Am 4. November 1915 legte EINSTEIN seine beriihmte Arbeit "Zur allgemeinen Relativitatstheorie" der PreuBischen Akademie der Wissenschaften zu Berlin vor. 50 Jahre spater organisierte die Deutsche Akademie der Wissenschaften im Andenken daran eine dreitagige Konferenz, in deren Verlauf auch eine Gedenkfeier abgehalten wurde. Ich hatte die Ehre, eine Gedenkrede iiber EINSTEIN und sein Werk zu halten. In der Zwischenzeit wurde unser Wissen urn viele wichtige neue Zusatze erweitert. Wir sehen nun, daB die Dynamik der Einsteinschen Theorie in einem Superraum ablauft. (...) Seine Struktur und seine Eigenschaften sind von graBter Bedeutung. Infolgedessen habe ich jenen Teil meines Berichtes von 1965, der iiber die Quantengeometrodynamik handelt, geandert und erweitert, urn vom § 12 an unser Wissen iiber den Super­ raum zusammenzufassen. Einige Teile des hier enthaltenen Materials sind schon friiher in anderer Form erschienen. Der Autor dankt fiir die Erlaubnis, dieses Material wieder ab­ drucken zu lassen, den folgenden Verlagen: Akademie-Verlag, Berlin; W. A. Benjamin, Inc., New York; Gordon and Breach, New York; und Springer-Verlag, New York und Heidelberg, sowie den Organisatoren jener Konferenzen, auf denen diese Beitrage vorgelegt wurden: Einstein-Symposium aus Deutsche Akademie der Wissenschaften zu Berlin, 1965; International School of Non-Linear Mathematics and Physics, Miinchen, J uli 1966; Academie Internationale de Philo sophie des Sciences, Oberwolfach/Freiburg i. Br., Juli 1966; Society of Engineering Science, Raleigh, North Carolina, Oktober 1966; Colloque Internationale sur Fluides et Champ Gravitationel en Relativite Generale, Paris, J uni 1967; und Battelle Ren­ contres in Mathematics and Physics, Seattle, Juli 1967. (shrink)

This report reviews what quantum physics and information theory have to tell us about the age-old question, How come existence? No escape is evident from four conclusions: (1) The world cannot be a giant machine, ruled by any preestablished continuum physical law. (2) There is no such thing at the microscopic level as space or time or spacetime continuum. (3) The familiar probability function or functional, and wave equation or functional wave equation, of standard quantum theory provide mere continuum idealizations (...) and by reason of this circumstance conceal the information-theoretic source from which they derive. (4) No element in the description of physics shows itself as closer to primordial than the elementary quantum phenomenon, that is, the elementary device-intermediated act of posing a yes-no physical question and eliciting an answer or, in brief, the elementary act of observer-participancy. Otherwise stated, every physical quantity, every it, derives its ultimate significance from bits, binary yes-or-no indications, a conclusion which we epitomize in the phrase, it from bit. (shrink)

Examines the philosophical, scientific, and theological aspects of the character of the human mind.

Ed. Daniel Greenberger, 750pp May 1995 164.95.

The geometry of lattice universes in general is reviewed, and particular attention is given to the 3-geometry of a 5-black hole model universe at the momentarily static phase of maximum expansion as an illustration of the insights to be won by considering symmetries and reflections. Three models for the black holes in this lattice universe are compared and contrasted. Reasons are given for working with Misner's “flange backup” model. The geometry interior to the individual tetrahedral cell of this lattice is (...) compared and contrasted with the electrostatic field produced by a point charge located in the center of a cavity of the same shape that has perfectly conducting walls. (shrink)

The following quotations describe in “nutshells” a few highlights of John Archibald Wheeler's contributions to physics. The contributions are arranged in roughly the following order: (i) concrete research results, (ii) innovative ideas that have become foundations for the research of others, (iii) insights that give guidance for the development of physics over the coming decades. Since most of Wheeler's work contains strong elements of two or even all three of these characteristics, the editors have not attempted (...) to delineate the dividing lines between the three categories. (shrink)

1857. After the fire of mutiny has swept through British India, young Lieutenant Victor Narraway arrives at a battered military base at Cawnpore. It is just two weeks before Christmas, but no one is able to celebrate: they have been betrayed. A soldier under arrest for dereliction of duty has killed a guard and escaped to join the rebels, taking crucial information that led to the massacre of nine men on patrol. Someone must have helped him, and medical orderly (...) class='Hi'>John Tallis is the only man unaccounted for at the time. He is now on trial for his life, and Narraway is commanded to defend him. Narraway knows that his is an impossible task. The British Army needs justice to be carried out in full, and there seems no doubt of Tallis's guilt. But Narraway cannot see any motive for his actions. Will an innocent man hang before Christmas? (shrink)

This book has been considered by academicians and scholars of great significance and value to literature. This forms a part of the knowledge base for future generations. So that the book is never forgotten we have represented this book in a print format as the same form as it was originally first published. Hence any marks or annotations seen are left intentionally to preserve its true nature.

What factors drove the transformation of the cyanobacterial progenitor of plastids (e.g. chloroplasts) from endosymbiont to bona fide organelle? This question lies at the heart of organelle genesis because, whereas intracellular endosymbionts are widespread in both unicellular and multicellular eukaryotes (e.g. rhizobial bacteria, Chlorella cells in ciliates, Buchnera in aphids), only two canonical eukaryotic organelles of endosymbiotic origin are recognized, the plastids of algae and plants and the mitochondrion. Emerging data on (1) the discovery of non‐canonical plastid protein targeting, (2) (...) the recent origin of a cyanobacterial‐derived organelle in the filose amoeba Paulinella chromatophora, and (3) the extraordinarily reduced genomes of psyllid bacterial endosymbionts begin to blur the distinction between endosymbiont and organelle. Here we discuss the use of these terms in light of new data in order to highlight the unique aspects of plastids and mitochondria and underscore their central role in eukaryotic evolution. BioEssays 29:1239–1246, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

The cryptomonads and chlorarachniophytes are two unicellular algal lineages with complex cellular structures and fascinating evolutionary histories. Both groups acquired their photosynthetic abilities through the assimilation of eukaryotic endosymbionts. As a result, they possess two distinct cytosolic compartments and four genomes—two nuclear genomes, an endosymbiont‐derived plastid genome and a mitochondrial genome derived from the host cell. Like mitochondrial and plastid genomes, the genome of the endosymbiont nucleus, or ‘nucleomorph’, of cryptomonad and chlorarachniophyte cells has been greatly reduced through the combined (...) effects of gene loss and intracellular gene transfer. This article focuses on the structure, function, origin and evolution of cryptomonad and chlorarachniophyte nucleomorph genomes in light of recent comparisons of genome sequence data from both groups. It is now possible to speculate on the reasons that nucleomorphs persist in cryptomonads and chlorarachniophytes but have been lost in all other algae with plastids of secondary endosymbiotic origin. BioEssays 29:392–402, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

Epstein et al. fail to show that L2 learners have full access to UG because they do not explain the relationship between UG and functional categories (FCs). Nor do they provide an explanation of why learners with (supposed) full knowledge of FCs fail to use them in a native-like way.

A flurry of recent publications have challenged consensus views on the tempo and mode of plastid (chloroplast) evolution in eukaryotes and, more generally, the impact of endosymbiosis in the evolution of the nuclear genome. Endosymbiont‐to‐nucleus gene transfer is an essential component of the transition from endosymbiont to organelle, but the sheer diversity of algal‐derived genes in photosynthetic organisms such as diatoms, as well as the existence of genes of putative plastid ancestry in the nuclear genomes of plastid‐lacking eukaryotes such as (...) ciliates and choanoflagellates, defy simple explanation. Collectively, these papers underscore the power of comparative genomics and, at the same time, reveal how little we know with certainty about the earliest stages of the evolution of photosynthetic eukaryotes. Editor's suggested further reading in BioEssaysEarly steps in plastid evolution: current ideas and controversies AbstractDinoflagellate mitochondrial genomes: stretching the rules of molecular biology Abstract. (shrink)

Ever since Darwin, scholars have noted that cultural entities such as languages, laws and theories seem to evolve through variation, selection and replication. These essays consider whether this comparison is just a metaphor.

Sheehan and coworkers have claimed [D. P. Sheehan et al., Found. Phys. 30, 1227 ; 32, 441 ; D. P. Sheehan, in Quantum Limits to the Second Law, AIP Conference Proceedings 643, p. 391] that a dilute gas trapped between an external shell and a gravitator can support a steady state in which energy flux by particles in one direction is balanced by energy flux by radiation in the opposite direction, and in which work can be extracted from an isothermal (...) heat reservoir, thereby violating the second law of thermodynamics. In this paper, we identify a fundamental error in their simulation and analysis of their model system that vitiates their conclusions. We analyze a simpler, exactly soluble, three-dimensional model of a very dilute gas in a gravitational field between two thermal reservoirs, and show that their conclusions are not supported for the simple model. We show that their method of simulation, when applied to either the simple model or their more complex model under simpler conditions where the answers are known, leads to unphysical results. We also show that, when appropriate sampling is done, their model gives results in accord with the second law and detailed balance. (shrink)

This is the third selection of major works on the Scottish Enlightenment and includes the same combination of hard-to-find and popular works as in the two previous collections. Contents: An Essay on the Natural Equality of Men [1793] William Lawrence Brown, New introduction by Dr. William Scott 308 pp An Enquiry into the Origin of Moral Virtue [1733] Archibald Campbell 586 pp The Philosophical Works [1765] William Dudgeon, New introduction by David Berman 300 pp Institutes of Moral Philosophy For (...) the use of Students in the College of Edinburgh [1769] Adam Ferguson 340 pp A Comparative view of the State and Faculties of Man with those of the Animal World [1774] John Gregory 426 pp An Apology for the Life and Writings of David Hume, Esq [1777] Samuel Jackson A Letter to Adam Smith, On the Life, Death and Philosophy of his friend David Hume Esq [1777] George Horne (Bishop of Norwich) 252 pp. (shrink)

Planctomycetes, Verrucomicrobia and Chlamydia are prokaryotic phyla, sometimes grouped together as the PVC superphylum of eubacteria. Some PVC species possess interesting attributes, in particular, internal membranes that superficially resemble eukaryotic endomembranes. Some biologists now claim that PVC bacteria are nucleus‐bearing prokaryotes and are considered evolutionary intermediates in the transition from prokaryote to eukaryote. PVC prokaryotes do not possess a nucleus and are not intermediates in the prokaryote‐to‐eukaryote transition. Here we summarise the evidence that shows why all of the PVC traits (...) that are currently cited as evidence for aspiring eukaryoticity are either analogous (the result of convergent evolution), not homologous, to eukaryotic traits; or else they are the result of horizontal gene transfers. (shrink)

To our knowledge, this is one of the first studies to test different theoretical models of working memory in childhood based on a computerized assessment. We tested this across several countries: Argentina, Brazil, Canada, Italy, and UK. The present study addressed the wider macro-cultural context and how this impacts working memory. We used two economic indices to characterize the participating countries and ranked the countries based on the Global Index of Cognitive Skills and Educational Attainment. Children between 5 and 10 (...) years completed the same set of short-term and working memory tests. There were two main findings. First, there was a similar pattern in verbal working memory across countries, which suggests that this skill may be relatively consistent across different cultural groups. In contrast, the pattern for visuo-spatial working memory was different across countries, which may explained by cultural differences and educational rankings of the countries. The second main finding was that both a domain-general model and a domain-specific model provided a reasonably good fit with the data, there was the high relationship between the verbal and visuo-spatial working memory constructs across the countries in the latter model. Thus, it may be a more parsimonious choice to rely on a three-factor model. The data also suggest culture-similar patterns in a computerized assessment of working memory. (shrink)

Recent advances in philosophy, artificial intelligence, mathematical psychology, and the decision sciences have brought a renewed focus to the role and interpretation of probability in theories of uncertain reasoning. Henry E. Kyburg, Jr. has long resisted the now dominate Bayesian approach to the role of probability in scientific inference and practical decision. The sharp contrasts between the Bayesian approach and Kyburg's program offer a uniquely powerful framework within which to study several issues at the heart of scientific inference, decision, and (...) reasoning under uncertainty. The commissioned essays for this volume take measure of the scope and impact of Kyburg's views on probability and scientific inference, and include several new and important contributions to the field. Contributors: Gert de Cooman, Clark Glymour, William Harper, Isaac Levi, Ron Loui, Enrique Miranda, John Pollock, Teddy Seidenfeld, Choh Man Teng, Mariam Thalos, Gregory Wheeler, Jon Williamson, and Henry E. Kyburg, Jr. (shrink)

Focused correlation compares the degree of association within an evidence set to the degree of association in that evidence set given that some hypothesis is true. Wheeler and Scheines have shown that a difference in incremental confirmation of two evidence sets is robustly tracked by a difference in their focus correlation. In this essay, we generalize that tracking result by allowing for evidence having unequal relevance to the hypothesis. Our result is robust as well, and we retain conditions for (...) bidirectional tracking between incremental confirmation measures and focused correlation. (shrink)

Polyphenic differences between individuals arise not through differences at the genome level but as a result of specific cues received during development. Polyphenisms often involve entire suites of characters, as shown dramatically by the polyphenic castes found in many social insect colonies. An understanding of the genetic architecture behind polyphenisms provides a novel means of studying the interplay between genomes, gene expression and phenotypes. Here we discuss polyphenisms and molecular genetic tools now available to unravel their developmental bases in insects. (...) We focus on several recent studies that have tracked gene-expression patterns during social insect caste determination. BioEssays 23:62–68, 2001. Published 2001 John Wiley & Sons, Inc. (shrink)

Polyphenic differences between individuals arise not through differences at the genome level but as a result of specific cues received during development. Polyphenisms often involve entire suites of characters, as shown dramatically by the polyphenic castes found in many social insect colonies. An understanding of the genetic architecture behind polyphenisms provides a novel means of studying the interplay between genomes, gene expression and phenotypes. Here we discuss polyphenisms and molecular genetic tools now available to unravel their developmental bases in insects. (...) We focus on several recent studies that have tracked gene‐expression patterns during social insect caste determination. BioEssays 23:62–68, 2001. Published 2001 John Wiley & Sons, Inc. (shrink)