Universally recognized as bringing about a revolutionary transformation of the notions of space, time, and motion in physics, Einstein's theory of gravitation, known as "general relativity," was also a defining event for 20th century philosophy of science. During the decisive first ten years of the theory's existence, two main tendencies dominated its philosophical reception. This book is an extended argument that the path actually taken, which became logical empiricist philosophy of science, greatly contributed to the current impasse over realism, whereas new possibilities are opened in revisiting and reviving the spirit of the more sophisticated tendency, a cluster of viewpoints broadly termed transcendental idealism, and furthering its articulation. It also emerges that Einstein, while paying lip service to the emerging philosophy of logical empiricism, ended up siding de facto with the latter tendency.
Ryckman's work speaks to several groups, among them philosophers of science and historians of relativity. Equations are displayed as necessary, but Ryckman gives the non-mathematical reader enough background to understand their occurrence in the context of his wider philosophical project.

This book delves into finite mathematics and its application in physics, particularly quantum theory. It is shown that quantum theory based on finite mathematics is more general than standard quantum theory, whilst finite mathematics is itself more general than standard mathematics.As a consequence, the mathematics describing nature at the most fundamental level involves only a finite number of numbers while the notions of limit, infinite/infinitesimal and continuity are needed only in calculations that describe nature approximately. It is also shown that the concepts of particle and antiparticle are likewise approximate notions, valid only in special situations, and that the electric charge and baryon- and lepton quantum numbers can be only approximately conserved.

This is one of the clearest expositions in laypersons terms of Einstein's theory of relativity and its paradigm-shifting implications for philosophy and common-sense notions of reality. Moritz Schlick, the influential German philosopher and leader of the positivist school of philosophy known as the Vienna Circle, wrote this short work in 1919 specifically to introduce readers unfamiliar with Einstein's theories to the profound importance of the physicist's immense contributions. Einstein himself reviewed Schlick's work before publication and is thanked in the preface for 'giving me many useful hints'. With a talent for illustrative analogies and a concise, lucid style of presentation, Schlick explains both the special and the general theories of relativity. Beginning with the older Newtonian view of space, time, and the laws governing matter, the author proceeds to show how Einstein's theories solved certain problems inherent in the old view and provided a radical new conception of reality. Since their original publication, numerous experiments have confirmed Einstein's ideas.;Thus, Schlick's work continues to be a valuable and highly accessible explication of one of science's most enduring achievements.

Dynamic Fields and Waves concentrates on electric and magnetic fields that vary with time, including light and electromagnetic waves. Written for an undergraduate introductory course but equally suitable for self-study, this practical, illustrated book discusses waves in general and light waves in particular, together with optical instruments, such as telescopes and microscopes, and electrical devices, such as generators and transformers. It also explores Einstein's special theory of relativity, which gives the most basic insight into space and time.

This modern introduction to particle physics equips students with the skills needed to develop a deep and intuitive understanding of the physical theory underpinning contemporary experimental results. The fundamental tools of particle physics are introduced and accompanied by historical profiles charting the development of the field. Theory and experiment are closely linked, with descriptions of experimental techniques used at CERN accompanied by detail on the physics of the Large Hadron Collider and the strong and weak forces that dominate proton collisions. Recent experimental results are featured, including the discovery of the Higgs boson. Equations are supported by physical interpretations, and end-of-chapter problems are based on datasets from a range of particle physics experiments including dark matter, neutrino, and collider experiments. A solutions manual for instructors is available online. Additional features include worked examples throughout, a detailed glossary of key terms, appendices covering essential background material, and extensive references and further reading to aid self-study, making this an invaluable resource for advanced undergraduates in physics.

This book is a tribute to the scientific legacy of GianCarlo Ghirardi, who was one of the most influential scientists in the field of modern foundations of quantum theory. In this appraisal, contributions from friends, collaborators and colleagues reflect the influence of his world of thoughts on theory, experiments and philosophy, while also offering prospects for future research in the foundations of quantum physics. The themes of the contributions revolve around the physical reality of the wave function and its notorious collapse, randomness, relativity and experiments.

This book presents the proceedings of The International Workshop on Frontiers in High Energy Physics (FHEP 2019), held in Hyderabad, India. It highlights recent, exciting experimental findings from LHC, KEK, LIGO and several other facilities, and discusses new ideas for the unified treatment of cosmology and particle physics and in the light of new observations, which could pave the way for a better understanding of the universe we live in. As such, the book provides a platform to foster collaboration in order to provide insights into this important field of physics.

This book collates papers presented at two international conferences (held at the Australian National University in 2018 and Birkbeck College London in 2019) exploring the relationships between big history and astrobiology and their wider implications for society. These two relatively new academic disciplines aim to integrate human history with the wider history of the universe and the search for life elsewhere. The book will show that, despite differences in emphasis, big history and astrobiology share much in common, especially their interdisciplinary approaches and the cosmic and evolutionary perspectives that they both engender. Specifically, the book addresses the unified, all-embracing, nature of knowledge, the impact of big history on humanity and the world at large, the possible impact of SETI on astrobiology and big history, the cultural signature of Earth's inhabitants beyond our own planet, and the political implications of a planetary worldview. The principal readership is envisaged to comprise scholars working in the fields of astrobiology, big history and space exploration interested in forging interdisciplinary links between these diverse topics, together with educators, and a wider public, interested in the societal implications of the cosmic and evolutionary perspectives engendered by research in these fields.

The Physical World offers a grand vision of the essential unity of physics that will enable the reader to see the world through the eyes of a physicist and understand their thinking. The text follows Einstein's dictum that 'explanations should be made as simple as possible, but no simpler', to give an honest account of how modern physicists understand their subject, including the shortcomings of current theory. The result is an up-to-date and engaging portrait of physics that contains concise derivations of the important results in a style where every step in a derivation is clearly explained, so that anyone with the appropriate mathematical skills will find the text easy to digest. It is over half a century since The Feynman Lectures in Physics were published. A new authoritative account of fundamental physics covering all branches of the subject is now well overdue. The Physical World has been written to satisfy this need. The book concentrates on the conceptual principles of each branch of physics and shows how they fit together to form a coherent whole. Emphasis is placed on the use of variational principles in physics, and in particular the principle of least action, an approach that lies at the heart of modern theoretical physics, but has been neglected in most introductory accounts of the subject.

This monograph presents the geoscientific context arising in decorrelative gravitational exploration to determine the mass density distribution inside the Earth. First, an insight into the current state of research is given by reducing gravimetry to mathematically accessible, and thus calculable, decorrelated models. In this way, the various unresolved questions and problems of gravimetry are made available to a broad scientific audience and the exploration industry. New theoretical developments will be given, and innovative ways of modeling geologic layers and faults by mollifier regularization techniques are shown. This book is dedicated to surface as well as volume geology with potential data primarily of terrestrial origin. For deep geology, the geomathematical decorrelation methods are to be designed in such a way that depth information (e.g., in boreholes) may be canonically entered. Bridging several different geo-disciplines, this book leads in a cycle from the potential measurements made by geoengineers, to the cleansing of data by geophysicists and geoengineers, to the subsequent theory and model formation, computer-based implementation, and numerical calculation and simulations made by geomathematicians, to interpretation by geologists, and, if necessary, back. It therefore spans the spectrum from geoengineering, especially geodesy, via geophysics to geomathematics and geology, and back. Using the German Saarland area for methodological tests, important new fields of application are opened, particularly for regions with mining-related cavities or dense development in today's geo-exploration.

The three neutrinos are ghostly elementary particles that exist all across the Universe. Though every second billions of them fly through us, they are extremely hard to detect. We used to think they had no mass, but recently discovered that in fact they have a tiny mass. The quest for the neutrino mass scale and mass ordering (specifying how the three masses are distributed) is an extremely exciting one, and will open the door towards new physics operating at energy scales we can only ever dream of reaching on Earth. This thesis explores the use of measurements of the Cosmic Microwave Background (the oldest light reaching us, a snapshot of the infant Universe) and maps of millions of galaxies to go after the neutrino mass scale and mass ordering. Neutrinos might teach us something about the mysterious dark energy powering the accelerated expansion of the Universe, or about cosmic inflation, which seeded the initial conditions for the Universe. Though extremely baffling, neutrinos are also an exceptionally exciting area of research, and cosmological observations promise to reveal a great deal about these elusive particles in the coming years.

Modern research has demonstrated that many stars are surrounded by planets-some of which might contain the right conditions to harbor life. This has only reinforced a question that has been tormenting scientists, philosophers and priests since Antiquity: Are there other inhabited worlds beyond our own? This book analyzes the many ways that humans have argued for and depicted extraterrestrial life over the centuries. The first known texts about the subject date from as early as the 6th century BC. Since that time, countless well-known historical characters like Lucretius, Aristotle, Thomas Aquinas, Cusanus, Bruno, Kepler, Descartes, and Huygens contributed to the debate; here, their lesser known opinions on the subject are studied in detail. It is often difficult for the modern mind to follow the thinking of our ancestors, which can only be understood when placed in the relevant context. The book thus extends its scope to the evolution of ideas about cosmology in general, as well as the culture in which these great thinkers wrote. The research is presented with the author's insights and humor, making this an easy and enjoyable read.

This book consolidates the latest research on the Hadean Eon - the first 500 million years of Earth history - which has permitted hypotheses of early Earth evolution to be tested, including geophysical models that include the possibility of plate tectonic-like behavior. These new observations challenge the longstanding Hadean paradigm - based on no observational evidence - of a desiccated, lifeless, continent-free wasteland in which surface petrogenesis was largely due to extraterrestrial impacts. The eon was termed "Hadean" to reflect such a hellish environment. That view began to be challenged in 2001 as results of geochemical analyses of greater than 4 billion year old zircons from Australia emerged. These data were consistent with the zircons forming in a world much more similar to today than long thought and interpreted to indicate that sediment cycling was occurring in the presence of liquid water. This new view leaves open the possibility that life could have emerged shortly after Earth accretion. The epistemic limitations under which the old paradigm persisted are closely examined. The book is principally designed as a monograph but has the potential to be used as a text for advanced graduate courses on early Earth evolution.

This monograph provides an introduction to deformations of Poincare symmetries focusing on models with a Lie group momentum space and associated non-commutative space-times. The emphasis is put on the emergence of such structures from quantum gravity, their mathematical features described in terms of Hopf algebras and applications to particle kinematics and field theory. Part I of this work focuses on the link between gravity and deformed symmetries in the case of 2+1 and 3+1 space-time dimensions. Part II is devoted to the description of classical particles with group valued momenta, their phase spaces and kinematics. The last part of these notes provides an introduction to the basic features of classical and quantum field theory on -Minkowski space-time, the prototypical example of non-commutative space-time exhibiting deformed Poincare symmetry. The text, being the first providing a detailed overview of these topics, is primarily intended for researchers and graduate students interested in non-commutative field theories and quantum gravity phenomenology.

"General Relativity Without Calculus" offers a compact but mathematically correct introduction to the general theory of relativity, assuming only a basic knowledge of high school mathematics and physics. Targeted at first year undergraduates (and advanced high school students) who wish to learn Einstein's theory beyond popular science accounts, it covers the basics of special relativity, Minkowski space-time, non-Euclidean geometry, Newtonian gravity, the Schwarzschild solution, black holes and cosmology. The quick-paced style is balanced by over 75 exercises (including full solutions), allowing readers to test and consolidate their understanding.

This thesis describes the application of state-of-the-art high-energy X-ray studies to the astronomical quest for understanding obscured active galactic nuclei (AGN). These AGN are supermassive black holes growing by accretion of matter located in the nuclei of galaxies. The material that feeds these black holes also obscures them from view, rendering them challenging to study. It is possible to study them by effectively 'X-raying' galactic nuclei to peer through these obscuring veils. Beginning with the proof-of-concept application of novel X-ray Monte Carlo codes to the Nuclear Spectroscopic Telescope ARray (NuSTAR) spectrum of a known heavily obscured AGN, the thesis establishes the relevant parameters that characterise the AGN spectrum and central black hole growth rate. Next the largest sample of known heavily obscured AGN is compiled, finding the strength of a prominent iron spectral feature to weaken with AGN power. This is puzzling, and suggests that there may be more hidden AGN than previously thought. Finally by combining an all-sky infrared selection with NuSTAR follow-up, new heavily obscured AGN are identified. Obscuration emits infrared radiation, meaning that the infrared-selected AGN catalogue should be representative of the underlying AGN population. The absence of such representative catalogues has continually plagued cosmological studies, and the resultant obscured AGN fraction will be strongly constraining for AGN models.

This book focuses on a critical discussion of the status and prospects of current approaches in quantum mechanics and quantum field theory, in particular concerning gravity. It contains a carefully selected cross-section of lectures and discussions at the seventh conference "Progress and Visions in Quantum Theory in View of Gravity" which took place in fall 2018 at the Max Planck Institute for Mathematics in the Sciences in Leipzig. In contrast to usual proceeding volumes, instead of reporting on the most recent technical results, contributors were asked to discuss visions and new ideas in foundational physics, in particular concerning foundations of quantum field theory. A special focus has been put on the question of which physical principles of quantum (field) theory can be considered fundamental in view of gravity. The book is mainly addressed to mathematicians and physicists who are interested in fundamental questions of mathematical physics. It allows the reader to obtain a broad and up-to-date overview of a fascinating active research area.

This book presents an alternative representation of Einstein's Special Theory of Relativity, which makes Special Relativity much more comprehensible. Moreover, one will come across a fundamental relationship between the Special Theory of Relativity and the mechanics of space lattice. In all previous formulations, the Einsteinian special principle of relativity, in one or the other form is used as the starting point for Special Relativity. In correspondence to this principle, one takes it as granted apriori, that all observers independent of their uniform motion to each other measure one and the same propagation velocity of a light signal. This book is thought of as a lecture for physicists, mathematicians and computer scientists and concentrates on the students of these fields. The book should reach a broad circle of interested readers from the fields of natural sciences and philosophy and provide and invigorating experience for engineers.

This book presents a direct measurement of quantum back action, or radiation pressure noise, on a macroscopic object at room temperature across a broad bandwidth in the audio range. This noise source was predicted to be a limitation for gravitational wave interferometers in the 1980s, but it has evaded direct characterization in the gravitational wave community due to the inherent difficult of reducing thermal fluctuations below the quantum back action level. This back action noise is a potential limitation in Advanced LIGO and Advanced Virgo, and Cripe's experiment has provided a platform for the demonstration of quantum measurement techniques that will allow quantum radiation pressure noise to be reduced in these detectors. The experimental techniques Cripe developed for this purpose are also applicable to any continuous measurement operating near the quantum limit, and could lead to the possibility of observing non-classical behavior of macroscopic objects.

This volume provides a detailed description of some of the most active areas in astrophysics from the largest scales probed by the Planck satellite to massive black holes that lie at the heart of galaxies and up to the much awaited but stunning discovery of thousands of exoplanets. It contains the following chapters: * Jean-Philippe UZAN, The Big-Bang Theory: Construction, Evolution and Status * Jean-Loup PUGET, The Planck Mission and the Cosmic Microwave Background * Reinhard GENZEL, Massive Black Holes: Evidence, Demographics and Cosmic Evolution * Arnaud CASSAN, New Worlds Ahead: The Discovery of Exoplanets Reinhard Genzel and Andrea Ghez shared the 2020 Nobel Prize in Physics "for the discovery of a supermassive compact object at the centre of our galaxy'", alongside Roger Penrose "for the discovery that black hole formation is a robust prediction of the general theory of relativity". The book corresponds to the twentieth Poincare Seminar, held on November 21, 2015, at Institut Henri Poincare in Paris. Originally written as lectures to a broad scientific audience, these four chapters are of high value and will be of general interest to astrophysicists, physicists, mathematicians and historians.

This richly annotated facsimile edition of "The Foundation of General Relativity" introduces a new generation of readers to Albert Einstein's theory of gravitation. Written in 1915, this remarkable document is a watershed in the history of physics and an enduring testament to the elegance and precision of Einstein's thought. Presented here is a beautiful facsimile of Einstein's original handwritten manuscript, along with its English translation and an insightful page-by-page commentary that places the work in historical and scientific context. Hanoch Gutfreund and Jurgen Renn's concise introduction traces Einstein's intellectual odyssey from special to general relativity, and their essay "The Charm of a Manuscript" provides a delightful meditation on the varied afterlife of Einstein's text. Featuring a foreword by John Stachel, this handsome edition also includes a biographical glossary of the figures discussed in the book, a comprehensive bibliography, suggestions for further reading, and numerous photos and illustrations throughout.

This book discusses some of the open questions addressed by researchers in general relativity. Photons and particles play important roles in the theoretical framework, since they are involved in analyzing and measuring gravitational fields and in constructing mathematical models of gravitational fields of various types. The authors highlight this aspect covering topics such as the construction of models of Bateman electromagnetic waves and analogous gravitational waves, the studies of gravitational radiation in presence of a cosmological constant and the gravitational compass or clock compass for providing an operational way of measuring a gravitational field. The book is meant for advanced students and young researchers in general relativity, who look for an updated text which covers in depth the calculations and, equally, takes on new challenges. The reader, along the learning path, is stimulated by provocative examples interspersed in the text that help to find novel representations of the uses of particles and photons.

This work is an introduction to the totality of the metaphysical philosophy of nature of Hedwig Conrad-Martius (1888-1966). Her own training and inclination as a realist phenomenologist enables a unique perspective on central issues in modern and contemporary (twentieth century) theoretical biology and physics. Here we find novel theories of, e.g., space and time, as well as development and evolution. This work is thus of interest to anyone studying the history of the phenomenological movement as well as religious cosmology. The philosophical basis for this cosmology is Conrad-Martius' "realontology" which is a phenomenological account of the essence of appearing reality. The full elaboration of the modes of appearing of what is real enables the unfolding of an analogical theory of "selfness" within the order of nature culminating in an account of the coming to be of humans, for whom there is an essentially distinctive world- and self-manifestation for which she reserves the term "spirit." Key to her position is the revival of ancient metaphysical themes in new transformed guises, especially potentiality and entelechy. Nature's status, as a self-actuation of world-constituting essence-entelechies, places Conrad-Martius in the middle of philosophical-theological discussions of, e.g., the hermeneutical mandate of demythologization as well as the nature of evolution. Of special interest is her insistence on both nature's self-actuating and evolving powers and a robust theory of creation.

Einstein said that the most incomprehensible thing about the universe is that it is comprehensible. But was he right? Can the quantum theory of fields and Einstein's general theory of relativity, the two most accurate and successful theories in all of physics, be united into a single quantum theory of gravity? Can quantum and cosmos ever be combined? In The Nature of Space and Time, two of the world's most famous physicists--Stephen Hawking (A Brief History of Time) and Roger Penrose (The Road to Reality)--debate these questions. The authors outline how their positions have further diverged on a number of key issues, including the spatial geometry of the universe, inflationary versus cyclic theories of the cosmos, and the black-hole information-loss paradox. Though much progress has been made, Hawking and Penrose stress that physicists still have further to go in their quest for a quantum theory of gravity.

"Relativity In our Time" is a book concerning the relevance of Einstein's theory to human relations in contemporary times. lt is physics and it is philosophy. lt is a discussion about one of the greatest of all pillars of 20th century thought and science. Based on a seminar course for a mixture of science and humanities students, the approach and narrative style leads the reader towards the frontier of thinking in this farreaching subject. Sachs deals with the whole spread of relativity, starting from the early history of Galileo and Faraday, he arrives at the foundation of the special theory. There is a logical transition to the general theory while the last part of the book covers the mind-testing realms of unified field theory, Mach's principle and cosmology. The book begins with atomistic, deterministic, classical physics and goes on towards a view of continuous fields of matter and a clearer view of spacetime. The reader is led into Einstein's extension of this theory towards a unified force field; consequently the authors address the issue of the validity of linear mathematics compared with the realism of a non- linear universe.; Such arguments today are leading towards a new paradigm in science - a study and description of nonlinear natural systems especially far from equilibrium systems; their energetics and dynamics. This book should be of value to postgraduates, undergraduates, secondary students and professionals in physics and philosophy and anyone with an interest in science subjects.