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19 of 20 people found the following review helpful:
3.0 out of 5 stars
Well written, but only for the true layperson, March 30, 2007
This is a gentle introduction to a fascinating subject: that information actually has a physical basis in the universe and that information theory (based on the work of Shannon to determine how much information can theoretically be transmitted across phone lines, but carried by Shannon and his successors far, far further)may actually be fundamental in explaining quantum mechanics and indeed our entire universe.
The book starts with basic description of entropy and definitions of information and proceeds to discussions of quantum mechanics, quantum computing, and such interesting topics as whether Black Holes destroy information or not (Hawkings bet they did, but ultimately conceded...as Seife notes, Hawkings may be the only one who actually changed his mind).
Seife is a clear writer and great at creating an argument step-by-step.
However... I was a math major, a physics minor and am a working computer scientist with years of coursework in automata and complexity theory. Though there was new material in this book for me, vast swathes were way too introductory for me. I really didn't need a 20 page description of how bits are the fundamental element of information and strings of bits can encode anything, or for that matter to rehash special relativity or the selfish gene theory. Though it mostly succeeds, this book may be a little too ambitious. It tries to start with first principles for the layman, but spans so many fields (thermodynamics, information theory, quantum mechanics, biology, cosmology, special and general relativity) that providing basic introductions to all of them greatly dilutes the new and interesting material.
I really wish I knew what to read next. From here it appears most things are other popularizations or deeply technical works for specialists in quantum computing. Hopefully somebody will write a "Selfish Gene" or "Elegant Universe" that goes into more detail while remaining popularly accessible for the scientifically trained.
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44 of 52 people found the following review helpful:
4.0 out of 5 stars
Information is physical, May 6, 2006
Charles Seife has not been the first to proclaim that the most fundamental entity in the universe is "information". Physicist John Wheeler, David Bohm, and Tom Siegfried among others have held this view as well, but no other author I've read has gone to such lengths to establish this idea as an undeniable conclusion.
In a consise staight-forward format, Siefe delves into biology, computer science, cosmology, Relativity, and quantum theory, to establish the notion that information and the second law of thermodynamics are intricately linked. And he does this without ever allowing the reader to become lost or confused.
Information is always physical, whether it is marks on paper, holes in a punch card, atoms in an electo-magnetic state on a CD, photon polarization, or up/down spin on an electron. All information has a physical representation. And like any physical thing in our universe, it abides by the laws of nature, including the laws of thermodynamics and Relativity. Information, like energy, can neither be created nor destroyed. Infomation always moves toward the most probable state: maximum entropy. And no information can travel faster than the speed of light.
The qubit, which is the quantum representation of the classical bit, abides by the laws of quantum physics, and despite the weird instantaneous quantum connection between particles in an entangled state demonstrated by Bell's theorem of inequality; the qubit does not violate faster-than-light communication. Oddly, the qubit does violate one tenant of Relativity--that no effect can precede its cause. It seems that the time-asymetrical qubit has no "before" or "after".
Unlike the classical bit wich resides in a binary, either/or state, the qubit can be in a superposition of states: Two states simultaneously. This fact is what makes the possibility of quantum computing so enticing. By nesting probable outcomes in a superposition of states many fewer yes/no questions are needed in algorithms, making quantum computing many orders of magnitude faster than classical computing.
But, far wider implications exist for the quantum qubit. Siefe believes that the qubit's superposition of states solves two contentious vagaries of the Copenhagen Interpretation of reality: What constitutes an observer? And is there a difference between the classical and quantum worlds?
Siefe says that there is no clear-cut demarcation between the subatomic and classical world, and there is no conscious observer required to collapse the wave function. This directly leads to a resolution of the famous Schrodinger's cat paradox. Since the universe at large is constantly involved in probing with light waves, neutrinos, and zero point energy, the universe itself acts as the observer. Large macro objects such as cats undergo decoherence (a collapse of the superposition of states into a classical bit) very rapidly, while a single subatomic particle or photon take a much longer time, being less likely to come into contact with nature's measurements.
Information is so fundamental that Siefe believes Richard Dawkins popular book called "The Selfish Gene", would have been more appropriately titled "Selfish Information". Siefe says that when it comes to biological organisms, information is even more selfish than the gene, and can run contrary to survival of the fittest. He cites several examples of information reproducing itself even though it is detrimental to the organism, and at times, to the entire species. Information will attempt to replicate even at the expense of the proliferation of the organism carrying the information.
This book was very enticing, and left me with some questions. Is it information that is the most basic entity, or is it "meaning" as physicist David Bohm maintains? Is there a difference between information and meaning? Experiments with polarization of light lead me to suspect that there is a difference.
And, finally, is the brain really a classical machine as Siefe says, or is it a quantum machine as Evan Harris Walker maintains? (See my review: "The Physics of Consciousness" on Amazon). Either way, Charles Seife is right on the mark with this work. I give this book 4.5 stars for being an excellent and fun read.
This review by David Kreiter, author of Quantum Reality: A New Philosophical Perspective.
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77 of 94 people found the following review helpful:
3.0 out of 5 stars
Interesting, but a little annoying, November 3, 2006
Seife begins with an introduction to information theory. He talks about redundancy and the relationship of entropy and probability to information. He recalls the work of Turing and Shannon. Then he reviews relativity as he leads us to quantum mechanics. He recalls the paradox of Schrodinger's cat and other peculiarities of QM.
In general what he tries to explain to the general reader is how science is reinvestigating the fundamentals of physics from the standpoint of information theory, which apparently is going to replace physics. If Seife is correct, professors of physics are going to become professors of information theory, if that hasn't already happened. To me replacing matter and energy with information is not helpful. But to physicists apparently it is not only helpful but something splendid.
Consequently, there is a kind of "gee whiz" quality to Seife's expression, a quality that I found somewhat off-putting. Enthusiasm is fine and the ready acceptance of new ideas is agreeable when the ideas have experimental backing. For example he writes (speaking of a hypothetical creature inside the event horizon of a black hole): "...no matter how hard it tried, the creature would be utterly unable to send us a message...The pull of the black hole is too strong. Even if there were a huge population of these creatures swirling around the black hole, all screaming and signaling as loud as they possibly could, Earth would never receive a single bit or qubit of information about them." (pp. 242-243)
Considering the physical conditions inside a black hole, the image of creatures "screaming and signaling" is absurd to say the least, and frankly ludicrous.
Also there is this from page 248: "Indeed, most cosmologists think that the universe is infinitely large...that it has no borders--and that it doesn't have a funky shape that curls around on itself, as a handful of scientists have unconvincingly argued. If you take a rocket ship and travel in one direction for years and years and years, you will never come across an uncrossable boundary and you will never revisit the place you set off from."
This is news to me. The universe is infinite? It used to be the case that the one thing that physicists wanted banished from their equations was any notion of infinity! All kinds of absurdities, paradoxes and incomprehensibles would pop up when infinities were allowed. Speaking of which, Seife also champions the many worlds interpretation of quantum mechanics over the standard Copenhagen interpretation put forward by Bohr and Heisenberg.
Personally, I've always liked the many worlds interpretation because it is so audacious and because it expands the mind so wonderfully. However, if, as Seife seems to imply, most physicists believe in the many worlds interpretation, I must say I am astounded. What is going on? The many worlds interpretation leads to parallel universes! universes that cannot be detected by any means we know of. They actually cannot be part of any real physics since there is no experimental method that allows us to search for or detect parallel universes.
Has physics come to this? Are the postmoderns right? Is physics now no more than a cultural construct that doesn't even care whether its theories are falsifiable or not? Are Newton and Einstein and James Clerk Maxwell rolling over in their graves? To me the "spooky action at a distance," and particles being in the same place at the same time, and the startling fact that an observation of any kind will always disturb a quantum event to an uncertainty, etc., is nowhere near as benumbing as the idea that a new universe is created with every tick of a quantum divergence. I mean I love it, but how can I believe it?
There's also a superficial quality to this book that is hard to get away from. It's as though Seife does not understand such things as entanglement and superposition well enough to explain them to the general reader. However he's not alone in this. Even the best books on QM for the general reader (e.g., The Quantum World: Quantum Physics for Everyone (2004) by Kenneth Ford), have left me feeling dissatisfied. Perhaps it is impossible to convey the reality of quantum mechanics to non-physicists. However, there is no excuse for falling into such an expression as this: "Parallel universes reveal how superposition works, and how distant entangled particles can instantly 'communicate' with each other over vast distances." (p. 242) This is like saying "vampires reveal how blood nourishes cells in the body." You start with a imaginary entity (a parallel universe, a vampire) and you conclude that this entity reveals something. Parallel universes may exist but nobody has seen one yet, and almost by definition nobody ever will, so it is specious to claim they reveal anything.
Here's yet another example of this sort of fuzzy writing to which Seife--a professor of journalism, by the way, and the author of the acclaimed Zero (2000) and Alpha and Omega (2003)--is inexplicable drawn: "The mysteries of quantum mechanics become much less mysterious--once you believe that information creates the structure of space and time." (p. 242) I have no idea how information might create the structure of space and time, and I certainly cannot comprehend how my belief in such a notion might make QM less mysterious. Seife really needs to explain how this might work. No doubt the failing is mine. However, I suspect I'm not alone.
Bottom line: this book is fun to read, but exasperating because of its fuzzy superficiality. The superficiality may be unavoidable, but the fuzziness is not.
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