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This book is a treatise on time and on background independence in physics. It first considers how time is conceived of in each accepted paradigm of physics: Newtonian, special relativity, quantum mechanics (QM) and general relativity (GR). Substantial differences are moreover uncovered between what is meant by time in QM and in GR. These differences jointly source the Problem of Time: Nine interlinked facets which arise upon attempting concurrent treatment of the QM and GR paradigms, as is required in particular for a background independent theory of quantum gravity. A sizeable proportion of current quantum gravity programs - e.g. geometrodynamical and loop quantum gravity approaches to quantum GR, quantum cosmology, supergravity and M-theory - are background independent in this sense. This book's foundational topic is thus furthermore of practical relevance in the ongoing development of quantum gravity programs. This book shows moreover that eight of the nine facets of the Problem of Time already occur upon entertaining background independence in classical (rather than quantum) physics.By this development, and interpreting shape theory as modelling background independence, this book further establishes background independence as a field of study. Background independent mechanics, as well as minisuperspace (spatially homogeneous) models of GR and perturbations thereabout are used to illustrate these points.

You are reading the word "now" right now. But what does that mean? What makes the ephemeral moment "now" so special? Its enigmatic character has bedeviled philosophers, priests, and modern-day physicists from Augustine to Einstein and beyond. Einstein showed that the flow of time is affected by both velocity and gravity, yet he despaired at his failure to explain the meaning of "now." Equally puzzling: why does time flow? Some physicists have given up trying to understand, and call the flow of time an illusion, but the eminent experimentalist physicist Richard A. Muller protests. He says physics should explain reality, not deny it. In Now, Muller does more than poke holes in past ideas; he crafts his own revolutionary theory, one that makes testable predictions. He begins by laying out-with the refreshing clarity that made Physics for Future Presidents so successful-a firm and remarkably clear explanation of the physics building blocks of his theory: relativity, entropy, entanglement, antimatter, and the Big Bang. With the stage then set, he reveals a startling way forward.Muller points out that the standard Big Bang theory explains the ongoing expansion of the universe as the continuous creation of new space. He argues that time is also expanding and that the leading edge of the new time is what we experience as "now." This thought-provoking vision has remarkable implications for some of our biggest questions, not only in physics but also in philosophy-including the ongoing debate about the reality of free will. Moreover, his theory is testable. Muller's monumental work will spark major debate about the most fundamental assumptions of our universe, and may crack one of physics's longest-standing enigmas

From the reviews: "...useful for experts in mathematical physics...this is a very interesting book, which deserves to be found in any physical library." (OPTICS & PHOTONICS NEWS, July/August 2005

¿Sabe que buena parte de lo que vemos se lo inventa el cerebro? La genética y los valores adquiridos determinan la forma en la que vemos el mundo. Así pues, aprendiendo a entender cómo interpreta el cerebro las imagenes podremos crear una fotografia que destaque sobre las demas.En Fotografia sin tecnicismos, el autor nos enseña que los dispositivos son tan solo herramientas a nuestro servicio y que podemos aprender a hacer grandes fotos entrenando nuestra maestria y empleando la psicologia de la percepcion. No necesitara hacer inversiones en costosos aparatos ni aprender demasiada teoria. Aqui no encontrara marcas ni modelos, no hay aplicaciones o programas especiales. Es la perfecta guia de ayuda, donde todo esta basado en la verdadera esencia de una buena foto, donde encontrara los secretos, la maestria y las habilidades que le motiven para obtener la mejor foto con un equipo reflex o con un simple smartphone.Con Fotografia sin tecnicismos, podremos ser espectadores de nosotros mismos y desarrollar una mente imparcial, en la que ofrezcamos a los ojos de nuestros espectadores imagenes que se salgan de la zona de confort, de la sensorialidad para pasar a la perceptualidad (Schwartz, psicologo).

A new essay collection by the noted Polish poet For Adam Zagajewski--one of Poland's great poets--the project of writing, whether it be poetry or prose, is an occasion to advance what David Wojahn has characterized as his "restless and quizzical quest for self-knowledge." Slight Exaggeration is an autobiographical portrait of the poet, arranged not chronologically but with that same luminous quality that distinguishes Zagajewski's spellbinding poetry--an affinity for the invisible. In a mosaic-like blend of criticism, reflections, European history, and aphoristic musings, Zagajewski tells the stories of his life in glimpses and reveries--from the Second World War and the occupation of Poland that left his family dispossessed to Joseph Brodsky's funeral on the Venetian island of San Michele--interspersed with intellectual interrogations of the writers and poets (D. H. Lawrence, Giorgos Seferis, Zbigniew Herbert, Paul Valery), composers and painters (Brahms, Rembrandt), and modern heroes (Helmuth James Graf von Moltke) who have influenced his work. A wry and philosophical defense of mystery, Slight Exaggeration recalls Zagajewski's poetry in its delicate negotiation between the earthbound and the ethereal, "between brief explosions of meaning and patient wandering through the plains of ordinary days." With an enduring inclination to marvel, Zagajewski restores the world to us--necessarily incomplete and utterly astonishing

«Il est tentant de voir la poésie comme un des quelques véhicules importants qui nous emportent vers le haut ; et de comprendre que la ferveur précède l'ironie. La ferveur, ce chant ardent du monde auquel répond notre chant imparfait. «Nous avons besoin de la poésie tout comme nous avons besoin du Beau (même s'il existe, a ce qu'on raconte, des pays d'Europe où ce mot est strictement interdit). Le Beau n'est pas pour les esthètes, le Beau est pour tous ceux qui cherchent une voie sérieuse ; c'est un appel, une promesse, ce n'est probablement pas une promesse de bonheur, comme le voulait Stendhal, mais celle d'un grand voyage interminable.» Dans les textes écrits entre 1993 et 2002 qui composent ce recueil, Adam Zagajewski nous livre ses impressions poétiques et artistiques avec l'intelligence, la sincérité et le talent qui le caractérisent.

La difícil situació de les abelles al nostre planeta és un fet més que reocupant. ¿I qui millor per prendre consciència sobre aquesta greu amenaça ambiental que les noves generacions que heretaran la