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The End of Time: The Next Revolution in Our Understanding of the Universe
Time is an illusion. Although the laws of physics create a powerful impression that time is flowing, in fact there are only timeless ‘nows’. In The End of Time, the British theoretical physicist Julian Barbour describes the coming revolution in our understanding of the a quantum theory of the universe that brings together Einstein’s general theory of relativity – which denies the existence of a unique time – and quantum mechanics – which demands one. Barbour believes that only the most radical of ideas can resolve the conflict between these two that there is, quite literally, no time at all. The End of Time is the first full-length account of the crisis in our understanding that has enveloped quantum cosmology. Unifying thinking that has never been brought together before in a book for the general reader, Barbour reveals the true architecture of the universe and demonstrates how physics is coming up sharp against the extraordinary possibility that the sense of time passing emerges from a universe that is timeless. The heart of the book is the author’s lucid description of how a world of stillness can appear to be teeming with in this timeless world where all possible instants coexist, complex mathematical rules of quantum mechanics bind together a special selection of these instants in a coherent order that consciousness perceives as the flow of time. Finally, in a lucid and eloquent epilogue, the author speculates on the philosophical implications of his Does free will exist? Is time travel possible? How did the universe begin? Where is heaven? Does the denial of time make life meaningless? Written with exceptional clarity and elegance, this profound and original work presents a dazzlingly powerful argument that all will be able to follow, but no-one with an interest in the workings of the universe will be able to ignore.
371 pages, Hardcover
First published September 1, 1999
About the author
Julian Barbour
8 books73 followersJulian Barbour (1937) is a British physicist with research interests in quantum gravity and the history of science.
Since receiving his PhD degree on the foundations of Einstein's general theory of relativity at the University of Cologne in 1968, Barbour has supported himself and his family without an academic position, working part-time as a translator. He has research interests in quantum gravity and the history of science.
Since receiving his PhD degree on the foundations of Einstein's general theory of relativity at the University of Cologne in 1968, Barbour has supported himself and his family without an academic position, working part-time as a translator. He has research interests in quantum gravity and the history of science.
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March 17, 2022
Plato Rules OK?
I suspect that most of us have thought at some point about the mystery of time. But very few have considered seriously what it might be. And only a handful, perhaps, could explain in a comprehensible way how time is constructed. And, I’m sure, there are less than a handful who with any plausibility deny its existence entirely - Julian Barbour is one of these. And he makes an interesting case.
According to Barbour, time is a constructive illusion, a concept without any extra-linguistic existence. We use it like a ‘god of the gaps’ to explain that for which we have no other theory. The illusion is the sensory equivalent of a flat earth or the appearance of instantaneous gravitational action at a distance. What we experience, or name as experience, is our interpretation of various states of entropy, a measure of the disorder of the cosmos.
Time then is really the feeling of progression from states of lower to states of higher entropy, from relative order to disorder. Such a concept might seem a scientific splitting of hairs, except that it has a profound implication: the ‘direction’ of time depends on what ‘side’ of successive entropy states one happens to be. Successive states might be ‘before’ or ‘after’ each other depending on the perspective of the conscious being involved. Since the past is always the domain of lesser entropy, time, the gradient of entropy, can run in opposite directions simultaneously. The past is a conjecture, a supposition made on the basis of incomplete information, not a fact.
Barbour believes that there are evolutionary reasons for our creation of the idea of time. We are programmed to detect ‘records’, sequences of entropic states, at the expense of other perceptual sensitivities. We are able to manipulate, really order, these records through consciousness to great effect in finding food, establishing social structures, in ‘anticipating’ consequences. In short, time is a survival tactic, an expediency which may no longer be expedient. What it is not is a physical reality.
Perhaps the principle reason I am attracted to Barbour’s theory (in addition to its sheer provocation) is that it vindicates much of Platonic thinking. Plato’s ‘forms’ for example have a credibility inside a timeless universe which had been lost in the methods of Aristotelian science. Instants, what Barbour calls Nows, are things. Space and time are not more fundamental than things, in which things mysteriously float; they are part of the ‘configuration’ of things as they exist. This highly technical term of configuration seems remarkably similar, if not equivalent, to the Platonic ‘eternal ideas’.
The End of Time is challenging, but not because Barbour’s exposition is flawed or interrupted by technical scientific and mathematical proof texts. It is challenging because it reveals the depth of presumption about the world that we carry around with us nonchalantly. Exposing these unwarranted presumptions is often a matter of confronting not just common sense but an entire culture of thought that has worked reasonably well. In a sense, what Barbour is doing is equivalent to Luther’s nailing of his theses on the door of Wittenberg Cathedral. Neither Luther nor Barbour could have a clear idea of the consequences. Nevertheless, they’re bound to be exciting.
Postscript: for a good short summary of much of Barbour see: https://www.lesswrong.com/posts/rrW7y...
To see how badly the subject can be written about, consult this academic text on time. Its lack of literary skill, I’ll wager, is matched by its opaqueness of thought: https://www.goodreads.com/review/show...
I suspect that most of us have thought at some point about the mystery of time. But very few have considered seriously what it might be. And only a handful, perhaps, could explain in a comprehensible way how time is constructed. And, I’m sure, there are less than a handful who with any plausibility deny its existence entirely - Julian Barbour is one of these. And he makes an interesting case.
According to Barbour, time is a constructive illusion, a concept without any extra-linguistic existence. We use it like a ‘god of the gaps’ to explain that for which we have no other theory. The illusion is the sensory equivalent of a flat earth or the appearance of instantaneous gravitational action at a distance. What we experience, or name as experience, is our interpretation of various states of entropy, a measure of the disorder of the cosmos.
Time then is really the feeling of progression from states of lower to states of higher entropy, from relative order to disorder. Such a concept might seem a scientific splitting of hairs, except that it has a profound implication: the ‘direction’ of time depends on what ‘side’ of successive entropy states one happens to be. Successive states might be ‘before’ or ‘after’ each other depending on the perspective of the conscious being involved. Since the past is always the domain of lesser entropy, time, the gradient of entropy, can run in opposite directions simultaneously. The past is a conjecture, a supposition made on the basis of incomplete information, not a fact.
Barbour believes that there are evolutionary reasons for our creation of the idea of time. We are programmed to detect ‘records’, sequences of entropic states, at the expense of other perceptual sensitivities. We are able to manipulate, really order, these records through consciousness to great effect in finding food, establishing social structures, in ‘anticipating’ consequences. In short, time is a survival tactic, an expediency which may no longer be expedient. What it is not is a physical reality.
Perhaps the principle reason I am attracted to Barbour’s theory (in addition to its sheer provocation) is that it vindicates much of Platonic thinking. Plato’s ‘forms’ for example have a credibility inside a timeless universe which had been lost in the methods of Aristotelian science. Instants, what Barbour calls Nows, are things. Space and time are not more fundamental than things, in which things mysteriously float; they are part of the ‘configuration’ of things as they exist. This highly technical term of configuration seems remarkably similar, if not equivalent, to the Platonic ‘eternal ideas’.
The End of Time is challenging, but not because Barbour’s exposition is flawed or interrupted by technical scientific and mathematical proof texts. It is challenging because it reveals the depth of presumption about the world that we carry around with us nonchalantly. Exposing these unwarranted presumptions is often a matter of confronting not just common sense but an entire culture of thought that has worked reasonably well. In a sense, what Barbour is doing is equivalent to Luther’s nailing of his theses on the door of Wittenberg Cathedral. Neither Luther nor Barbour could have a clear idea of the consequences. Nevertheless, they’re bound to be exciting.
Postscript: for a good short summary of much of Barbour see: https://www.lesswrong.com/posts/rrW7y...
To see how badly the subject can be written about, consult this academic text on time. Its lack of literary skill, I’ll wager, is matched by its opaqueness of thought: https://www.goodreads.com/review/show...
October 5, 2014
People who read pop science books will know by now that the physics world is rather like that of Star Wars. The dominant String Theorists are the Empire; led by the Vader-like Ed Witten, they control the corrupt funding agencies and rule science with an iron fist. Ranged against them, we have the eccentric and charismatic Rebels. Lee Smolin's Periphery Institute is clearly the main Rebel base, and Peter Woit comes across as a typical Han Solo figure. I rather fancy Roger Penrose as Obi-Wan Kenobi and Fotini Markopoulou as Princess Leia. Luke Skywalker, alas, does not yet appear to have turned up. But I've got no doubts about Julian Barbour: he can't be anyone but Yoda. Even something of a physical resemblance, wouldn't you say?
You may have trouble with some of this book, but try reading it aloud in a Yoda voice and much will become clear. "Time, an illusion it is. Platonia, a relative configuration space it is. A blue mist, collect over Platonia it does." The blue mist, which plays a large part in the book, could be glossed as the quantum mechanical probability density function, but you may well prefer to think of it as the Force; the wave function's real and imaginary parts are the red and green mists.
I am afraid that my fluency in Yoda is limited, so I will reluctantly switch to English and leave the translation as an exercise to a more linguistically gifted reader. Joking aside, the opening part of Barbour's argument is very sensible. He starts by considering the question of what "time" is, and comes up with some good answers. He wants to go back to Mach's Principle, and think only about relative measurements: the example used though much of the book is "Triangle Space", a toy universe with two dimensions of space and one of time, which contains just three objects moving under the influence of gravity. He asks you to consider what you can do if you're just given snapshots of instants ("Nows") in Triangle Space, and shows how you can reconstruct the notion of time from them in a straightforward and pleasing way.
He takes this idea as his starting point, and then applies it to successively more complicated models of physics. It's easy to do it in Special Relativity. General Relativity is much harder, and he only sketches the argument. The problem is that a "Now" in General Relativity is a very slippery notion, since you can cut up space-time in infinitely many different ways. But I believe him when he says he's found a way to make it work there too.
He runs into the real problems, though, when he adds quantum mechanics to the mix. Here, the reasoning became hard to follow, but, as I understand him, it goes something like this. The normal (time-dependent) Schrödinger Equation makes integral reference to time, which it sharply distinguishes from space. This clashes violently with General Relativity, which views them both as parts of the same thing, and, despite repeated attempts, no one can figure out how to pull apart the four dimensions of General Relativity into three space-like ones and one time-like one in a way that will mesh with the Schrödinger Equation.
Barbour says that's because it can't be done. Instead, he makes the radical suggestion that the Universe's structure is better modeled by a version of the time-independent Schrödinger Equation, which describes static solutions to the normal Schrödinger Equation. These static solutions are the "Nows", the instants of time. The motivation is not implausible: as another reviewer points out, the time-independent Schrödinger Equation is supposed to be appropriate in situations where energy is constant and there are no external inputs. Those conditions evidently apply to the whole Universe. It's very hard to know whether to believe the argument. Your first response is that it has to be a technical trick. However, as Barbour points out, there are many examples in physics where things which at first looked like technical tricks turned out to be deep insights, and it's often best to trust the math and see where it goes.
So the Universe is technically static, and consists of a gigantic collection of "Nows". Motion is an illusion; it springs from the fact that the "Nows" are related to each other, and, crucially, that there is a tendency for them to contain "time-capsules", by which he means structures which look like records of past events; as he says, we only believe in the past because we have memories and other records of it. He illustrates using a nice example with a charged particle moving through a cloud chamber, where the track of water droplets is the time-capsule. He also compares with Leibniz's philosophy; in Leibniz's terms, the "Nows" are, roughly, monads, and there is pre-established harmony between them due to the fact that they are all solutions to the same equation.
As the book progresses, it becomes more and more mystical and Yoda-like. I had real trouble believing the final sections, which to me came across as the purest hand-waving and poeticising. In particular, he admits himself that he doesn't have a clear explanation of why the "Nows" containing "time-capsules" should tend to get high probabilities, something that is essential to the theory. But there's no doubt that he's asking interesting and original questions, and I'm certainly not competent to judge whether the answers make sense. Maybe he's right, and "time" is just one of those approximations which hold in our everyday world where quantum and relativity effects can safely be ignored, but break down in more extreme situations. If you want to read a really unusual physics book which takes the fundamental issues seriously, you might want to check this one out.
You may have trouble with some of this book, but try reading it aloud in a Yoda voice and much will become clear. "Time, an illusion it is. Platonia, a relative configuration space it is. A blue mist, collect over Platonia it does." The blue mist, which plays a large part in the book, could be glossed as the quantum mechanical probability density function, but you may well prefer to think of it as the Force; the wave function's real and imaginary parts are the red and green mists.
I am afraid that my fluency in Yoda is limited, so I will reluctantly switch to English and leave the translation as an exercise to a more linguistically gifted reader. Joking aside, the opening part of Barbour's argument is very sensible. He starts by considering the question of what "time" is, and comes up with some good answers. He wants to go back to Mach's Principle, and think only about relative measurements: the example used though much of the book is "Triangle Space", a toy universe with two dimensions of space and one of time, which contains just three objects moving under the influence of gravity. He asks you to consider what you can do if you're just given snapshots of instants ("Nows") in Triangle Space, and shows how you can reconstruct the notion of time from them in a straightforward and pleasing way.
He takes this idea as his starting point, and then applies it to successively more complicated models of physics. It's easy to do it in Special Relativity. General Relativity is much harder, and he only sketches the argument. The problem is that a "Now" in General Relativity is a very slippery notion, since you can cut up space-time in infinitely many different ways. But I believe him when he says he's found a way to make it work there too.
He runs into the real problems, though, when he adds quantum mechanics to the mix. Here, the reasoning became hard to follow, but, as I understand him, it goes something like this. The normal (time-dependent) Schrödinger Equation makes integral reference to time, which it sharply distinguishes from space. This clashes violently with General Relativity, which views them both as parts of the same thing, and, despite repeated attempts, no one can figure out how to pull apart the four dimensions of General Relativity into three space-like ones and one time-like one in a way that will mesh with the Schrödinger Equation.
Barbour says that's because it can't be done. Instead, he makes the radical suggestion that the Universe's structure is better modeled by a version of the time-independent Schrödinger Equation, which describes static solutions to the normal Schrödinger Equation. These static solutions are the "Nows", the instants of time. The motivation is not implausible: as another reviewer points out, the time-independent Schrödinger Equation is supposed to be appropriate in situations where energy is constant and there are no external inputs. Those conditions evidently apply to the whole Universe. It's very hard to know whether to believe the argument. Your first response is that it has to be a technical trick. However, as Barbour points out, there are many examples in physics where things which at first looked like technical tricks turned out to be deep insights, and it's often best to trust the math and see where it goes.
So the Universe is technically static, and consists of a gigantic collection of "Nows". Motion is an illusion; it springs from the fact that the "Nows" are related to each other, and, crucially, that there is a tendency for them to contain "time-capsules", by which he means structures which look like records of past events; as he says, we only believe in the past because we have memories and other records of it. He illustrates using a nice example with a charged particle moving through a cloud chamber, where the track of water droplets is the time-capsule. He also compares with Leibniz's philosophy; in Leibniz's terms, the "Nows" are, roughly, monads, and there is pre-established harmony between them due to the fact that they are all solutions to the same equation.
As the book progresses, it becomes more and more mystical and Yoda-like. I had real trouble believing the final sections, which to me came across as the purest hand-waving and poeticising. In particular, he admits himself that he doesn't have a clear explanation of why the "Nows" containing "time-capsules" should tend to get high probabilities, something that is essential to the theory. But there's no doubt that he's asking interesting and original questions, and I'm certainly not competent to judge whether the answers make sense. Maybe he's right, and "time" is just one of those approximations which hold in our everyday world where quantum and relativity effects can safely be ignored, but break down in more extreme situations. If you want to read a really unusual physics book which takes the fundamental issues seriously, you might want to check this one out.
Want to read
October 22, 2018به شدت شیفته این کتاب هستم تا پیداش کنم اگر کسی راهنمایی کنه خیلی ممنون میشم
با این کتا ب توسط این ویدیو 54 دقیقه ای آشنا شدم که خود نویسنده در مورد ماهیت زمان صحبت میکنه و راستش منتظر کلی مغلطه بودم ولی به این نتیجه رسیدم که مغلطه گر بزرگ خودم هستم
https://www.youtube.com/watch?v=KkjXu...
با این کتا ب توسط این ویدیو 54 دقیقه ای آشنا شدم که خود نویسنده در مورد ماهیت زمان صحبت میکنه و راستش منتظر کلی مغلطه بودم ولی به این نتیجه رسیدم که مغلطه گر بزرگ خودم هستم
https://www.youtube.com/watch?v=KkjXu...
March 21, 2008
if you love Roger Penrose and Lee Smolin, and REALLY UNDERSTAND WHAT THEY ARE TALKING ABOUT, you might like this book. basically, the paradoxical incongruity between quantum theory and general relativity is attacked once more. i was blown away. the strongest argument, for me, that time does not really exist was this: if you look at any ISOLATED quantum system with CONSTANT ENERGY, you will expect it to be in a STATIONARY STATE. think of any isolated atom, with all its electrons sitting in orbitals. you will always use the time-INDEPENDENT schrodinger equation to find the possible states. time will simply not enter into the problem. BUT THIS IS EXACTLY THE SITUATION WITH THE WAVEFUNCTION FOR THE ENTIRE UNIVERSE. constant energy? check. no interaction with 'something else'? check. ergo, the wavefunction of the entire universe should not contain time. it doesn't evolve! holy crap!
he talks a lot about Machian mechanics and tries to explain how and why we might have the mistaken (extremely convincing) impression that time does, in fact, pass. i will definitely be going out and reading every word by Julian Barbour i can get my hands on.
the funny (not ha ha funny) thing is that even though this was an AMAZING book, i'm not at all surprised that it has a horrible rating both here and over at amazon. Barbour seems to have tried to make his book accessible to the "educated layman", but people who don't have a degree in physics will probably find this book to be totally impenetrable. and frankly, i wish he hadn't tried. his thesis is both astounding and very well-supported (that the passage of time is an illusion), but it is based on some extremely advanced principles. yet he has tried to lay it out without a single equation. NO MATH! instead of talking about the real and imaginary components of complex wavefunctions and the corresponding probability amplitude, he introduces the analogy of a 'red mist', 'green mist', and 'blue mist' which pervade space. he waxes poetic at every turn, bringing in soaring lines from shakespeare and keats and many others, as well as spinning some purple prose of his own, in order to broaden the appeal of the book.
unfortunately, this alternates with arguments that i think simply cannot mean much if you don't have a very good grasp of both QM and relativity. it was a five-star book for me, but yeah, not for you, most likely.
he talks a lot about Machian mechanics and tries to explain how and why we might have the mistaken (extremely convincing) impression that time does, in fact, pass. i will definitely be going out and reading every word by Julian Barbour i can get my hands on.
the funny (not ha ha funny) thing is that even though this was an AMAZING book, i'm not at all surprised that it has a horrible rating both here and over at amazon. Barbour seems to have tried to make his book accessible to the "educated layman", but people who don't have a degree in physics will probably find this book to be totally impenetrable. and frankly, i wish he hadn't tried. his thesis is both astounding and very well-supported (that the passage of time is an illusion), but it is based on some extremely advanced principles. yet he has tried to lay it out without a single equation. NO MATH! instead of talking about the real and imaginary components of complex wavefunctions and the corresponding probability amplitude, he introduces the analogy of a 'red mist', 'green mist', and 'blue mist' which pervade space. he waxes poetic at every turn, bringing in soaring lines from shakespeare and keats and many others, as well as spinning some purple prose of his own, in order to broaden the appeal of the book.
unfortunately, this alternates with arguments that i think simply cannot mean much if you don't have a very good grasp of both QM and relativity. it was a five-star book for me, but yeah, not for you, most likely.
February 12, 2016
I got interested in this book after attending a seminar given by Barbour at the University of New Brunswick.
THIS REVIEW HAS BEEN CURTAILED IN PROTEST AT GOODREADS' CENSORSHIP POLICY
See the complete review here:
http://arbieroo.booklikes.com/post/66...
THIS REVIEW HAS BEEN CURTAILED IN PROTEST AT GOODREADS' CENSORSHIP POLICY
See the complete review here:
http://arbieroo.booklikes.com/post/66...
Read
October 8, 2020A fabulous book that really made me think about previously accepted concepts - everyone interested in this sort of science should read this book, they will be glad they did!
Read
September 21, 2009I strongly suspect the main problem is that I was too stupid and distractable to do a good job reading this, but as far as I could glean:
This book contains, in order of most pages devoted to the least:
-Holding the reader's hand and reassuring them that it's not too hard to understand it
-Referring to what will be explained and made much clear later in the book
-Repeating or rephrasing minor points or peripheral frameworks in order to make the ideas easier to picture
-Brief summaries of or mere references to concepts in physics
-Bafflingly irrelevant personal stories
-Lamenting the state of the system that won't accept the ideas of outsides because they are too wedded to the status quo
-Actual substance on how time might not exist
Okay, the actual substance could probably be moved up two or three slots, but if you take into account that the vast majority of it is just reiteration, it's still down pretty low. I know that there is legitimacy to the claim that being inside the system that defines the status quo can make people more reluctant to accept different or difficult ideas, but that is not evidence either way for whether that different or difficult idea is true. And maybe it does make sense to sort of pepper the entire human landscape with your ideas by presenting them to public. I just don't know if writing this pop science book really helped. I've noticed this problem, where a scientist tries to educate non-scientists by writing a book, because that is the best way to get to the public, except that the book just goes on and on and could have been much clearer and more effective if it had been concise, like an article. Is it that people won't buy a pop science book if it's too short? I mean, if you're going to take out absolutely all of the actual science and dumb it down for the public to read, why make them read 300 pages if there's not that much information left? I would have gladly read an entire book on the subject, if the entire book had been illuminating and explanatory.
This book contains, in order of most pages devoted to the least:
-Holding the reader's hand and reassuring them that it's not too hard to understand it
-Referring to what will be explained and made much clear later in the book
-Repeating or rephrasing minor points or peripheral frameworks in order to make the ideas easier to picture
-Brief summaries of or mere references to concepts in physics
-Bafflingly irrelevant personal stories
-Lamenting the state of the system that won't accept the ideas of outsides because they are too wedded to the status quo
-Actual substance on how time might not exist
Okay, the actual substance could probably be moved up two or three slots, but if you take into account that the vast majority of it is just reiteration, it's still down pretty low. I know that there is legitimacy to the claim that being inside the system that defines the status quo can make people more reluctant to accept different or difficult ideas, but that is not evidence either way for whether that different or difficult idea is true. And maybe it does make sense to sort of pepper the entire human landscape with your ideas by presenting them to public. I just don't know if writing this pop science book really helped. I've noticed this problem, where a scientist tries to educate non-scientists by writing a book, because that is the best way to get to the public, except that the book just goes on and on and could have been much clearer and more effective if it had been concise, like an article. Is it that people won't buy a pop science book if it's too short? I mean, if you're going to take out absolutely all of the actual science and dumb it down for the public to read, why make them read 300 pages if there's not that much information left? I would have gladly read an entire book on the subject, if the entire book had been illuminating and explanatory.
March 12, 2023
L'azote de notre ADN, le calcium de nos dents, le fer de notre sang, le carbone de nos tartes aux pommes ont été fabriqués à l'intérieur des étoiles qui s'effondrent. Nous sommes faits de starstuff. – Carl Sagan.
Dans la banlieue d’une de ces galaxies nommée Voie lactée, sur une planète proche d’une étoile appelée Soleil, apparaît l’homme, capable de s’émerveiller devant la beauté et l’harmonie du cosmos, doué d’une conscience et d’une intelligence lui permettant de s’interroger sur l’Univers qui l’a engendré. L’infiniment petit a donc accouché de l’infiniment grand, et pour comprendre l’origine de l’Univers et, par conséquent, notre propre origine, il nous faut une théorie physique qui soit capable d’unifier la mécanique quantique avec la relativité et de décrire une situation où les quatre forces fondamentales qui -contrôlent l’Univers sont sur un pied d’égalité.
Ce n'est pas un livre spécial, mais j'aime toujours les livres de cosmologie et de physique parce que Quelque part, quelque chose d'incroyable attend d'être connu. C'est moi qui ai décidé de prendre cette voie. Cela en fait partie.
The wreckage of stars - I built a world from this wreckage🖤
Dans la banlieue d’une de ces galaxies nommée Voie lactée, sur une planète proche d’une étoile appelée Soleil, apparaît l’homme, capable de s’émerveiller devant la beauté et l’harmonie du cosmos, doué d’une conscience et d’une intelligence lui permettant de s’interroger sur l’Univers qui l’a engendré. L’infiniment petit a donc accouché de l’infiniment grand, et pour comprendre l’origine de l’Univers et, par conséquent, notre propre origine, il nous faut une théorie physique qui soit capable d’unifier la mécanique quantique avec la relativité et de décrire une situation où les quatre forces fondamentales qui -contrôlent l’Univers sont sur un pied d’égalité.
Ce n'est pas un livre spécial, mais j'aime toujours les livres de cosmologie et de physique parce que Quelque part, quelque chose d'incroyable attend d'être connu. C'est moi qui ai décidé de prendre cette voie. Cela en fait partie.
The wreckage of stars - I built a world from this wreckage🖤
March 30, 2016
This is absolutely one of my favourite science books. I picked it up initially because the premise fascinated me. The nonexistence (as an objective reality, mind you) of time was something I've always sort of intuited, and to see physics exploring the same conclusions immediately sparked my interest. Ironically, though, that is not the strongest part of this book.
I think any good science book should not only explain to you a theory and its application, but give you the context as well. A good science book will teach you why the idea it presents is important, what its impact might be if true, and most importantly it will teach you anything you need to know about the subject (in this case, Physics) to understand the idea, from the ground up. And a good science book will do this without dumbing things down.
This is a good science book, for all those reasons and more. In fact, this book taught me much of what I know about theoretical physics.
Barbour's history as a science historian also shows, as he explores not only the idea but his personal story of how he began to come to these conclusions and his quest to find a way to test them.
At its heart, this book espouses a whole philosophy about the universe, and a revolutionary one at that. It is a counter argument to both string theory and western religion. It is one of the most fascinating things you will ever read, if you have the tenacity to make it through to the end.
But the best thing about this book is that it understands its own ideas may not be true, and in fact (in the great tradition of science) probably aren't. And it goes on to tell us that this is okay, because that is how science works, and because these are things we need to be exploring anyway.
This book will teach you physics, challenge your philosophy, and leave you with a new appreciation for science and the universe. Barbour is a credit to the world.
P.S. During the reading of this book was the first and probably only time in my life when I have ever uttered the phrase "aww, poor quantum wave packets!"
I think any good science book should not only explain to you a theory and its application, but give you the context as well. A good science book will teach you why the idea it presents is important, what its impact might be if true, and most importantly it will teach you anything you need to know about the subject (in this case, Physics) to understand the idea, from the ground up. And a good science book will do this without dumbing things down.
This is a good science book, for all those reasons and more. In fact, this book taught me much of what I know about theoretical physics.
Barbour's history as a science historian also shows, as he explores not only the idea but his personal story of how he began to come to these conclusions and his quest to find a way to test them.
At its heart, this book espouses a whole philosophy about the universe, and a revolutionary one at that. It is a counter argument to both string theory and western religion. It is one of the most fascinating things you will ever read, if you have the tenacity to make it through to the end.
But the best thing about this book is that it understands its own ideas may not be true, and in fact (in the great tradition of science) probably aren't. And it goes on to tell us that this is okay, because that is how science works, and because these are things we need to be exploring anyway.
This book will teach you physics, challenge your philosophy, and leave you with a new appreciation for science and the universe. Barbour is a credit to the world.
P.S. During the reading of this book was the first and probably only time in my life when I have ever uttered the phrase "aww, poor quantum wave packets!"
March 7, 2023
My math stops at second year college calculus and linear algebra, with a smattering of group theory, and I never took a college level physics course, though I have read a lot of popular books on physics, including several that push my math to its edge and bit beyond, so I am not qualified to judge Barbour in a rigorous way. But I have long been fascinated by the theory of the pre-Socratic philosopher Parmenides that motion and time are illusions, so I was immediately drawn to the idea of a serious theory of physics based on the idea that time does not exist. And I believe that this kind of daring out of the box thinking that questions such a fundamental concept as time is more likely to be the basis for the next great strides in physics than more and more diddling with non-falsifiable string theory.
Barbour doesn't completely do away with anything resembling time. He sees the universe that we perceive as a pathway through an infinite number of static instances of reality which each contain a record of other instances along the path that we perceive as time. Maybe. I don't know. In the end it didn't appeal to me. I saw how his concept could simplify and solve some difficult points in other theories, but I felt that his construction of the pathway through instances was a little strained, as was his idea that all of the instances that we inhabit must be "time capsules" with built in histories that we perceive as the past. From my position of relative ignorance, it seems more likely that time does exist and that it is an expression of entropy and incomplete information as advocated by Carlo Rovelli in The Order of Time.
I also found Barbour's effort at writing a popular science book for a broad audience to be less than it might have been. It was both too complicated and too simple. He stays completely away from math, but his attempts to provide simplified non-mathematical explanations were not as good as top quality popular science writers like Stephen Hawking and Murray Gell-Mann. I found I had to reread his simplified explanations to understand them, when I would have been able to instantly grasp the same points if he had been a better writer or if he had favored us with a few equations.
Nevertheless, my hat is off to anyone willing to challenge time and to do his physics on a farm giving up an academic career that would have been frustrated by his dedication to a cool theory that sits so far outside of the mainstream.
Barbour doesn't completely do away with anything resembling time. He sees the universe that we perceive as a pathway through an infinite number of static instances of reality which each contain a record of other instances along the path that we perceive as time. Maybe. I don't know. In the end it didn't appeal to me. I saw how his concept could simplify and solve some difficult points in other theories, but I felt that his construction of the pathway through instances was a little strained, as was his idea that all of the instances that we inhabit must be "time capsules" with built in histories that we perceive as the past. From my position of relative ignorance, it seems more likely that time does exist and that it is an expression of entropy and incomplete information as advocated by Carlo Rovelli in The Order of Time.
I also found Barbour's effort at writing a popular science book for a broad audience to be less than it might have been. It was both too complicated and too simple. He stays completely away from math, but his attempts to provide simplified non-mathematical explanations were not as good as top quality popular science writers like Stephen Hawking and Murray Gell-Mann. I found I had to reread his simplified explanations to understand them, when I would have been able to instantly grasp the same points if he had been a better writer or if he had favored us with a few equations.
Nevertheless, my hat is off to anyone willing to challenge time and to do his physics on a farm giving up an academic career that would have been frustrated by his dedication to a cool theory that sits so far outside of the mainstream.
April 9, 2009
Julian Barbour is the foremost representative of the Machian view of physics, epitomized by the idea that time disappears on the cosmological view replaced by the comparison of changes with changes within time. There is no time for the universe itself. Turns out he can defend that view with a timeless view of both GTR and of QM by way of the stationary state DeWitt-Wheeler equation. He also has an explanation of why there seems to be time in terms of traces and time-capsules which result from quantum measurements or branching depending on your view. I'm sympathetic to Barbour, but if you were not, he doesn't do a very good job of discussing alternatives and a crucial issue, the relativity of rotation does not get mentioned. He just formulates GTR in a timeless relational framework and I guess the physical invariance or relativity of rotating reference frames you are supposed to get out of that. I didn't see that however, nor did I see a mechanism for the exchange of inertia and gravitation in different rotating frames. I did see an interesting explanation of inertial or force-free frames as islands within a dynamical universe, and the so-called un-Machian solutions of GTR would then be interpreted as such islands seemingly free of force, but really just special cases of a dynamics of matter, space and force.
August 18, 2016
I was too far into this before it became a chore, and feeling unable to rescind the investment I'd made, I ploughed on.The problem for me was mainly one of clarity and lack of allegorical description when dealing with complex theories, which I felt should have been present in a work aimed at a lay readership a part of which I presumed myself to be. There seemed to be a lack in the consistency of the intellectual level of to whom the book is addressed. On the one hand you are reminded of Pythagoras's theorem and the Two Slit experiment and on the other you are asked to perform arduous visualisations to grasp interconnections of theoretical particles in multiple dimensions.
A greater part of the book is dedicated to the retreading of Relativity theory, Quantum theory, Mach's Principle and Schrodinger's equations, which I guess would be familiar to most readers who get past the notes on the back cover and are covered far more lucidly by other popular authors. It is then shown how the established theories can still remain relevant within the authors newer conceptual framework of a Timeless Configuration Space, where our experiences are constructed by the action of Probability Waves on Time Capsules under the influence of Psychophysical Parallelism.
Although I comprehended most of it in a "general way", I felt that the author, who works independently of the scientific community, was aiming primarily at academic recognition through a rigorous and credible exposition of his theory, which was won at the expense of clarity to the general reader.
A greater part of the book is dedicated to the retreading of Relativity theory, Quantum theory, Mach's Principle and Schrodinger's equations, which I guess would be familiar to most readers who get past the notes on the back cover and are covered far more lucidly by other popular authors. It is then shown how the established theories can still remain relevant within the authors newer conceptual framework of a Timeless Configuration Space, where our experiences are constructed by the action of Probability Waves on Time Capsules under the influence of Psychophysical Parallelism.
Although I comprehended most of it in a "general way", I felt that the author, who works independently of the scientific community, was aiming primarily at academic recognition through a rigorous and credible exposition of his theory, which was won at the expense of clarity to the general reader.
December 4, 2011
I mean the idea behind the book was really good. I was excited to read about a whole new way to excuse ourselves from this time like track forward we seem to find ourselves in. Some of the backing seemed pretty sound from my grasp of these issues. The problem is, I was left with kind of giant question mark at the end? The conclusion was frankly so poorly written that I found myself re reading the original entry chapters to kind of tie MYSELF back to the context since the author didn't do it for me. Perhaps everyone does not need this kind of hand holding but frankly I was a bit lost. It wasn't a boring book though and I think he made a lot of interesting points, although I when it got the the latter half even I found it started to meander and the backing seemed to get thinner and thinner for the ideas he was trying to present. I think that's why this book really could have used a better ending. Just to really tie all these loose ends together and give some kind of final shabang to the whole Ending of time as it were.
October 15, 2010
I have since long been open to the idea that time is only an illusion, a static extension in a complex multi-dimensional form. Barbour's book does no good job in promoting that idea, even though it wants to. All his babble about Platonia (Barbour's name for the static multiverse) and the existence of 'time capsules' (micro-sized qualities of atoms that allow observers to distinguish between past and future), is too far-fetched. Instead of opening readers' eyes to the possibility that all events past, present and future may actually co-exist in a higher dimensional shape, Barbour estranges the reader from it by elaborating on his terribly complex but unconvincing world view that no sentient being could go along with.
September 6, 2018
In an unnerving moment of synchronicity, as I battled through the muddy trenches of page 299 of this fascinating book, scrunched up in the mottled shade of a pine forest on the painfully idyllic island of Mljet, a kingfisher landed on a nearby branch. At least I think it was a kingfisher – a relatively small bird with a bright blue “cape”, it tweeted a few times, loudly, as if demanding that I pay attention to it, and then flittered away.
“This means something”, I thought to myself, echoing Close Encounters, and then promptly shook off the feeling and went back to feeling inadequate, i.e. reading the book.
I have gotten to a gnarly point where I know enough about physics to wrestle with some very deep, foundational issues, such as Mach’s principle that forms part of the core of this book, and yet I do not know enough physics to grapple with these issues on a direct equations-on-blackboard manner. This leads to mental jiu-jitsu with books such as Barbour’s, written neither for a complete layman, who would, I suspect, quickly become mired in its technical (and philosophical) arguments, yet neither for an expert who would find his “red and blue mist stand for parts of a complex function” allegories annoying and distracting (as I did, knowing a bit of the “ole quannum”).
The idea of the book, that time is an illusion generated by a non-temporal best-match sequencing of 3d “frames” in an all-encompassing configuration space, generally seems solid as an idea, but I have no, heh, idea if the evidence is solid, or if the conjectures are in any way realistic – each part of the book started off very clear, then grew difficult, but understandable, and then slowly, at about the 80% mark, became incomprehensibly complex.
What I definitely did get out of the book and am very grateful for is the hammering-home of the idea of configuration spaces, and the way they are utilized in physical analyses – Barbour returns to this concept over and over, and emphasizes it particularly in relation to the Schrödinger equation in a way it was not emphasized in anything I’ve read before, providing a few eye-opening fringe benefits to reading this work.
I suspect, however, that this is a book I will return to once I’ve packed a few more tensors under the belt.
“This means something”, I thought to myself, echoing Close Encounters, and then promptly shook off the feeling and went back to feeling inadequate, i.e. reading the book.
I have gotten to a gnarly point where I know enough about physics to wrestle with some very deep, foundational issues, such as Mach’s principle that forms part of the core of this book, and yet I do not know enough physics to grapple with these issues on a direct equations-on-blackboard manner. This leads to mental jiu-jitsu with books such as Barbour’s, written neither for a complete layman, who would, I suspect, quickly become mired in its technical (and philosophical) arguments, yet neither for an expert who would find his “red and blue mist stand for parts of a complex function” allegories annoying and distracting (as I did, knowing a bit of the “ole quannum”).
The idea of the book, that time is an illusion generated by a non-temporal best-match sequencing of 3d “frames” in an all-encompassing configuration space, generally seems solid as an idea, but I have no, heh, idea if the evidence is solid, or if the conjectures are in any way realistic – each part of the book started off very clear, then grew difficult, but understandable, and then slowly, at about the 80% mark, became incomprehensibly complex.
What I definitely did get out of the book and am very grateful for is the hammering-home of the idea of configuration spaces, and the way they are utilized in physical analyses – Barbour returns to this concept over and over, and emphasizes it particularly in relation to the Schrödinger equation in a way it was not emphasized in anything I’ve read before, providing a few eye-opening fringe benefits to reading this work.
I suspect, however, that this is a book I will return to once I’ve packed a few more tensors under the belt.
September 13, 2020
I don't fundamentally agree with this notion of timelessness. I think, if anything what is shown is that the present is pregnant with the structure of its potential future and the memory of its past, and that we are in a perpetual state of becoming in the present, guided by all this structure. With that proviso in mind, I find a lot to agree with and to ponder in this book. A unique perspective and insight on some deep and current problems in theoretical physics. No conforming with standard approaches, he gives his own specific reasons for the views that he holds, although they may often be quite complicated. On that, I would criticise slightly the expression at times of the ideas seems a bit clunky and repetitive of certain points. Still, if you want an honest assessment of where theoretical physics is and where it may potentially be in the future, then this is a good book to go for and will not insult your intelligence like many of the popular science books around that are only interested these days in promoting over simplified narratives for people to conform to on authority and require little deep thought or introspection but give you merely a few gimmicky gotcha style points to attack "non-Scientists" with, with little interest in truth, reality and being reasonable. I point this out here, because I would say I have some bitterness at wasting some years of my life in the past, taking various popular science books to be a genuine and sincere search for the truth of something, when they have become just an industry for giving people comforting lies to stop thought. Julian Barbour is in that rare breed that is free of that industrialised mass produced form of popular science, along with the likes of Roger Penrose and Lee Smolin.
July 26, 2016
Not very convincing. Argument is that space-time doesn’t exist. It is an illusion. Like the sun seeming to orbit the earth. States of the universe exist and seem to order themselves in a temporal sequence. Life may really be more like an event simulation than like a continuous simulation. States move from one quantum state to another quantum state in a quantum “time”. States of existence may be probabilistic (like quantum physics) where the uncertainty is not in knowing what state the system is in but in fact the system is in more than one state simultaneously and one state is detected only in the process of observation (like Schrodinger’s cat, both dead & alive). Many-worlds interpretation: more than one world exists but we are only aware of one world.
April 17, 2023
I don't know how credible the ideas advanced in this book are; I don't suppose more than a few hundred people in the world are actually qualified to give an opinion on that. Dr. Barbour writes very well (his education has clearly ranged far beyond his speciality), and though I did not always agree with him, I enjoyed reading his book and learnt a lot from it, particularly about working with configuration spaces and fun things you can do with the Schrödinger wave equation.
I remain unconvinced of the nonexistence of time.
I remain unconvinced of the nonexistence of time.
March 14, 2013
Julian made a good effort. He sees the problem: that the next big leap will require a leap in mathematics (or some reality-describing language) akin to Newton/Leibniz.
Instead the book gets rambly with descriptions of red or green multidimensional mists.
I am sure Julian could see it in his mind, but he failed to communicate.
It was pretty readable, but taught nothing.
Instead the book gets rambly with descriptions of red or green multidimensional mists.
I am sure Julian could see it in his mind, but he failed to communicate.
It was pretty readable, but taught nothing.
Currently reading
July 17, 2008My x-wife gave me this book in 2002, and I have not had the chance to really read it. Right now I am putting a potential Theory of Everything, and this book was mentioned in the last book I read because it contains a clear idea about how construct a background-independent theory.
September 27, 2018
This is a very important and a very difficult book: important because it aims to persuade us to question the way we perceive reality; difficult because it uses the language of mathematics to do so. If you are not a mathematician or a physicist, therefore, you would at least do well to review your school books. In The End of Time, Julian Barbour, a British mathematician and theoretical physicist, puts forth his theory that it does not exist. He takes pains to assure the lay reader that the math itself will not be completely necessary to understanding, and indeed if one has the patience to persist past inscrutable diagrams and enigmatic equations there is yet much to take away.
A good deal about the history of science is included, from Greek philosopher Heraclitus to Copernicus to Einstein. Some of this history is not widely known about key figures, for example, the quarrel between Newton and Leibniz, the latter with his often mocked notion of “the best of all possible worlds.” The information about how discoveries into the nature of the universe have come about is very helpful in seeing Barbour’s point of view. I was surprised to note how philosophical or even theological questions were so often at the root of inquiries.
We learn that the idea of time being a fabrication is not new; the ancient Greeks debated it. But with science having quarried to the quantum level, where the mechanics of those most infinitesimal particles defies long accepted rules of nature, Barbour argues for a “new revolution in physics,” his subtitle. We need to rethink the foundation of the Newtonian framework of space and time, to question its necessity.
Barbour is courageous, I must say, in attempting to convince us of the nonexistence of time and even of space, being that such a notion of reality challenges our everyday perceptions. He asserts that Newton’s assumptions of absolute time and space became entrenched without adequate examination because the consequent mechanical laws are found to work at observable scales. Now, however, at the quantum scale they do not: particles become waves, influence each other at a distance, occupy two locations simultaneously; effects precede causes.
According to Barbour, physics must now go back and reexamine the foundational concept - the existence of time and space - as it closes in on the ultimate essence of reality, with timelessness increasingly being considered the only solution to the question of quantum weirdness. Barbour sets out to resolve the issues, solve the equations, by eliminating time as a factor, not just at the level of the immeasurably small, but likewise in the universe of quantum cosmology. The laws of nature cannot change at different levels, which fact has been the sticking point in the search for a valid reconciliation of relativity with quantum mechanics - the holy grail of physics since Einstein. Concerning those conundrums springing up at the Planck scale, Barbour suggests that a particle may be seen to become a wave because ultimately the essence of the universe is not particulate, but a matter of wave functions; and where we detect in our large hadron collider that an effect has preceded its cause in defiance of logic, we must suspect that time is not a natural phenomenon but merely an invention. At one level we detect particles, below which are only waves which can appear to be particles; and at one level we perceive a river we call time, while under it is the motionless river bed.
I am not qualified to judge whether Barbour has proven the nonexistence of time, and he admits that timelessness is still theoretical; but I for one and surely many people have an intuitive sense of it. The mere fact that we never actually feel it move is suggestive. His description of a timeless state is thought provoking: a reality of sequential “nows” replacing the river of time, with no past or future, where all being is created in each instant - no big bang. These instants change imperceptibly, leaving twin delusions of the persistence of objects in the short term and the passage of time in the long run. A Buddhist, particularly of the Zen school, would find himself perfectly at home in the strange land Barbour dubs “Platonia,” a timeless place, where infinite and amazing configurations encompass at once the entire potentiality of the universe. That motionless river bed, as I see it, is surely “the path on which there is no coming or going,” the very same revealed by the Buddha, without benefit of math or scientific instrumentation. Buddhism embraces the timeless state of ultimate reality, in which temporal forms come forth from voidness, deluding us as to their substantiality and permanence. Given the congruity, or at least compatibility, of the author’s vision with its precepts, I am very surprised that Buddhism is not even in the index.
Science has long since persuaded us that things are not as our senses perceive them. With the microscope, the telescope, the electron-microscope, the particle accelerator, we know that perception is clearly a matter of scale. That is Barbour’s message in The End of Time. At present we have no access to the ultimate level, to reveal it through experiment. Has he been able to demonstrate it mathematically? I cannot say, but would only observe that the eye cannot see itself. Whatever science may study as an object cannot claim the status of ultimate, simply because it has left the scientist, the observer, outside of it, as in a hall of infinitely reflecting mirrors.
It was a rough slog wading through this book. I did considerable underlining, and will surely be going back to study those sections for years to come. As I attempt to wrap my mind around the fantastical, mind bending concept of timelessness, I envision myself a time capsule on the landscape of Platonia, where the blue mist has settled. Leave it to a Brit to be at once abstruse and fanciful in the same ouvre!
A good deal about the history of science is included, from Greek philosopher Heraclitus to Copernicus to Einstein. Some of this history is not widely known about key figures, for example, the quarrel between Newton and Leibniz, the latter with his often mocked notion of “the best of all possible worlds.” The information about how discoveries into the nature of the universe have come about is very helpful in seeing Barbour’s point of view. I was surprised to note how philosophical or even theological questions were so often at the root of inquiries.
We learn that the idea of time being a fabrication is not new; the ancient Greeks debated it. But with science having quarried to the quantum level, where the mechanics of those most infinitesimal particles defies long accepted rules of nature, Barbour argues for a “new revolution in physics,” his subtitle. We need to rethink the foundation of the Newtonian framework of space and time, to question its necessity.
Barbour is courageous, I must say, in attempting to convince us of the nonexistence of time and even of space, being that such a notion of reality challenges our everyday perceptions. He asserts that Newton’s assumptions of absolute time and space became entrenched without adequate examination because the consequent mechanical laws are found to work at observable scales. Now, however, at the quantum scale they do not: particles become waves, influence each other at a distance, occupy two locations simultaneously; effects precede causes.
According to Barbour, physics must now go back and reexamine the foundational concept - the existence of time and space - as it closes in on the ultimate essence of reality, with timelessness increasingly being considered the only solution to the question of quantum weirdness. Barbour sets out to resolve the issues, solve the equations, by eliminating time as a factor, not just at the level of the immeasurably small, but likewise in the universe of quantum cosmology. The laws of nature cannot change at different levels, which fact has been the sticking point in the search for a valid reconciliation of relativity with quantum mechanics - the holy grail of physics since Einstein. Concerning those conundrums springing up at the Planck scale, Barbour suggests that a particle may be seen to become a wave because ultimately the essence of the universe is not particulate, but a matter of wave functions; and where we detect in our large hadron collider that an effect has preceded its cause in defiance of logic, we must suspect that time is not a natural phenomenon but merely an invention. At one level we detect particles, below which are only waves which can appear to be particles; and at one level we perceive a river we call time, while under it is the motionless river bed.
I am not qualified to judge whether Barbour has proven the nonexistence of time, and he admits that timelessness is still theoretical; but I for one and surely many people have an intuitive sense of it. The mere fact that we never actually feel it move is suggestive. His description of a timeless state is thought provoking: a reality of sequential “nows” replacing the river of time, with no past or future, where all being is created in each instant - no big bang. These instants change imperceptibly, leaving twin delusions of the persistence of objects in the short term and the passage of time in the long run. A Buddhist, particularly of the Zen school, would find himself perfectly at home in the strange land Barbour dubs “Platonia,” a timeless place, where infinite and amazing configurations encompass at once the entire potentiality of the universe. That motionless river bed, as I see it, is surely “the path on which there is no coming or going,” the very same revealed by the Buddha, without benefit of math or scientific instrumentation. Buddhism embraces the timeless state of ultimate reality, in which temporal forms come forth from voidness, deluding us as to their substantiality and permanence. Given the congruity, or at least compatibility, of the author’s vision with its precepts, I am very surprised that Buddhism is not even in the index.
Science has long since persuaded us that things are not as our senses perceive them. With the microscope, the telescope, the electron-microscope, the particle accelerator, we know that perception is clearly a matter of scale. That is Barbour’s message in The End of Time. At present we have no access to the ultimate level, to reveal it through experiment. Has he been able to demonstrate it mathematically? I cannot say, but would only observe that the eye cannot see itself. Whatever science may study as an object cannot claim the status of ultimate, simply because it has left the scientist, the observer, outside of it, as in a hall of infinitely reflecting mirrors.
It was a rough slog wading through this book. I did considerable underlining, and will surely be going back to study those sections for years to come. As I attempt to wrap my mind around the fantastical, mind bending concept of timelessness, I envision myself a time capsule on the landscape of Platonia, where the blue mist has settled. Leave it to a Brit to be at once abstruse and fanciful in the same ouvre!
April 18, 2020
Interesting concept of timelessness dissected from physics. Barbour thesis is similar to Bergsonian qualitative multiplicity in time. However, the book is dry and repetitive in describing the notion that time does not exist, which according to Barbour what we call time is a simply complex of rules that govern the change (which again, similar to the critique raised by Bergson, what he called quantitative multiplicity).
April 27, 2022
Absolutely wonderful book. I read it for my high school thesis on the end of the universe and I found it to be very approachable by people with some minor knowledge in astrophysics. It may be a bit too advanced for a first times, but it is truly mesmerising.
May 17, 2009
I am very interested in sorting out the nature of "time" - is time a fundamental dimension? was there an absolute time=0? will it go on to infinity? The idea that time will go to infinity, that the universe will plod on forever really bothers me. It seriously makes me sick to my stomach. This is regardless of my thoughts on death...it bothers me whether I'll be relaxing in heaven or my spirit ceases to exist or I enjoy becoming parts of future trees and animals. I'm not sure that the world "ending" (time not going to infinity) would make things any better. But I think I'm hoping for something along the lines that time is an illusion that we experience, but that really we are in some sort of timeless universe. This I believe is the argument made in this book, "The End of Time".
Much of the book is a brief history of physics, highlighting the treatment of time and space in physics theories through the past few centuries. It raises lots of interesting perspectives and puzzles regarding. I found this review very interesting and educational - especially since I had to learn much of this in school but hadn't really put it all in perspective (just solved formulas). I could generally follow Newtonian physics and Einstein's relativity. Then it got into quantum physics and I could only somewhat grasp matters. Unfortunately quantum physics is crucial to Barbour's time-independent physics framework, and so I could not really get a firm grasp of his theory. Sounded interesting though!
If I could ever use a book club it would be for this book. I need someone to walk me through the last few chapters! If anyone has any further reading recommendations (or deep thoughts to share) on this topic please let me know!
Much of the book is a brief history of physics, highlighting the treatment of time and space in physics theories through the past few centuries. It raises lots of interesting perspectives and puzzles regarding. I found this review very interesting and educational - especially since I had to learn much of this in school but hadn't really put it all in perspective (just solved formulas). I could generally follow Newtonian physics and Einstein's relativity. Then it got into quantum physics and I could only somewhat grasp matters. Unfortunately quantum physics is crucial to Barbour's time-independent physics framework, and so I could not really get a firm grasp of his theory. Sounded interesting though!
If I could ever use a book club it would be for this book. I need someone to walk me through the last few chapters! If anyone has any further reading recommendations (or deep thoughts to share) on this topic please let me know!
January 18, 2020
Czy czas nie jest największą iluzją, którą stworzył człowiek wykorzystując jego walory do porządkowania świata? Pytanie to można rozważać na kilku poziomach, szczególnie intensywnie po ludzku - egzystencjalnie i fizycznie - jako element podstawowej struktury rzeczywistości. Być może jest tak, jak dowcipnie podsumował John Wheeler: "Czas jest sposobem, w jaki natura zapobiega temu, aby wszystko działo się naraz."
Julian Barbour to słynny dysydent akademicki, który prowadzi badania nad fizyką fundamentalną poza głównym nurtem. Mieszka na angielskiej wsi, tak 'między ogrodem i muzyką klasyczną' (polecam dokument przygotowany dla 'Polityki', który jest głównie wywiadem, jaki przeprowadził z nim Karol Jałochowski). Barbour całe swoje życie intelektualne poświęcił na wykazanie, że czas jest wtórną koncepcją, która pojawia się, jako konsekwencja głębszych prawd o fizykalnej rzeczywistości, stając się zaledwie pomocnym narzędziem do opisu świata. "Koniec czasu. Nowa wizja rewolucji w fizyce" jest podsumowaniem dociekań Barboura, taką próbą popularnego pozbierania w jednym miejscu najważniejszych jego przekonań związanych z czasem. Książka, choć wydana w oryginale w 1999, ukazując się po polsku po niemal dwóch dekadach, nie straciła na aktualności.
Fizyk w książce zawarł wiele idei, które zbudowały w jego umyśle wizję świata bezczasowego i w konsekwencji skłoniły go do zanegowania istnienia ruchu, który traktuje, jako iluzję. Do takich wniosków doprowadziła go stworzona konstrukcja wielowymiarowej przestrzeni konfiguracyjnej, która jest areną wszystkich możliwych stanów cząstek Wszechświata (analizowany przykład oparł na 3-wymiarowej przestrzeni, wprowadzony na stronach 72-84), a którą nazwał Platonią. Właściwie cała książka, jest próbą wykazania, że zarówno język klasycznej fizyki (teorii względności Einsteina) jak i tej kwantowej, da się zastąpić tworami Platonii, a czas jest swoistym epifenomenem wyłaniającym się z analiz zachowania elementów tej struktury (str. 225):
"Ważną rzecz jest jednak to, aby uwolnić się od podejścia, że czas jest 'czymś'. Czas nie istnieje. Wszystko, co istnieje, to obiekty, które ulęgają zmianom. To, co nazywamy czasem jest - przynajmniej w fizyce klasycznej - po prostu zespołem praw rządzących tymi zmianami."
Powyższy sąd jest odważną deklaracją autora, którą fizycy zbyliby milczeniem, jeśli Barbour zawiesiłby dalsze sądy i wnioski jakościowe i ilościowe, bo wtedy byłaby to wyłącznie filozoficzna emfaza. Jednak on zbudował na tej idei model fizyczno-matematyczny, który można weryfikować na kilku poziomach. Ostatecznie dominujący nurt fizyków podchodzi bardzo sceptycznie do różnych elementów wizji Barboura. Główne zarzuty większości środowiska skupiają się na wykazaniu, że model jego jest niefalsyfikowany i operacyjnie pozbawiony dodatkowej predykcji, którą posiadają już 'standardowe teorie fizyczne'. Większość tych krytycznych uwag można wyczytać z załączonej na końcu (str. 563-567) rozmowy z fizyczką Fay Dowker. Hipotezy Barboura traktowane są, co najwyżej, jako jedna z prób zbudowania kwantowej grawitacji.
To, czym mnie Barbour najbardziej zaciekawił, poza pewnymi nieszablonowymi detalami związanymi z przestrzenią konfiguracyjną, było wnikliwą opowieścią o historii fizyki i pewną niewysłowioną jawnie tęsknotą zmierzającą w kierunku pozbywania narracji o świecie, na najbardziej podstawowym poziomie, elementów wtórnych. Barbour pokazał, jak rozumienie rzeczywistości i zjawisk ją tworzących zdeterminował Newton i jego absolutny czas i przestrzeń. Opisał rewolucję Einsteina, która te absolutne przymioty usunęła, ale jednocześnie 'zafiksowała' fizyków na myślenie o podstawowym elemencie świata, czyli czasoprzestrzeni, jako czymś oczywistym. Wrócił do idei Macha i pytań o bezwładność i sens uwzględnienia oddziaływania całego Wszechświata na lokalne zjawiska. Zaczerpnął z pewnych idei Schrödingera o stanach stacjonarnych i równań Wheelera-De Witta, by rozwijając myśl Johna Bella i idee Hugha Everatta związane z wieloświatem, nałożyć na Platonię kwantowe funkcje prawdopodobieństwa.
Atrakcyjność koncepcji bezczasowego Wszechświata w ujęciu Barboura polega według mnie na tym, że sporo zjawisk, które wyjaśnia fizyka kwantowa czy teoria Einsteina, udało mu się wpisać w Platonię - konstrukcję bez czasu. Projekt nie jest zakończony i wymaga wielu dalszych badań. Fizyk jest niewątpliwie marzycielem z bardzo wysublimowanym poczuciem estetyki. Ostatni rozdział "Życie bez czasu", to bardzo piękna miniaturka zbierająca wszystkie jego fascynacje światem przyrody, poezji, malarstwa, fizyki i matematyki. Dogłębna znajomość literatury, włącznie z rosyjską, której jest tłumaczem (twierdzi, że przetłumaczył na angielski 80 milionów słów z rosyjskiej literatury), pomogła mu w opisaniu sensu zawiłych równań fizyki matematycznej poprzez analogie malarskie (przydatne w wywodzie okazały się prace Williama Turnera, szczególnie obraz "Burza śnieżna", jako przykład zamrożonej w czasie jednej klatki konfiguracji Platonii). Postarał się na wielostronne, i trafiające do różnych odbiorców, analogie by wszystkim umożliwić odnalezienie się w zawiłościach fizyki współczesnej. Tak było na przykład, gdy przytoczył i skomentował piękne słowa Tennessee Williamsa (str. 531):
"Williams kontynuuje: ^Wyrywanie wieczności z rozpaczliwej ulotności jest wielką magiczną sztuczką ludzkiej egzystencji.^ To prawda, choć nie jest to magiczna sztuczka, tylko po prostu otwarcie naszych oczu."
Barbour starał się treść książki przystosować do szerokiego grona odbiorców. To udało mu się częściowo. Pewne partie (sama przestrzeń konfiguracyjna, idee Macha, zasada najmniejszego działania czy wykazywanie liczby niezbędnych stopni swobody w układach kilku-wymiarowej Platonii) mogą być dość niezrozumiałe czy zbyt trudne przy pierwszym czytaniu. Na szczęście spore fragmenty, w szczególności opis podstawowych praw mechaniki kwantowej, wypadły świetnie dydaktycznie, również dzięki licznym literackim analogiom. Czytelnicy prac Rogera Penrose'a będą intelektualnie usatysfakcjonowani.
Gorąco polecam wszystkim - może na raty, z przerwami. Myślę, że warto, bo Barbour ma nam coś ciekawego do przekazania, choć może się ostatecznie po ludzku mylić. Czas pokaże.
DOBRA - 6.5/10
Julian Barbour to słynny dysydent akademicki, który prowadzi badania nad fizyką fundamentalną poza głównym nurtem. Mieszka na angielskiej wsi, tak 'między ogrodem i muzyką klasyczną' (polecam dokument przygotowany dla 'Polityki', który jest głównie wywiadem, jaki przeprowadził z nim Karol Jałochowski). Barbour całe swoje życie intelektualne poświęcił na wykazanie, że czas jest wtórną koncepcją, która pojawia się, jako konsekwencja głębszych prawd o fizykalnej rzeczywistości, stając się zaledwie pomocnym narzędziem do opisu świata. "Koniec czasu. Nowa wizja rewolucji w fizyce" jest podsumowaniem dociekań Barboura, taką próbą popularnego pozbierania w jednym miejscu najważniejszych jego przekonań związanych z czasem. Książka, choć wydana w oryginale w 1999, ukazując się po polsku po niemal dwóch dekadach, nie straciła na aktualności.
Fizyk w książce zawarł wiele idei, które zbudowały w jego umyśle wizję świata bezczasowego i w konsekwencji skłoniły go do zanegowania istnienia ruchu, który traktuje, jako iluzję. Do takich wniosków doprowadziła go stworzona konstrukcja wielowymiarowej przestrzeni konfiguracyjnej, która jest areną wszystkich możliwych stanów cząstek Wszechświata (analizowany przykład oparł na 3-wymiarowej przestrzeni, wprowadzony na stronach 72-84), a którą nazwał Platonią. Właściwie cała książka, jest próbą wykazania, że zarówno język klasycznej fizyki (teorii względności Einsteina) jak i tej kwantowej, da się zastąpić tworami Platonii, a czas jest swoistym epifenomenem wyłaniającym się z analiz zachowania elementów tej struktury (str. 225):
"Ważną rzecz jest jednak to, aby uwolnić się od podejścia, że czas jest 'czymś'. Czas nie istnieje. Wszystko, co istnieje, to obiekty, które ulęgają zmianom. To, co nazywamy czasem jest - przynajmniej w fizyce klasycznej - po prostu zespołem praw rządzących tymi zmianami."
Powyższy sąd jest odważną deklaracją autora, którą fizycy zbyliby milczeniem, jeśli Barbour zawiesiłby dalsze sądy i wnioski jakościowe i ilościowe, bo wtedy byłaby to wyłącznie filozoficzna emfaza. Jednak on zbudował na tej idei model fizyczno-matematyczny, który można weryfikować na kilku poziomach. Ostatecznie dominujący nurt fizyków podchodzi bardzo sceptycznie do różnych elementów wizji Barboura. Główne zarzuty większości środowiska skupiają się na wykazaniu, że model jego jest niefalsyfikowany i operacyjnie pozbawiony dodatkowej predykcji, którą posiadają już 'standardowe teorie fizyczne'. Większość tych krytycznych uwag można wyczytać z załączonej na końcu (str. 563-567) rozmowy z fizyczką Fay Dowker. Hipotezy Barboura traktowane są, co najwyżej, jako jedna z prób zbudowania kwantowej grawitacji.
To, czym mnie Barbour najbardziej zaciekawił, poza pewnymi nieszablonowymi detalami związanymi z przestrzenią konfiguracyjną, było wnikliwą opowieścią o historii fizyki i pewną niewysłowioną jawnie tęsknotą zmierzającą w kierunku pozbywania narracji o świecie, na najbardziej podstawowym poziomie, elementów wtórnych. Barbour pokazał, jak rozumienie rzeczywistości i zjawisk ją tworzących zdeterminował Newton i jego absolutny czas i przestrzeń. Opisał rewolucję Einsteina, która te absolutne przymioty usunęła, ale jednocześnie 'zafiksowała' fizyków na myślenie o podstawowym elemencie świata, czyli czasoprzestrzeni, jako czymś oczywistym. Wrócił do idei Macha i pytań o bezwładność i sens uwzględnienia oddziaływania całego Wszechświata na lokalne zjawiska. Zaczerpnął z pewnych idei Schrödingera o stanach stacjonarnych i równań Wheelera-De Witta, by rozwijając myśl Johna Bella i idee Hugha Everatta związane z wieloświatem, nałożyć na Platonię kwantowe funkcje prawdopodobieństwa.
Atrakcyjność koncepcji bezczasowego Wszechświata w ujęciu Barboura polega według mnie na tym, że sporo zjawisk, które wyjaśnia fizyka kwantowa czy teoria Einsteina, udało mu się wpisać w Platonię - konstrukcję bez czasu. Projekt nie jest zakończony i wymaga wielu dalszych badań. Fizyk jest niewątpliwie marzycielem z bardzo wysublimowanym poczuciem estetyki. Ostatni rozdział "Życie bez czasu", to bardzo piękna miniaturka zbierająca wszystkie jego fascynacje światem przyrody, poezji, malarstwa, fizyki i matematyki. Dogłębna znajomość literatury, włącznie z rosyjską, której jest tłumaczem (twierdzi, że przetłumaczył na angielski 80 milionów słów z rosyjskiej literatury), pomogła mu w opisaniu sensu zawiłych równań fizyki matematycznej poprzez analogie malarskie (przydatne w wywodzie okazały się prace Williama Turnera, szczególnie obraz "Burza śnieżna", jako przykład zamrożonej w czasie jednej klatki konfiguracji Platonii). Postarał się na wielostronne, i trafiające do różnych odbiorców, analogie by wszystkim umożliwić odnalezienie się w zawiłościach fizyki współczesnej. Tak było na przykład, gdy przytoczył i skomentował piękne słowa Tennessee Williamsa (str. 531):
"Williams kontynuuje: ^Wyrywanie wieczności z rozpaczliwej ulotności jest wielką magiczną sztuczką ludzkiej egzystencji.^ To prawda, choć nie jest to magiczna sztuczka, tylko po prostu otwarcie naszych oczu."
Barbour starał się treść książki przystosować do szerokiego grona odbiorców. To udało mu się częściowo. Pewne partie (sama przestrzeń konfiguracyjna, idee Macha, zasada najmniejszego działania czy wykazywanie liczby niezbędnych stopni swobody w układach kilku-wymiarowej Platonii) mogą być dość niezrozumiałe czy zbyt trudne przy pierwszym czytaniu. Na szczęście spore fragmenty, w szczególności opis podstawowych praw mechaniki kwantowej, wypadły świetnie dydaktycznie, również dzięki licznym literackim analogiom. Czytelnicy prac Rogera Penrose'a będą intelektualnie usatysfakcjonowani.
Gorąco polecam wszystkim - może na raty, z przerwami. Myślę, że warto, bo Barbour ma nam coś ciekawego do przekazania, choć może się ostatecznie po ludzku mylić. Czas pokaże.
DOBRA - 6.5/10
March 10, 2009
I have mixed feelings about this book. His idea that there is no such thing as time and that this insight will unify physics is really, really impressive. It makes sense once you wrap your brain around it and can really change world outlook. However, he has a huge problem getting where he's going. He makes these incredibly intuitive leaps without explaining why until later and then by then we've forgotten exactly where he was going. I like what he had to say, I wish it had been better structured and better explained.
The idea that each moment or "Now" as Barbour calls them, is actually a configuration of particles that may include in it a history of those moments "before" (e.g. the configuration of your brain that "remembers" what you had for breakfast that morning) and that configurations with histories are astronomically more likely than those without was an amazing insight and really made me think. Unfortunately, I didn't gather that until I was deep into the second to last chapter. That illustrates perfectly my issues with this book.
The idea that each moment or "Now" as Barbour calls them, is actually a configuration of particles that may include in it a history of those moments "before" (e.g. the configuration of your brain that "remembers" what you had for breakfast that morning) and that configurations with histories are astronomically more likely than those without was an amazing insight and really made me think. Unfortunately, I didn't gather that until I was deep into the second to last chapter. That illustrates perfectly my issues with this book.
September 23, 2013
The author puts forth the theory that time is just an illusion and does not exist. According to this idea, all events
are just a series of "nows" that our minds string together as a movie, giving us the illusion of time moving forward.
As I understand it, each "now" is like a parallel/different world (or analogous to a different/parallel world) along the
lines of Everett's 'many-worlds hypothesis'.
Getting into a little more (technical) detail, Barbour seems to believe that the universe is governed by static quantum
cosmology that is governed by the static (time-independent) Schroedinger equation or a static Wheeler-Dewitt type equation,
"which may have one or many solutions, and that each of its well-behaved solutions concentrates its probability density on
time capsules".
At least at a human common-sense instinctual level, it's hard to believe that we are living in a timeless universe, and Barbour's theory
is not accepted by the physics community at large ...
are just a series of "nows" that our minds string together as a movie, giving us the illusion of time moving forward.
As I understand it, each "now" is like a parallel/different world (or analogous to a different/parallel world) along the
lines of Everett's 'many-worlds hypothesis'.
Getting into a little more (technical) detail, Barbour seems to believe that the universe is governed by static quantum
cosmology that is governed by the static (time-independent) Schroedinger equation or a static Wheeler-Dewitt type equation,
"which may have one or many solutions, and that each of its well-behaved solutions concentrates its probability density on
time capsules".
At least at a human common-sense instinctual level, it's hard to believe that we are living in a timeless universe, and Barbour's theory
is not accepted by the physics community at large ...
February 16, 2013
A shattering work that challenges the key discovery of the 20th century: whether time is a hard function in the theory of relativity. if not then time itself is relative. unearthing less commonly known theories discovered in parallel to einstein, barbour dissects his arguments carefully then speculates madly. both gestures not only appear valid, but probably more scientifically stable than relativity's highly unstable spawn: quantum dynamics. barbour makes the case for restating the quantum as solely mechanical. remember: Einstein never fully bought quantum because it never plugged into time easily. Barbour explains a path from this confusion into what might be the fundamental wool being lifted from everyone's eyes. time travel in in no way possible. Only something called 'now' travel.
August 29, 2014
Very instructive in teaching the reader about the many different ways one can view time in physics as well as the notion of an absolute and relative universe. Barbour gives us the basics of what we need to know to understand the basics of his theory that time is really an illusion. If that sounds like nebulous hippie-dippie nonsense to you, reading this book will convince you otherwise, because there's nothing like that in there -- Barbour supports his theory with sound logic, which is what makes the book impressive.
Only four stars because the book could be better about describing the implications of his theory, and I was left with a lot of questions he did not answer.
Only four stars because the book could be better about describing the implications of his theory, and I was left with a lot of questions he did not answer.
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