Rating: 
Summary: Theoretically intriguing, but not a good popularization
Review: Basically what this book boils down to is this: there are difficulties with the treatment of time in theoretical physics. Does it occupy a separate dimension in space-time? Why does it appear to run only in one direction? Can it run backwards, as it seems in theory that it might be able to? To answer the riddle of time, Julian Barbour has made a novel proposition: that time does not exist.Here is a crude summary of his hypothesis. Our universe exists within a configuration space that he calls Platonia, which defines all possible configurations of matter and energy in all possible universes. As the configuration of the universe changes moment-by-moment, it "moves" within Platonia. But the possible configurations are discrete and static (what the author calls Nows), so what appears to an observer as motion and time is actually just infinitesimal leaps within Platonia. Each configuration is dependent on the last, and no other next configuration, outside of those made possible by the vanishingly small variations allowed by the uncertainty principle and the wave functions that govern probability, is likely. It's certainly a new way of looking at things, and by tossing aside the notion of an absolute time, it might make some of the physical equations that seem to describe the universe easier to apply. It also does a nifty job of explaining why time cannot be manipulated as such, and why it doesn't run backwards every so often. Even if the universe ceases expansion due to gravity and eventually collapses in a Big Crunch (and his theory does not predict anything about that), time will not flow backwards because the discrete configurations during the contraction phase are still dependent on what came before. However, we still have this little problem of the appearance of time. Just because the universe resides in only the present fleeting moment does not necessarily mean that there was no history leading up to any particular configuration. One must still look back at all of the previous configurations to the beginning of the universe to explain the universe as it is Now. Just as the Newtonian laws of motion work well at nonrelativistic speeds, the concept of time has enormous usefulness here in the macroscopic world. Barbour may disagree, but it still means something to say that an event happened so many years ago, even if the difference is measured not by time but by the number of discrete configurations of the universe between then and Now. Barbour's theory of a timeless universe does not make any predictions about how the universe may have come about in the first place. It may yet, but he does not present anything here. Perhaps it was buried in his rambling about the supposedly all-encompassing Wheeler-DeWitt equation, and I just missed it. Admittedly, I am a layman. I cannot tell whether Barbour's theory has any predictive value. I would think that if it did, Barbour would have at least hinted at what it might be. As it is, I am left with the impression that he considers the implications "intuitively obvious to the casual observer", as they used to say in my college physics courses. That leaves me exactly nowhere. I can't tell that his theory of a timeless universe actually accomplishes anything other than justifying the Wheeler-DeWitt equation and the timeless zero energy Schroedinger equation, neither of which were reproduced in the book. The epilogue, in which he explores the philosophical implications of a timeless universe, is pretty much useless speculation grouped under section headers like, "Does Free Will Exist?" and "Is There A Role For A Creator In Quantum Cosmology?" and even "Where Is Heaven?" Thankfully, he doesn't seem to conclude the existence of the Judeo-Christian god, but this sort of stuff is out of place here. The argument for a timeless universe is not laid out terribly well. Granted, this is his attempt at convincing people that are a lot smarter than I am that a different framework for looking at the universe is needed. But the best science popularizations leave you feeling smarter, and I'm not so sure that I do.
Rating: 
Summary: A little too arcane for the average reader
Review: Boy, talk about a difficult book to get through. I've no doubt that Mr. Barbour knows what he's talking about, but I have to admit that I got thoroughly lost on more than one occasion. Just when I thought I had the thread of his argument pinned down, he embarked on a new more arcane path, and I was lost again. I have to admit I am not really a math-physics type person, but I do read a fair amount of literature for amateurs on the topic of theoretical physics, and time is one of those subjects that intrigues me the most. I'm not quite sure for whom the book is intended either, because although it lost me as a neophyte, I can't imagine that it would hold the attention of someone well grounded and/or professionally involved in physics; it has too many words and too few mathematical formulae. In all though, I found the concept of time as a, more or less, static collection of instants all shuffled together like playing cards or like the frames of a 35mm film strip a provocative one. I just can't help feeling, though, that there is something significant missing in the author's argument. I'm sure he would insist that it is just the overwhelming psychological experience of time "flowing" that is throwing me off, but when I think of his perspective on time and history, I find the only way it makes sense is if I stand outside of the system to see how it might work. I find it difficult to see how the information about past experiences can be passed on to my memory in any given instant without some sort of connection between all the instants of which "I" am a part. That however would make consciousness a unique and special entity, which I find difficult to accept. Although consciousness has sometimes been claimed to be a factor in generating Newtonian reality from quantum "observations," I think there has been sufficient discussion that refutes it. Again, I found the book way over my head, but I hope to reread it on another occasion with hope of achieving better understanding. Definitely not a book to start with if you're not heavily into physics.
Rating: 
Summary: Complex concept but I had no problem following conceptually
Review: Does time really exist? What if time were actually an illusion? If time did not really exist them quantum physics and classical physics could be united into a unified theory. On the other hand, if time does not exist then what are we to make of theories such as a space-time continuum? In this text Julian Barbour clearly analyses the concept of time and puts forth the current evidence for its non-existence. The arguments are compelling, the logic strong, and the results convincing - or at least it is convincing enough to consider it as a real possibility. Julian Barbour is a theoretical physicist who takes this complex and counter-intuitive concept and puts it forth in layman's terms. This is a highly recommended book for anyone interested in theoretical physics and how it is changing our view of our world. "The End of Time" is sure to become an authoritative reference for any discussion on the existence of time.
Rating: 
Summary: Give 'em a break--he's British!
Review: Give Mr. Barbour a break--he's British and doesn't speak like we do. Perhaps this is why my compatriates are having such a difficult time processing this book. This book is not easy!! It requires time and effort. It is not a light read. I see that many reviewers are frustrated. Part of this frustration is due to the resistance to accepting and entertaining living in a timeless universe. One reviewer was correct in pointing out that Barbour does very little to reconcile our conventional sense of time with his timelessness. He admits in the beginning of the book that he doesn't know how to deal with consciousness. If you are a minimalist iconoclast, you will enjoy this book! If you expect every implication to be addressed you will be dissapointed. Much is left to the reader to ponder the details. What Barbour has to say is profound, unconventional, bold, etc. What is frustrating is that the reader must just accept what Barbour says unless the reader can delve into the mathematics. This is where I returned it to the library.
Rating:
Summary: I Am Not Here
Review: In our limited fashion we all approach this from the realm of existence. Platonia is only an architectural representation of a nonexistence. I would like mr. barbour to take his theory to the next level. Hello, Mr. Barbour? Are you out there? That is a rhetorical question...of course you're not.
Rating:
Summary: Some revolutionary ideas re space and time.
Review: Interesting arguments, centered on a very revolutionary way of looking at space-time. I think his arguments could have been much more efficiently laid out; it was occasionally frustrating plowing through some of the material. Writing this book for the layman necessarily requires a good deal of redundancy in order to spiral towards some understanding. But the ideas are worth the effort. The book would profit immensely from a few side-bars for the more mathematically inclined.
For those who have had some physics:
Barbour argues for a universe which evolves as a path through a configuration space, with an appropriate metric (ie, action) determining which point (ie, which NOW) comes next. This view has no TIME, pe se. Time (as we sense it) is merely a record of changes occuring as we move along the path. These ideas challenge current conceptions, and hold out hope for a much simpler holistic view of the universe. If you enjoy such topics, you should also check out books by Lee Smolin, Brian Greene, and Eric Chaisson.
Rating:
Summary: Fantastic Ideas
Review: Julian Barbour has presented some fantastic ideas that I really like. In a nutshell, he claims that our current framework for physics [absolute space and time] is a problem and he instead suggests what he calls "Platonia" as the framework. In Platonia, time does not exist, nor absolute space. The important thing is where the matter in the universe is relative to all the other matter in the universe [relative configuration].
When a scientific theory breaks down, the first thing to do is check the assumptions that are built into the theory. Given the failure of even finding a Unified Theory [or Theory of Everything], particularly with the definition of time, it is about "time" that physicists started examining their assumptions. The assumptions that are under suspicion are the very existence of absolute time and space. [Does space exist as the box that we put matter into, or is it the matter that exists and we draw the box around it in order to describe it?]
Hooray for Dr. Barbour for having the courage to challenge our most sacred cows! I hope others will take up the challenge as it appears there is much to be done.
The reading is a bit dense at times and some of the analogies he uses were better left out [they are more confusing than illuminating]. I would have appreciated some mathematical examples. I worry that he may have missed the mark in going into too much detail for the non-physicist and not enough detail for the physicist.
Rating:
Summary: Provocative but Flawed
Review: Oddly, the most succinct and lucid statement of Barbour's theory comes, not from him, but from a reader whose email he quotes in the footnotes at the end of the book: "All moments are simultaneous ... My conscious mind feeds them to me in a linear sequence strung out with a bunch of other moments in an illusion of a continuous flow of action." (p. 340, trade paperback edition) Barbour comments that this reader's views are "often very close to my own position." I see two problems here. First, the hypothesis seems essentially solipsistic - it's not clear if it can ever be tested, proved, or disproved. Second, how can "my conscious mind feed these moments to me" in a world of total stasis, a world where everything is frozen and motionless? Either consciousness itself is exempt from the timelessness of the rest of the system (but Barbour seems to think it isn't) or consciousness, being part of a timeless reality, is frozen and unable to engage in any processes - including the process of "feeding" moments to me. In other words, if time is an illusion created by a filmstrip of single frames being run in our heads, then what is running the movie, and how can the movie run at all when nothing can move? The theory seems to raise more questions than it answers. Still, questions are always valuable, so - three stars!
Rating:
Summary: A must read
Review: Of course people may have trouble with this book! It grapples with one of the most counter-intuitive hypotheses ever pondered. Unsurprisingly, befuddled readers will readily point fingers at the author's "poor exposition". When someone fails to understand Joyce or Faulkner, it's the reader's fault, but when someone can't understand a science author, then it's the writer's fault.... The fact is that if the author (or anyone else, for that matter) understood the nature of time well enough to spoon-feed us with a crystal-clear, airtight argument (together with its attendant implications, as some readers demand) such insight would already be in the news as the single greatest breakthrough in the history of physics. As it is, the ideas presented in the book are speculative and unstructured. They may even be flawed. So what? To date, they constitute one of the few (if not the only) non-technical discussions of current thoughts on the most baffling aspect of physical reality. This book is clearly meant for those who want to "read about it first", whenever some interesting idea first appears in print, no matter how undigested. As for those readers who would rather wait for the Discovery-Channel version of everything, their stance is legitimate, but can hardly be blamed on a book.
Rating:
Summary: The End of Time
Review: The essential idea from Julian Barbour's book is that the laws of physics can be formulated in such a way that time does not enter explicitly into the equations. If we accept this idea for the moment (and not all physicists do), the question then becomes: is making time disappear in this way just a mathematical trick, or does it lead to better physics? Barbour has taken on an especially difficult task in trying to explain these esoteric concepts in a work of popular science. The book doesn't succeed, in my view, and the most I can do here is give him credit for trying. My negative review does not reflect any disagreement with his ideas - it is up to his peers in physics, not me, to decide whether he is on to something or not. I just don't think he's succeeded in putting his ideas across to a general audience. The book is so wordy, and its exposition so plodding and foggy and vague, that it is hard to imagine that most people would get much out of it. I really don't like to write negative reviews, but sometimes they can be useful in steering readers away from books that are likely to frustrate and turn them off. Barbour is a respected physicist, an original thinker, and an interesting person, whose life trajectory has taken him far from the typical academic career. But I really hope he'll take on a co-writer, somebody who knows how to write clearly and informatively about popular science, on his next book.
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