Physical Origins Of Time Asymmetry

We say that the processes going on in the world about us are asymmetric in time or display an arrow of time. Yet this manifest fact of our experience is particularly difficult to explain in terms of the fundamental laws of physics. This volume reconciles these profoundly conflicting facts.

In this essay collection, leading physicists, philosophers, and historians attempt to fill the empty theoretical ground in the foundations of information and address the related question of the limits to our knowledge of the world. Over recent decades, our practical approach to information and its exploitation has radically outpaced our theoretical understanding - to such a degree that reflection on the foundations may seem futile. But it is exactly fields such as quantum information, which are shifting the boundaries of the physically possible, that make a foundational understanding of information increasingly important. One of the recurring themes of the book is the claim by Eddington and Wheeler that information involves interaction and putting agents or observers centre stage. Thus, physical reality, in their view, is shaped by the questions we choose to put to it and is built up from the information residing at its core. This is the root of Wheeler’s famous phrase “it from bit.” After reading the stimulating essays collected in this volume, readers will be in a good position to decide whether they agree with this view.

Why is the future so different from the past? Why does the past affect the future and not the other way around? What does quantum mechanics really tell us about the world? In this important and accessible book, Huw Price throws fascinating new light on some of the great mysteries of modern physics, and connects them in a wholly original way. Price begins with the mystery of the arrow of time. Why, for example, does disorder always increase, as required by the second law of thermodynamics? Price shows that, for over a century, most physicists have thought about these problems the wrong way. Misled by the human perspective from within time, which distorts and exaggerates the differences between past and future, they have fallen victim to what Price calls the "double standard fallacy": proposed explanations of the difference between the past and the future turn out to rely on a difference which has been slipped in at the beginning, when the physicists themselves treat the past and future in different ways. To avoid this fallacy, Price argues, we need to overcome our natural tendency to think about the past and the future differently. We need to imagine a point outside time -- an Archimedean "view from nowhen" -- from which to observe time in an unbiased way. Offering a lively criticism of many major modern physicists, including Richard Feynman and Stephen Hawking, Price shows that this fallacy remains common in physics today -- for example, when contemporary cosmologists theorize about the eventual fate of the universe. The "big bang" theory normally assumes that the beginning and end of the universe will be very different. But if we are to avoid the double standard fallacy, we need to consider time symmetrically, and take seriously the possibility that the arrow of time may reverse when the universe recollapses into a "big crunch." Price then turns to the greatest mystery of modern physics, the meaning of quantum theory. He argues that in missing the Archimedean viewpoint, modern physics has missed a radical and attractive solution to many of the apparent paradoxes of quantum physics. Many consequences of quantum theory appear counterintuitive, such as Schrodinger's Cat, whose condition seems undetermined until observed, and Bell's Theorem, which suggests a spooky "nonlocality," where events happening simultaneously in different places seem to affect each other directly. Price shows that these paradoxes can be avoided by allowing that at the quantum level the future does, indeed, affect the past. This demystifies nonlocality, and supports Einstein's unpopular intuition that quantum theory describes an objective world, existing independently of human observers: the Cat is alive or dead, even when nobody looks. So interpreted, Price argues, quantum mechanics is simply the kind of theory we ought to have expected in microphysics -- from the symmetric standpoint. Time's Arrow and Archimedes' Point presents an innovative and controversial view of time and contemporary physics. In this exciting book, Price urges physicists, philosophers, and anyone who has ever pondered the mysteries of time to look at the world from the fresh perspective of Archimedes' Point and gain a deeper understanding of ourselves, the universe around us, and our own place in time.

The present volume of Time and Science series is devoted to Physical Sciences and Cosmology. Today more than ever, the question 'is Time an ontological property, a necessary ingredient for the physical description of the world, or a purely epistemological element, relative to our situation in the world?' worry physicists and cosmologists alike. For many of them, Relativity (and particularly General Relativity), as well as its reconciliation with quantum mechanics in the elaboration of a quantum theory of gravitation, points to a negative answer to the first alternative, and leads them to deny the objective reality of time. For others, the answer is nuanced by the evidence of an emerging temporal property when one climbs the scales of the complexity of systems and/or the applicability of the statistical laws of thermodynamics. But for some, the illusion of the unreality of time comes from certain confusions that they denounce, and plead for the re-establishment of time at the heart of physical theories.

Every human being is aware of the flow of time. This fact is embodied in the existence of such notions as the past and the future, the two domains being separated from each other by the single moment of the present. While the past is regarded as fixed and definite, the future is viewed as unknown, uncertain, and undetermined. The only perceivable moment is the present, the `now' - the ever-changing point moving from the past into the future. Physics tells us a different story: not only are the vast majority of physical laws time-reversible, but the concept of the `now' itself has no place at all in physics. In other words, the equations of physics do not distinguish between the past and the future and seem to be completely oblivious to the very idea of the present. This book discusses the biological and psychological aspects of perception of time, and the problems related to the determination of location arising from quantum physics, together with comments and opinions from philosophers and physicists.

No one can escape a sense of awe when reflecting on the workings of the mind: we see, we hear, we feel, we are aware of the world around us. But what is the mind? What do we mean when we say we are “aware” of something? What is this peculiar state in our heads, at once utterly familiar and bewilderingly mysterious, that we call awareness or consciousness? In Physics in Mind, eminent biophysicist Werner R. Loewenstein argues that to answer these questions, we must first understand the physical mechanisms that underlie the workings of the mind. And so begins an exhilarating journey along the sensory data stream of the brain, which shows how our most complex organ processes the vast amounts of information coming in through our senses to create a coherent, meaningful picture of the world. Bringing information theory to bear on recent advances in the neurosciences, Loewenstein reveals a web of immense computational power inside the brain. He introduces the revolutionary idea that quantum mechanics could be fundamental to how our minds almost instantaneously deal with staggering amounts of information, as in the case of the information streaming through our eyes. Combining cutting-edge research in neuroscience and physics, Loewenstein presents an ambitious hypothesis about the parallel processing of sensory information that is the heart, hub, and pivot of the cognitive brain. Wide-ranging and brimming with insight, Physics in Mind breaks new ground in our understanding of how the mind works.