The Meaning of Quantum Gravity

The Meaning of Quantum Gravity PDF Author: Horst-Heino Borzeszkowski
Publisher: Springer
ISBN: 9789401082297
Category : Science
Languages : en
Pages : 132

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Book Description
In discussing the question of whether General Relativity Theory really needs to be quantized, a simply negative answer cannot be accepted, of course. Such an answer is not satisfying because, first, Einstein's gravitational equations connect gravity and non-gravitational matter and because, second, it can be taken for granted that non-gravitational matter has an atomic or quantum structure such that its energy-momentum tensor standing on the right-hand side of Einstein's equations is formed out of quantum operators. These two facts make it impossible to read the left-hand side of Einstein's equations as an ordinary classical function. This does not necessarily mean, however, that we must draw the conclusion that General Relativity Theory, similar to electrodynamics, could or should be quantized in a rigorous manner and that this quantization has similar consequences to quantum electrodynamics. In other words, when for reasons of consistency quantization is tried, then one has to ask whether and where the quantization procedure has a physical meaning, i.e., whether there exist measurable effects of quantum gravity. IQ accordance with these questions, we are mainly dealing with the discus sion of the principles of quantized General Relativity Theory and with the estimation of quantum effects including the question of their measurability. This analysis proves that it is impossible to distinguish between classical and quantum General Relativity Theory for the extreme case of Planck's orders of magnitude. In other words, there does not exist a physically meaningful rigorous quantization conception for Einstein's theory.

The Meaning of Quantum Gravity

The Meaning of Quantum Gravity PDF Author: Horst-Heino Borzeszkowski
Publisher: Springer
ISBN: 9789401082297
Category : Science
Languages : en
Pages : 132

Get Book Here

Book Description
In discussing the question of whether General Relativity Theory really needs to be quantized, a simply negative answer cannot be accepted, of course. Such an answer is not satisfying because, first, Einstein's gravitational equations connect gravity and non-gravitational matter and because, second, it can be taken for granted that non-gravitational matter has an atomic or quantum structure such that its energy-momentum tensor standing on the right-hand side of Einstein's equations is formed out of quantum operators. These two facts make it impossible to read the left-hand side of Einstein's equations as an ordinary classical function. This does not necessarily mean, however, that we must draw the conclusion that General Relativity Theory, similar to electrodynamics, could or should be quantized in a rigorous manner and that this quantization has similar consequences to quantum electrodynamics. In other words, when for reasons of consistency quantization is tried, then one has to ask whether and where the quantization procedure has a physical meaning, i.e., whether there exist measurable effects of quantum gravity. IQ accordance with these questions, we are mainly dealing with the discus sion of the principles of quantized General Relativity Theory and with the estimation of quantum effects including the question of their measurability. This analysis proves that it is impossible to distinguish between classical and quantum General Relativity Theory for the extreme case of Planck's orders of magnitude. In other words, there does not exist a physically meaningful rigorous quantization conception for Einstein's theory.

Quantum Gravity

Quantum Gravity PDF Author: Carlo Rovelli
Publisher: Cambridge University Press
ISBN: 1139456156
Category : Science
Languages : en
Pages : 516

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Book Description
Quantum gravity is perhaps the most important open problem in fundamental physics. It is the problem of merging quantum mechanics and general relativity, the two great conceptual revolutions in the physics of the twentieth century. The loop and spinfoam approach, presented in this 2004 book, is one of the leading research programs in the field. The first part of the book discusses the reformulation of the basis of classical and quantum Hamiltonian physics required by general relativity. The second part covers the basic technical research directions. Appendices include a detailed history of the subject of quantum gravity, hard-to-find mathematical material, and a discussion of some philosophical issues raised by the subject. This fascinating text is ideal for graduate students entering the field, as well as researchers already working in quantum gravity. It will also appeal to philosophers and other scholars interested in the nature of space and time.

Three Roads To Quantum Gravity

Three Roads To Quantum Gravity PDF Author: Lee Smolin
Publisher: Basic Books
ISBN: 0465013244
Category : Science
Languages : en
Pages : 251

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Book Description
"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

Covariant Loop Quantum Gravity

Covariant Loop Quantum Gravity PDF Author: Carlo Rovelli
Publisher: Cambridge University Press
ISBN: 1107069629
Category : Science
Languages : en
Pages : 267

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Book Description
A comprehensible introduction to the most fascinating research in theoretical physics: advanced quantum gravity. Ideal for researchers and graduate students.

Introduction to Quantum Effects in Gravity

Introduction to Quantum Effects in Gravity PDF Author: Viatcheslav Mukhanov
Publisher: Cambridge University Press
ISBN: 9780521868341
Category : Mathematics
Languages : en
Pages : 298

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Book Description
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Quantum Space

Quantum Space PDF Author: Jim Baggott
Publisher: Oxford University Press
ISBN: 019253680X
Category : Science
Languages : en
Pages : 448

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Book Description
Today we are blessed with two extraordinarily successful theories of physics. The first is Albert Einstein's general theory of relativity, which describes the large-scale behaviour of matter in a curved spacetime. This theory is the basis for the standard model of big bang cosmology. The discovery of gravitational waves at the LIGO observatory in the US (and then Virgo, in Italy) is only the most recent of this theory's many triumphs. The second is quantum mechanics. This theory describes the properties and behaviour of matter and radiation at their smallest scales. It is the basis for the standard model of particle physics, which builds up all the visible constituents of the universe out of collections of quarks, electrons and force-carrying particles such as photons. The discovery of the Higgs boson at CERN in Geneva is only the most recent of this theory's many triumphs. But, while they are both highly successful, these two structures leave a lot of important questions unanswered. They are also based on two different interpretations of space and time, and are therefore fundamentally incompatible. We have two descriptions but, as far as we know, we've only ever had one universe. What we need is a quantum theory of gravity. Approaches to formulating such a theory have primarily followed two paths. One leads to String Theory, which has for long been fashionable, and about which much has been written. But String Theory has become mired in problems. In this book, Jim Baggott describes

Einstein's Unfinished Revolution

Einstein's Unfinished Revolution PDF Author: Lee Smolin
Publisher: Knopf Canada
ISBN: 0345809122
Category : Science
Languages : en
Pages : 347

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Book Description
A daring new vision of the quantum universe, and the scandals controversies, and questions that may illuminate our future--from Canada's leading mind on contemporary physics. Quantum physics is the golden child of modern science. It is the basis of our understanding of atoms, radiation, and so much else, from elementary particles and basic forces to the behaviour of materials. But for a century it has also been the problem child of science, plagued by intense disagreements between its intellectual giants, from Albert Einstein to Stephen Hawking, over the strange paradoxes and implications that seem like the stuff of fantasy. Whether it's Schrödinger's cat--a creature that is simultaneously dead and alive--or a belief that the world does not exist independently of our observations of it, quantum theory is what challenges our fundamental assumptions about our reality. In Einstein's Unfinished Revolution, globally renowned theoretical physicist Lee Smolin provocatively argues that the problems which have bedeviled quantum physics since its inception are unsolved for the simple reason that the theory is incomplete. There is more, waiting to be discovered. Our task--if we are to have simple answers to our simple questions about the universe we live in--must be to go beyond it to a description of the world on an atomic scale that makes sense. In this vibrant and accessible book, Smolin takes us on a journey through the basics of quantum physics, introducing the stories of the experiments and figures that have transformed the field, before wrestling with the puzzles and conundrums that they present. Along the way, he illuminates the existing theories about the quantum world that might solve these problems, guiding us toward his own vision that embraces common sense realism. If we are to have any hope of completing the revolution that Einstein began nearly a century ago, we must go beyond quantum mechanics as we know it to find a theory that will give us a complete description of nature. In Einstein's Unfinished Revolution, Lee Smolin brings us a step closer to resolving one of the greatest scientific controversies of our age.

The Physics of God and the Quantum Gravity Theory of Everything: And Other Selected Works

The Physics of God and the Quantum Gravity Theory of Everything: And Other Selected Works PDF Author: James Redford
Publisher: Eliva Press
ISBN: 9781636482774
Category : Philosophy
Languages : en
Pages : 270

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Book Description
For anyone who has ever wondered about such questions as what the meaning of life is, what the purpose of their own life is, whether there is life after death, whether God exists, what the future holds for humanity, and why anything exists at all as opposed to nothingness, then this book answers all of those questions using the known laws of physics. This work details physicist and mathematician Prof. Frank J. Tipler's Omega Point cosmology, which has been published and extensively peer-reviewed in leading physics journals. The Omega Point cosmology is a proof (i.e., mathematical theorem) demonstrating that sapient life (in the form of, e.g., immortal superintelligent human-mind computer-uploads and artificial intelligences) is required by standard physics (viz., the Second Law of Thermodynamics, General Relativity, and Quantum Mechanics) to take control over all matter in the universe, for said life to eventually force the collapse of the universe, and for the computational resources of the universe (in terms of both processor speed and memory storage) to diverge to infinity as the universe collapses into a final singularity, termed the Omega Point. Said Omega Point cosmology is also an intrinsic component of the Feynman-DeWitt-Weinberg quantum gravity/Standard Model Theory of Everything (TOE) correctly describing and unifying all the forces in physics, of which TOE is itself mathematically forced by the aforementioned known physical laws. The Omega Point final singularity has all the unique properties claimed for God in the traditional religions. This book additionally addresses the societal implications of the Omega Point cosmology.

Towards Quantum Gravity

Towards Quantum Gravity PDF Author: Jerzy Kowalski-Glikman
Publisher: Springer Science & Business Media
ISBN: 3540669108
Category : Science
Languages : en
Pages : 387

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Book Description
The aim of this book is to give graduate students an overview of quantum gravity but it also covers related topics from astrophysics. Some well-written contributions can serve as an introduction into basic conceptual concepts like time in quantum gravity or the emergence of a classical world from quantum cosmology. This makes the volume attractive to philosophers of science, too. Other topics are black holes, gravitational waves and non-commutative extensions of physical theories.

Approaches to Quantum Gravity

Approaches to Quantum Gravity PDF Author: Daniele Oriti
Publisher: Cambridge University Press
ISBN: 0521860458
Category : Science
Languages : en
Pages : 605

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Book Description
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.