Download or read book Effective Spacetime written by Karen Crowther and published by Springer. This book was released on 2016-07-07 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the notion that quantum gravity may represent the "breakdown" of spacetime at extremely high energy scales. If spacetime does not exist at the fundamental level, then it has to be considered "emergent", in other words an effective structure, valid at low energy scales. The author develops a conception of emergence appropriate to effective theories in physics, and shows how it applies (or could apply) in various approaches to quantum gravity, including condensed matter approaches, discrete approaches, and loop quantum gravity.

Download or read book Emergent Quantum Mechanics written by Jan Walleczek and published by MDPI. This book was released on 2019-04-02 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emergent quantum mechanics explores the possibility of an ontology for quantum mechanics. The resurgence of interest in "deeper-level" theories for quantum phenomena challenges the standard, textbook interpretation. The book presents expert views that critically evaluate the significance—for 21st century physics—of ontological quantum mechanics, an approach that David Bohm helped pioneer. The possibility of a deterministic quantum theory was first introduced with the original de Broglie-Bohm theory, which has also been developed as Bohmian mechanics. The wide range of perspectives that were contributed to this book on the occasion of David Bohm’s centennial celebration provide ample evidence for the physical consistency of ontological quantum mechanics. The book addresses deeper-level questions such as the following: Is reality intrinsically random or fundamentally interconnected? Is the universe local or nonlocal? Might a radically new conception of reality include a form of quantum causality or quantum ontology? What is the role of the experimenter agent? As the book demonstrates, the advancement of ‘quantum ontology’—as a scientific concept—marks a clear break with classical reality. The search for quantum reality entails unconventional causal structures and non-classical ontology, which can be fully consistent with the known record of quantum observations in the laboratory.

Download or read book Conversations on Quantum Gravity written by Jácome Armas and published by Cambridge University Press. This book was released on 2021-08-26 with total page 719 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading theorists share their important insights into the ongoing quest of theoretical physics to find a quantum theory of gravity.

Download or read book Approaches to Quantum Gravity written by Daniele Oriti and published by Cambridge University Press. This book was released on 2009-03-05 with total page 605 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing contributions from leading researchers in this field, this book provides a complete overview of this field from the frontiers of theoretical physics research for graduate students and researchers. It introduces the most current approaches to this problem, and reviews their main achievements.

Download or read book Classical and Quantum Aspects of Gravity in Relation to the Emergent Paradigm written by Sumanta Chakraborty and published by Springer. This book was released on 2017-08-01 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis explores the connection between gravity and thermodynamics and provides a unification scheme that opens up new directions of exploration. Further elaborating on the Hawking effect and the possibility of singularity avoidance, the author not only discusses the information loss paradox at a broader level but also provides a possible solution to it. As the final frontier, it describes some novel effects arising from the microscopic structure of spacetime. Taken as a whole, the thesis addresses three major research areas in gravitational physics: it starts with classical gravity, proceeds to the black hole information loss paradox, and closes with Planck scale physics. The thesis is written in a lucid and pedagogical style, with an introduction accessible to researchers from other branches of physics and a d iscussion presenting open questions and future directions, which will benefit and hopefully inspire next-generation researchers.

Download or read book Quantum Relativity written by David R. Finkelstein and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past years the author has developed a quantum language going beyond the concepts used by Bohr and Heisenberg. The simple formal algebraic language is designed to be consistent with quantum theory. It differs from natural languages in its epistemology, modal structure, logical connections, and copulatives. Starting from ideas of John von Neumann and in part also as a response to his fundamental work, the author bases his approach on what one really observes when studying quantum processes. This way the new language can be seen as a clue to a deeper understanding of the concepts of quantum physics, at the same time avoiding those paradoxes which arise when using natural languages. The work is organized didactically: The reader learns in fairly concrete form about the language and its structure as well as about its use for physics.

Download or read book From Quantum to Emergent Gravity written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A First Course in Loop Quantum Gravity written by Rodolfo Gambini and published by OUP Oxford. This book was released on 2011-09-22 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an accessible introduction to loop quantum gravity and some of its applications, at a level suitable for undergraduate students and others with only a minimal knowledge of college level physics. In particular it is not assumed that the reader is familiar with general relativity and only minimally familiar with quantum mechanics and Hamiltonian mechanics. Most chapters end with problems that elaborate on the text, and aid learning. Applications such as loop quantum cosmology, black hole entropy and spin foams are briefly covered. The text is ideally suited for an undergraduate course in the senior year of a physics major. It can also be used to introduce undergraduates to general relativity and quantum field theory as part of a 'special topics' type of course.

Download or read book Beyond Spacetime written by Nick Huggett and published by Cambridge University Press. This book was released on 2020-05-14 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of essays discussing the philosophy and foundations of quantum gravity. Written by leading philosophers and physicists in the field, chapters cover the important conceptual questions in the search for a quantum theory of gravity, and the current state of understanding among philosophers and physicists.

Download or read book Neutron Interferometry written by Helmut Rauch and published by . This book was released on 2015 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: The quantum interference of de Broglie matter waves is probably one of the most startling and fundamental aspects of quantum mechanics. It continues to tax our imaginations and leads us to new experimental windows on nature. Quantum interference phenomena are vividly displayed in the wideassembly of neutron interferometry experiments, which have been carried out since the first demonstration of a perfect silicon crystal interferometer in 1974. Since the neutron experiences all four fundamental forces of nature (strong, weak, electromagnetic, and gravitational), interferometry withneutrons provides a fertile testing ground for theory and precision measurements. Many Gedanken experiments of quantum mechanics have become real due to neutron interferometry.Quantum mechanics is a part of physics where experiment and theory are inseparably intertwined. This general theme permeates the second edition of this book. It discusses more than 40 neutron interferometry experiments along with their theoretical motivations and explanations. The basic ideas andresults of interference experiments related to coherence and decoherence of matter waves and certain post-selection variations, gravitationally induced quantum phase shifts, Berry`s geometrical phases, spinor symmetry and spin superposition, and Bell's inequalities are all discussed and explained inthis book. Both the scalar and vector Aharonov-Bohm topological interference effects and the neutron version of the Sagnac effect are presented in a self-contained and pedagogical way. Interferometry with perfect crystals, artificial lattices, and spin-echo systems are also topics of this book. Itincludes the theoretical underpinning as well as connections to other areas of experimental physics, such as quantum optics, nuclear physics, gravitation, and atom interferometry. The observed phase shifts due to the Earth's gravity and rotation indicate a close connection to relativity theory.Neutron interferometry can be considered as a central technique of quantum optics with massive particles. It has stimulated the development of interferometry with atoms, molecules and clusters.The book is written in a style that will be suitable at the senior undergraduate and beginning of graduate level. It will interest and excite many students and researchers in neutron, nuclear, quantum, gravitational, optical, and atomic physics. Lecturers teaching courses in modern physics andquantum mechanics will find a number of interesting and historic experiments they may want to include in their lectures.

Download or read book Something Deeply Hidden written by Sean Carroll and published by Penguin. This book was released on 2020-09-01 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: INSTANT NEW YORK TIMES BESTSELLER As you read these words, copies of you are being created. Sean Carroll, theoretical physicist and one of this world’s most celebrated writers on science, rewrites the history of twentieth-century physics. Already hailed as a masterpiece, Something Deeply Hidden shows for the first time that facing up to the essential puzzle of quantum mechanics utterly transforms how we think about space and time. His reconciling of quantum mechanics with Einstein’s theory of relativity changes, well, everything. Most physicists haven’t even recognized the uncomfortable truth: Physics has been in crisis since 1927. Quantum mechanics has always had obvious gaps—which have come to be simply ignored. Science popularizers keep telling us how weird it is, how impossible it is to understand. Academics discourage students from working on the "dead end" of quantum foundations. Putting his professional reputation on the line with this audacious yet entirely reasonable book, Carroll says that the crisis can now come to an end. We just have to accept that there is more than one of us in the universe. There are many, many Sean Carrolls. Many of every one of us. Copies of you are generated thousands of times per second. The Many-Worlds theory of quantum behavior says that every time there is a quantum event, a world splits off with everything in it the same, except in that other world the quantum event didn't happen. Step-by-step in Carroll's uniquely lucid way, he tackles the major objections to this otherworldly revelation until his case is inescapably established. Rarely does a book so fully reorganize how we think about our place in the universe. We are on the threshold of a new understanding—of where we are in the cosmos, and what we are made of.

Download or read book When Gravity Breaks Down written by Balungi Francis and published by . This book was released on 2020-04-10 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Newton's view, all objects exert a force that attracts other objects. That universal law of gravitation worked pretty well for predicting the motion of planets as well as objects on Earth and it's still used, for example, when making the calculations for a rocket launch. But Newton's view of gravity didn't work for some things, like Mercury's peculiar orbit around the sun. The orbits of planets shift over time, and Mercury's orbit shifted faster than Newton predicted.Einstein's idea was that gravity is not a force, but it is really an effect caused by the curvature of space and time. Although all its predictions have almost been confirmed by experiment, General relativity fails to explain details near space time singularities at the centre of Black holes and the mysterious dark matter. Which means Einstein equations cannot explain the motion of stars in galaxies and galaxy clusters. Mordehai Milgrom MOND explains the motion of stars in galaxies correctly without assuming Dark matter. Therefore MOND is an alternative to Newton's law of Universal gravitation. However the most serious problem facing Milgrom's law is that it cannot completely eliminate the need for dark matter in all astrophysical systems.Most theorists believe that gravitons must exist, and that they could be candidates for Dark matter, because quantum theory has successfully explained every other force of nature. But not everyone agrees. No theory claiming to unify quantum theory with GR has been successfully verified, and this has raised suspicions that perhaps gravity isn't like any other force - in which case gravitons may not exist.The theory of quantum gravity is expected to be able to provide a satisfactory description of the microstructure of space time at the so called Planck scales, at which all fundamental constants of the ingredient theories, c (speed of light), h ( Planck constant) and G ( Newton's constant), come together to form units of mass, length and time. The search for the full theory of quantum gravity has been stymied by the fact that gravity's quantum properties never seem to manifest in actual experience.One option for a solution to this conundrum is string theory, or the idea that everything we perceive as a particle or force is simply an excitation of a closed or open string, vibrating at specific but unique frequencies. One of the major criticisms of string theory has to do not with the theory so much as with theorists. Not only that, the strings of string theory are stupendously small, thought to be somewhere around the Planck scale, a bare 10-34 meters across. That's far, far smaller than anything we can possibly hope to probe even with our most precise instruments. The strings are so small, in fact, that they appear to us to be point-like particles, such as electrons and photons and neutrons. We simply can't ever stare at a string directly.Therefore emergent gravity or entropic gravity is a theory in modern physics that describes gravity as an entropic force, a force with macro-scale homogeneity but which is subject to quantum level disorder and not a fundamental interaction.The theory has been controversial within the physics community but has sparked research and experiments to test its validity. The problem is, if emergent gravity just reproduces General Relativity, there's no way to test the idea. What we need instead is a prediction from emergent gravity that deviates from General Relativity.Finally when all is said and done, the fifth force is proposed and its first result is that it reproduces the MOND and Emergent gravity results from one single force equation and solves all gravitational problems leaving none untouched. Although it is accurate there is one problem; it can't explain the origin of gravity.Gravity is then fixed by postulating that it is as a result of the Casimir effect due to vacuum polarizations with sounding experimental proof. This book will help you fix Gravity.

Download or read book String Theory and the Scientific Method written by Richard Dawid and published by Cambridge University Press. This book was released on 2013-05-02 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: String theory has played a highly influential role in theoretical physics for nearly three decades and has substantially altered our view of the elementary building principles of the Universe. However, the theory remains empirically unconfirmed, and is expected to remain so for the foreseeable future. So why do string theorists have such a strong belief in their theory? This book explores this question, offering a novel insight into the nature of theory assessment itself. Dawid approaches the topic from a unique position, having extensive experience in both philosophy and high-energy physics. He argues that string theory is just the most conspicuous example of a number of theories in high-energy physics where non-empirical theory assessment has an important part to play. Aimed at physicists and philosophers of science, the book does not use mathematical formalism and explains most technical terms.

Download or read book The Emergence of Spacetime in String Theory written by Tiziana Vistarini and published by Routledge. This book was released on 2019-06-12 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nature of space and time is one of the most fascinating and fundamental philosophical issues which presently engages at the deepest level with physics. During the last thirty years this notion has been object of an intense critical review in the light of new scientific theories which try to combine the principles of both general relativity and quantum theory—called theories of quantum gravity. This book considers the way string theory shapes its own account of spacetime disappearance from the fundamental level.

Download or read book Jacob Bekenstein The Conservative Revolutionary written by Brink Lars and published by World Scientific. This book was released on 2019-09-12 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Jacob Bekenstein, an Israeli physicist of the Hebrew University, Jerusalem, planted the seeds of a revolution of our understanding of space-time. Using conservative intuitive methods including time-old gedanken experiments, he discovered that black holes have thermodynamical properties such as entropy.Moreover, he found that their entropy was not extensive, unlike that of any other thermodynamical system considered before, but rather is proportional to the surface of their horizon. Furthermore, Bekenstein pioneered the study of black holes by focusing on their information content aspects. This led him to obtain bounds of a holographic nature on the amount of information that can be stored in a given region of space-time.This book contains a series of scientific and personal contributions by his contemporaries who recall the struggle against his ideas and then with them: the fate accompanying many revolutionary ideas. This is followed by original scientific contributions by many of the leaders of current research on black hole physics and holography. They have trodden his path and expanded it. The impact of Jacob Bekenstein's visionary ideas is just starting to be understood.

Download or read book Three Roads To Quantum Gravity written by Lee Smolin and published by Basic Books. This book was released on 2008-03-18 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: "It would be hard to imagine a better guide to this difficult subject." -- Scientific American In Three Roads to Quantum Gravity, Lee Smolin provides an accessible overview of the attempts to build a final "theory of everything." He explains in simple terms what scientists are talking about when they say the world is made from exotic entities such as loops, strings, and black holes and tells the fascinating stories behind these discoveries: the rivalries, epiphanies, and intrigues he witnessed firsthand. "Provocative, original, and unsettling." -- The New York Review of Books "An excellent writer, a creative thinker." -- Nature

Download or read book The Emergent Multiverse written by David Wallace and published by OUP Oxford. This book was released on 2012-05-24 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Emergent Multiverse presents a striking new account of the 'many worlds' approach to quantum theory. The point of science, it is generally accepted, is to tell us how the world works and what it is like. But quantum theory seems to fail to do this: taken literally as a theory of the world, it seems to make crazy claims: particles are in two places at once; cats are alive and dead at the same time. So physicists and philosophers have often been led either to give up on the idea that quantum theory describes reality, or to modify or augment the theory. The Everett interpretation of quantum mechanics takes the apparent craziness seriously, and asks, 'what would it be like if particles really were in two places at once, if cats really were alive and dead at the same time'? The answer, it turns out, is that if the world were like that—if it were as quantum theory claims—it would be a world that, at the macroscopic level, was constantly branching into copies—hence the more sensationalist name for the Everett interpretation, the 'many worlds theory'. But really, the interpretation is not sensationalist at all: it simply takes quantum theory seriously, literally, as a description of the world. Once dismissed as absurd, it is now accepted by many physicists as the best way to make coherent sense of quantum theory. David Wallace offers a clear and up-to-date survey of work on the Everett interpretation in physics and in philosophy of science, and at the same time provides a self-contained and thoroughly modern account of it—an account which is accessible to readers who have previously studied quantum theory at undergraduate level, and which will shape the future direction of research by leading experts in the field.