that though such systems are capable of displaying highly complex and even chaotic behaviors, most of their experimentally observable behaviors will be simple. Partial orderings are illustrated with examples drawn from many branches of physics, including solid …

Quantum Deformation Of Quantum Gravity, Seth Major, L. Smolin

Articles

We describe a deformation of the observable algebra of quantum gravity in which the loop algebra is extended to framed loops. This allows an alternative nonperturbative quantization which is suitable for describing a phase of quantum gravity characterized by states which are normalizable in the measure of Chern-Simons theory. The spinor identities are extended to a set of relations which are governed by the Kauffman bracket so that the spin network basis is deformed to a basis of SU(2)q spin networks. This deformation parameter, q, is eih̵2G2Λ6" role="presentation" style="box-sizing: border-box; display: inline-block; line-height: normal; font-size: 14.4px; word-wrap: …

Research Vs. Teaching: An Ethical Dilemma For The Academic Physicist, Alvin M. Saperstein

Ethics in Science and Engineering National Clearinghouse

The usual discussions of academic ethics and freedom revolve around the issues of what we may teach. Here, I'm concerned with how we teach and examine. Thus this paper is concerned with process rather than substance--perhaps an unusual concern for an academic but currently of interest to me, having recently served a year in the federal bureaucracy where process is dominant over substance.

A physician who knew of improved procedures to facilitate the health of a patient but chose to use older, proven less effective, means, purely for his/her own convenience, would clearly be guilty of medical malpractice--unethical behavior. I …

Ethics, Physics, And Public Policy, Tina Kaarsberg

Ethics in Science and Engineering National Clearinghouse

This paper discusses the ethical aspects of physicists', and the physics community's involvement in public policy. The work of individual physicists is often quite distant from any societal impact and thus public policy is not normally considered an important ethical consideration for individual physicists. However, in light of the great societal impact of physics-based technologies, the physics profession, by definition, has a major impact on public policy. In addition, most physicists in the U.S. benefited considerably from public funding in their physics education, and many continue to depend upon federal and state funding. Thus, there is a strong ethical argument …

Should Physics Students Take A Course In Ethics? Physicists Respond, Bonnie Wylo, Marshall Thomsen

Ethics in Science and Engineering National Clearinghouse

Should physics students take a course in ethics? A National Science Foundation grant was written by the authors in an attempt (in part) to answer this question. One might first ask, why might physics students take a course in ethics? There are three reasons that might combine to persuade one of the necessity. First, the formal training can be quite practical and useful in the daily life of a physicist, as discussed below. Second, the National Science Teachers Association suggests an ethical component in the training of high school physics teachers (NSTA Standards for Science Teacher Preparation, available at www.nsta.org). …

Publication Practices In Physics, Marshall Thomsen

Ethics in Science and Engineering National Clearinghouse

Publication of research results in scholarly journals plays an important role in the scientific community. These publications provide both a means for dissemination of new results and a means for evaluating the quality of scientific work and the scientists who perform it. This paper will examine motivations for publishing, ethical issues in publication, some relevant ethical codes, and some corrective measures that have been taken to shore up areas of ethical concern. Finally, the impact of new communications technologies on the future of publication will be considered.

Ethical Issues In Physics: Ethical Harassment, Caroline L. Herzenberg

Ethics in Science and Engineering National Clearinghouse

The concept of ethical harassment is identified and discussed. It is proposed that we search for societal mechanisms that may lead to some progress in the curtailment of ethical harassment. It is proposed that the right to act ethically should be regarded as a fundamental human and professional right.

Dynamics Of Conversion Of Conduction Electrons Into A Collective Charge-Density-Wave Current, Alexander S. Kovalev, Yuriy V. Pershin Dr, Alexander S. Rozhavsky

Faculty Publications

The exactly solvable model which describes the dynamics of transformation of conduction electrons into nonlinear charge-carrying excitations of charge-density waves in quasi-one-dimensional Peierls-Frohlich conductors is formulated and studied by the inverse scattering transformation method. The pair of self-trapped conduction electrons transform into a charged 2π kink localized in a single conducting chain and surrounded by dipoles in neighboring chains.

Oscillatory Doubly Diffusive Convection In A Finite Container, Adam S. Landsberg, Edgar Knobloch

WM Keck Science Faculty Papers

Oscillatory doubly diffusive convection in a large aspect ratio Hele-Shaw cell is considered. The partial differential equations are reduced via center-unstable manifold reduction to the normal form equations describing the interaction of even and odd parity standing waves near onset. These equations take the form of the equations for a Hopf bifurcation with approximate D4 symmetry, verifying the conclusions of the preceding paper [A.S. Landsberg and E. Knobloch, Phys. Rev. E 53, 3579 (1996)]. In particular, the amplitude equations differ in the limit of large aspect ratios from the usual Ginzburg-Landau description in having additional nonlinear terms with O(1) coefficients. …

Oscillatory Bifurcation With Broken Translation Symmetry, Adam S. Landsberg, Edgar Knobloch

WM Keck Science Faculty Papers

The effect of distant endwalls on the bifurcation to traveling waves is considered. Previous approaches have treated the problem by assuming that it is a weak perturbation of the translation invariant problem. When the problem is formulated instead in a finite box of length L and the limit L--> [infinity] is taken, one obtains amplitude equations that differ from the usual Ginzburg-Landau description by the presence of an additional nonlinear term. This formulation leads to a description in terms of the amplitudes of the primary box modes, which are odd and even parity standing waves. For large L, the equations …

Basic Astronomy Labs, Terry L. Smith, Michael D. Reynolds, Jay S. Huebner

Physics Faculty Research and Scholarship

Providing the tools and know-how to apply the principles of astronomy first-hand, these 43 laboratory exercises each contain an introduction that clearly shows budding astronomers why the particular topic of that lab is of interest and relevant to astronomy. About one-third of the exercises are devoted solely to observation, and no mathematics is required beyond simple high school algebra and trigonometry.Organizes exercises into six major topics—sky, optics and spectroscopy, celestial mechanics, solar system, stellar properties, and exploration and other topics—providing clear outlines of what is involved in the exercise, its purpose, and what procedures and apparatus are to be used. …

Deep Inelastic Scattering Of Polarized Electrons By Polarized ³He And The Study Of The Neutron Spin Structure, P. L. Anthony, R. G. Arnold, H. R. Band, H. Borel, P. E. Bosted, V. Breton, G. D. Cates, T. E. Chupp, F. S. Dietrich, J. Dunne, R. Erbacher, J. Felbauum, H. Fonvielle, R. Gearhart, R. Holmes, E. W. Hughes, J. R. Johnson, D. Kawall, C. Keppel, S. E. Kuhn, R. M. Lombard-Nelsen, J. Marroncle, T. Maruyama, W. Meyer, Z.- E. Meziani, H. Middleton, J. Morgenstern, N. R. Newbury, G. G. Petratos, R Pitthan, R. Prepost, Y. Robin, S. E. Rock, S. H. Rokni, G. Shapiro, T. Smith, P. A. Souder, M. Spengos, F. Staley, L. M. Stuart, Z. M. Szlata, Y. Terrien, A. K. Thompson, J. L. White, M. Woods, J. Xu, C. C. Young, G. Zaplac, E142 Collaboration

Physics Faculty Publications

The neutron longitudinal and transverse asymmetries A₁ⁿ and A₂ⁿ have been extracted from deep inelastic scattering of polarized electrons by a polarized ³He target at incident energies of 19.42, 22.66, and 25.51 GeV. The measurement allows for the determination of the neutron spin structure functions g₁ⁿ (x,Q²) and g₂ⁿ(x,Q²) over the range 0.032 of 2 (GeV/c)². The data are used for the evaluation of the Ellis-Jaffe and Bjorken sum rules. The neutron spin structure function g₁ⁿ(x,Q²) is small and …

Inclusive Electron Scattering From Nuclei At X≃1, J. Arrington, P. Anthony, R. G. Arnold, E. J. Beise, J. E. Belz, P. E. Bosted, H.- J. Bulten, M. S. Chapman, K. P. Coulter, F. Dietrich, R. Ent, M. Epstein, B. W. Filippone, H. Gao, R. A. Gearhart, D. F. Geesaman, J.- O. Hansen, R. J. Holt, H. E. Jackson, C. E. Jones, C. E. Keppel, E. R. Kinney, S. Kuhn, K. Lee, W. Lorenzon, A. Lung, N.C.R. Malkins, D. J. Margaziotis, R. D. Mckeown, R. G. Milner, B. Mueller, J. Napolitano, J. Nelson, T.G. O'Neill, V. Papavassiliou, G. G. Petratos, D. H. Potterveld, S. E. Rock, M. Spengos, Z. M. Szalata, L. H. Tao, K. Van Bibber, J.F.J. Van Den Brand, J. L. White, D. Winter, B. Zeidman

Physics Faculty Publications

The inclusive A(e,e') cross section for x≃1 was measured on ²H, C, Fe, and Au for momentum transfers Q² from 1 to 6.8 (GeV/c)². The scaling behavior of the data was examined in the region of transition from y scaling to x scaling. Throughout this transitional region, the data exhibit ξ scaling, reminiscent of the Bloom-Gilman duality seen in free nucleon scattering.