39 internautes sur 41 ont trouvé ce commentaire utile
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This is a rich topic with James Gleick's recent and eclectic volume stimulating more popular interest in the perspectives, small and large, that information theory may offer us. This book's treatment of `information' from different perspectives starts well but subsides into unnecessarily complex and discursive verbage. The volume assays a range of topics, and bibliographies accompany each chapter. The topics (chapters) are organised in the themes of history, physics and biology, with philosophy and theology combined at the end. Alas, the detail of this review trails off about half way through as I sped up my reading, finding less rewards and continuing with the main aim of getting it over with. A concluding chapter is definitely needed to wrap up the many strands of thinking. I dislike writing negative reviews, preferring to focus on the positive and noting that preferences vary. However, I felt it important to flag to readers of Paul Davies's books that he is only an editor here, writing one chapter, and that the collection of essays does not deliver the level of exposition that his books usually do.
In Part 1, History, Ernan McMullan surveys the changing theories of matter in Western philosophy. His writing and vocabulary reflect a philosophical review and may be considered poetic or opaque depending on reader preference. More importantly, it offers one of the most concise and intelligible accounts of our perception of matter from Aristotle to dark matter that this reviewer has ever read. As a philosopher reviewing science, his emphases are incisive and clear, and have no doubt benefited from the comments of the editors, as he states. His references break an academic tradition in slightly favouring the more recent and accessible assessments of theories rather than their original proponents. Philip Clayton challenges materialism, and thereby science, with less convincing arguments which give inadequate weight to empiricism and the scientific method.
Part 2, Physics, starts with an eclectic appraisal of information theory in physics by Paul Davies who is always interesting and entertaining. There were loose ends: I am not sure if the `measurement to infinite' precision question was answered in terms of all phenomena, or why the 10 to the power 90 particles in the universe included photons and not gravitons. Davies needs to focus more so that readers can get their head around a discrete topic rather than gain a general impression of a field of study. Please note, this won't stop me buying his books. Seth Lloyd introduces the concept of the universe being a quantum computer where events generate outcomes, each of which may be considered a bit of information and resulting in the "complex order and structure" we know. Henry Stapp made my heart race when he undertook to provide "a non-paradox-laden description of the quantum universe and the place of our minds in it". Stapp's claim that our mind have been conditioned by three centuries of orthodox physics extended this appeal but his arguments became impenetrable, with a conclusion that his analysis is concordant with the "idea of a powerful God" coming out of the blue. I would like to give his interesting theory another chance and a re-read, perhaps with a strong coffee. I also wonder if this is an overly distilled decant of his views in Mindful Universe.
In Part3, Biology, John Maynard Smith examines DNA transcription and central dogma predictably with examples below the par we see from Dawkins and others. He touches on epigenetics, although not by this newer name. Except for statements such as "genes and regulatory proteins carry information, but enzymes do not", one needs to read between the lines to decide what information means in the context of biology. In fairness, more clarity is occasionally offered by Deacon, often through helpful analogy, in his attempt to argue against sceptical paradigms that conclude "either content is fundamentally relativistic, holistic, and ungrounded or else is merely epiphenomenal and ineffectual except in its arbitrary correlation with the physical properties of the signs that convey it". Such word strings are common in this book. Chapters by Kuppers, Hoffmeyer and Rolston unfortunately maintain similarly loquacious arguments, using unnecessarily obscure terms and vocabulary to arrive precipitously at esoteric points. Rolston's treatment of group selection offers promise, but examination through the concept of `caring' is haphazard. These chapters trawl the literature up to a point, but their inefficient arguments make them a chore to read.
Chapters in Part 4, Philosophy and Theology, continued to attempt to answer interesting questions with sophistic and mangled logic, with embarrassing levels of self citation. These chapters would leave any reader concluding that studies of science and religion mix in the manner of oil and water.
I would buy the book again, at least to read a couple of great chapters and for the bibliographies.
24 internautes sur 24 ont trouvé ce commentaire utile
David J. Kreiter
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This book is divided into four main Categories: History, Physics, Biology, and Philosophy and Theology, with contributions by 15 prominent authors including the two editors, Paul Davies, and Niels Henrik Gregersen.
Information, like the concepts of matter and energy has been difficult to define. According to Terrence Deacon, the definition of energy wasn't fully realized until it was discovered that energy is not a substance, but rather, a dynamic process of change that is always conserved. Just as with the concept of energy, he said, we must give up the idea of thinking of information as some "artifact" or "commodity". In the broadest sense, says John F. Haught, information can mean whatever gives form, order, pattern, or identify to something.
Today most physicists divide information into two broad categories: syntactic information and semantic information. Syntactic information is sometimes called Shannon information after Claude Shannon who discovered that information can be thought of as a measure of entropy and probability. This is both a quantitative and physical definition, which describes how much information any system can carry and is not concerned with the meaning of the information. The more information a system carries the less entropy it contains, which also happens to be the least probable state of the system. Likewise, the most probable state of a system has a high degree of entropy and carries little information. So we can think of information as a complementarity between the message and the medium. Both are needed for a complete description of information. The second type of information is called semantic information, and it deals with the content of the message--what it means.
Paul Davies says that most physicists now believe that information and not particles and fields are the ground of all being. Beginning with the ancient Greeks up until recent times it has been assumed that the laws of physics, and their mathematically descriptive counterpart were objective aspects of the universe cast in stone, and it was the job of the physicist to uncover these objective truths. This idea was furthered by monotheistic thinking which suggested that the discovery of these objective truths were a window into the mind of God, an idea that has gone unchallenged for three centuries. Davis states: "The fusion of Platonism and Monotheism created the powerful orthodox scientific concept of the laws of physics as ideal, perfect infinitely precise, immutable, eternal unchanging mathematical forms that reside in an abstract platonic heaven beyond space and time. All of these assumptions must be jettisoned to come to an understanding that the laws and states of the universe co-evolve."
For many--from Plato to physicist/ mathematician, Roger Penrose-- mathematics has been assumed to be an objective construct of the universe from which matter and information find expression, but an evolving view among physicists is that information is the basic entity of reality from which the laws of physics, and matter emerge. After all says Davies, "Laws are an informational statement." Mathematics has been successful in describing the laws of physics, not because mathematics is somehow an objective aspect of the universe, but because mathematics and the laws of physics co-emerge from computations carried out since the beginning of time by the ultimate quantum computer--the universe at large.
There can be no separation between the information processing nature of the universe and the information processing revolution of life itself. Both the syntactic and the semantic concept of information are involved in the interplay between organisms and their environment in the sense that far from equilibrium system (organisms) need to be associated with an environment that supports the organisms condition. Both the environment (the signal medium) and the organism (the message) are needed for the co-evolution of the organism/environmental system.
According to Keith Ward and Arthur Peacocke, the information contained in DNA is not semantic information because no understanding is required for the translation and transcription processes that code for proteins. This kind of information belongs to a third category he calls "Shaping" or coded information and it requires no sentience. The functioning of the parts can only be explained by how they contribute to the organism as a whole, and this is true whether we are speaking of the universe as a whole or a living organism. Since consciousness is primordial and contains all possible states, we should not look to the simple to explain the complex, but rather the complex to explain the simple.
John Haught maintains that the idea of "God" as a designer is getting harder and harder to defend in light of the fact that the universe is constantly evolving. Information is a complementarity of order and disorder. Too much order is too rigid and does not allow for novelty and evolution. "If the universe or life were simply designed," says Haught, "it would be frozen in a fixed and eternally unchanging identity. Design is a dead end." Though Haught says that whether or not one calls such a primordial consciousness "God" is partly a matter of taste, it hasn't stopped him and other contributors to the last section of this work in making a desperate attempt to shoe-horn God into the equation.
This work was a very exhaustive and comprehensive treatment of the topic of information, and it greatly informed me on the subject. I would highly recommend this to anyone willing to wade through some fairly dense material in order to get to a clear understanding of the nature of information.
This review by David Kreiter author of: "Confronting the Quantum Enigma: Albert, Niels, and John" (2011), and "Quantum Reality: A New Philosophical Perspective."