MACH'S Principle,Gravitation and Electromagnetism: The Electromagnetic Inertia of Charged Elementary Particles

The question of the magnitude and behaviour of the electromagnetic contribution to the mass of an elementary charged particle is explored. It is shown that, if the “cut-off” of relativistic quantum electrodynamics is taken as an approximation to the physical process embodied in the postulates: I. That the bare charge of an elementary particle may only emit and absorb virtual photons having energies that are integral multiples of some fundamental energy, and II. that the observed charge of an elementary particle is a constant independent of its “radius”, the electromagnetic mass of such a particle is always finite, even when the radius of the particle becomes zero. Alternative postulates that will resolve the cut-off dilemma are briefly discussed. It is noted that the “MACHianess” of electromagnetic mass (in terms of PAULI'S criterion for “MACHianess”) depends on the detailed structure of postulate II, and that extant experimental results do not permit one, at present, to decide the issue with certainty.     

The Improvement of Star Catalogues by the Incorporation of New Data

Simple formulas are given by which a star's position and proper motion may be improved by the incorporation of new observations of the position when measures for the precision of all data and the “zero correlation” epoch of the old data are available. These formulas are particularly useful for “updating” positions in the General Catalogue (G.C.) or similar catalogues.     

Measuring impact crater depth throughout the solar system

One important, almost ubiquitous, tool for understanding the surfaces of solid bodies throughout the solar system is the study of impact craters. While measuring a distribution of crater diameters and locations is an important tool for a wide variety of studies, so too is measuring a crater's “depth.” Depth can inform numerous studies including the strength of a surface and modification rates in the local environment. There is, however, no standard data set, definition, or technique to perform this data-gathering task, and the abundance of different definitions of “depth” and methods for estimating that quantity can lead to misunderstandings in and of the literature. In this review, we describe a wide variety of data sets and methods to analyze those data sets that have been, are currently, or could be used to derive different types of crater depth measurements. We also recommend certain nomenclature in doing so to help standardize practice in the field. We present a review section of all crater depths that have been published on different solar system bodies which shows how the field has evolved through time and how some common assumptions might not be wholly accurate. We conclude with several recommendations for researchers which could help different data sets to be more easily understood and compared.     

Cosmogony of galaxies as based on the spatial distribution of matter

A morphological box for the space distribution of galaxies and dark matter as the consequence of various types of cosmogonical hypotheses is presented. A short review of concepts of clustering of galaxies is given. One has to distinguish between the phenomena of “clusters of galaxies” and of “clustering of galaxies”. The second notion is more general. The investigations of KIANG , FLIN , and PEEBLES speak in favour of general clustering rather than overal existence of individual clusters. Individuals such as our Supergalaxy, Coma cluster etc. seem rather to be exceptional features.     

From the Arrow of Time to the Arrow of Life

Astrobiology, like many (but not all) sciences, must take into account questions of the “Why?”, “Where?”, “How?” and “When?” type. In this introductory chapter, we explain why, in this book, we will only consider two of these questions that are, moreover, deeply interrelated. Chronology is by definition related to the “when?” question but as soon as we are interested in the history of Earth or the history of life, it is impossible to treat these questions and their answers without explicit references to the “how?” questions. We also present in this chapter the genesis and the aim of the book.     

Eddingtons Zahlen,Einsteins Kriterium und Rydbergs rationelles Dimensionssystem

The discussions about the meaning of the “hierarchy of interactions” and in connection with this about the role of Eddington's “cosmological number” imply the question of the “big numbers” in physics. According to Einstein's and Bridgman's criteria such “big numbers” are hints at unsolved problems in the foundations of physics. Eddington gives a theory of the big number like cosmological quantities. – A new point of view on this question may be to remember Rydberg's suggestion on independigly physical dimensions of lengths L, surfaces S, and volumina V, and to remember Dällenbach's suggestion to introduce a new universal constant α which describes the operational connections between the quardrate of lengths L² and the surface S in microphysics. Coulomb's and Nwton's laws have the same structure. But, the electrical forces are depending on L^-2 and the gravitational forces are depending on S^-1 ∼ (1/α) L^-2 because “gravitation is geometry”. In Planck's elementary units h, c and f Dällenbach's “surface-constant of the vacuum” α is a pure number α ≈ hc/fm², th. i. Eddington's cosmological number ω ∼ 10⁴⁰. However, Rydberg's physical dimensions in geometry and Dällenbach's constant suggest new formulations of the question of “geometrization of physics” and “physicallization of geometry” and the connections between cosmology and microphysics.     

The standard cosmological model and CMB anisotropies

This is a course on cosmic microwave background (CMB) anisotropies in the standard cosmological model, designed for beginning graduate students and advanced undergraduates. “Standard cosmological model” in this context means a Universe dominated by some form of cold dark matter (CDM) with adiabatic perturbations generated at some initial epoch, e.g., Inflation, and left to evolve under gravity alone (which distinguishes it from defect models). The course is primarily theoretical and concerned with the physics of CMB anisotropies in this context and their relation to structure formation. Brief presentations of the uniform Big Bang model and of the observed large-scale structure of the Universe are given. The bulk of the course then focuses on the evolution of small perturbations to the uniform model and on the generation of temperature anisotropies in the CMB. The theoretical development is performed in the (pseudo-)Newtonian gauge because it aids intuitive understanding by providing a quick reference to classical (Newtonian) concepts. The fundamental goal of the course is not to arrive at a highly exact nor exhaustive calculation of the anisotropies, but rather to a good understanding of the basic physics that goes into such calculations.     

On the relation of dynamics to statistical mechanics

A new conceptual framework for the foundations of statistical mechanics starting from dynamics is presented. It is based on the classification and the study of invariants in terms of the concepts of our formulation of non-equilibrium statistical mechanics. A central role is played by thecollision operator. The asymptotic behaviour of a class of states is determined by the collisional invariants independently of the ergodicity of the system. For this class of states we have an approach to thermodynamical equilibrium. We discuss the existence of classes of states which approach equilibrium. The complex microstructure of the phase space, as expressed by the weak stability concept which was introduced by Moser and others, plays here an essential role. The formalism that we develop is meaningful whenever the “dissipativity condition” for the collision operator is satisfied. Assuming the possibility of a weak coupling approximation, this is in fact true whenever Poincaré's theorem on the nonexistence of uniform invariants holds. In this respect, our formalism applies to few body problems and no transition to the thermodynamic limit is required. Our approach leads naturally to a ‘classical theory of measurement’. In particular a precise meaning can now be given to ‘thermodynamic variables’ or to ‘macrovariables’ corresponding to a measurement in classical dynamics.     

Stability of shell distributions

Stability criteria for parallel propagating plasma waves driven unstable by a nearly isotropic bump-in-energy “half-shell” beam of electrons along a magnetic field are investigated. Comparison with the drifting Maxwellian at equal densities reveals smaller growth rates for the half-shell and a shift in the unstable wavenumbers towards smaller phase velocities. The limit of complete isotropy is stable to the waves under consideration.     

The dynamics of dense particle disks

We investigate the mechanical equilibrium and collisional transport processes in differentially rotating dense particle disks in which the filling factor is not small, so that the ordinary Boltzmann kinetic theory is not accurate. Our treatment is based on the Enskog theory of dense hard sphere gases, except that the spheres are inelastic. We show that the viscous instability which has been suggested as a source of the structure in Saturn's B ring does not arise in our models. However, the ring may be subject to a phase transition similar to the liquid-solid transition seen in molecular dynamics simulations of elastic hard spheres; in this case the ring could have alternating zero-shear (“solid”) and high-shear (“liquid”) zones.     

X-RADIOGRAPHY OF SLABS OF THE ALLENDE METEORITE

X-radiographs of eight slabs of the Allende meteorite, each about 8 mm thick, reveal significant chemical and textural heterogeneities of our Allende fragment at the 100–1000 g level. They also reveal systematic arrangements of chondrules (“strings”). Our preliminary interpretation is that the observed features are probably all due to regolith processes on Allende's parent body, and that these processes included “mini” slope slides along dry, “sandy” slopes.     

Stability of the planar full 2-body problem

The stability of the Full Two-Body Problem is studied in the case where both bodies are non-spherical, but are restricted to planar motion. The mutual potential is expanded up to second order in the mass moments, yielding a highly symmetric yet non-trivial dynamical system. For this system we identify all relative equilibria and determine their stability properties, with an emphasis on finding the energetically stable relative equilibria and conditions for Hill stability of the system. The energetically stable relative equilibria always correspond to the classical “gravity gradient” configuration with the long ends of the two bodies pointed at each other, however there always exists a second equilibrium in this configuration at a closer separation that is unstable. For our model system we precisely map out the relations between these different configurations at a given value of angular momentum. This analysis identifies the fundamental physical constraints and limitations that exist on such systems, and has immediate applications to the stability of asteroid systems that are fissioned due to a rapid spin rate. Specifically, we find that all contact binary asteroids which are spun to fission will initially lie in an unstable dynamical state and can always re-impact. If the total system energy is positive, the fissioned system can disrupt directly from this relative equilibrium, while if it is negative the system is bound together.     

The sky brightness when the rising sun is in eclipse

Part of the “Xia-Shang-Zhou Chronology Project” is the study of a historical record of “double dawn” and its astronomical interpretation. We used the light meter on ordinary cameras to determine the sky variation during normal sunrises and sunsets, set up a way of calculating the variation when the rising sun is in eclipse, and identified the range and intensity of the double dawn phenomenon. For this, we organized a mass participation of the observation of the 1997-03-09 eclipse in Xinjiang Province. The observations are in good agreement with our model calculation and prove that an eclipsed sunrise could indeed give rise to the phenomenon of “double dawn”     

Noble gases in presolar diamonds I: Three distinct components and their implications for diamond origins

Abstract— High-purity separates of presolar diamond were prepared from 14 primitive chondrites from 7 compositional groups. Their noble gases were measured using stepped pyrolysis. Three distinct noble gas components are present in diamonds, HL, P3, and P6, each of which is found to consist of five noble gases. P3 , released between 200 °C and 900 °C, has a “planetary” elemental abundance pattern and roughly “normal” isotopic ratios. HL , consisting of isotopically anomalous Xe-HL and Kr-H, Ar with high ³⁸Ar/³⁶Ar, and most of the gas making up Ne-A2 and He-A, is released between 1100 °C and 1600 °C. HL has “planetary” elemental ratios, except that it has much more He and Ne than other known “planetary” components. HL gases are carried in the bulk diamonds, not in some trace phase. P6 has a slightly higher median release temperature than HL and is not cleanly separated from HL by stepped pyrolysis. Our data suggest that P6 has roughly “normal” isotopic compositions and “planetary” elemental ratios. Both P3 and P6 seem to be isotopically distinct from P1, the dominant “planetary” noble-gas component in primitive chondrites. Release characteristics suggest that HL and P6 are sited in different carriers within the diamond fractions, while P3 may be sited near the surfaces of the diamonds. We find no evidence of separability of Xe-H and Xe-L or other isotopic variations in the HL component. However, because ～10¹⁰ diamonds are required to measure a Xe composition, a lack of isotopic variability does not constrain diamonds to come from a single source. In fact, the high abundance of diamonds in primitive chondrites and the presence of at least three distinct noble-gas components strongly suggest that diamonds originated in many sources. Relative abundances of noble-gas components in diamonds correlate with degree of thermal processing (see companion paper), indicating that all meteorites sampled essentially the same mixture of diamonds. That mixture was probably inherited from the Sun's parent molecular cloud.     

Meteorite and meteoroid: New comprehensive definitions

Abstract– Meteorites have traditionally been defined as solid objects that have fallen to Earth from space. This definition, however, is no longer adequate. In recent decades, man‐made objects have fallen to Earth from space, meteorites have been identified on the Moon and Mars, and small interplanetary objects have impacted orbiting spacecraft. Taking these facts and other potential complications into consideration, we offer new comprehensive definitions of the terms “meteorite,”“meteoroid,” and their smaller counterparts: A meteoroid is a 10‐μm to 1‐m‐size natural solid object moving in interplanetary space. A micrometeoroid is a meteoroid 10 μm to 2 mm in size. A meteorite is a natural, solid object larger than 10 μm in size, derived from a celestial body, that was transported by natural means from the body on which it formed to a region outside the dominant gravitational influence of that body and that later collided with a natural or artificial body larger than itself (even if it is the same body from which it was launched). Weathering and other secondary processes do not affect an object’s status as a meteorite as long as something recognizable remains of its original minerals or structure. An object loses its status as a meteorite if it is incorporated into a larger rock that becomes a meteorite itself. A micrometeorite is a meteorite between 10 μm and 2 mm in size. Meteorite– “a solid substance or body falling from the high regions of the atmosphere” ( Craig 1849 ); “[a] mass of stone and iron that ha[s] been directly observed to have fallen down to the Earth’s surface” (translated from Cohen 1894 ); “[a] solid bod[y] which came to the earth from space” ( Farrington 1915 ); “A mass of solid matter, too small to be considered an asteroid; either traveling through space as an unattached unit, or having landed on the earth and still retaining its identity” ( Nininger 1933 ); “[a meteoroid] which has reached the surface of the Earth without being vaporized” (1958 International Astronomical Union (IAU) definition, quoted by Millman 1961 ); “a solid body which has arrived on the Earth from outer space” ( Mason 1962 ); “[a] solid bod[y] which reach[es] the Earth (or the Moon, Mars, etc.) from interplanetary space and [is] large enough to survive passage through the Earth’s (or Mars’, etc.) atmosphere” ( Gomes and Keil 1980 ); “[a meteoroid] that survive[s] passage through the atmosphere and fall[s] to earth” ( Burke 1986 ); “a recovered fragment of a meteoroid that has survived transit through the earth’s atmosphere” ( McSween 1987 ); “[a] solid bod[y] of extraterrestrial material that penetrate[s] the atmosphere and reach[es] the Earth’s surface” ( Krot et al. 2003 ).     

Biographical index “Astronomers of Ukraine” at the UkrVO portal

The new electronic database developed by the authors and titled “Astronomers of Ukraine” is described as a source of the main biographical data on astronomers of Ukraine from the 15th century until the beginning of the 21st century. The database is an upgrading component of the Ukrainian Virtual Observatory portal and contains the main biobibliographical data and papers concerning astronomers of Ukraine, as well as links to their publications. The existing biographical sources about astronomers in the world are discussed briefly. A list of the principal publications about astronomers of Ukraine is given.     

A search for radio remnants of ancient oriental “guest stars” with the westerbork telescope

Seven 1.5° × 1.5° fields in which “guest stars” had been reported by ancient oriental astronomers have been surveyed at 610 MHz for radio remnants with the Westerbork Telescope. No diffuse radio emission was detected. A list of discrete radio sources in the fields is given together with suggested optical identifications for those sources with |b| < 15°.     

Multiverses of the past

More than 2000 years ago, Epicurus taught that there are an infinite number of other worlds, both like and unlike ours, and Aristotle taught that there are none. Neither hypothesis can currently be falsified, and some versions of current multiverses perhaps never can be, which has contributed to occasional claims that “this isn't science!” (a common complaint about cosmology for centuries). Define “cosmos”, or “world”, or “universe” to mean the largest structure of which you and the majority of knowledgeable contemporaries will admit to being a part. This begins with the small, earth‐centered worlds of ancient Egyptian paintings, Greek mythology, and Genesis, which a god could circumnavigate in a day and humans in a generation. These tend to expand and become helio‐rather than geo‐centric (not quite monotonically in time) and are succeeded by various assemblages of sun‐like stars with planets of their own. Finite vs. infinite assemblages are debated and then the issue of whether the Milky Way is unique (so that “island universes” made sense, even if you were against the idea) for a couple of centuries. Today one thinks as a rule of the entire 4‐dimensional space‐time we might in principle communicate with and all its contents. Beyond are the modern multi‐verses, sequential (cyclic or oscillating), hierarchical, or non‐communicating entities in more than four dimensions. Each of these has older analogues, and, in every milieu where the ideas have been discussed, there have been firm supporters and firm opponents, some of whose ideas are explored here. Because astronomical observations have firmly settled some earlier disputes in favor of very many galaxies and very many stars with planets, “other worlds” can now refer only to other planets like Earth or to other universes. The focus is on the latter (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)