Frontiers Collection – serie

Over the course of the past decade, decoherence has become a ubiquitous scienti?c term popular in all kinds of research, from fundamental theories of quantum physics to applications in nanoengineering. Decoherence has been hailed as the solution to long-standing foundational problems dating back to the beginnings of quantum mechanics. It has been cursed as the key obstacle to next-generation technologies, such as quantum computers (another se- ingly omnipresent ?eld of research). And while decoherence has been directly observed in various experiments, its scope and meaning have often been m- understood and misrepresented. Decoherence makes a fantastic subject of research, as it touches upon many di?erent facets of physics, from phi- sophically inclined questions of interpretation all the way to down-to-earth problems in experimental settings and engineering applications. This book will introduce the reader, in an accessible and self-contained manner, to these various fascinating aspects of decoherence. It will focus in particularontherelationofdecoherencetotheso-calledquantum-to-classical transition, i. e. , the question of how decoherence may explain the emergence of the classical appearance of the macroscopic world around us from the underlying quantum substrate. Thescopeofthisbookisrelativelybroadinordertofamiliarizethereader withthemanyfacetsofdecoherence,inboththetheoreticalandexperimental domains. Throughout the book, I have sought to maintain a healthy balance betweentheconceptualideasassociatedwiththedecoherenceprogramonthe one hand and the formal and mathematical details on the other hand. This book will establish a proper understanding of decoherence as a pure quantum phenomenon and will emphasize the importance of the correct interpretation of theconsequences and achievements of decoherence.

Significant, and usually unwelcome, surprises, such as floods, financial crisis, epileptic seizures, or material rupture, are the topics of Extreme Events in Nature and Society. The book, authored by foremost experts in these fields, reveals unifying and distinguishing features of extreme events, including problems of understanding and modelling their origin, spatial and temporal extension, and potential impact. The chapters converge towards the difficult problem of anticipation: forecasting the event and proposing measures to moderate or prevent it. Extreme Events in Nature and Society will interest not only specialists, but also the general reader eager to learn how the multifaceted field of extreme events can be viewed as a coherent whole.

Nothing happens in the world without energy conversion and entropy production.  These fundamental natural laws are familiar to most of us when applied to the evolution of stars, biological processes, or the working of an internal combustion engine, but what about industrial economies and wealth production, or their constant companion, pollution?  Does economics conform to the First and the Second  Law of Thermodynamics?  In this important book, Reiner Kümmel takes us on a fascinating tour of these laws and their influence on natural, technological, and social evolution.  Analyzing economic growth in Germany, Japan, and the United States in light of technological constraints on capital, labor, and energy, Professor Kümmel upends conventional economic wisdom by showing that the  productive power of energy far outweighs its small share of costs, while for labor just the opposite is true.  Wealth creation by energy conversion is accompanied and limited by polluting emissions that are coupled to entropy production.   These facts constitute the Second Law of Economics. They take on unprecedented  importance in a world that is facing peak oil, debt-driven economic turmoil, and threats from pollution and climate change.  They complement the First Law of Economics: Wealth is allocated on markets, and the legal framework determines the outcome.  By applying the First and Second Law we understand the true origins of wealth production, the issues that imperil the goal of sustainable development, and the technological options that are compatible both with this goal and with natural laws.  The critical role of energy  and entropy in the productive sectors of the economy must be realized if we are to create a road map that avoids a Dark Age of shrinking natural resources, environmental degradation, and increasing social tensions.

Nothing happens in the world without energy conversion and entropy production.  These fundamental natural laws are familiar to most of us when applied to the evolution of stars, biological processes, or the working of an internal combustion engine, but what about industrial economies and wealth production, or their constant companion, pollution?  Does economics conform to the First and the Second  Law of Thermodynamics?  In this important book, Reiner Kümmel takes us on a fascinating tour of these laws and their influence on natural, technological, and social evolution.  Analyzing economic growth in Germany, Japan, and the United States in light of technological constraints on capital, labor, and energy, Professor Kümmel upends conventional economic wisdom by showing that the  productive power of energy far outweighs its small share of costs, while for labor just the opposite is true.  Wealth creation by energy conversion is accompanied and limited by polluting emissions that are coupled to entropy production.   These facts constitute the Second Law of Economics. They take on unprecedented  importance in a world that is facing peak oil, debt-driven economic turmoil, and threats from pollution and climate change.  They complement the First Law of Economics: Wealth is allocated on markets, and the legal framework determines the outcome.  By applying the First and Second Law we understand the true origins of wealth production, the issues that imperil the goal of sustainable development, and the technological options that are compatible both with this goal and with natural laws.  The critical role of energy  and entropy in the productive sectors of the economy must be realized if we are to create a road map that avoids a Dark Age of shrinking natural resources, environmental degradation, and increasing social tensions.

This open access book chronicles the rise of a new scientific paradigm offering novel insights into the age-old enigmas of existence. Over 300 years ago, the human mind discovered the machine code of reality: mathematics. By utilizing abstract thought systems, humans began to decode the workings of the cosmos. From this understanding, the current scientific paradigm emerged, ultimately discovering the gift of technology. Today, however, our island of knowledge is surrounded by ever longer shores of ignorance. Science appears to have hit a dead end when confronted with the nature of reality and consciousness. In this fascinating and accessible volume, James Glattfelder explores a radical paradigm shift uncovering the ontology of reality. It is found to be information-theoretic and participatory, yielding a computational and programmable universe.

This richly illustrated book explores the fascinating and ubiquitous occurrence of spirals and vortices in human culture and in nature. Spiral forms have been used as elements in the arts for thousands of years, whereas their role in nature and science – from DNA and sea shells to galaxies – is still a topic of investigation in numerous fields. Following an introduction to the cultural history of spiral forms, the book presents contributions from leading experts, who describe the origins, mechanisms and dynamics of spirals and vortices in their special fields. As a whole the book provides a valuable source of information, while also taking the reader on an aesthetic and scientific journey through the world of spiral forms.

This book explores fascinating topics at the edge of life, guiding the reader all the way from the relation of life processes to the second law of thermodynamics and the abundance of complex organic compounds in the universe through to the latest advances in synthetic biology and metabolic engineering. The background to the book is the extraordinary scientific adventures that are being undertaken as progress is made toward the creation of an artificial cell and the control of life processes. This journey involves input from research areas as diverse as genetic engineering, physical chemistry, and information theory. Life is to be thought of not only as a chemical event but also as an information process, with the genome a repository of information gathered over time through evolution. Knowledge of the mechanisms affecting the increase in complexity associated with evolutionary paths is improving, and there appear to be analogies with the evolution of the technologies promoting the development of our society. The book will be of wide interest to students at all levels and to others with an interest in the subject.

This book addresses key conceptual issues relating to the modern scientific and engineering use of computer simulations. It analyses a broad set of questions, from the nature of computer simulations to their epistemological power, including the many scientific, social and ethics implications of using computer simulations. The book is written in an easily accessible narrative, one that weaves together philosophical questions and scientific technicalities. It will thus appeal equally to all academic scientists, engineers, and researchers in industry interested in questions (and conceivable answers) related to the general practice of computer simulations.

This collection of prize-winning essays addresses the controversial question of how meaning and goals can emerge in a physical world governed by mathematical laws. What are the prerequisites for a system to have goals? What makes a physical process into a signal? Does eliminating the homunculus solve the problem? The three first-prize winners, Larissa Albantakis, Carlo Rovelli and Jochen Szangolies tackle exactly these challenges, while many other aspects (agency, the role of the observer, causality versus teleology, ghosts in the machine etc.) feature in the other award winning contributions. All contributions are accessible to non-specialists.These seventeen stimulating and often entertaining essays are enhanced versions of the prize-winning entries to the FQXi essay competition in 2017.The Foundational Questions Institute, FQXi, catalyzes, supports, and disseminates research on questions at the foundations of physics and cosmology, particularly new frontiers and innovativeideas integral to a deep understanding of reality, but unlikely to be supported by conventional funding sources.

Are there truly fundamental entities in nature? Or are the things that we regard as fundamental in our theories – for example space, time or the masses of elementary particles – merely awaiting a derivation from a new, yet to be discovered theory based on elements that are more fundamental? This was the central question posed in the 2018 FQXi essay competition, which drew more than 200 entries from professional physicists, philosophers, and other scholars. This volume presents enhanced versions of the fifteen award-winning essays, giving a spectrum of views and insights on this fascinating topic. From a prescription for “when to stop digging” to the case for strong emergence, the reader will find here a plethora of stimulating and challenging ideas - presented in a largely non-technical manner - on which to sharpen their understanding of the language of physics and even the nature of reality.

It is commonly held that there is no place for the 'now’ in physics, and also that the passing of time is something subjective, having to do with the way reality is experienced but not with the way reality is. Indeed, the majority of modern theoretical physicists and philosophers of physics contend that the passing of time is incompatible with modern physical theory, and excluded in a fundamental description of physical reality. This book provides a forceful rebuttal of such claims. In successive chapters the author explains the historical precedents of the modern opposition to time flow, giving careful expositions of matters relevant to becoming in classical physics, the special and general theories of relativity, and quantum theory, without presupposing prior expertise in these subjects. Analysing the arguments of thinkers ranging from Aristotle, Russell, and Bergson to the proponents of quantum gravity, he contends that the passage of time, understood as a local becoming of events out of those in their past at varying rates, is not only compatible with the theories of modern physics, but implicit in them.

In this book, a global team of experts from academia, research institutes and industry presents their vision on how new nano-chip architectures will enable the performance and energy efficiency needed for AI-driven advancements in autonomous mobility, healthcare, and man-machine cooperation. Recent reviews of the status quo, as presented in CHIPS 2020 (Springer), have prompted the need for an urgent reassessment of opportunities in nanoelectronic information technology. As such, this book explores the foundations of a new era in nanoelectronics that will drive progress in intelligent chip systems for energy-efficient information technology, on-chip deep learning for data analytics, and quantum computing. Given its scope, this book provides a timely compendium that hopes to inspire and shape the future of nanoelectronics in the decades to come.

In this book, a global team of experts from academia, research institutes and industry presents their vision on how new nano-chip architectures will enable the performance and energy efficiency needed for AI-driven advancements in autonomous mobility, healthcare, and man-machine cooperation. Recent reviews of the status quo, as presented in CHIPS 2020 (Springer), have prompted the need for an urgent reassessment of opportunities in nanoelectronic information technology. As such, this book explores the foundations of a new era in nanoelectronics that will drive progress in intelligent chip systems for energy-efficient information technology, on-chip deep learning for data analytics, and quantum computing. Given its scope, this book provides a timely compendium that hopes to inspire and shape the future of nanoelectronics in the decades to come.

“Tell me," Wittgenstein once asked a friend, "why do people always say, it was natural for man to assume that the sun went round the earth rather than that the earth was rotating?" His friend replied, "Well, obviously because it just looks as though the Sun is going round the Earth." Wittgenstein replied, "Well, what would it have looked like if it had looked as though the Earth was rotating?”  What would it have looked like if we looked at all sciences from the viewpoint of Wittgenstein’s philosophy? Wittgenstein is undoubtedly one of the most influential philosophers of the twentieth century. His complex body of work has been analysed by numerous scholars, from mathematicians and physicists, to philosophers, linguists, and beyond. This volume brings together some of his central perspectives as applied to the modern sciences and studies the influence they may have on the thought processes underlying science and on the world view it engenders. The contributions stem from leading scholars in philosophy, mathematics, physics, economics, psychology and human sciences; all of them have written in an accessible style that demands little specialist knowledge, whilst clearly portraying and discussing the deep issues at hand.

“Tell me," Wittgenstein once asked a friend, "why do people always say, it was natural for man to assume that the sun went round the earth rather than that the earth was rotating?" His friend replied, "Well, obviously because it just looks as though the Sun is going round the Earth." Wittgenstein replied, "Well, what would it have looked like if it had looked as though the Earth was rotating?”  What would it have looked like if we looked at all sciences from the viewpoint of Wittgenstein’s philosophy? Wittgenstein is undoubtedly one of the most influential philosophers of the twentieth century. His complex body of work has been analysed by numerous scholars, from mathematicians and physicists, to philosophers, linguists, and beyond. This volume brings together some of his central perspectives as applied to the modern sciences and studies the influence they may have on the thought processes underlying science and on the world view it engenders. The contributions stem from leading scholars in philosophy, mathematics, physics, economics, psychology and human sciences; all of them have written in an accessible style that demands little specialist knowledge, whilst clearly portraying and discussing the deep issues at hand.

Einstein once remarked "After a certain high level of technical skill is achieved, science and art tend to coalesce in aesthetics, plasticity, and form. The greatest scientists are always artists as well". In this volume, some of the world’s leading thinkers come together to expound on the interrelations between sciences and arts. While one can segregate art and place it outside the scientific realm, it is, nevertheless, inextricably linked to our essential cognitive/emotional/perceptual modalities and abilities, and therefore lies alongside and in close contact with the method of science and philosophy. What inspiration can scientists draw from art and how can scientific spirit foster our understanding and creation of aesthetic works? How are art and science grounded in our cognition? What role does perception play in science and art? Are criteria for beauty in art and science the same? How does evolution shape our understanding of art? How do science, art and scientifico-artistic frameworks shape society as a whole and help us address its pressing issues? The epistemological and ontological aspects haunt artists, philosophers and scientists alike. The essays in this volume address these manifold questions while also elucidating the pragmatic role they play in our daily life.

Einstein once remarked "After a certain high level of technical skill is achieved, science and art tend to coalesce in aesthetics, plasticity, and form. The greatest scientists are always artists as well". In this volume, some of the world’s leading thinkers come together to expound on the interrelations between sciences and arts. While one can segregate art and place it outside the scientific realm, it is, nevertheless, inextricably linked to our essential cognitive/emotional/perceptual modalities and abilities, and therefore lies alongside and in close contact with the method of science and philosophy. What inspiration can scientists draw from art and how can scientific spirit foster our understanding and creation of aesthetic works? How are art and science grounded in our cognition? What role does perception play in science and art? Are criteria for beauty in art and science the same? How does evolution shape our understanding of art? How do science, art and scientifico-artistic frameworks shape society as a whole and help us address its pressing issues? The epistemological and ontological aspects haunt artists, philosophers and scientists alike. The essays in this volume address these manifold questions while also elucidating the pragmatic role they play in our daily life.

This book is about morphogenesis as the genesis of forms. It is not restricted to plants growing from seed or animals developing from an embryo (although these do supply the most abundant examples) but also addresses kindred processes, from inorganic to social to biomorphic technology. It is about our morphogenetic universe: unplanned, unfair and frustratingly complicated but benevolent in allowing us to emerge, survive, and inquire into its laws.

This book is about morphogenesis as the genesis of forms. It is not restricted to plants growing from seed or animals developing from an embryo (although these do supply the most abundant examples) but also addresses kindred processes, from inorganic to social to biomorphic technology. It is about our morphogenetic universe: unplanned, unfair and frustratingly complicated but benevolent in allowing us to emerge, survive, and inquire into its laws.

This book provides a vivid account of the early history of molecular simulation, a new frontier for our understanding of matter that was opened when the demands of theoretical physicists were met by the availability of the modern computers. Since their inception, electronic computers have enormously increased their performance, thus making possible the unprecedented technological revolution that characterizes our present times. This obvious technological advancement has brought with it a silent scientific revolution in the practice of theoretical physics. In particular, in the physics of matter it has opened up a direct route from the microscopic physical laws to observable phenomena. One can now study the time evolution of systems composed of millions of molecules, and simulate the behaviour of macroscopic materials and actually predict their properties. Molecular simulation has provided a new theoretical and conceptual tool that physicists could only dream of whenthe foundations of statistical mechanics were laid.  Molecular simulation has undergone impressive development, both in the size of the scientific community involved and in the range and scope of its applications. It has become the ubiquitous workhorse for investigating the nature of complex condensed matter systems in physics, chemistry, materials and the life sciences. Yet these developments remain largely unknown outside the inner circles of practitioners, and they have so far never been described for a wider public. The main objective of this book is therefore to offer a reasonably comprehensive reconstruction of the early history of molecular simulation addressed to an audience of both scientists and interested non-scientists, describing the scientific and personal trajectories of the main protagonists and discussing the deep conceptual innovations that their work produced.

This book provides a vivid account of the early history of molecular simulation, a new frontier for our understanding of matter that was opened when the demands of theoretical physicists were met by the availability of the modern computers. Since their inception, electronic computers have enormously increased their performance, thus making possible the unprecedented technological revolution that characterizes our present times. This obvious technological advancement has brought with it a silent scientific revolution in the practice of theoretical physics. In particular, in the physics of matter it has opened up a direct route from the microscopic physical laws to observable phenomena. One can now study the time evolution of systems composed of millions of molecules, and simulate the behaviour of macroscopic materials and actually predict their properties. Molecular simulation has provided a new theoretical and conceptual tool that physicists could only dream of whenthe foundations of statistical mechanics were laid.  Molecular simulation has undergone impressive development, both in the size of the scientific community involved and in the range and scope of its applications. It has become the ubiquitous workhorse for investigating the nature of complex condensed matter systems in physics, chemistry, materials and the life sciences. Yet these developments remain largely unknown outside the inner circles of practitioners, and they have so far never been described for a wider public. The main objective of this book is therefore to offer a reasonably comprehensive reconstruction of the early history of molecular simulation addressed to an audience of both scientists and interested non-scientists, describing the scientific and personal trajectories of the main protagonists and discussing the deep conceptual innovations that their work produced.

This book explores the role of exaptation in diverse areas of life, with examples ranging from biology to economics, social sciences and architecture. The concept of exaptation, introduced in evolutionary biology by Gould and Vrba in 1982, describes the possibility that already existing traits can be exploited for new purposes throughout the evolutionary process. Edited by three active scholars in the fields of biology, physics and economics, the book presents an interdisciplinary collection of expert viewpoints illustrating the importance of exaptation for interpreting  current reality in various fields of investigation. Using the lenses of exaptation, the contributing authors show how to view the overall macroscopic landscape as comprising many disciplines, all working in unity within a single complex system. This book is the first to discuss exaptation in both hard and soft disciplines and highlights the role of this concept in understanding the birth of innovation by identifying  key elements and ideas. It also offers a comprehensive guide to the emerging interdisciplinary field of exaptation, provides didactic explanations of the basic concepts, and avoids excessive jargon and heavy formalism. Its target audience includes graduate students in physics, biology, mathematics, economics, psychology and architecture; it will also appeal to established researchers in the humanities who wish to explore or enter this new science-driven interdisciplinary field.

This book explores the role of exaptation in diverse areas of life, with examples ranging from biology to economics, social sciences and architecture. The concept of exaptation, introduced in evolutionary biology by Gould and Vrba in 1982, describes the possibility that already existing traits can be exploited for new purposes throughout the evolutionary process. Edited by three active scholars in the fields of biology, physics and economics, the book presents an interdisciplinary collection of expert viewpoints illustrating the importance of exaptation for interpreting  current reality in various fields of investigation. Using the lenses of exaptation, the contributing authors show how to view the overall macroscopic landscape as comprising many disciplines, all working in unity within a single complex system. This book is the first to discuss exaptation in both hard and soft disciplines and highlights the role of this concept in understanding the birth of innovation by identifying  key elements and ideas. It also offers a comprehensive guide to the emerging interdisciplinary field of exaptation, provides didactic explanations of the basic concepts, and avoids excessive jargon and heavy formalism. Its target audience includes graduate students in physics, biology, mathematics, economics, psychology and architecture; it will also appeal to established researchers in the humanities who wish to explore or enter this new science-driven interdisciplinary field.

This book addresses the current challenges of sustainable development, including its social, economic and environmental components. The author argues that we need to develop a new concept of time based on inter-generational solidarity, which focuses both on the long- and the short term. The evolution of man's notions of time are analyzed from prehistory to modern times, showing how these concepts shape our worldviews, our ecological paradigms and our equilibrium with our planet.  Practical approaches to dealing with the major medium- and long term sustainability challenges of the 21st century are presented and discussed.  This is a thought provoking and timely book that addresses the main global socioeconomic and environmental challenges facing the current and future generations, using science-based analysis and perspectives. It presents an historical narrative of the advent of progress, economic growth and technology, and discusses the structural changes needed to co-create sustainable pathways. It provides hope for our future on Earth, mankind’s common home.António Guterres, Secretary-General of the United NationsThis is an amazing, almost mind-boggling book. The author takes a look at the true whole, i.e., the development of the human enterprise since its very beginning. This enterprise is evidently a possibility under the boundary conditions of cosmological dynamics and natural evolution, but evidently also a highly improbable one. It is all but a miracle that the Earth system in its present form exists and happens to support a technical civilization. Will this civilization last long, will it transform itself into something even more exceptional, or will it perish in disgrace?Santos dares to address these grandest of all questions, equipped with a unique transdisciplinary wisdom drawing on physics, cybernetics, geology, biology, economics, anthropology, history, and philosophy. And he dares to dive into the deepest abysses of thinking, where categorial monsters like time and progress lurk. Thereby, he takes us on fascinating journey, during which we perceive and grasp things we have never seen and understood before. One of the best essays I have ever read.John Schellnhuber,  founding director of the Potsdam Institute for Climate Impact Research (PIK) and former chair of the German Advisory Council on Global Change

Earth is, to our knowledge, the only life-bearing body in the Solar System. This extraordinary characteristic dates back almost 4 billion years. How to explain that Earth is teeming with organisms and that this has lasted for so long? What makes Earth different from its sister planets Mars and Venus?The habitability of a planet is its capacity to allow the emergence of organisms. What astronomical and geological conditions concurred to make Earth habitable 4 billion years ago, and how has it remained habitable since? What have been the respective roles of non-biological and biological characteristics in maintaining the habitability of Earth?This unique book answers the above questions by considering the roles of organisms and ecosystems in the Earth System, which is made of the non-living and living components of the planet. Organisms have progressively occupied all the habitats of the planet, diversifying into countless life forms and developing enormous biomassesover the past 3.6 billion years. In this way, organisms and ecosystems "took over" the Earth System, and thus became major agents in its regulation and global evolution. There was co-evolution of the different components of the Earth System, leading to a number of feedback mechanisms that regulated long-term Earth conditions.For millennia, and especially since the Industrial Revolution nearly 300 years ago, humans have gradually transformed the Earth System. Technological developments combined with the large increase in human population have led, in recent decades, to major changes in the Earth's climate, soils, biodiversity and quality of air and water. After some successes in the 20th century at preventing internationally environmental disasters, human societies are now facing major challenges arising from climate change. Some of these challenges are short-term and others concern the thousand-year evolution of the Earth's climate. Humans should become the stewards of Earth.

Earth is, to our knowledge, the only life-bearing body in the Solar System. This extraordinary characteristic dates back almost 4 billion years. How to explain that Earth is teeming with organisms and that this has lasted for so long? What makes Earth different from its sister planets Mars and Venus?The habitability of a planet is its capacity to allow the emergence of organisms. What astronomical and geological conditions concurred to make Earth habitable 4 billion years ago, and how has it remained habitable since? What have been the respective roles of non-biological and biological characteristics in maintaining the habitability of Earth?This unique book answers the above questions by considering the roles of organisms and ecosystems in the Earth System, which is made of the non-living and living components of the planet. Organisms have progressively occupied all the habitats of the planet, diversifying into countless life forms and developing enormous biomassesover the past 3.6 billion years. In this way, organisms and ecosystems "took over" the Earth System, and thus became major agents in its regulation and global evolution. There was co-evolution of the different components of the Earth System, leading to a number of feedback mechanisms that regulated long-term Earth conditions.For millennia, and especially since the Industrial Revolution nearly 300 years ago, humans have gradually transformed the Earth System. Technological developments combined with the large increase in human population have led, in recent decades, to major changes in the Earth's climate, soils, biodiversity and quality of air and water. After some successes in the 20th century at preventing internationally environmental disasters, human societies are now facing major challenges arising from climate change. Some of these challenges are short-term and others concern the thousand-year evolution of the Earth's climate. Humans should become the stewards of Earth.

This book presents a comprehensive review of various aspects of the novel and rapidly developing field of active matter, which encompasses a wide variety of self-organized self-driven energy-consuming media or agents. Most naturally occurring examples are of biological origin, spanning all scales from intracellular structures to swimming and crawling cells and microorganisms, to living tissues, bacterial colonies and flocks of birds. But the field also encompasses artificial systems, from colloids to soft robots. Intrinsically out of equilibrium and free of constraints of time-reversal symmetry, such systems display a range of surprising and unusual behaviors.​In this book, the author emphasizes connections between fluid-mechanical, material, biological and technological aspects of active matter. He employs a minimum of mathematical tools, ensuring that the presentation is accessible to a wider scientific community. Richly illustrated, it gives the reader a clear picture of this fascinating field, its diverse phenomena and its open questions.

This book presents a comprehensive review of various aspects of the novel and rapidly developing field of active matter, which encompasses a wide variety of self-organized self-driven energy-consuming media or agents. Most naturally occurring examples are of biological origin, spanning all scales from intracellular structures to swimming and crawling cells and microorganisms, to living tissues, bacterial colonies and flocks of birds. But the field also encompasses artificial systems, from colloids to soft robots. Intrinsically out of equilibrium and free of constraints of time-reversal symmetry, such systems display a range of surprising and unusual behaviors.​In this book, the author emphasizes connections between fluid-mechanical, material, biological and technological aspects of active matter. He employs a minimum of mathematical tools, ensuring that the presentation is accessible to a wider scientific community. Richly illustrated, it gives the reader a clear picture of this fascinating field, its diverse phenomena and its open questions.

For a brief time in history, it was possible to imagine that a sufficiently advanced intellect could, given sufficient time and resources, in principle understand how to mathematically prove everything that was true. They could discern what math corresponds to physical laws, and use those laws to predict anything that happens before it happens. That time has passed. Gödel’s undecidability results (the incompleteness theorems), Turing’s proof of non-computable values, the formulation of quantum theory, chaos, and other developments over the past century have shown that there are rigorous arguments limiting what we can prove, compute, and predict. While some connections between these results have come to light, many remain obscure, and the implications are unclear. Are there, for example, real consequences for physics — including quantum mechanics — of undecidability and non-computability? Are there implications for our understanding of the relations between agency, intelligence, mind, and the physical world? This book, based on the winning essays from the annual FQXi competition, contains ten explorations of Undecidability, Uncomputability, and Unpredictability. The contributions abound with connections, implications, and speculations while undertaking rigorous but bold and open-minded investigation of the meaning of these constraints for the physical world, and for us as humans.​