Relativistic Jets from Active Galactic Nuclei,edited by M. Boetttcher,D.E. Harris,and H. Krawczynski

Current theories of particle physics lead to the unavoidable conclusion that there must have been several phase transitions in the early Universe. Further, in the context of these theories, it is possible that cosmological phase transitions would have produced topological defects that may be roaming our heavens today. A finding of these fossils from the early Universe would provide a direct confirmation of the thermal history of the cosmos, insight into astrophysical phenomena, and vital information about particle physics. The elimination of unobserved topological defects provides important constraints on particle physics and may also suggest novel cosmology. I describe some of the research on cosmic topological defects and recent efforts to address cosmological issues in condensed matter systems.     

Cosmologies with Photon Creation and the 3K Relic Radiation Spectrum

A new Planckian type distribution for cosmologies with photon creation is derived using thermodynamics and semiclassical considerations. This spectrum is preserved during the evolution of the universe and compatible with the present spectral shape of the cosmic microwave background radiation (CMBR). Accordingly, the widely spread feeling that cosmologies with continuous photon creation are definitely ruled out by the COBE limits on deviation of the CMBR spectrum from blackbody shape should be reconsidered. It is argued that a crucial test for this kind of cosmologies is provided by measurements of the CMBR temperature at high redshifts. For a given redshift z greater than zero, the temperature is smaller than the one predicted by the standard FRW model.     

The tilted universe

The simplest interpretation of the CMBR dipole anisotropy is that it arises due to our motion with respect to the cosmic rest frame. However, the existence of a superhorizon-sized isocurvature perturbation can give rise to a dipole anisotropy intrinsic to the CMBR. In this case the cosmic rest frame and the CMBR rest framedo not coincide, and when viewed from the CMBR rest frame the universe appears tilted: matter streams uniformly from one side of the universe to the other. The intrinsic dipole model provides an explanation for the puzzling observation that most of the matter within a l00^–1 Mpc cube centered on our galaxy has a large velocity (of order 600 km s^–1) with respect to the CMBR rest frame.This essay received the first award from the Gravity Research Foundation, 1991—Ed.     

Change in singing voice production, objectively measured

Although subglottal pressures in conversational speech are relatively easily measured and thus known, the higher values that sometimes occur in singing (especially in tenors) have received little attention in the literature. Still more unusual is the opportunity to measure a large-scale change over decades in the application of pressure in singing production. This study compares measurements of subglottal pressure in a tenor/singing teacher (JS) at two points in his career: in his early thirties, when he was a subject in HS's dissertation study on the efficiency of voice production; and recently, in his fifties, in connection with JS's forthcoming book on the history of the pedagogy of Bel Canto. Although a single case study, its points of special interest include the high values initially measured (up to100 cm H₂O) and the reduction of this figure by more than 50% in the maximal values of the recent measurements. The study compares these values with those of other singers in the same laboratory (both with esophageal balloon and directly, with a catheter passed through the glottis) and in the literature, as well as discusses in detail the problems pertaining to the measurement (repeatability, correcting for lung volume, etc.).

As a sophisticated subject, JS makes some pertinent observations about the changes in his use of subglottal pressure.     

Working group report: Neutrino and astroparticle physics

This is the report of neutrino and astroparticle physics working group at WHEPP-8. We present the discussions carried out during the workshop on selected topics in the above fields and also indicate progress made subsequently. The neutrino physics subgroup studied the possibilities of constraining neutrino masses, mixing and CPT violation in lepton sector from future experiments. Neutrino mass models in the context of Abelian horizontal symmetries, warped extra dimensions and in the presence of triplet Higgs were studied. Effect of threshold corrections on radiative magnification of mixing angles was investigated. The astroparticle physics subgroup focused on how various particle physics inputs affect the CMBR fluctuation spectrum, and on brane cosmology. This report also contains an introduction on how to use the publicly available code CMBFAST to calculate the CMBR fluctuations.     

Quenched! The ISABELLE Saga, I

The story of ISABELLE, a colliding-beam accelerator conceived in 1971, officially approved in 1978, partially constructed, and terminated in 1983, is an important episode in the history of post-World War II science in the United States.The events surrounding its planning, construction, and termination reveal much about the ambitions, strategies, and tensions of American high-energy physicists, their collaborations and rivalries, and the difficulties of funding and constructing a large scientific facility in the age of Big Science. In this article, the first of two parts, I cover the period up to the beginning of construction in 1978. I place ISABELLE in the context of the early history of colliders, outline the physics goals that motivated the machine, and describe the research and motivations behind its innovative but ultimately problematic superconducting magnet design. I cover the key technological and administrative steps that the laboratory took to get the project underway and steer it past several review committees. I also treat some of the conflicts within the laboratory, and between Brookhaven and other laboratories, especially Fermilab, that hampered the project. Robert P. Crease is a Professor in the Department of Philosophy of Stony Brook University in Stony Brook, New York, and historian at Brookhaven National Laboratory.     

Polarization of the cosmic microwave background radiation

In re-ionized models, the measurement of polarization of CMBR can be a good criterion to narrow down the parameter space for cosmological models. A Vishniac-type effect in second order polarization over arc minute scales has been calculated. It has been shown that while the effect is very small (∼10⁻² μK) for CDM models, it can be significant (∼0.3μK) for some isocurvature models.     

宇宙质心参考系

根据实际天文观测论述了膨胀着的宇宙系统的时间可以与空间分开来讨论;宇宙的空间是平直的。在宇宙质心坐标系中,由背景辐射温度、宇宙密度和宇宙半径（最远星系的距离）3个观测数据计算了宇宙这个引力系统的总能量,结果表明系统是一个引力束缚态,将来会收缩。在均匀分布的初始条件下计算了收缩过程,这是同步自由落体过程。在宇宙的膨胀过程与其收缩过程对称的假设之下,建立膨胀时间与背景辐射温度的一对一的对应关系。According to astronomical observation we point out that the time of our expanding cosmic system can be discussed separating from the space. And the space in our universe is flat. In the cosmic center-of-mass frame（CCF）, based on the temperature of CMBR, the cosmic density and the cosmic radii, the distance of the farmost galaxy, the total energy of our universe asa gravitation system has been calculated. It shows that our universe is in a gravitational bound state, and it will contract. In CCF the contracting progress is a synchronized freely falling body under initial condition of uniform distribution. Uder assumption of the symmetry of cosmic expanding and contracting progresses, th one-to-one correspondence of the expanding time to the temperature of CMBR can be obtained.     

“Incerto Tempore, Incertisque Loci”: Can We Compute the Exact Time at Which a Quantum Measurement Happens?

Without addressing the measurement problem (i. e., what causes the wave function to “collapse,” or to ”branch,” or a history to become realized, or a property to actualize), I discuss the problem of the timing of the quantum measurement: Assuming that in an appropriate sense a measurement happens, when precisely does it happen? This question can be posed within most interpretations of quantum mechanics. By introducing the operator M, which measures whether or not the quantum measurement has happened, I suggest that, contrary to what is often claimed, quantum mechanics does provide a precise answer to this question, although a somewhat surprising one.     

A new look at the accelerating universe

We show that the cosmological model having zero cosmological constant, but containing the vacuum energy of a simple quantized free scalar field of low mass (VCDM model), agrees with the cosmic microwave background radiation (CMBR) and supernova (SNe-Ia) data at least as well as the classical cosmological model with a small nonzero cosmological constant. We also show that in the VCDM model the ratio of vacuum pressure to vacuum energy density is less than -1. We display the VCDM results for a set of parameters that give a very good fit to the CMBR power spectrum, and show that the same parameters also give a good fit to the SNe-Ia data.     

Thermal Radiation Laws of a <Emphasis Type="Italic">q</Emphasis>-deformed Boson System in <Emphasis Type="Italic">m</Emphasis> Dimensions

Within the theoretical framework of multidimensional space and q bosons, we generalize our hypothesis of regarding the CMBR as the radiation of q bosons, and investigate the thermal radiation laws of a q boson system in m dimensions. Utilizing the new radiation laws, we make a numerical calculation and the results show that these new laws have some special features. We consider that this work may provide more insight into the theory of q bosons and the study on the CMBR.     

Bianchi Type III Anisotropic Dark Energy Models with?Constant Deceleration Parameter

The Bianchi type III dark energy model with constant deceleration parameter is investigated. The equation of state parameter ω is found to be time dependent and its existing range for this model is consistent with the recent observations of SN Ia data, SN Ia data (with CMBR anisotropy) and galaxy clustering statistics. The physical aspects of the dark energy models is discussed.     

A brief history of measurement

The aim of this paper is to situate the subject of measurement and metrology in its historical and philosophical context. Everyone agrees that the numeration of objects and the quantification of the characteristics of some simple systems are very ancient practices encountered in any specific civilisation. Indeed the link between measurement and numeration comes from the beginnings. This is recalled here, as are the links between units and money, between references and authority. Then, the paper identifies and exhibits the different epistemological gaps occurred – or occurring – in the history of measurement in the western countries: geometry versus arithmetics, model versus experiment, prediction versus uncertainty, determinism versus quantum physics. Those gaps are described in relationship to the evolution of the internationally agreed system of units.     

Cosmic microwave background radiation anisotropies and data analysis

The theory of generation of CMBR temperature and polarization fluctuations is briefly reviewed. Also discussed is the present status of observations and the nature of future surveys.     

Non-destructive testing for inelastic critical strength

Non-destructive experimental prediction of the instability strength of a structure has been demonstrated for a few cases. A brief history of the theory, some early efforts and recent demonstrations are discussed in reference [1]. Previous efforts have been restricted to elastic critical strength prediction. A procedure now is suggested for extending the technology to the inelastic range.     

Samuel Pierpont Langley and his Contributions to the Empirical Basis of Black-Body Radiation

In this paper I deal with an early phase of the history of research on black-body radiation. In this phase, from 1880-1900, the American astrophysicist Samuel Pierpont Langley (1834-1906) invented and used a key instrument, the bolometer, to measure for the first time radiation curves that displayed the characteristic features of asymmetry and of a shifting of their maxima to shorter wavelengths with increasing temperature. I emphasize the complex development of the construction of the bolometer and the early experiments performed with it. I also discuss how these developments became important for theoretical research on the black-body radiation formula. My aim is to show that the often-neglected experimental part of the history of research on black-body radiation represents an important precondition for the theoretical developments that followed.     

Superhorizon fluctuations and acoustic oscillations in relativistic heavy ion collisions

We focus on the initial state spatial anisotropies, originating at the thermalization stage, for central collisions in relativistic heavy-ion collisions. We argue that the physics of fluctuations at the early stages of heavy ion collisions has strong similarities with the physics of density fluctuations in the early universe which give rise to remarkable acoustic peaks in the cosmic microwave background radiation (CMBR) power spectrum. Following the method of analysis in CMBR physics, we propose that a plot of root mean square values of the flow coefficients ?{[`(v_n² )] } o v_n^rms\sqrt {\overline {v_n^2 } } \equiv v_n^{rms} , calculated in a laboratory fixed coordinate system, for a large range of n from 1 to about 30, can give non-trivial information about the initial stages of the system and its evolution. We also argue that for all wavelengths λ of the anisotropy (at the surface of the plasma region) much larger than the acoustic horizon size H_s^fr H_s^{f^r } at the freezeout stage, the resulting values of V _n ^mns should be suppressed by a factor of order 2H_s^fr /l2H_s^{f^r } /\lambda .     

John Bardeen and the Theory of Superconductivity: A Late Revision of a Homework Assignment for J. M. Luttinger

This account of the history of the Bardeen–Cooper–Schrieffer theory of superconductivity has its roots in an assignment that Quin Luttinger designed for me in 1963 when I was his graduate student. It improves on my student work by tracing the story from historical source materials as well as published papers, thus reflecting the contingencies and human elements that shape all research in physics. I also made an attempt to portray general features of how John Bardeen approached solving problems in physics.     

Contextuality,Complementarity, Signaling,and Bell Tests

This is a review devoted to the complementarity–contextuality interplay with connection to the Bell inequalities. Starting the discussion with complementarity, I point to contextuality as its seed. Bohr contextuality is the dependence of an observable’s outcome on the experimental context; on the system–apparatus interaction. Probabilistically, complementarity means that the joint probability distribution (JPD) does not exist. Instead of the JPD, one has to operate with contextual probabilities. The Bell inequalities are interpreted as the statistical tests of contextuality, and hence, incompatibility. For context-dependent probabilities, these inequalities may be violated. I stress that contextuality tested by the Bell inequalities is the so-called joint measurement contextuality (JMC), the special case of Bohr’s contextuality. Then, I examine the role of signaling (marginal inconsistency). In QM, signaling can be considered as an experimental artifact. However, often, experimental data have signaling patterns. I discuss possible sources of signaling—for example, dependence of the state preparation on measurement settings. In principle, one can extract the measure of “pure contextuality” from data shadowed by signaling. This theory is known as contextuality by default (CbD). It leads to inequalities with an additional term quantifying signaling: Bell–Dzhafarov–Kujala inequalities.