It is shown by means of general principles and specific examples that, contrary to a long-standing misconception, the modern mathematical physics of compressible fluid dynamics provides a generally consistent and efficient language for describing many seemingly fundamental physical phenomena. It is shown to be appropriate for describing electric and gravitational force fields, the quantized structure of charged elementary particles, the speed of light propagation, relativistic phenomena, the inertia of matter, the expansion of the universe, and the physical nature of (...) time. New avenues and opportunities for fundamental theoretical research are thereby illuminated. (shrink)

We give an explicit solution of a model Boltzmann kinetic equation describing a gas between two walls maintained at different temperatures. In the model, which is essentially one-dimensional, there is a probability for collisions to reverse the velocities of particles traveling in opposite directions. Particle number and speeds (but not momentum) are collision invariants. The solution, which depends on the stochastic collision kernels at the walls, has a linear density profile and the energy flux satisfies Fourier's law.

In recent years, computational sciences such as computational hydrodynamics or computational field theory have supplemented theoretical and experimental investigations in many scientific fields. Often, there is a seemingly fruitful overlap between theory, experiment, and numerics. The computational sciences are highly dynamic and seem a fairly successful endeavor---at least if success is measured in terms of publications or engineering applications. However, for theories, success in application and correctness are two very different things; and just the same may hold for "methodologies" like (...) computer simulations. A lively debate on the epistemic status of computer simulations has thus emerged within the philosophy of science. This paper discusses possible problems when computer simulation and laboratory experiment are intertwined. In present experiments, stochastic methods in the form of Monte Carlo simulations are often involved in generating experimental data. It is questioned as to how far a realistic stance can be maintained when such stochastic elements are involved. Taking experiments in high energy physics as a study case, this paper contends that using these types of entangled material and numerical experiments as a source of new phenomena or for theory testing must presuppose a certain understanding of causality and thus binds us at least to a weak form of realism. (shrink)

I maintain that quantum mechanics is fundamentally about a system of N particles evolving in three-dimensional space, not the wave function evolving in 3N-dimensional space.

The issue of scientific realism is discussed in terms of the specific details of the practice of experimental meson and baryon spectroscopy in the field of High-Energy Physics (HEP), during the period from 1966 to 1970. The philosophical positions of I. Hacking, A. Fine, J. Leplin, and N. Rescher that concern scientific realism are presented in such a manner as to allow for the evaluation of their appropriateness in the description of this experimental research field. This philosophical analysis (...) focuses on the empirical adequacy of these four philosophical models that purport to describe the process of acquiring knowledge of the physical world. In this specific case, an experiment performed by the HEP research group at the University of Notre Dame to study the scattering interaction. (shrink)

The problems of the tolal energy and quasilocalenergy density or an isolated spherically symmetric static system in general relativity (GR) are considered with examples of some exact suintions. The field formulation of GR dereloped earlier hy L. P. Grishchuk. el al. (1984). in ihe framework of which all the dynamical fields, including the gravitation field, are considered in a fixed background spacetime is used intensively. The exact Schwarzschild and Reissner Nordstrom solutions are investigated in detail, and the results are (...) compared with those in the recent work by J. D. Brown and J. W. York. Jr. (1993) as well as discussed with respect to the principle of nonlocalization of the gravitational energy in GR. Those examples are illustrative and simple because the background is selected as Minkowski spacetime and, in fact, the field configurations are studied in the framework of special relativity. It is shown that some problems of the Schwarzschild solution which are difficult to resolve in the standard geometrical framework of GR are resolved in the framework of the field formulation. (shrink)

The ambiguous material identity of nanotechnology is a minor mystery of the history of contemporary science. This paper argues that nanotechnology functioned primarily in discourses of social, not physical or biological science, the problematic knowledge at stake concerning the economic value of state-supported basic science. The politics of taxonomy in the United States Department of Energy’s Office of Basic Energy Sciences in the 1990s reveals how scientists invoked the term as one of several competing and equally valid candidates (...) for reframing materials sciences in ways believed consonant with the political tenor of the time. The resulting loss of conceptual clarity in the sociology of science traces ultimately to the struggle to bridge the disjunction between the promissory economy of federal basic science and the industrial economy, manifested in attempts to reconcile the precepts of linearity and interdisciplinarity in changing socio-economic conditions over a half century. (shrink)

Part II of this three-part paper presents some of the most important theorems that can be deduced from the four postulates of the unified theory discussed in Part I. In Part IIa, it is shown that the maximum energy that can be extracted adiabatically from any system in any state is solely a function of the density operator $\hat \rho$ associated with the state. Moreover, it is shown that for any state of a system, nonequilibrium, equilibrium or stable equilibrium, (...) a unique propertyS exists which is proportional to the total energy of the system minus the maximum energy that can be extracted adiabatically from the system in combination with a reservoir. For statistically independent systems, propertyS is extensive, it is invariant during all reversible processes, and it increases during all irreversible processes. (shrink)

In this article, we draw upon the Conceptual Profile Theory to discuss the negotiation of meanings related to the energy concept in an 11th grade physics classroom. This theory is based on the heterogeneity of verbal thinking, that is, on the idea that any individual or society does not represent concepts in a single way. According to this perspective, the processes of conceptualization consist of the use of a repertoire of different socially stabilized signifiers, adjusted to the context (...) in which they occur. We start by proposing zones of a conceptual profile model for energy, each zone being characterized by its own commitments and identifiable by certain modes of talking about energy. Based on classroom evidence, we claim that teachers and students negotiate meanings that interpenetrate the domains of everyday and scientific knowledge. Being inevitable and necessary, this heterogeneity of conceptual thinking needs to be considered in teaching design in order to allow its awareness on the part of the students. We argue that students’ conceptual development goals should be considered in terms of general goals of science education, which points to the need of overcoming the encapsulation of scientific school knowledge. We show that the Conceptual Profile Theory provides a basis for science education that can promote the crossing of cultural boundaries, seeking relations between science and the spheres of everyday life. (shrink)

Engineering Dynamics spans the full range of mechanics problems, from one-dimensional particle kinematics to three-dimensional rigid-body dynamics, including an introduction to Lagrange's and Kane's methods. It skillfully blends an easy-to-read, conversational style with careful attention to the physics and mathematics of engineering dynamics, and emphasizes the formal systematic notation students need to solve problems correctly and succeed in more advanced courses.

In this paper, we introduce the concept of N-dimensional generalized Minkowski space, i.e., a space endowed with a metric tensor, whose coefficients do depend on a set of non-metrical coordinates. This is the first of a series of papers devoted to the investigation of the Killing symmetries of generalized Minkowski spaces. In particular, we discuss here the infinitesimal-algebraic structure of the space-time rotations in such spaces. It is shown that the maximal Killing group of these spaces is the direct (...) product of a generalized Lorentz group and a generalized translation group. We derive the explicit form of the generators of the generalized Lorentz group in the self-representation and their related, generalized Lorentz algebra. The results obtained are specialized to the case of a 4-dimensional, “deformed” Minkowski space \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $${\widetilde M}$$ \end{document}4, i.e., a pseudoeuclidean space with metric coefficients depending on energy. (shrink)

Consideration of the property of action is proposed to provide a more meaningful definition of efficient energy use and sustainable production in ecosystems. Action has physical dimensions similar to angular momentum, its magnitude varying with mass, spatial configuration and relative motion. In this article, the relationship of action to thermodynamic processes such as the spontaneous increase in entropy of the second law is explained and the utility of action for measuring changes in energy and material distribution is promoted. (...) In particular, the view that increases in entropy and action are equivalent to disorder is challenged. Given that the development of action states may be assigned an economic value and the various sources of free energy assigned a price, action theory may provide a novel mechanism for the economic allocation of resources. The importance of the diversity and redundancy of energy resources and work processes to optimize action is highlighted. (shrink)

Surface and line elements in three-dimensional space are given in terms of the delta function. We extend the representation to N-dimensional phase space to obtain the relation between the equi-energy surface and the density of states.

This paper addresses the doubts voiced by Wigner about the physical relevance of the concept of geometrical points by exploiting some facts known to all but honored by none: Almost all real numbers are transcendental; the explicit representation of any one will require an infinite amount of physical resources. An instrument devised to measure a continuous real variable will need a continuum of internal states to achieve perfect resolution. Consequently, a laboratory instrument for measuring a continuous variable in a finite (...) time can report only a finite number of values, each of which is constrained to be a rational number. It does not matter whether the variable is classical or quantum-mechanical. Now, in von Neumann’s measurement theory (von Neumann, Mathematical Foundations of Quantum Mechanics, Princeton University Press, Princeton, [1955]), an operator A with a continuous spectrum—which has no eigenvectors—cannot be measured, but it can be approximated by operators with discrete spectra which are measurable. The measurable approximant F(A) is not canonically determined; it has to be chosen by the experimentalist. It is argued that this operator can always be chosen in such a way that Sewell’s results (Sewell in Rep. Math. Phys. 56: 271, [2005]; Sewell, Lecture given at the J.T. Lewis Memorial Conference, Dublin, [2005]) on the measurement of a hermitian operator on a finite-dimensional vector space (described in Sect. 3.2) constitute an adequate resolution of the measurement problem in this theory. From this follows our major conclusion, which is that the notion of a geometrical point is as meaningful in nonrelativistic quantum mechanics as it is in classical physics. It is necessary to be sensitive to the fact that there is a gap between theoretical and experimental physics, which reveals itself tellingly as an error inherent in the measurement of a continuous variable. (shrink)

The Reeh-Schlieder theorem asserts the vacuum and certain other states to be spacelike superentangled relative to local quantum fields. This motivates an inquiry into the physical status of various concepts of localization. It is argued that a covariant generalization of Newton-Wigner localization is a physically illuminating concept. When analyzed in terms of nonlocally covariant quantum fields, creating and annihilating quanta in Newton-Wigner localized states, the vacuum is seen to not possess the spacelike superentanglement that the Reeh-Schlieder theorem displays relative to (...) local fields, and to be locally empty as well as globally empty. Newton-Wigner localization is then shown to be physically interpretable in terms of a covariant generalization of the center of energy, the two localizations being identical if the system has no internal angular momentum. Finally, some of the counterintuitive features of Newton-Wigner localization are shown to have close analogues in classical special relativity. (shrink)

Conspectus of part of John R. Smythies' Analysis of Perception (1956). It presents a summary of his ideas on phenomenal space – the space of one’s imagination, dreams, psychedelic experiences, somatic sensations, visions, hynagogia, etc. – and its relation to physical space.

Physical vacuum is a special superfluid medium populated by enormous amount of virtual particle-antiparticle pairs. Its motion is described by the modified Navier–Stokes equation: the pressure gradient divided by the mass density is replaced by the gradient from the quantum potential; time-averaged the viscosity vanishes, but its variance is not zero. Vortex structures arising in this medium show infinitely long lifetime owing to zero average viscosity. The nonzero variance is conditioned by exchanging the vortex energy with zero-point vacuum fluctuations. (...) The vortex has a non-zero core where the orbital speed vanishes. The speed reaches a maximal value on the core wall and further it decreases monotonically. The vortex trembles around some average value and possesses by infinite life time. The vortex ball resulting from topological transformation of the vortex ring is considered as a model of a particle with spin. Anomalous magnetic moment of electron is computed. (shrink)

Following the ideas of Poincaré, Reichenbach, and Grunbaum concerning the convention of setting up clock systems, we analyze clock systems and light propagation within the framework of four-dimensional symmetry. It is possible to construct a new four-dimensional symmetry framework incorporatingcommon time: observers in different inertial frames of reference use one and the same clock system, which is located in any one of the frames. Consequently, simultaneity has a meaning independent of position and independent of frame of reference. A (...) further consequence is that the two-way speeds of light alone are isotropic in any frame. By the choice of clock system there will be one frame in which the one-way speed of light is isotropic. This frame can be arbitrarily chosen. The difference between one-way speeds and two-way speeds of light signals is considered in detail. (shrink)

The question is discussed whether the description of the gravitational Doppler effect as a simple energy effect is consistent with its general-relativistic description as a metric-time effect. The difference between a local description and a global one is stressed. In the local description one is permitted to ignore metric effects. The global description yields a position-dependent rate of proper time in a gravitational field, and the energy, or the frequency, of a “freely falling” photon is described as a (...) constant of motion. An experiment of nonlocal character measuring, simultaneously, the gravitational Doppler effect and the position-dependent rate of proper time may be performed by the use of a geostationary satellite. A simple general-relativistic treatment of the satellite experiment is obtained by transforming the Schwarzschild metric to a rotating frame, and describing the motion of free particles and the rates of standard clocks in the resulting metric. (shrink)

Here, in our approximation of polaron theory, we examine the importance of introducing theT product, which turn out to be a very convenient theoretical approach for the calculation of thermodynamical averages.We focus attention on the investigation of the so-called linear polaron Hamiltonian and present in detail the calculation of the correlation function, spectral function, and Green function for such a linear system.It is shown that the linear polaron Hamiltonian provides an exactly solvable model of our system, and the result obtained (...) with this approach holds true for an arbitrary coupling constant which describes the strength of interaction between the electron and the lattice vibrations. Then, with the help of a variational technique, we show the possibility of reducing the real polaron Hamiltonian to a socalled trial or approximate linear model Hamiltonian.We also consider the exact calculation of free energy with a special technique that reduces calculations with the help of the T product, which, in our opinion, works much better and is easier than other analogous considerations, for example, the path-integral or Feynman-integral method.(1,2)Here we furthermore recall our own work,(4) where it was shown that the results of Refs. 7 and 8 concerning the impedance calculation in the polaron model may be obtained directly without the use of the path-integral method.The study of the polaron system's thermodynamics is carried out by us in the framework of the functional method. A calculation of the free energy and the momentum distribution function is proposed.Note also that the polaron systems with strong coupling(9) proved to be useful in different quantum field models in connection with the construction of dynamical models of composite particles. A rigorous solution of the special strong-coupling polaron problem, describing the interaction of a nonrelativistic particle with a quantum field, was given by Bogolubov.(3) The works of Tavkhelidze, Fedyanin, Khrustalev, and others(10–13) are dedicated to the further development and generalization of the Bogolubov method.Notice, too, that the electron-photon interaction effects play an important part in many problems of modern solid state theory (see, e.g., Refs. 7 and 14–19).The present paper summarizes a set of lectures delivered as a special course in the physics department of Moscow State University. (shrink)

In Epistemic Cultures (1999), Karin Knorr Cetina argues that different scientific fields exhibit different epistemic cultures. She claims that in high energy physics (HEP) individual persons are displaced as epistemic subjects in favor of experiments themselves. In molecular biology (MB), by contrast, individual persons remain the primary epistemic subjects. Using Ed Hutchins' (1995) account of navigation aboard a traditional US Navy ship as a prototype, I argue that both HEP and MB exhibit forms of distributed cognition. That is, (...) in both fields cognition is distributed across individual persons and complex artifacts. The cognitive system producing the knowledge is heterogeneous. Nevertheless, in both fields we can reserve epistemic agency for the human components of these systems. We do not need to postulate new distributed cognitive agents, let alone ones exhibiting new forms of consciousness. (shrink)

The book called "Philosophy of the Gita," by Prof. Ramesh N. Patel, is a striking philosophical study of the celebrated Sanskrit text called the Bhagavad-gita which is known simply as the Gita. Patel's book proposes and develops a new hermeneutic called archaic coherentism and applies it to the Gita to distill and decode a comprehensive metaphysic and philosophy of action embedded in the text. A new conceptual translation of the Sanskrit text brings out this philosophy in clear detail. Philosophical essays (...) preceding the translation include analysis of the often-neglected background of war and morality, discussion of action, freedom and self-identity, delineation of a new synoptic philosophy of Hinduism, and unearthing of a strikingly original and innovative metaphysics of existence, energy and triple individuation. The translation of the Gita is followed by two critical essays called "Emerging Philosophy" and "Coherence and Exegesis." Patel's translation focuses on the conceptual rendering of every term, with no Sanskrit word left untranslated, even including the tough ones like guna and Brahman. The essay called "Emerging Philosophy" does away with all Sanskrit terms, to facilitate the understanding of the newly decoded Gita's philosophy as a whole. The essay called "Coherence and Exegesis" critically examines several scholarly standpoints on the Gita with Patel's sound philosophical reasoning. The innovative philosophy of the Gita that emerges through the book's analysis includes an original theory of individuation revealing a Platonic-type Form of individuation evolving at three levels: essential, actional and physical. The book is written for professional philosophers and Sanskritist Indologists. It generally assumes familiarity with logical problems of philosophy and with Sanskrit terms in Indian philosophy. The author has a rare dual training in Sanskrit and philosophy. He skillfully exploits both in this book to achieve an unusual outcome that should be of great interest and challenge to both professional philosophers as well as scholars of Indology. (shrink)

This book addresses a wide range of topics relating to the properties and behavior of condensed matter under extreme conditions such as intense magnetic and electric fields, high pressures, heat and cold, and mechanical stresses. It is divided into four sections devoted to condensed matter theory, molecular chemistry, theoretical physics, and the philosophy and history of science. The main themes include electronic correlations in material systems under extreme pressure and temperature conditions, surface physics, the transport properties of low- (...) class='Hi'>dimensional electronic systems, applications of the density functional theory in molecular systems, and graphene. The book is the outcome of a workshop held at the University of Catania, Italy, in honor of Professor Renato Pucci on the occasion of his 70th birthday. It includes selected invited contributions from collaborators and co-authors of Professor Pucci during his long and successful career, as well as from other distinguished guest authors. (shrink)

In a previous paper a theoretical method permitting superluminal travel was suggested. A difficulty with the global conservation of energy and momentum is settled here.

In this research, the -dimensional variable-coefficient Caudrey–Dodd–Gibbon–Kotera–Sawada model used in soliton hypothesis and implemented by operating the Hirota bilinear scheme is studied. A few modern exact analytical outcomes containing interaction between a lump-two kink soliton, interaction between two-lump, the interaction between two-lump soliton, lump-periodic, and lump-three kink outcomes for the -D VC Caudrey–Dodd–Gibbon–Kotera–Sawada equation by Maple Symbolic packages are obtained. By employing Hirota’s bilinear technique, the extended soliton solutions according to bilinear frame equation are received. For this model, the (...) contemplated model can be got by multi-D binary Bell polynomials. In addition, the analytical analysis of the high-order soliton outcomes to present the discipline of outcomes. The effect of the free parameters on the behavior of acquired figures of a few obtained solutions for the nonlinear rational exact cases was also discussed. The above technique could also be employed to get exact solutions for other nonlinear models in physics, applied mathematics, and engineering. (shrink)

The analysis of a previous paper, in which it was shown that the energy for the Aharonov-Bohm effect could be traced to the interaction energy between the magnetic field of the electron and the background magnetic field, is extended to cover the case in which the magnetic field of the electron is shielded from the background magnetic field by a superconducting material. The paradox that arises from the fact that such a shielding would apparently preclude the possibility of (...) an interaction energy is resolved and, within the limits of the ideal situation considered, the observed experimental result is derived. (shrink)

The particle internal clock conjectured by de Broglie in 1924 was investigated in a channeling experiment using a beam of ∼80 MeV electrons aligned along the 〈110〉 direction of a 1 μm thick silicon crystal. Some of the electrons undergo a rosette motion, in which they interact with a single atomic row. When the electron energy is finely varied, the rate of electron transmission at 0° shows a 8% dip within 0.5% of the resonance energy, 80.874 MeV, for (...) which the frequency of atomic collisions matches the electron’s internal clock frequency. A model is presented to show the compatibility of our data with the de Broglie hypothesis. (shrink)

© 2016 Regents of the University of California.The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,062 new measurements from 721 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give (...) numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 117 reviews are many that are new or heavily revised, including those on Pentaquarks and Inflation. The complete Review is published online in a journal and on the website of the Particle Data Group. The printed PDG Book contains the Summary Tables and all review articles but no longer includes the detailed tables from the Particle Listings. A Booklet with the Summary Tables and abbreviated versions of some of the review articles is also available. (shrink)

The Reeh-Schlieder theorem asserts the vacuum and certain other states to be spacelike superentangled relative to local fields. This motivates an inquiry into the physical status of various concepts of localization. It is argued that a covariant generalization of Newton-Wigner localization is a physically illuminating concept. When analyzed in terms of nonlocally covariant quantum fields, creating and annihilating quanta in Newton-Wigner localized states, the vacuum is seen to not possess the spacelike superentanglement that the Reeh-Schlieder theorem displays relative to local (...) fields, and to be locally empty as well as globally empty. Newton-Wigner localization is then shown to be physically interpretable in terms of a covariant generalization of the center of energy, the two localizations being identical if the system has no internal angular momentum. Finally, some of the counterintuitive features of Newton-Wigner localization are shown to have close analogues in classical special relativity. (shrink)

It is necessary to take into account the data of science in the theoretical debates conducted by scientists contributing ontological theories in order to develop new approaches to theological issues in Islamic thought. Even, Kalam scholars with the duty of defending and basing the principles of Islam in the classical sense have established a theological understanding intertwined with science in understanding both existence philosophically and the Script theologically. With its discoveries and theories in the last century, it can be argued (...) that modern science has made a serious progress compared to the past. Maintaining its own methodology and paradigm, every scientific discipline has the opportunity to benefit from the methods and data of other disciplines. Consequently, it is possible to assert that Kalam can enjoy the same opportunity too, as long as staying in its own problem area. According to modern science, the motion system is the unity of structures that enable living things to move. Moreover, Bones and joints, which are the structures of the skeletal system, are passive elements of the movement system. Muscles, on the other hand, are the active elements of the movement system and provide the movement of the body by affecting the bones and joints. Muscle tissue shapes the body by adhering to the bones, besides enabling movement activity to occur. One of the most important systems that provide movement is the nervous system. Because for a person to have movement, the muscles must contract, and the muscles must be stimulated for the contraction of the muscles. The system that enables this contraction to occur is the nervous system. Energy is also required for contraction to occur in the human body. Muscles create energy for movement by first providing their energy from the ATP molecule present in the muscle cells. Considering the movement theories of classical theology scholars, it is seen that they shaped the occurrence of human actions through the concept of potency. While the scholars classify power as spiritual/mental and physical strength in terms of its structure, they have characterized it as accident in terms of its nature. In this context, we can say that the equivalent of the power, which is regarded as necessary for the formation of human acts by the theologians, is the movement system in today's science. The spirit/mental that scholars regard as a structure of power for the occurrence of human action can be regarded as the electrical activity that activates muscles when considered within the framework of the movement system of today's science. It is seen that Kalam scholars emphasize physical competence in their definitions of power as well. At this point, Ash'arians defined the power as the soundness of organs, Mu’tazila expressed it as the presence of organs and their being away from disasters, and the Mâturîdîs stated it as the organs being healthy. With these definitions, Kalam scholars mean that a person should also be physically competent to make a movement. The structures scientifically accepted as biological and physical competence in the movement system are the skeletal system, muscles and nervous system. Therefore, we can say that the strength of the physical fitness/well-being emphasized in the definition of power by theologians corresponds scientifically to the skeletal system, muscles and nervous system. One of the issues that Kalam scholars discuss about power is the issue of the accident of power. The reason why they describe power as an accident is to emphasize its impermanence and to show that it was created by Allah. So, in modern science, electrical activity must occur in the brain in order for human organs to move. The occurrence of this electrical activity is independent of the human being. The fact that electrical activity occurs independently from human beings shows that it conforms to Kalam scholars’ definition of the accident. As a result, we can say that the theory of power created by scholars for human movement has a counterpart in the movement system put forward by today's science. (shrink)

Through the explicit introduction of hyperplane dependence as a form of relativistic dynamical evolution, we construct a manifestly covariant description of a single positive energy particle interacting with any one of a large class of “moving” external potentials. In1+1 dimensions, the simplified mathematics allows us to display a number of general properties of solutions to the equations of motion for evolution on hyperplanes.

For quantum systems, whose energy ratios En/E0 are integers, and |E0| is the smallest energy, the time dependent wavefunctions and expectation values of time independent operators have time periodicitiy with a time period T equal to T = h/|E0|, where h is the Planck constant. This periodicity is imposed on the wavefunctions due to undersampling in energy, but following a similarity with aliasing in signal analysis, it may allow to probe future and past events under the condition (...) that our world is in reality a true four-dimensional, “static” space–time. We suggest an experiment to test that possibility. A positive result will indicate that we live in a four-dimensional space–time. A negative result (not getting signals from the future) will indicate that four-dimensional space–time is not physical one and that we live in a three-dimensional space with a time. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Diacritics 31.4 (2001) 54-82 [Access article in PDF] Seeing With The Body The Digital Image In Postphotography Mark B. N. Hansen In a well-known scene from the 1982 Ridley Scott film Bladerunner, Rick Deckard scans a photograph into a 3-D rendering machine and directs the machine to explore the space condensed in the two-dimensional photograph as if it were three-dimensional [see fig. 1]. Following Deckard's commands to (...) zoom in and to pan right and left within the image space, the machine unpacks the "real" three-dimensional world represented by the two-dimensional photograph [see figs. 2-3]. After catching a glimpse of his target—a fugitive replicant—reflected from a mirror within the space, Deckard instructs the machine to move around behind the object obstructing the two-dimensional photographic view of the replicant and to frame what it sees [see figs. 4-5]. Responding to the print command issued by Deckard, the machine dispenses a photograph of the replicant which is, quite literally, a close-up of an invisible—indeed nonexistent—part of the two-dimensional original [see fig. 6]. And yet, following the fantasy of this scene, this impossible photograph is—or would be—simply the image of one particular data point within the data set comprising this three-dimensional data space. As fascinating as it is puzzling, this scene of an impossible rendering—a rendering of two-dimensional data as a three-dimensional space—can be related to the crisis brought to photography by digitization in two ways. On the one hand, in line with the film's thematic questioning of photography as a reliable index of memory, this scene foregrounds the technical capacity of digital processing to manipulate photographs. In this way, it thematizes the threat posed by digital technologies to traditional indexical notions of photographic realism. On the other hand, in what has turned out to be a far more prophetic vein, the scene presents a radically new understanding of the photographic image as a three-dimensional "virtual" space. Such an understanding presupposes a vastly different material existence of the photographic image: instead of a physical inscription of light on sensitive paper, the photograph has become a data set that can be rendered in various ways and thus viewed from various perspectives.The first position corresponds to the arguments made by William Mitchell in his now classic book, The Reconfigured Eye. In a comprehensive analysis of the techniques and possibilities of digital imaging, Mitchell concentrates on demarcating the traditional photographic image from its digital doppelgänger. While the specter of manipulation has always haunted the photographic image, it remains the exception rather than the rule: "There is no doubt that extensive reworking of photographic images to produce seamless transformations and combinations is technically difficult, time-consuming, and outside the mainstream of photographic practice. When we look at photographs we presume, unless we have some clear indications to the contrary, that they have not been reworked" [Mitchell 7]. To buttress this claim, Mitchell sketches three criteria for evaluating traditional photographic images: (1) does the image follow the conventions of photography and seem internally coherent? (2) does the visual evidence it presents [End Page 54]Stills from Blade Runner (Ridley Scott, 1982), courtesy of Warner Brothers Home Video. Rick Deckard navigates a two-dimensional image as a three-dimensional space." width="72" height="33" />Click for larger viewFigure 1Still from Blade Runner (Ridley Scott, 1982), courtesy of Warner Brothers Home Video. Rick Deckard navigates a two-dimensional image as a three-dimensional space.Stills from Blade Runner (Ridley Scott, 1982), courtesy of Warner Brothers Home Video. Rick Deckard navigates a two-dimensional image as a three-dimensional space." width="72" height="32" />Click for larger viewFigure 2Still from Blade Runner (Ridley Scott, 1982), courtesy of Warner Brothers Home Video. Rick Deckard navigates a two-dimensional image as a three-dimensional space.Stills from Blade Runner (Ridley Scott, 1982), courtesy of Warner Brothers Home Video. Rick Deckard navigates a two-dimensional image as a three-dimensional space." width="72" height="33" />Click... (shrink)

The impact of the KK-modes in d-brane models of gravity with large compactification radii and TeV-scale quantum gravity on the hadronic potential at small impact parameters is examined. The effects of the gravitational hadron form factors obtained from the hadron generalized parton distributions (GPDs) on the behavior of the gravitational potential and the possible spin correlation effects are also analysed.

The connection between quantum mechanics and classical statistical mechanics has motivated in the past the representation of the Schrödinger quantum-wave equation in terms of “projections” onto the quantum configuration space of suitable phase-space asymptotic kinetic models. This feature has suggested the search of a possible exact super-dimensional classical dynamical system, denoted as Schrödinger CDS, which uniquely determines the time-evolution of the underlying quantum state describing a set of N like and mutually interacting quantum particles. In this paper the realization (...) of the same CDS in terms of a coupled set of Hamiltonian systems is established. These are respectively associated with a quantum-hydrodynamic CDS advancing in time the quantum fluid velocity and a further one the RD-CDS, describing the relative dynamics with respect to the quantum fluid. (shrink)

The relativistic transformation equations for the pressure, volume, energy, and momentum of a gas in a closed container are discussed. Considerations are given in support of pressure noninvariance, volume dilatation, and the fact that the energy and momentum of a gas form a four-vector. It is shown that the relativistic transformation formula for temperature resulting from the Lorentz invariance requirement of the equation of state of an ideal gas coincides with the Ott formula.

A model of a three-dimensional quantum vacuum based on Planck energy density as a universal property of a granular space is suggested. The possibility to provide an unifying explanation of dark matter and dark energy as phenomena linked with the fluctuations of the three-dimensional quantum vacuum is explored. The changes and fluctuations of the quantum vacuum energy density generate a curvature of space–time similar to the curvature produced by a “dark energy” density. The formation (...) of large scale structures in the universe associated to the flattening of the orbital speeds of the spiral galaxies can be explained in terms of primary fluctuations of the quantum vacuum energy density without attracting the idea of dark matter. (shrink)

A new theory of four-dimensional symmetry introduced by Hsu has been criticized as logically inconsistent. We answer the criticisms that have been raised and show that in fact this theory is not logically inconsistent.

We discuss some aspects of the relation between dualities and gauge symmetries. Both of these ideas are of course multi-faceted, and we confine ourselves to making two points. Both points are about dualities in string theory, and both have the ‘flavour’ that two dual theories are ‘closer in content’ than you might think. For both points, we adopt a simple conception of a duality as an ‘isomorphism’ between theories: more precisely, as appropriate bijections between the two theories’ sets of states (...) and sets of quantities. The first point is that this conception of duality meshes with two dual theories being ‘gauge related’ in the general philosophical sense of being physically equivalent. For a string duality, such as T-duality and gauge/gravity duality, this means taking such features as the radius of a compact dimension, and the dimensionality of spacetime, to be ‘gauge’. The second point is much more specific. We give a result about gauge/gravity duality that shows its relation to gauge symmetries to be subtler than you might expect. For gauge theories, you might expect that the duality bijections relate only gauge-invariant quantities and states, in the sense that gauge symmetries in one theory will be unrelated to any symmetries in the other theory. This may be so in general; and indeed, it is suggested by discussions of Polchinski and Horowitz. But we show that in gauge/gravity duality, each of a certain class of gauge symmetries in the gravity/bulk theory, viz. diffeomorphisms, is related by the duality to a position-dependent symmetry of the gauge/boundary theory. (shrink)

We give an introductory review of gauge/gravity duality, and associated ideas of holography, emphasising the conceptual aspects. The opening sections gather the ingredients, viz. anti-de Sitter spacetime, conformal field theory and string theory, that we need for presenting, in Sect. 5, the central and original example: Maldacena’s AdS/CFT correspondence. Sections 6 and 7 develop the ideas of this example, also in applications to condensed matter systems, QCD, and hydrodynamics. Sections 8 and 9 discuss the possible extensions of holographic ideas to (...) de Sitter spacetime and to black holes. Section 10 discusses the bearing of gauge/gravity duality on two philosophical topics: the equivalence of physical theories, and the idea that spacetime, or some features of it, are emergent. (shrink)

Wolfgang Pauli referred to him as 'my discovery,' Robert Oppenheimer described him as 'one of the most gifted theorists' and Niels Bohr found him enormously stimulating. Who was the man in question, Gunnar Källén (1926-1968)? His appearance in the physics sky was like a shooting star. His contributions to the scientific debate caused excitement among young and old. Similar to his friend and mentor, Wolfgang Pauli, he demanded honesty and rigor in physics - a distinct dividing line between (...) fact and speculation. In his obituary, Arthur S. Wightman would write: 'Gunnar Källén was a proud continuer of the tradition in quantum field theory established by Wolfgang Pauli. His papers on quantum electrodynamics in the period 1950-1954 carried the non-perturbative approach to quantum electrodynamics forward to a point beyond which very little essential progress has been made up to the present day. At the time I was trying to puzzle out the grammar of the language of quantum field theory, and here was Källén already writing poetry in the language!'. In addition to being a remarkable scientist, Källén had a very interesting personality, well worth exploring. In her book, physicist Cecilia Jarlskog traces both the personal and scientific trajectory of this unsung hero of the early days of high-energy physics and quantum field theory. A number of invited contributions by members of the Källén family and distinguished researchers from the field, all of them personally acquainted with Källén, combine to form an authentic portrait of the researcher and the man. Last but not least, the reader will become acquainted with some aspects of the history of particle physics in those days, as related by Källén and those who corresponded with him. A commented selection of his most important and not easily accessible papers is included as an added bonus for specialists. (shrink)

Electrical resistivity and ac-calorimetric measurements reveal a complex magnetic phase diagram for single crystals of the ferromagnetic Kondo-lattice compound CeAgSb2 at high pressures up to 80 kbar. The ferromagnetic order at TC = 9.6 K at ambient pressure is completely suppressed at a critical pressure PC = 35 kbar. Another magnetic transition, possibly antiferromagnetic, found above 27 kbar, attains a maximum value TN 6 K at 44 kbar and then appears to be completely suppressed by 50 kbar. Thermodynamic and transport (...) measurements in the ferromagnetic state indicate an energy gap Δ 30 K in the spin-wave excitation spectrum at ambient pressure which decreases to Δ 10 K at P = 30 kbar. No superconductivity is observed at ambient pressure above T 0.1 K, under applied pressure in the ferromagnetic state (P = 28.5 kbar), nor in the antiferromagnetic state (P = 33 − 46 kbar) above 0.3 K. © 2003 The American Physical Society. (shrink)

Contrary to the predominant way of doing physics, we claim that the geometrical structure of a general differentiable space-time manifold can be determined from purely dynamical considerations. Anyn-dimensional manifoldV a has associated with it a symplectic structure given by the2n numbersp andx of the2n-dimensional cotangent fiber bundle TVn. Hence, one is led, in a natural way, to the Hamiltonian description of dynamics, constructed in terms of the covariant momentump (a dynamical quantity) and of the contravariant position vectorx (...) (a geometrical quantity). That is, the Hamiltonian description furnishes a natural way of relating dynamics and geometry. Thus, starting from the Hamiltonian state function (for a particle)—taken as the fundamental dynamical entity—we show that general relativistic physics implies a general pseudo-Riemannian geometry, whereas the physics of the special theory of relativity is tied up with Minkowski space-time, and nonrelativistic dynamics is bound up to Newton-Cartan space-time. (shrink)

Recently highly-efficient quantum engines were devised by exploiting the stochastic energy changes induced by quantum measurement. Here we show that such an engine can be based on an interaction-free measurement, in which the meter seemingly does not interact with the measured object. We use a modified version of the Elitzur–Vaidman bomb tester, an interferometric setup able to detect the presence of a bomb triggered by a single photon without exploding it. In our case, a quantum bomb subject to a (...) gravitational force is initially in a superposition of being inside and outside one of the interferometer arms. We show that the bomb can be lifted without blowing up. This occurs when a photon traversing the interferometer is detected at a port that is always dark when the bomb is located outside the arm. The required potential energy is provided by the photon even though it was not absorbed by the bomb. A natural interpretation is that the photon traveled through the arm which does not contain the bomb—otherwise the bomb would have exploded—but it implies the surprising conclusion that the energy exchange occurred at a distance despite a local interaction Hamiltonian. We use the weak value formalism to support this interpretation and find evidence of contextuality. Regardless of interpretation, this interaction-free quantum measurement engine is able to lift the most sensitive bomb without setting it off. (shrink)

Diffusion theory explains in physical terms how materials move through a medium, e.g. water or a biological fluid. There are strong and widely acknowledged grounds for doubting the applicability of this theory in biology, although it continues to be accepted almost uncritically and taught as a basis of both biology and medicine. Our principal aim is to explore how this situation arose and has been allowed to continue seemingly unchallenged for more than 150 years. The main shortcomings of diffusion theory (...) will be briefly reviewed to show that the entrenchment of this theory in the corpus of biological knowledge needs to be explained, especially as there are equally valid historical grounds for presuming that bulk fluid movement powered by the energy of cell metabolism plays a prominent note in the transport of molecules in the living body. First, the theory's evolution, notably from its origins in connection with the mechanistic materialist philosophy of mid nineteenth century physiology, is discussed. Following this, the entrenchment of the theory in twentieth century biology is analyzed in relation to three situations: the mechanism of oxygen transport between air and mammalian tissues; the structure and function of cell membranes; and the nature of the intermediary metabolism, with its implicit presumptions about the intracellular organization and the movement of molecules within it. In our final section, we consider several historically based alternatives to diffusion theory, all of which have their precursors in nineteenth and twentieth century philosophy of science. (shrink)

A process of idea filtration in two distinct streams of physics i.e., 1) The dimensionality perspective of spacetime, and 2) The quantum perspective leads us to an understanding of what might be a true reality of all that we perceive. The conclusions arrived at in this paper are a bit perplexing in the sense that our perceived reality could be a manifestation of a combination of 4D + n (n > 0) flat space-time, universal wave function, and cognizance. The (...) work is based on a review and analysis of the main concepts in quantum theory, relativistic physics, and cosmology. Key ideas and conclusions are filtered and logically connected to arrive at what might be a view of the true reality. A significant part of the paper is dedicated to the concept of the “observer” and the “ability of cognizance” that should accompany the “observer”. Though the “observer” is central to modern physics, it is not known what constitutes observation, and the term observer, often open to interpretations, does not have a standard definition and hence, is lacking in clarity. In our analysis, we have argued that the environment, in which the observer-observed system is embedded, emerges as an all-knowing, cognizant, and ideal observer that has the knowledge of the observer-observed system. At a philosophical level, we link to the fundamentals of physics, “consciousness” or “ability of cognizance” as an unavoidable and key element in not only carrying out the observation but perhaps, as believed by many, having a role in shaping the reality perceived. In the review and analysis of another stream of physics, that of General Theory of Relativity (GTR) and cosmology, we examine the question of reality from a cosmological and dimensionality perspective. Research on the 4D and 5D constructs of the universe indicates that the “reality” perceived in 4D spacetime as matter, distance, time, etc., is a manifestation of a higher dimensional 4D + n (n > 0) reality. Theoretical research on this front points towards a 4D-spacetime embedded in a 5D or higher dimensional flat space with matter and energy being a manifestation of the higher dimensions. The flow of logic in this paper leans towards a view of an ultimate true reality that is flat 4D + n (n > 0) space combined with cognizance, universal wave function, and the environment. (shrink)

Energy contributes significantly in almost all aspects of human life as well as economic activities and plays a crucial role in the infrastructural development of a county to alleviate poverty. Generating energy from a renewable source such as small hydropower through the application of pump operating as a turbine mode called Pump as Turbine is one of the best alternatives to provide clean and inexpensive energy. Using Pump as Turbine helps in generating reasonably priced hydroelectric power for (...) communities in underdeveloped counties. This study investigates the effects of internal flow behaviour and performance of Pump as Turbine under different rotational speed and flow rate. The rotational speed is an essential physical parameter as it affects the Pump as Turbine operation. A model-specific speed centrifugal pump model with head 32, flow rate of 12.5 and the rotational speed of 2900 rpm, has been selected for the study. Numerical simulations have been conducted using the k-ω turbulence model to solve three-dimensional equations. The pump mode experimental data were used to confirm the results for better analysis. The results predicted that vortex and turbulent kinetic energy increase per rotational speed increase. Also, at the higher rotational speed, very high recirculation of flow is detected at the blade suction chamber, although the pressure side has a smooth flow. This study provides beneficial information which will serve as a reference to help improve PAT performance along with selecting PAT for a small hydropower site. Future works will consider the impact of blade thickness and cavitation in Pump as Turbine. (shrink)