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One of our foremost thinkers and public intellectuals offers a radical new view of the nature of time and the cosmos. The fact that time is real may seem obvious. You experience it passing every day when you watch clocks tick, bread toast, and children grow. But most physicists see things differently, from Newton to Einstein to today’s quantum theorists. For them, time isn’ One of our foremost thinkers and public intellectuals offers a radical new view of the nature of time and the cosmos. The fact that time is real may seem obvious. You experience it passing every day when you watch clocks tick, bread toast, and children grow. But most physicists see things differently, from Newton to Einstein to today’s quantum theorists. For them, time isn’t real. You may think you experience time passing, but they say it’s just an illusion. Lee Smolin, author of the controversial bestseller The Trouble with Physics, argues this limited notion of time is holding physics back. It’s time for a major revolution in scientific thought. The reality of time could be the key to the next big breakthrough in theoretical physics. What if the laws of physics themselves were not timeless? What if they could evolve? Time Reborn offers a radical new approach to cosmology that embraces the reality of time and opens up a whole new universe of possibilties. There are few ideas that, like our notion of time, shape our thinking about literally everything, with major implications for physics and beyond—from climate change to the economic crisis. Smolin explains in lively and lucid prose how the true nature of time impacts our world.


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One of our foremost thinkers and public intellectuals offers a radical new view of the nature of time and the cosmos. The fact that time is real may seem obvious. You experience it passing every day when you watch clocks tick, bread toast, and children grow. But most physicists see things differently, from Newton to Einstein to today’s quantum theorists. For them, time isn’ One of our foremost thinkers and public intellectuals offers a radical new view of the nature of time and the cosmos. The fact that time is real may seem obvious. You experience it passing every day when you watch clocks tick, bread toast, and children grow. But most physicists see things differently, from Newton to Einstein to today’s quantum theorists. For them, time isn’t real. You may think you experience time passing, but they say it’s just an illusion. Lee Smolin, author of the controversial bestseller The Trouble with Physics, argues this limited notion of time is holding physics back. It’s time for a major revolution in scientific thought. The reality of time could be the key to the next big breakthrough in theoretical physics. What if the laws of physics themselves were not timeless? What if they could evolve? Time Reborn offers a radical new approach to cosmology that embraces the reality of time and opens up a whole new universe of possibilties. There are few ideas that, like our notion of time, shape our thinking about literally everything, with major implications for physics and beyond—from climate change to the economic crisis. Smolin explains in lively and lucid prose how the true nature of time impacts our world.

29 review for Time Reborn: From the Crisis in Physics to the Future of the Universe

  1. 4 out of 5

    Manny

    The sense of beauty leads us astray. - James Joyce, UlyssesPhysics is in a strange state right now. On the surface, things may seem to be going well; the elusive Higgs particle was detected for the first time last year, and there are interesting signs that we may soon discover what dark matter is made of. But on the truly fundamental issues, there has been little progress. Three items in particular stand out. First, our two central theories, quantum mechanics and General Relativity, are each very The sense of beauty leads us astray. - James Joyce, UlyssesPhysics is in a strange state right now. On the surface, things may seem to be going well; the elusive Higgs particle was detected for the first time last year, and there are interesting signs that we may soon discover what dark matter is made of. But on the truly fundamental issues, there has been little progress. Three items in particular stand out. First, our two central theories, quantum mechanics and General Relativity, are each very successful on their own, but not compatible with each other. Second, there is no good explanation for the fact that all the physical constants of our universe appear to be finely tuned to make life possible. Third, and perhaps most embarrassing of all, no one can convincingly explain the presence of an arrow of time. People have different strategies for dealing with these questions. Here in Geneva, the de facto physics capital of the world, the most common approach is simply to ignore them. T, who's just published some excellent papers in his speciality, is unconcerned when he comes to dinner the other day. "Cosmology isn't physics," he says. "Physics is about things I can put in a teaspoon." "What about stars?" I ask. I know that some astrophysicists are interested in T's work. T waves away my objections; evidently, he is talking about a fairly large teaspoon. The point he wants to make is that you can't put the whole universe in a teaspoon, even in principle. T isn't worried about questions that have to do with the whole universe. They are none of his business. I have read several books over the last few years by people who have a different take on these issues. Paul Davies, Martin Rees and Leonard Susskind, for example, argue that there might well be more universes than the one we see around us. Perhaps there could even be an infinite number of them, all with very different properties. In that case, things are not as mysterious as they first appear. Everything imaginable happens in some universe, and in a few of them the numbers have worked out just right to produce the complex, highly structured world we see around us, in which there is a clear progression from past to future. Some of these people have produced detailed theoretical scenarios explaining how the other universes might have come to be; Susskind's The Cosmic Landscape describes one of the most popular versions. There is, however, the problem that we can't see any direct evidence of these other worlds, and no one is able to suggest experiments that could determine whether or not they exist. As followers of Karl Popper say, it is not clear that the theory is falsifiable. Susskind replies that he is unconcerned by this criticism: he is more worried that people will reject the right theory for nit-picking methodological reasons. But if your theories aren't falsifiable, are you still doing science? Susskind says he is. Other people are less sure. Helge Kragh, the eminent Danish historian of science, has been a particularly vocal critic. If many physicists are refusing even to think about the fundamental problems and others are addressing them in a way which is often claimed to be contrary to the principles of science, it's reasonable to say that the field is in crisis. Smolin, a cutting-edge theoretician with a broad range of interests, has been telling us this for some time. In his 2006 book, The Trouble with Physics , his emphasis was on sociology: he warned that research was focusing too much on string theory, which quite likely wasn't going to deliver, and argued that an attack on a broader front was required. In his new book, the point of view is more that of philosophy. He wants to reexamine the underlying assumptions and see if they need replacing. He thinks this is necessary: right now, as he puts it, people are trying to market things as science which in fact are radical metaphysical fantasies. To start with, one of his absolute demands is falsifiability. Two themes in particular dominate the book; one, as the title suggests, is time, and the other is physical law. Smolin argues that there is a deep connection between them. In the picture of science which many scientists use without even reflecting on what they are doing, physical laws are mathematical objects. They do not form part of our everyday existence, but live in an eternal, Platonic world of abstract entities. Yet somehow these abstractions are supposed to be intimately linked to our "real" world. I thought his analysis was insightful, and helps explain why science is so often compared with religion. A scientist who subscribes to the Platonic picture is not in fact that far from being a kind of priest. He probably doesn't believe in God (most scientists don't), but he still claims to be able to mediate between our world and the eternal world of mathematics. There is a major difference between the world we experience and the Platonic world. For us, things are constantly changing; the eternal world is frozen in a single moment. But this is exactly where science has scored its greatest victory. Starting with Galileo, scientists have found ways to conceptualize time as space. Smolin starts with the trivial example of someone throwing a ball, and considers how this can (apparently) be captured as the parabola the ball follows. The dynamic experience of watching the ball fly through the air is replaced by a static curve, or even better by the equation describing that curve. Newton extended the picture further, and Einstein completed it. Relativity fuses space and time together into the single concept of space-time. It is all very beautiful, and Smolin, who says his first exposure to real science was reading Einstein, is particularly receptive to its beauty. But, he explains, you just don't seem to be able to progress any further once you accept Einstein's "block-universe" view. He argues that something has gone wrong, and we need to backtrack; from there, he goes on to outline the daring research program that he and his collaborators have been pursuing. First, he wants to put time center stage, and say that it really does exist in its own right. This means doing something we have been taught for a century to believe is wrong, and claiming that an absolute notion of time exists, in other words that there is a universal time according to which it is meaningful for distant events to be simultaneous. Second, and even more heretically, he wants to abolish the special status of physical laws. They will no longer be inhabitants of the Platonic world, but just part of our normal world, subject to change like everything else. He spends rather more than half of the book sketching out this framework in fair detail. I would like to say that I was immediately attracted by the elegance of the scheme, but that would not be true. I am in fact shocked. It looks ugly, and it is very much at odds with most of the science I know. However, as the great chess master Aron Nimzowitsch used to say, the beauty of a move lies not in its appearance, but in the thought behind it. One of Einstein's basic principles, which led him to General Relativity, was that anything which acts must itself be acted on. In his case, he argued that, since space acts on matter, matter must act on space. At the time, this must have seemed crazy to many people, but now it makes perfect sense. The idea that physical laws are mutable just takes the idea a step further. And if physical laws can change, it is reasonable to argue that time needs to play a more central role; then one can go further, as Smolin does, to talk about how the laws of nature could gradually evolve over time to look like the ones we now see around us. So I have mixed feelings about the book. My instinctive reaction is that it will probably be shown to be wrong. But that's exactly why it's science: it makes falsifiable predictions. Smolin's main competitor, the multiverse theory, is in no danger of being disproved, since the other universes aren't observable. No wonder it initially seems more attractive. And Smolin evidently knows all the angles. He's not doing this because he likes craziness; he's doing it because he's tried the obvious ideas, and they don't work. To conclude, the thing I am most struck by in Time Reborn is that it suggests we have reached a boundary in science. Basically, Smolin agrees with our friend T. He says that science, as we know it today, is about things you can put in teaspoons - possibly very large teaspoons, but still teaspoons. If we want to make progress on the issues currently baffling us, which concern the whole universe, we need to figure out a way of doing science that represents a fundamental break with what has gone before. Maybe it's not possible. Maybe we've come as far as we can, and the remaining questions are simply outside the scope of scientific inquiry. But if they are things that people can understand at all, it seems plausible that the answers will be something like what Smolin presents here; perhaps not specifically this idea, but something equally bold and different. It's fascinating to read a status report from these fearless explorers on the absolute limits of human knowledge.

  2. 4 out of 5

    Manuel Antão

    If you're into stuff like this, you can read the full review. Shitty Philosophy and Physics : “Time Reborn - From the Crisis in Physics to the Future of the Universe” by Lee Smolin “I propose that time and its passage are fundamental and real and the hopes and beliefs about timeless truths and timeless realms are mythology.” In “Time Reborn - From the Crisis in Physics to the Future of the Universe” by Lee Smolin     Impermanence, Buddhist style?   Buddhism seems to acknowledge the play of opposites I' If you're into stuff like this, you can read the full review. Shitty Philosophy and Physics : “Time Reborn - From the Crisis in Physics to the Future of the Universe” by Lee Smolin “I propose that time and its passage are fundamental and real and the hopes and beliefs about timeless truths and timeless realms are mythology.” In “Time Reborn - From the Crisis in Physics to the Future of the Universe” by Lee Smolin     Impermanence, Buddhist style?   Buddhism seems to acknowledge the play of opposites I've referred to elsewhere. Recognising the yin-yang nature of the universe, in order to claim there is constant 'flux' (fluidity, rather than change; a subtle difference) - or for argument's sake, change - Buddhists balance that by asserting a 'greater' reality - the one, eternal, stable, whole (a supposed 'deeper' reality).   Contradiction and paradox is near the heart of evidenced, reasoned contemplation?   As for Aristotle: time is a measurement of change is a measurement of time. Change makes time possible, and vice-versa. In principle, it seems that time persists, even in conditions of perfect stillness. Yet any attempt to conceive a temporal progression, absent all change, seems to lead us into perplexing self-contradictions: any attempt to imagine how such unchanging time-flow could be measured, requires changing. It seems that time must be more than change; yet remove change, and time vanishes!  But if time is just a means to measure change, then in principle, it should permit the possibility of a world where change is cyclical. Yet our understanding seems to limit time to a linear, one way progression.   Or does it?     If you're into shitty physics, read on.

  3. 4 out of 5

    Brian Clegg

    As I write this we are a third of the way through 2013 (time is important here) and I can say with hand on heart this is the best popular science book I have read all year. Lee Smolin’s book is largely accessible (more on this later) and simply mind-boggling in its scope. What he does here is take on time, and specifically the position of time in physics. Even taken as a simple book on time this is brilliant. The fact is, the majority of books that claim to be about time tell you nothing. It’s st As I write this we are a third of the way through 2013 (time is important here) and I can say with hand on heart this is the best popular science book I have read all year. Lee Smolin’s book is largely accessible (more on this later) and simply mind-boggling in its scope. What he does here is take on time, and specifically the position of time in physics. Even taken as a simple book on time this is brilliant. The fact is, the majority of books that claim to be about time tell you nothing. It’s striking that A Brief History of Time tells us that amongst a list of deep scientific questions that have answers suggested by ‘Recent breakthroughs in physics, made possible in part by fantastic new technologies’, is ‘What is the nature of time?’ But you can search the book from end to end for any suggestion of what time is or how it works. There is plenty on how we observe time, and how interaction with matter can change these observations, but nothing deeper. Smolin gives what is, for me, the best analysis of the nature of time from a physics viewpoint in a popular science book I have ever seen. He goes on to describe how most physicists consider that ‘time does not exist’, and comes up with an approach where time becomes real in physics. Now I do have one issue with Smolin here. He says that amongst his non-scientific friends ‘the idea that time is an illusion is a… commonplace.’ This is garbage (or at least his friends are non-representative). The vast majority of people who aren’t physicists or philosophers would say ‘Of course time exists.’ However, Smolin sets off to first persuade us it doesn’t, using the most common arguments of current physics, and then to show how this is a mistake. In fact, I think the reason most people wouldn’t agree is because it isn’t really true that modern physics says time doesn’t exist. What it says is that the idea of time as a moving present that heads from the past into the future isn’t real, and that there are plenty of concepts in physics like natural laws that appear to be outside of time, and so time isn’t as fundamental as people think. Nor, relativity shows us, is it absolute. This isn’t the same as something not existing or being an illusion, and I think the physicists who use this label have spent too much time talking to philosophers. Dogs aren’t fundamental to the laws of physics, but this doesn’t mean they don’t exist. Nonetheless, current mainstream physics does prefer time to be kept in a box – and this is where Smolin breaks out. He shows us that pretty well all of physics is based on the idea that we are dealing with closed systems, where in reality there is no so such thing – meaning that it is quite possible that pretty well all existing physics is just an approximation. And he comes up with a mechanism where time, something that actually ticks by and has a universal meaning, can exist (though at the expense of space being quite so real as we thought). In doing this, Smolin will have irritated a whole lot of physicists. Some will simply not agree – any string theorists, for example, would dismiss his loop quantum gravity viewpoint. Many others will simply not be able to cope. Physicists are, on the whole, a fairly conservative bunch (with a small ‘c’) – they aren’t very good at coming with radical shifts in viewpoint like this. Of course this doesn’t make Smolin right, but it is a fascinating bit of speculation. The book isn’t perfect. Smolin’s writing style is workmanlike, but suffers from too academic a viewpoint – he doesn’t have the common touch. Oddly, it’s not so much that he baffles us with science, but rather he baffles us with labels which don’t have enough science attached. He has a tendency to use terminology and then say effectively ‘but you don’t need to know what that’s all about.’ I think popular science is much better if you avoid the jargon and instead explain what lies beneath. Also he uses really scrappy hand-drawn illustrations that I suspect are supposed to make them look more friendly and approachable, but actually makes them practically incomprehensible. These are minor moans though. Whether or not you agree with the physics, this is a book to get you thinking, awash with ideas and totally fascinating. It isn’t the easiest popular science book to understand – it is very much of the ‘read each sentence slowly, and some times several times’ school, yet it is a superb contribution to the field that really puts that cat among the pigeons. Three cheers for Lee Smolin who is, for me, apart from lacking that common touch, the nearest thing we have in the present day to the late, great Fred Hoyle. Review first published on www.popularscience.co.uk and reproduced with permission

  4. 5 out of 5

    Gendou

    There is something essential about the Now which is just outside the realm of science. Smolin argues that time is real, because he experiences it, as a sequence of moments. He claims this is evidence not accounted for in the standard Newtonian paradigm (i.e. Plato's timeless mathematical world). He lumps both Quantum Mechanics and General Relativity under this paradigm, and, as it happens, ALL mathematical models that have time written down as a coordinate system! Throughout the book, Smolin e There is something essential about the Now which is just outside the realm of science. Smolin argues that time is real, because he experiences it, as a sequence of moments. He claims this is evidence not accounted for in the standard Newtonian paradigm (i.e. Plato's timeless mathematical world). He lumps both Quantum Mechanics and General Relativity under this paradigm, and, as it happens, ALL mathematical models that have time written down as a coordinate system! Throughout the book, Smolin employs the Leibniz's Principle of Sufficient Reason, over and over. He doesn't seem to realize that this principle is the undoing of his central argument. This principle states, "For every proposition P, if P is true, then there is a sufficient explanation for why P is true." Neuroscience provides a sufficient explain, based on the "timeless" physical laws of chemistry, to explain how people experience time as a succession of moments. Namely, time is governed by the firings of brain neurons, regulated by the accumulation and then purging of charged ions called neurotransmitters. This is a type of clock, not unlike any mechanical clock, and gives rise to the subjective experience of the passage of time. No dualism required. Here in the real world, it is always some time, some present moment. No mathematical object can have this particularity, because, once constructed, mathematical objects are timeless. Smolin spends much of the book addressing and attempting to dispel the myth that time is an illusion. I see this as him sinking down to a base, impatient philosophy. There is this strange, unscientific view that things are either "real" or "emergent" which plagues physics. In truth, a thing can be equally real, regardless of wether it happens to be emergent or fundamental. In quantum physics, the word "real" means it observed to happen 100% of the time. In metaphysics, a component of nature is "real" only in context of a theoretical framework. Theories can remain viable, to the point that we accept them as true, but aren't proved true. This is basic science philosophy! The fact that we can model spacetime as a 4-dimensional, unchanging object in General Relativity doesn't undermine the "reality" of time. It may mean General Relativity isn't easily compatible idea of laws that evolve in time. For example, a new theory might introduce some non-linear effect that makes a 4-dimensional model incomplete. But that doesn't mean the time dimension, in General Relativity, is unreal. Smolin makes a similar argument about Quantum Mechanics. He says that quantum mechanics is incomplete because it does not model the observer or the whole universe. These are true limitations on Quantum Mechanics, but demanding that nature be described, at once, in totality, by any theory, is unjustified! Smolin throws Quantum Mechanics under the bus to try and support his opinion about time. It isn't convincing. The main message of this book is that ... time is real and laws evolve. Smolin has an awesome idea, first printed in his excellent book The Life of the Cosmos. He proposes that the laws of nature evolve by small incremental changes, much like biological evolution. New universes are "born" by the formation of black holes, and they inherit, with small mutation, the laws of nature from their "parent" universe. This is the only example I have seen of true application of the Anthropic Principle. But this book doesn't propose any different way for the laws to evolve. There are lots of new arguments from Smolin, but they are all squishy, philosophical, and metaphysical nonsense. Metaphysics is important, but Smolin hasn't provided anything new and good here. Just new and bad. Smolin overviews crackpot stuff like the Hard problem of determinism, Shape Dynamics, Albino Squirrel, the Meta-laws Dilemma, Barbour's "heap of moments", hidden variables in Quantum Mechanics, subjective "qualia", and Boltzmann brains, both of which are fascinating, but ultimately useless. These aren't really worth addressing here, but if anyone's curious about one or more of them, I will happily post details. He ends the book with an out of place admonition about how humanity should respond to global warming. Kinda lame.

  5. 5 out of 5

    Nick Wellings

    Lee Smolin's 'Perimeter Institute' in Waterloo Canada sounds like a pretty happening place. Bright young things collaborate on foundational issues in a multimillion dollar purpose built building where the researchers demanded and got full length floor to ceiling blackboards*, glassboards, whiteboards, blackboards in the lounge areas, probably even on the coffee machines and in the toilet cubicles too, which is a good thing I suppose because physics is in trouble and these guys need all the scrib Lee Smolin's 'Perimeter Institute' in Waterloo Canada sounds like a pretty happening place. Bright young things collaborate on foundational issues in a multimillion dollar purpose built building where the researchers demanded and got full length floor to ceiling blackboards*, glassboards, whiteboards, blackboards in the lounge areas, probably even on the coffee machines and in the toilet cubicles too, which is a good thing I suppose because physics is in trouble and these guys need all the scribbling space they can get. I GOT 99 PROBLEMS... Physics has deep problems right now. Shove a pacyderm in a room at a physics party and watch them try and skirt round it. This gentle mammal wears the colours General Relativity and Quantum Mechanics. Physics knows that at the core of its success are two mutually incompatible theories. General Relativity is really good for large scale things like how stars work and how time travel might not be possible and how clocks work under acceleration. Quantum mechanics is great at describing the really small, the submolecular world of the quantum. Physics has been trying to marry these up into one theory for about seventy years and we haven't got too far.In some ways this is because physicists are clever and generate multiple ideas for a few problems. This is natural part of how science evolves. We're definitely at some kind of boundary, banging our heads on problems that are only slowly yielding to analysis. Enter Lee Smolin. STRUCTURE: Part one of Time Reborn has to build the groundwork for his theory and Smolin's presentation of the history of physics is breezy and good and to the point. As mentioned by other reviewers though, some illustrations are a bit poor. (Compare any in Greene's output or even Penrose's own hand drawn illustrations in 'Road to Reality' for example.) Along the way Smolin uses a few Leibnitz ideas, the identity of indiscernables and the principal of sufficient reason. These are his philosophical primitives and his foundational maxims and he uses them a lot to gauge whether his ideas are right. I don't know enough about Leibnitz to know if PSR has been thoroughly demolished in the analytic turn of philosophy of the 20th Century but the theory of indiscernibles seems pretty irreproachable on a naive take. (Of course I know that philosophers love to puzzle these things out and recognise that again, 20thC logic can rigorise and interrogate a lot of these seemingly common-sensical ideas to show them as specious, groundless or only applicable in certain cases (I.e. non privileged and not admitting loose application to physical theories.) So whether Smolin's application of those rules is logically rigorous, or if his misapplies them is outside my skill area. Part two explains his theory proper. THE PROBLEM OF TIME Crucially for Smolin, the majority of these theories have inherited a Newtonian legacy: They are all time independent or are formulated as if time does not exist. Smolin says this is a big impediment to progression. He doesn't like this. His is an attempt to get back to basics. Let's privilege time, he says, because it solves a lot of problems. To admit that time exists is the most sensible way out for physics. So: arrow of time? No problem because if physics admits time exists, the arrow of time is not a problem any more. There is no contradiction between the formulas we use which don't need time, and the world we live in, which does. So too, we don't need to invoke Anthropic Principle. So too can we make Quantum mechanics less of a probabilistic oddity. However, to do so seems to bring back pernicious problems of non locality and 'spooky action', but Smolin gives us a cute way out of this by suggesting non locality seems true on a global scale but on his geometrically determined spacetime, the building blocks can be both very close and far away. (I find this idea of geometrically constructed space naively and intuitively appealing. I think if anything, God was a geometer before he was a philosopher... Lord knows how well ever prove that these tiny vertices, graphs and quantum nets are right.) Smolin reminds us that all theories to date are weasly, our best approximations of the world we observe, and even our observations and experiments are calculated to reinforce this. He also has interesting things to say about symmetry as a component of theory (avoid it, he says, as it is a misleading principle). Further a lot of these theories have a lot of explanatory power but no method whereby we can test them, and hence no falsification potential. Bad news if you're concerned for the Truth of your theory. [For those interested Page 248 is a nice graphic explaining the dilemmas physics faces as Smolin sees it.] PROBLEMS WITH TIME REBORN Smolin's project is not without a few issues though. To privilege Time he must downplay space. He has to work contrary to General Relativity. He suggests space emerges from his 'Graphity' and that its naive appearance to us has misled us to overesteem its place in our physics, but he suggests that toy models of Quantum Graphity can have space as an emergent property. Conveniently he explains how the model can also be shown to generate a universe in the manner of a Big Freeze (geometrogenesis) which also neatly might explain distribution of Cosmic Mirowave Background radiation. (Such emergent spacetimes are not new, most recently Maldacena suggested a 'holographic' model where our world appears on a boundary of a special type of spacetime - the duality of AdS/CFT correspondence - which I think is still arXiv's most cited HEP paper ever.) To his credit, Smolin acknowledges the above conflict with Relativity. His proposed solution is clever. On a personal level, see above for my gut reaction against using Liebnitz to discuss 21st Century physics. Smolin also has cause to suggest a Principle of Precedence to buttress his ideas in QM. This seemed really rickety when given in natural language: the idea is that observed Laws are merely habituated pattern based on past history. However, Smolin does pretty well in the 'Quantum Mechanics and The Liberation Of The Atom' section to suggest that a sum of precedence is all that is a character of natural law: one admits its non-eternalism, in effect one temporalises timeless Law, and in so doing admits a degree of freedom. This is critical because Newtonian determinism can still obtain where necessary and QM can be truly freed from probabilities and sums of histories. My opinion: On the whole I liked the book. The prose was solid and only a few times did I have a 'what??' Moment of bafflement. In addition I learned about Quantum Graphity, Kocher and Conway's Free Will theorem and I learnt about Grete Hermann and how she showed von Neumann's objection to hidden variables was based on a hole in his proof and how this pretty monumental thing was ignored for about 40 years till Bell found it again. Time Reborn is more a rallying call for open minded pursuit of physics, weight given to Smolin's pet ideas naturally. I can't say if they are true or not as I lack the mathematics and physics background to even begin to question anything his team writes. (Therefore its a good thing in a way that the book has not one equation in it as far as I could see. None! Nada! Zip! All the same I did miss this a bit as even I can see some equations are elegant and powerful.) Naively the ideas in Time Reborn feel more right than say string theory which has been languishing in the doldrums for nearly 30 years now but we still don't know, in the words of Peter Woit if we are 'even wrong'. The answers will be worked on still by the next generation, some of whom are being trained by Perimeter's outreach and engagement team even now, and probably for time to come. Best keep scribblin', kids. NOTES: * Smolin semi-jokingly tells us that the researchers petitioned the architects to increase the number of dimensions in the place to maximise interaction by raising the neighbour quotient, the idea being that a guy in the basement interacts less with a girl on the fourth floor, so that the number of well placed researchers next to each other could be optimal. (Ain't maths cool?) Sadly the architects neglected to help but Smolin says they did offer to cover the entire building inside with slate and glass so the guys and girls could scribble like savant-toddlers all over everything.

  6. 5 out of 5

    Rohan

    This book was extremely tough for me to understand. I took almost 45 days to finish this one simply because I wanted to make sure I understand everything that Lee Smolin was talking about. Some of the concepts were too complex for me and took me few days of web research to process. But on the whole, this book was a philosophical experience for me. Even though it sounds simple, the whole concept of doing 'Physics in a Box' was mind-boggling to me in the initial chapters. As the chapters went by, This book was extremely tough for me to understand. I took almost 45 days to finish this one simply because I wanted to make sure I understand everything that Lee Smolin was talking about. Some of the concepts were too complex for me and took me few days of web research to process. But on the whole, this book was a philosophical experience for me. Even though it sounds simple, the whole concept of doing 'Physics in a Box' was mind-boggling to me in the initial chapters. As the chapters went by, it was an eye opening experience for someone like me who recently (an year back) found interest in Physics. Before this book, the kind of books I read were almost meant for laymen and they never really presented underlying concepts about which Physicists are actually researching and publishing every year. This book closed that gap for me. Even though I cannot say I understood each and every point mentioned in this book in its entirety, I really did enjoy getting so up close with the Philosophical and Scientific thoughts of a Physicist. The good thing is that Author has a great list of references for almost all the previous research done on various topics presented in this book. While using (and not using) the concept of time, the Author covers the history of important theories in physics as popularized by Newton, Boltzmann, Leibnitz, Einstein and others and goes on to talk about Inflation, Duality, multiverses, baby universes, loop quantum gravity. Lee Smolin proposes interesting solutions to many of the problems that physics faces today. I personally felt enlightened to know about these particular theories/concepts: Causal Dynamical Triangulations, Quantum Graphity, Spin-Foam Models, Shape Dynamics. It was amazing to know how speculative the field of Physics has been over the years and how until a cosmological theory is proved wrong by any doable experiment, it is assumed a serious possibility no matter how improbable it might sound. Some of the most important conclusions and statements in this book are never quite highlighted and this is the only complaint I have. Even this is understandable because the book does talk about lot of them (important things). This one is a great read. Even though it is difficult to understand at times and even though the writing style is a little too academic and research oriented, 'Time Reborn' is a genuine attempt at trying to popularize the notion of time with respect to Physics and its future.

  7. 4 out of 5

    Simon Mcleish

    Annoyingly poorly argued book about moving beyond current ideas of time in physics, with some interesting ideas. Smolin spends most of the book discussing the "timelessness" of modern physics, both relativity and quantum mechanics, without ever properly defining what he means by the term. It's clearly not whether the theories have a time parameter in them, but it seems in some places to mean that time is treated as a whole, as it is in the "block universe" of relativity, and in others that the l Annoyingly poorly argued book about moving beyond current ideas of time in physics, with some interesting ideas. Smolin spends most of the book discussing the "timelessness" of modern physics, both relativity and quantum mechanics, without ever properly defining what he means by the term. It's clearly not whether the theories have a time parameter in them, but it seems in some places to mean that time is treated as a whole, as it is in the "block universe" of relativity, and in others that the laws of physics themselves do not change. Smolin thinks we need to look at changing laws in order to fix some of the problems with these theories, but his ensuing discussion of what form these changes may take is infuriatingly inconsistent and contains logical flaws (there is a particularly glaring one on p.163 of this edition). Sometimes he seems to be envisaging laws changing only at the creation of a new universe (if his earlier ideas about black holes in one universe containing new generations of universes inside them is adopted); at others, he seems to be talking about changes between distant parts of the same universe or over time, again in a single universe. Where was the editor when they were needed?

  8. 4 out of 5

    Karl-O

    An interesting talk by Smolin, apparently of the ideas outlined in this book, can be found in this link, with an equally interesting comment by Sean M. Carroll: http://www.edge.org/conversation/thin... An interesting talk by Smolin, apparently of the ideas outlined in this book, can be found in this link, with an equally interesting comment by Sean M. Carroll: http://www.edge.org/conversation/thin...

  9. 4 out of 5

    Forrest

    . . . on second thought, maybe Smolin is wrong and existing theories were right all along? The book's not closed on this one yet. . . . on second thought, maybe Smolin is wrong and existing theories were right all along? The book's not closed on this one yet.

  10. 4 out of 5

    Darren

    The Controversy Before I can even begin a review of the book, I do feel that a bit of background must be provided on the scientific context in which this book appears. Smolin is a prominent if controversial figure within the theoretical physics community, well known for work on the cutting edge of our knowledge and promoting that work directly to the general public well before it has become widely accepted within the physics community itself. Back in the 1990's, he published a work that focused on The Controversy Before I can even begin a review of the book, I do feel that a bit of background must be provided on the scientific context in which this book appears. Smolin is a prominent if controversial figure within the theoretical physics community, well known for work on the cutting edge of our knowledge and promoting that work directly to the general public well before it has become widely accepted within the physics community itself. Back in the 1990's, he published a work that focused on the idea that the universe (or rather a series of reproducing universes) evolved over time. The basic idea of Smolin's proposal for an evolving universe is that a universe can create other universes through the creation of black holes, meaning that it's highly probable that the universe we're in is one that is optimized for the creation of black holes. As I said, he's controversial! Then, in 2001, he wrote The Three Roads to Quantum Gravity, which argued that differing approaches to the problem of quantum gravity (string theory, M-Theory, and loop quantum gravity) could work together to come up with an underlying theory of quantum gravity. This was a controversial stance within the physics community because string theory and M-Theory are both highly prominent theories that have been developed and worked on by a large number of scientists over the previous couple of decades ... while loop quantum gravity was an approach which Smolin himself had helped to develop and pioneer, but which had nowhere near the same amount of acceptance within the theoretical physics community. In other words, The Three Roads to Quantum Gravity was seen by some as an attempt to artificially elevate Smolin's own pet theory to equal status with the prevailing approach to quantum gravity, even though many theoretical physicists did not believe it earned that status. In his 2006 The Trouble With Physics: The Rise of String Theory, the Fall of a Science, and What Comes Next, Smolin goes even further, claiming that the approach at the heart of string theory is fundamentally harming physics itself. In this book, he outlined 5 great problems in theoretical physics which, while still a controversial list, basically hits the mark of a number of things that theoretical physics really can't explain without speculating well beyond the foundation provided by the current evidence. He points out that string theory has failed to solve this problem ... or even to anticipate that some of these problems would arise. Needless to say, for a community that had spent three decades investing time, energy, and resources into developing string theory, this was not a welcome book, and the "string wars" have certainly had some memorable exchanges, even informing romantic breakdowns on television's The Big Bang Theory. The current book that I'm about to review is just as controversial ... if not moreso. I found it an engaging book and am certainly recommending it, but it should be read with a great deal of care and skepticism. As I will discuss in the review, many aspects of Smolin's approach involves assumptions of his own which are, at best, no more certain than the assumptions he is trying to argue against. Smolin's "Crisis in Science" Revisited In Time Reborn: From the Crisis in Physics to the Future of the Universe, theoretical physicist Lee Smolin of Canada's The Perimeter Institute is once again taking a bold new scientific vision directly to the popular audience. This time, he's tackling the notion of time itself. In his stance, the current scientific understanding of time is that time is not "real" and he feels that's a fundamental flaw, one that could be corrected by taking time serious as a real quantity ... in fact, it would in his vision be one of the only real quantities, with the rest of the universe - indeed the very laws of the universe - evolving within time. What he suggests is that instead of laws of physics that eternal and everlasting, physicists instead treat physics in a more "relational" way, in which they are viewed as dynamic systems of behaviors. A key point in this is that Smolin himself is candidly honest that he's not presenting such a theory himself (at least not at this time): "The purpose of this book is to suggest that there is another way. We need to make a clean break and embark on a search for a new kind of theory that can be applied to the whole universe -- a theory that avoids the confusions and paradoxes, answers the unanswerable questions, and generates genuine physical predictions for cosmological observations. I do not have such a theory, but what I can offer is a set of principles to guide the search for it." Why does Smolin believe that such a theory is necessary? In part, it is an argument not rooted so much on science itself as on the field of natural philosophy and specifically grounded in the work of philosopher Gottfried Leibniz. The Principle of Sufficient Reason Leibniz is well known in scientific circles for having independently developing calculus at the same time that Sir Isaac Newton was also doing so, but Leibniz's body of work as a philosopher is far more well-developed than that. Specifically, he held a belief that all things that happen in the universe have an exact cause. Leibniz was deeply religious, so his stance was basically that God had a reason for every choice he made and that none of these choices could be arbitrary. Smolin does not rely on a divinity for his argument, but he is willing to accept as a fundamental principle that everything that happens has a reason for that thing happening as opposed to something else, and given knowledge of all of the factors going into the result, there would be no other possible outcome. This of course seems like a perfectly reasonable ... except that the last century's work in quantum physics has drastically challenged this notion. In situations such as the quantum double slit experiment and the EPR Paradox, it really seems as if things happen on the quantum level with a given probability. In the customary formulation of the EPR paradox, for example, when a particle decays into two particles of opposite spin, there is really no way to determine prior to the event which particle will have which spin. The best we can do is estimate the probabilities. And, in our understanding of quantum physics, this isn't just a matter of us missing some information ... there's actually no way to tell which is which. Smolin rejects this conclusion, insisting that there must be something fundamental that quantum physics has missed. He is a proponent of a hidden variables theory, even though most physicists agree that Bell's Theorem has really ruled out the possibility of any such theory. At least, to date, no one has come up with one that really works. Cosmological Fallacy Having embraced Leibniz's stance, Smolin introduces the idea of a cosmological fallacy, which he defines as: "It remains a great temptation to take a law or principle we can successfully apply to all the world's subsystems and apply it to the universe as a whole. To do so is to commit a fallacy I will call the cosmological fallacy." Now, this takes some parsing out to really figure this out. First of all, realize that all of cosmology (and astrophysics, for that matter) involves taking results we observe on Earth and extending them to apply to distant parts of the universe. In other words, we basically assume that the physics we observe here on Earth and in our nearby region of space applies equally well to distant regions in space. In other words, our world and region of space are not particularly special. This is a principle called the Copernican principle. Smolin does not seem to be arguing against this practice. However, the whole reason that we develop these findings on Earth is through testing them with experiments that are carefully controlled, so we know as precisely as we can which influences are caused by which components of the system. This cannot, of course, be done to the universe as a whole. Smolin rightly identifies this as a major problem in cosmology. We have a sample of only one universe, after all. But what about the multiverse, you ask? Smolin views this as an attempt by physicists to create a hypothetical set of possible universes, so that applying normal methodologies seems valid. But, since we actually can't observe these universes, I admit that it's a highly suspect conclusion. Smolin's Science Despite his goal of treating time as "real" in a new way, Smolin is not suggesting that any current scientific evidence is incorrect. In other words, he's not saying that relativity itself is wrong when it talks about the fluid nature of time, only that there might be alternative explanations or theoretical structures which would yield the same correct results as relativity but would be a bit less relativistic in how it talks about time. (He discusses one approach in the book, called shape dynamics, at a very high level.) My Conclusion Smolin makes a compelling but not airtight case for problems with the current understanding of time, but repeatedly while reading the book I felt like Smolin was trying to shoehorn the laws of physics into his own preconceptions of what they should be. We certainly have strong intuitions about time and Smolin's approach involves taking those intuitions more seriously than the mathematical results we've found thus far in physics, which have suggested that time is fluid and that the arrow of time itself is an artifact of entropy. I think this would be useful book for those interested in gaining a deeper understanding of the scientific issues related to time, but I really think that it should only be read alongside Sean Carroll's From Eternity to Here: The Quest for the Ultimate Theory of Time, which presents the more general consensus understanding of time within theoretical physics. Reading Smolin's book alone, without a deep understanding of the physics involved, will very possibly lead the reader to thinking that the flaws are more serious and pervasive than they may actually be. The above review is from: http://physics.about.com/od/physicsbo...

  11. 4 out of 5

    Blair

    Mystics, philosophers, poets and 20th century physicists all agree - time is an illusion. Newton’s laws work equally well with time going backwards, and Einstein showed that time is relative to the motion of the observer. In contrast, this book argues that time is not only real, it is the most fundamental property of the universe. It certainly provides a lot of new ideas to inspire fresh thinking about this subject. He does a wonderful job of introducing subjects such as thermodynamics or quantum Mystics, philosophers, poets and 20th century physicists all agree - time is an illusion. Newton’s laws work equally well with time going backwards, and Einstein showed that time is relative to the motion of the observer. In contrast, this book argues that time is not only real, it is the most fundamental property of the universe. It certainly provides a lot of new ideas to inspire fresh thinking about this subject. He does a wonderful job of introducing subjects such as thermodynamics or quantum entanglement in a few pages. Unfortunately he did not do the same for basic quantum mechanics or relativity theory. Some readers may be confused or even misled by his statements on these subjects without knowing the proper context. His philosophical basis begins with the principle of sufficient reason, which declares that there is a rational reason for every choice that nature makes. The more basic assumption of a single objective reality is left unstated. He challenges the notion that there are eternal laws outside the universe that govern it. As the universe by definition includes everything, this concept is self-contradictory. Instead, any laws must be a part of the universe. These laws emerge from what the universe contains. We have learned that our universe is not eternal and unchanging; it has been expanding from its origin in the Big Bang. In other words, it is evolving. As biological evolution can be seen as the exploration in time by the biosphere, the laws of physics also evolve, and emerge in time. Time is at the heart of this relationship. He describes normal science as “Physics in a Box”, which is conducting experiments with restricted conditions, isolated from everything else. But he points out that we cannot really create an isolated experiment to test, for example, Newton’s laws, as every particle in the universe affects every other particle, at least through gravitation. A cosmology of the entire universe may involve principles that we cannot detect in that kind of limited environment. Conservation laws, such as the conservation of energy, are fundamental to physics. We are assured they are connected the assumed symmetries in the universe. But he claims that there can be no fundamental symmetries in nature because they are derived from a study of subsets of the universe, and do not take into account interactions with the rest of an evolving universe. I do not see how this follows; maybe those interactions are also symmetrical. But who knows, maybe total energy is actually increasing in an expanding universe. Quantum mechanics presents the biggest challenge to our notions of position and causality. He notes that in QM “there are cats that are both alive and dead at the same time, an infinitude of simultaneously existing universes, reality that depends on what is measured or who is observing, particles that signal each other across vast distances at speeds exceeding that of light”. While the theory works in the experiments that we do, he agrees with Einstein that it is incomplete. It provides no physical picture of what is going on, there is no precise outcome, and measurement and observation are built into the theory. It is not really a true theory at all, it is an experimental method, where the choice of experiment affects the results. Quantum mechanics cannot be taken as universal, because it only applies to the small subsystems we experiment on. He claims it is missing “relational hidden variables” that relate each particle to the rest of the universe. Unlike the “hidden variables” that Einstein proposed in his critique of quantum mechanics, these are non-local, involving the “spooky action at a distance” that Einstein so disliked. He suggests the principle of precedence to explain quantum behavior, where an event is more likely to happen if it occurred before in the past. The position of an electron is therefore determined by the fact that it is connected with all other electrons in the universe, and when it finds one in the same quantum state it copies its properties, including its relative position. I think it would make more sense to invoke the already existing Pauli exclusion principle, which says that no particles can share the same quantum state. Extend that across the universe, and each electron places itself where no other electron is located. But either system is like entanglement on a bigger scale, and implies some kind of universal simultaneity. He goes further to say Aristotle was right that there is a preferred version of motion and rest. However, this “preferred global time” has a family of observers at each point in space, and depends on the distribution of matter and energy in the universe, not quite what Aristotle had in mind. To get around a perceived contradiction between universal time and relativity theory, he introduces a variant of relativity called Shape Dynamics. Its main principle is that all that is real in physics is connected with the shapes of objects, and all real change is simply changes in those shapes. The fact that objects seem to have an intrinsic size is an illusion. In exchange for making size relative, we achieve the goal of a single rate at which time flows throughout the universe. Because he did not introduce relativity theory properly, the reader might get the impression that time flows randomly. Time always flows in the same direction, but at different rates depending on the motion of the observers. More specifically, if I travel on a very fast rocket, when I return to Earth I will be younger than the twin brother I left behind. Does shape dynamics claim that I will be smaller instead? Let me propose the following thought experiment: When we look into space, we see the stars moving away from us equally in all directions. Either we are in a special place, or the universe itself is expanding and it will look similar from every point in space. If I am in a fast rocket, it will move faster than the stars are moving around on their own. The stars in front of me will be moving toward me, and the ones behind be will be receding. It is obvious that I am the one moving in an absolute sense, rather than the trillions of stars moving relative to me. Before I begin my rocket journey, my brother and I measure the age of the universe, based on the acceleration of the stars away from us. Lets assume we can do this very accurately. Then I fly off for one year, and return to Earth and find him ten years older. We measure the age of the universe again. I feel it should be one year older, but the result will be ten years older. The universe aged faster than I did. The age does not depend on from where we measure it. I was the one doing the moving, so the Earth measurement should roughly agree with one made from any of the trillions of stars. I could have made this measurement any time during my journey, and observed the universe was aging more quickly than I was. Thus the age of the universe serves as an absolute clock. The universe IS the clock. Then why do we need all the cute mathematical tricks to conjure up shape dynamics? Einstein did not develop special relativity by tinkering with Newton’s equations. He added a new factor to take into account the constant speed of light. Any advance on relativity will need a new physical concept, not just a refactoring job. The author seems to be trapped in his own physics in a box. Locally, two objects in motion have clocks that run at different speeds relative to one another. On a universal scale there is a constant time. The basic premise here is that time is constant, and space is emergent. That seems quite reasonable, given that space is expanding from the Big Bang. In discussing the emergence of space, he points out that it appears to have only a few dimensions. This means we have more separation from other objects than if there were more dimensions. Compare a two dimensional neighborhood of houses with a three-dimensional apartment building: more dimensions give you more neighbors. In the early universe all points in space were connected. If space is quantized, so there are a finite number of points with a certain size. One assumes this size must increase as the universe expands, unless new points are being manufactured. As it cooled, the links required energy so most of them were turned off, and space as we know it emerged. Entanglement involves turning on some of these non-local connections. My favorite part of the book begins with his great introduction to thermodynamics. He points out that the second law of thermodynamics does not describe the universe as a whole very well. Instead, the universe has a history of increasing complexity. He explains this is because gravity is anti-thermodynamic. It attracts particles to come together, which creates order from disorder. Further, the fact that fusion occurs when there is sufficient mass in a star creates energy. And it is energy flow that drives the creation of complexity and self-organization, which leads to planets with life on them. This is a great book for stimulating thought on the most universal topic that can exist. He is trying to explain very complex ideas to a non-specialist audience. This difficult task is sometimes done very well, and other times it is hard to follow. I highly recommend it.

  12. 4 out of 5

    Paperclippe

    I'm... not so sure about all this. I'm going to preface this by saying I was completely whacked out on cough syrup thanks to a miserable month-long cold for almost the entire duration of my listening to the audiobook of "Time Reborn," and that may have colored my opinions a bit. Also, a major disclaimer: I am not a scientist by any measure, nor am I mathematically adept beyond a high school level. However, I spend most of my time being a general nerd and have decimated the popular science section I'm... not so sure about all this. I'm going to preface this by saying I was completely whacked out on cough syrup thanks to a miserable month-long cold for almost the entire duration of my listening to the audiobook of "Time Reborn," and that may have colored my opinions a bit. Also, a major disclaimer: I am not a scientist by any measure, nor am I mathematically adept beyond a high school level. However, I spend most of my time being a general nerd and have decimated the popular science section of every bookstore and library within a twenty-mile radius of my home, and then some. With that under consideration, let's continue. First, I do want to say that the reader of the audiobook was amazing. This was one of the first non-fiction and especially scientific audiobooks that I have listened to that, having not been read by its author, still contained a huge amount of personality. The tone of voice and rhythm really made things relatable and easy to follow. Which makes the fact that I'm really not buying into Mr. Smolin's arguments here all the more notable. I had previously attempted to read "The Singular Universe and the Reality of Time" coauthored by Lee Smolin and Roberto Mangabeira Unger, which could be considered the "technical" version of this "popular" science book, and found that I just really couldn't get into it. In fact, I never even made it to Smolin's section, because the first half of the book, authored by Unger, contained a lot of assumptions with which I wasn't really willing to get on board. Having now listened to Time Reborn, I wish I'd tried a little harder, if only because then I might have a more cohesive reason as to why I find the arguments in the book so... wishy-washy. Thus begins the actual review of Time Reborn: I feel like Lee Smolin might be a bit of a terrible hypocrite. I'm going to state up front that I'm not a believer in string theory, because I find that it tries too hard to be beautiful while simultaneously ignoring the ugly fact that there is absolutely no evidence for - or against - it. It just kind of... is, and is meaningless, and has no real bearing on anything at all. I'm looking at you, Brian Greene. Anyway, it took me until the last 10% of the book to realize - and I think on purpose - that Lee Smolin was basing most of his arguments from a place where string theory is a given. And that's pretty much how the whole book is written. I noticed it at first when he gave a really unclear definition of what the anthropic principle was, defining it in such a way that suited his means, and was not entirely incorrect, but was far from concise and was farther from the definition I'd seen cited in a hundred popular science books before this one. It may have been the cough medicine, but I found his definitions of many things I previously thought I understood more confusing than helpful. He also had the nasty tendency to, whenever the subject broached something technical, either to say that he wouldn't bother getting into that here or would explain it in such highly technical and impenetrable language that it was nigh impossible to understand without a physics dictionary at hand. It felt very much like a magician pulling the wool over the eyes of the unwitting subject. Being at least reasonably well-versed in popular cosmology (which is to say, knowing, if only just, that the rabbit was in the hat the whole time), this felt incredibly dishonest to me, as did the fact that he would dismiss opposing theories like the Boltzmann brains, using "probablies" and "most likelies" and then writing them off, but allowing his own theories to slide through on those same hairs-breadth. There were some good points in this book, but the specifics of them are completely blotted out by how much I felt like I was being strung along (har har) by someone at a dinner who has a pet project and wants to tell you all about it and who talks over any objections you might raise, if you'll just let him finish. It was so irritating that even the fact that I'm not sure I even disagree with the main premise of this book - that time is real and unidirectional, and not a construct of consciousness, but an active participant in the fundamental structure of the universe - only nets it two stars. Barely. The more I think about it the more I want to take one away, but I'll let it stand for now. Was it worth a listen? Yes, but only to see the other side, hear them out, and then allow one's self to step back, take a deep breath, and confirm that nope. I'm still not buying it.

  13. 4 out of 5

    Ryan Curry

    I had been meaning to read this book for quite a while before I finally picked it up. I can confidently say that Lee Smolin is one my favourite authors when it comes to popular topics in physics. He formulates his ideas in a way that I just can't seem to find elsewhere. I thoroughly enjoyed Time Reborn, and have a lengthy list of other books to investigate thanks to the endnotes and bibliography. Throughout the book Smolin explores some novel concepts in cosmology and does a very good job bringin I had been meaning to read this book for quite a while before I finally picked it up. I can confidently say that Lee Smolin is one my favourite authors when it comes to popular topics in physics. He formulates his ideas in a way that I just can't seem to find elsewhere. I thoroughly enjoyed Time Reborn, and have a lengthy list of other books to investigate thanks to the endnotes and bibliography. Throughout the book Smolin explores some novel concepts in cosmology and does a very good job bringing everything back to the reality of time. I think that anyone interested in the notion of time should read this book.

  14. 4 out of 5

    Randal Samstag

    From my blog post on time here: Smolin’s 2013 book, Time Reborn, covers much the same ground as Adam Frank’s book, About Time, telling the story of why classical physics banished time and (unlike Frank) why it needs to be considered as real. He is in definite opposition to Newton and Einstein’s expulsion of time from physics in their absolute and block universes. He maintains that physics needs to embrace a cosmology that respects the apparent irreversibility of time, the so-called arrow of time From my blog post on time here: Smolin’s 2013 book, Time Reborn, covers much the same ground as Adam Frank’s book, About Time, telling the story of why classical physics banished time and (unlike Frank) why it needs to be considered as real. He is in definite opposition to Newton and Einstein’s expulsion of time from physics in their absolute and block universes. He maintains that physics needs to embrace a cosmology that respects the apparent irreversibility of time, the so-called arrow of time. Just one concept Smolin develops is his question as to why the universe that we live in is so improbable, full of highly ordered things, like stars and us. He makes a distinction between a Leibnizean universe in which the “law of the identity of the indiscernibles” flourishes and a Boltzmanian universe in which everything runs down according to the second law of thermodynamics. His preference for the Leibnizean version for our universe is based on the observation that the second law holds only for closed systems, while the universe in which we live is an open system through which energy flows. This leads him to the conclusion that time is very real and needs to be brought back into physical theory. Much more could be said about this interesting book. Oh, look, Manny has already said it!

  15. 4 out of 5

    Adam

    A brilliant contrarian argument against much of the ideology (meta-physics) of contemporary theoretical physics, especially computationalism: the notion that "reality is what math feels like," as Max Tegmark famously put it--the neo-Platonic idea that mathematics is the ultimate reality and that the universe is finally a vast computation from a few simple algorithms. Smolin's underlying argument is that by taking mathematical models derived from isolating physical systems under study from their A brilliant contrarian argument against much of the ideology (meta-physics) of contemporary theoretical physics, especially computationalism: the notion that "reality is what math feels like," as Max Tegmark famously put it--the neo-Platonic idea that mathematics is the ultimate reality and that the universe is finally a vast computation from a few simple algorithms. Smolin's underlying argument is that by taking mathematical models derived from isolating physical systems under study from their context and relationships, physicists have developed powerful models with elegant mathematics--but because the systems under study aren't really isolated, the models are only approximations. That's why, Smolin goes on to say, time appears simply as one optional parameter in physical calculations based on math that is time-reversible--whereas everyday experience and the Second Law of Thermodynamics tell us that time is both real and irreversible. On this basis Smolin suggests new directions for physics based on hypotheses that might be experimentally testable. A wonderful counter to the also excellent works of Brian Greene and Sean Carroll, exponents of the mainstream view on these issues.

  16. 4 out of 5

    David Dinaburg

    Tossing off the word “crisis” is enough of a signifier to fulfill the burden of “shocking-subtitle” that most non-fiction carries. The remainder of the subtitle in Time Reborn: From the Crisis in Physics to the Future of the Universe has the potential to be more egregiously hyperbolic but for the fact that most readers are unlikely to be current on the cosmological scuttlebutt. A theoretical physicist or cosmologist would not be having a first encounter these theories in a pop-sci book, so their Tossing off the word “crisis” is enough of a signifier to fulfill the burden of “shocking-subtitle” that most non-fiction carries. The remainder of the subtitle in Time Reborn: From the Crisis in Physics to the Future of the Universe has the potential to be more egregiously hyperbolic but for the fact that most readers are unlikely to be current on the cosmological scuttlebutt. A theoretical physicist or cosmologist would not be having a first encounter these theories in a pop-sci book, so their actual knowledge of a crisis in physics is wasted. Time Reborn is for the layperson, so the subtitle has the air of a marketing catchphrase rather than an impactful phrasing of what is to come. Though, in the case of a short generic like Time Reborn, distinguishment—not significance—may be the goal. Those burdened by the metaphysical presupposition that the purpose of science is to discover timeless truths represented by timeless mathematical objects might think that eliminating time and so making the universe akin to a mathematical object is a route to scientific cosmology. But it turns out to be the opposite. The bulk of Time Reborn is a refresher course in physics so that the reader has the basic knowledge to understand how little time figures into modern theoretical physics. In fact, it is actively excluded. To put it back, you need to know—well, everything. Mathematics entered science as an expression of a belief in the timeless perfection of the heavens. Useful as mathematics has turned out to be, the postulation of timeless mathematical laws is never completely innocent, for it always carries a trace of the metaphysical fantasy of transcendence from our earthly world to one of perfect forms. What happens is the reader—the one that can be counted on as having almost no basic theoretical understanding—is walked through two thousand years of math and physics and is spit out on the other side completely ready to accept whatever current cosmological theory to which Time Reborn has spent the last 200 pages building. Within the framework of the history presented, the conclusions seems inevitable; it would take a reader that brings in far more outside information than I to feel confident in proclaiming how strong these modern theories of fundamental time are. What Time Reborn does well is take a dense subject and inject interesting writing and clear vignettes to make physics unintimidating. Not once does the author talk down to the reader, nor needless complicate the subject in an attempt to academia-up the book. The fast-paced historical journey leads right up to the “crisis in physics” to which the seemingly alarmist—but wholly accurate—subtitle refers: Most of what we know about nature has come from experiments in which we artificially mark off and isolate a phenomenon from the continual whirl of the universe....What Descartes, Galileo, Kepler, and Newton learned to do was to isolate little pieces of the world, examine them, and record the changes in them. They showed us how to display the records of these motions in simple diagrams whose axes represent the positions and times in a way that is frozen and hence amenable to being studied at our leisure. In much the same way that social variables and personal intangibles have been diminished to fit within a mathematical equation that is computationally friendly, time has been scrubbed out of physics and math so that equations will function. They are approximations of the world, not definites, analogous to the way that the websites you click on are not you the person; within the framework of marketing engines, your clicks are how algorithms interpret—and corporations envision—you. You are become an equation built from tiny fractions of information, smashed together to provide workable—though woefully incomplete—data: The notion of effective theories subverts some well-worn notions, such as the platitude that simplicity and beauty are hallmarks of truth. Since we don’t know what could be lurking at higher energies, many hypotheses of physics beyond its specified domain are consistent with one or another effective theory. So these effective theories have an intrinsic simplicity, because they have to be consistent with the simplest and most elegant way they could be extended into unknown domains. A large part of the elegance of general relativity and the Standard model is explained by understanding them as effective theories. Their beauty is a consequence of their being effective and approximate. Simplicity and beauty, then, are signs not of truth but of a well-constructed approximate model of a limited domain of phenomena. Your facebook page—with its photos and multiple-choice dropdown boxes and “It’s Complicated” relationship status—is the simple version of you; the “math” version that computer algorithms can work with to increase their effective marketing. It isn’t really you, just a “well-constructed approximate model of limited domain”. So is there an offline, realworld version of physics that cannot be scaled up from the pageclick-esque data our mathematical formulae currently capture? Time Reborn drops this problem onto the head of quantum mechanics: Quantum mechanics is not a theory so much as a method for coding how experimenters interrogate microscopic systems. Neither the measuring instruments we use to interact with a quantum system nor the clock we use to measure time can be described in the language of quantum mechanics—nor can we, as observers, be so described. This suggest that to make a valid cosmological theory we will have to give up quantum mechanics and replace it with a theory that can be extended to the whole universe, including ourselves as observers and our measuring instruments and clocks. You cannot approximate a person en totale simply by extrapolating scraped data, and you cannot extend quantum mechanics from the micro to the macro, let alone to the cosmological. Seriously. If you only had information about what someone does online, and absolutely no prior experience or knowledge of what a person is, what identity of “personhood” could you build? You almost certainly don’t have enough data points to get it totally right, but even the information you have might lead you to completely wrong theories. Maybe you’d see that someone bought shoes, so you’d assume they had feet. Unless you thought that shoes were, uh, some sort of house—like how a snail uses a shell—and then what would people look like? Assuming you knew what shoes were. Or feet. Or the act of buying. Is the universe a snail? Or bipedal? We can’t know, we just know it orders a bunch of shoes. Not that we know what shoes are. There are many ways to think about the universe—online shopping analogies notwithstanding—and removing time has been a requirement for higher-level physical equations for centuries: How could something be the cause of Earth’s motion around the sun if there is a different and equally valid point of view according to which Earth isn’t moving at all? If motion is relative, an observer is free to adopt the point of view that all motion is defined relative to him. To resolve this impasses and be able to speak of causes of motion, Newton proposed that there must be an absolute meaning to position. This was, for him, position with respect to what he called “absolute space.” Newton argued that it was the Earth and not the sun that moved absolutely. No one has ever seen or detected absolute space. No one has ever measured a position that was not a relative position. So to the extent that the equations of physics refer to position in absolute space, they cannot be connected to experiment. Newton knew this and it didn’t bother him. He was a deeply religious thinker, and absolute space had a theological meaning for him. God saw the world in terms of absolute space, and that was enough for Newton. He would put it even more strongly: Space was one of God’s senses. Things exist in space because they exist in the mind of God. Einstein did it, too, though without Newton’s piety: The picture of the history of the universe, taken as one, as a system of events connected by causal relations, is called the block universe The reason for that perhaps peculiar name is that it suggests that what is real is the whole history at once—the allusion is to a block of stone, from which something solid and unchanging can be carved. The block universe marries space and time. It can be pictured as a kind of spacetime, with three dimensions for space and a fourth for time. An event taking place at a moment of time is represented as a point in spacetime, and the history of a particle is traced by a curve in spacetime called its world line. Thus, time has been completely subsumed by geometry; we say that time has be spatialized or geometricized. So our understanding of time and space changes to fit the current theories, all of which are simple enough and consistent enough to give physicists workable approximations of the world. But they cannot extend too far backwards, or too far forwards, or too big, or too small, because then things get weird. For example, you jump back to the big bang: everything in the universe is expanding outwards from this one event: The electromagnetic arrow of time can also be explained by time-asymmetric initial conditions. At the universe’s beginning, there were no electromagnetic waves. Light was produced only later, by the motion of matter. This explains why, when we look around, the images the light carries gives us information about the matter in the universe. If we just went by the laws of electromagnetism, it could be otherwise. The equations of electromagnetism allow the universe to being with light traveling freely. That is, light would have formed directly in the Big Bang rather than being emitted from matter later on. In a universe like that, any images of objects that light carried away from matter would be swamped by the light coming straight from the Big Bang. In other words, if everything originated in The Big Bang, then light originated there too. And we should all be blasted out by light. All the time. And maybe we are. Maybe our light is different light. But then, why didn’t what we’ve chosen to call light originate in The Big Bang? Light couldn't have begun at The Big Bang, or we'd be buried by it. So the universe changes over time. So it's possible time is more than an arbitrary construction. Got it. Let’s go the other direction—not the beginning, but the end: The simplest way to avoid the eternal dead universe would be if the universe had enough density of matter to stop the expansion and cause it to collapse. Matter attracts matter gravitationally, and this slows the expansion, so if there is enough matter the universe will collapse to a final singularity. Or perhaps quantum effects will stop the collapse and “bounce” the universe, turning contraction into expansion leading to a new universe. But there doesn’t seem to be enough matter to reverse the expansion, let alone counteract the tendency of dark energy to accelerate it. So nobody knows what’s going on outside of our narrow sliver of experience. Time Reborn: Nobody Knows What’s Going On was probably the working title. “Every experiment is a fight to extract the data you want from the unavoidable presence of noise coming from outside your imperfectly isolated system.” Science has gotten so good at ignoring the noise and working within our limitations that we’re starting to believe that the universe is as simple as the math that approximates it: Math in reality comes after nature. It has no generative power. Another way to say this is that mathematics conclusions are forced by logical implication, whereas in nature events are generated by causal processes acting in time. This is not the same thing; logical implications can model aspects of causal processes, but they’re not identical to causal processes. Logic is not the mirror of causality. At the end of Time Reborn, the reader will not have a pet cosmological theory or an answer to why quantum mechanics fails to scale up past the microcosmic level. Whether or not time will be reborn—if the relativities killed it off in the first place—requires an understanding of the many competing theories of time as an concept: We speak easily of “here” and “there” while believing that near and far objects are equally real. So some philosophers argue that “now” and “the future” are not really very different from “here” and “there”; they all denote a certain perspective that influences what you see around you but does not affect what is real. Or: Temperature is like this: Macroscopic bodies have temperatures, but single particles don’t, because the temperature of a body is the average of the energies of the atoms that make it up. Some physicists have proposed that time, like temperature, is meaningful only in the macro world but not relevant at the Planck scale. It isn’t a failure that Time Reborn doesn’t answer questions; what is important is that the framework in which we do physics, rely on math, and oversimplify the world to fit our algorithms and equations is examined and excoriated as wish fulfillment. The digital age continues to reduce people to numbers and alters the world to fit the lens of self-effacing code; it is increasingly important to avoid a fallacious “natural” justification for mathematical simplicity in attempting to understand the universe, else risk giving credence to a "true" or "pure" mathematical view of markets or web traffic or any other social construct. The most radical suggestion arising from this direction of thought is the insistence on the reality of the present moment and, beyond that, the principle that all that is real is so in a present moment. To the extent that this is a fruitful idea, physics can no longer be understood as the search for a precisely identical mathematical double of the universe. That dream must be seen now as a metaphysical fantasy that may have inspired generations of theorists but is now blocking the path to further progress.

  17. 4 out of 5

    Stephane

    Lee Smolin Time Reborn One of the books I am reading in order to gain a deeper understanding of time. From what I gather, most physicist think that time does not exist. Lee Smolin, on the other hand, thinks this is wrong. “If you are one of the many who believe that time is an illusion, I aim to change your mind. If you already believe that time is real, I hope to give you better reasons for your belief.” I don’t think I fit in either category; I am not a physicist or a cosmologist, I am merely cu Lee Smolin Time Reborn One of the books I am reading in order to gain a deeper understanding of time. From what I gather, most physicist think that time does not exist. Lee Smolin, on the other hand, thinks this is wrong. “If you are one of the many who believe that time is an illusion, I aim to change your mind. If you already believe that time is real, I hope to give you better reasons for your belief.” I don’t think I fit in either category; I am not a physicist or a cosmologist, I am merely curious. Like most, I suppose, I instinctively think that time must be real. So I would certainly be receptive to Smolin’s argument. The first part of the book demonstrates how the perspective of the unreality of time came about. To do so, Smolin charts a wide path, all the way back to the emergence of many modern ideas. He first explores how the contributions of Descartes, Galileo and Newton made “our conception of nature far more mathematical than before” allowing the laws of motion to be expressed in a timeless format (mathematic), which, in some ways, opened the door to the “mystic” view that a series of numbers representing a motion is more “real” than the motion itself, and thus that this motion could exist outside of time. Follows the greatest challenge to the existence of time, Einstein’s relativity. Smolin focuses on the concepts of the relativity of simultaneity and block universe, both are an assault on the reality of the present. Considering two events, very far from each other, happening without causal relation, two observers will have different answers to the questions of which one happened first, or whether or not they are simultaneous. And they will be both right. There is no objective simultaneity and space and time are inextricably linked. The logical conclusion is the concept of block universe: reality is the entire history of the universe; in that sense, past, present and future are equally real. I think I followed the first part reasonably well, but during the second part, where Smolin attempts to demonstrate the reality of time, I became a little lost. This is probably on me, not on him. The way I saw it, Smolin thinks that our basic mistake is to attempt to generalize models that are successful in explaining local phenomenon to the entire universe. In other words, he thinks that the laws describing what happen in small part of the universe do not work as a theory of the universe as a whole. I was not able to fully follow is arguments. In searching for a new framework, he invokes, Leibniz’s principle of sufficient reason (there is a reason for every state of affair), the principles of the identity of the indiscernible (no separable entities can have all their properties in common), explanatory closure (if I know a and a entails than b is true, than I know b…) and of no unreciprocated action (nothing in the universe can act on something without being acted on). I include them here partly to remember them, partly to show how broad Smolin's path is. He weaves philosophy, cosmology and physic in an argument that I admittedly, as I already stated, I had a hard time to follow, but that supposes that the laws of physics are not timeless, and that time must exist. There is no shortage of mind-bending ideas and concepts in the book. The evolution of the law of nature is one, the cosmological natural selection, the idea that the Big Bang is a bounce, and that trace of older universes could be found in ours, therefore, the history of the universes can explain our universe, the vision of gravity as a force driving self-organization and complexity… and a lot more! Smolin concludes rather philosophically, with a brief look at our social and economic systems, by pleading for an integration of scientific disciplines; we have much to gain if we can reconcile the ecology and the economic, the technical and the natural. In fact, perhaps our survival depends on that. He argues that the reality of time can serve as a platform for a new dialogue between the social and natural sciences. In the some ways, the conclusion felt like the introduction of a different book, and it was a little odd, but I liked it. Also, I agree with him: global problems need global solutions, not just from a territorial standpoint, but also from a knowledge perspective. In other words, we need contributions from all disciplines, and a framework that allows everybody to communicate effectively and to understand each other’s. Indeed, we need all hands on deck to solve complex problems like climate change or wealth distribution. Thinking in time, as Smolin repeats, certainly can’t hurt...

  18. 5 out of 5

    Sebastian

    Lee Smolin has an almost incredible knack for explaining profound and complicated things in a very clear manner, understandable even to dumbkopfs like myself. Furthermore, he seems to be a scientifically well-equipped person pondering truly deep issues in fundamental physics in a manner that seems to avoid some frequent pitfalls that even the smartest guys and gals working in the field seem to tumble into (e.g. assuming a background even in a background-independent theory, assuming a “view from Lee Smolin has an almost incredible knack for explaining profound and complicated things in a very clear manner, understandable even to dumbkopfs like myself. Furthermore, he seems to be a scientifically well-equipped person pondering truly deep issues in fundamental physics in a manner that seems to avoid some frequent pitfalls that even the smartest guys and gals working in the field seem to tumble into (e.g. assuming a background even in a background-independent theory, assuming a “view from the outside” of the universe even if no such view can exist, etc.). This, in itself, is invaluable and I praise the quantum spinfoam that there are people like him around, and that they are willing to spread the word among laypeople and hobbyist dabblers like me. However, there is a strong feeling of non-sequitur between his explanations of the problems physics is facing today, and his repeated conclusion that “therefore – time must be fundamentally real”. So I have a weird situation where I’m nodding my head throughout the book, agreeing wholeheartedly with the man, only to start shaking that same head as he inevitably lands onto the same odd conclusion every few chapters. Nevertheless, even if you, like myself, do not agree with that conclusion, there is much to be learned (or at least refreshed) in the discussions of the troubles with the current state of play in physics, and I feel that his general idea of “we have to go back a few steps and reevaluate everything from the ground up” might be the right one to get us out of the rut that physics has been stuck in for a while now. That being said, I don’t know if this is an obligatory part of popular science books now (first Tegmark, now Smolin), but there is a weird epilogue tacked on that seems to be “Smolin on stuff”, where he rambles on about a bunch of disconnected ideas, very loosely revolving about the topic of the book, but in fact heavily preachy about the future of mankind and the consequences of global warming, economic and political theory, etc. While I generally agree with many, if not most of his points, I’m not sure this is the place to make them – this bit of bait-and-switch at the end has mucked up the general feel of the book enough to actually knock a star off the overall rating.

  19. 5 out of 5

    Daniel

    Smolin is a very smart astrophysicist who has won many awards. He has published other books which are deemed influential by Newsweek magazine. Maybe that is why I could not follow his arguments fully. In essence physics is in trouble. The 2 most successful theories in physics, quantum physics and relativity, have so far not been unproven in science, but they contradict each other. So a new way is needed. Smolin proposed the ‘time is real’ theory. He suggested that there is actually a global time Smolin is a very smart astrophysicist who has won many awards. He has published other books which are deemed influential by Newsweek magazine. Maybe that is why I could not follow his arguments fully. In essence physics is in trouble. The 2 most successful theories in physics, quantum physics and relativity, have so far not been unproven in science, but they contradict each other. So a new way is needed. Smolin proposed the ‘time is real’ theory. He suggested that there is actually a global time almost like the external clock assumed implicitly in Newtonian physics. Unfortunately it contradicts general relativity’s simultaneity. Smolin is confident that that can be overcome; unfortunately he has not (yet) found proof. I could understand bits and pieces of the book, and found them rather fascinating, like the suggestion that black holes can spawn new universes. Or that he doesn’t think that space is infinite and so there would not be infinite copies of us (anyway that cannot be proved and belongs thus to metaphysics and not physics. Basically he disagree with the second half of Tegmark’s Our Mathematical Universe, and repeated the joke that equations alone would not bring forth the universe. However, like many smart professors, Smolin put forth a lot of arguments against the current accepted theories of physics assuming the reader already knows a lot about cosmology. I am a novice and thus do not understand the intricacies of the arguments. He really brought me back to my high school days when my physics teacher just kept mumbling to himself, writing on the blackboard. We were just left to learn ourselves then. Probably a good book for advanced readers who are knowledgable about cosmology, quantum physics and relativity. For the layman probably better off reading other books.

  20. 4 out of 5

    Shane Hall

    This review has been hidden because it contains spoilers. To view it, click here. Having read ‘Three Roads’ and ‘The Trouble’, I have become an admirer of Smolin’s candidness and clarity. For ‘Time Reborn’, the candidness remains but the clarity less so; perhaps that’s due to the subject matter being far more speculative in nature compared to his earlier works. In the main, the work is well structured and presents some fascinating ideas and possibilities for the nature of the very reality we live in. Having NOT read ‘Life..Cosmos’, I found the idea of the evolution of whole ge Having read ‘Three Roads’ and ‘The Trouble’, I have become an admirer of Smolin’s candidness and clarity. For ‘Time Reborn’, the candidness remains but the clarity less so; perhaps that’s due to the subject matter being far more speculative in nature compared to his earlier works. In the main, the work is well structured and presents some fascinating ideas and possibilities for the nature of the very reality we live in. Having NOT read ‘Life..Cosmos’, I found the idea of the evolution of whole genealogies of universes breathtaking and instantly more sensible than the present crop of ‘Who knows?’ approaches out there today. I did take exception to an interpretation that the author himself tried to redefine: this constant reference to ‘the real vs the illusory’. While decrying the physics community’s habit of proclaiming space ‘real’ and time an ‘illusion’, all he does is reverse the roles. That strikes me as just as short-sighted; while I wholeheartedly agree with him that time is real and of definitive consequence in how the mechanics of the universe operates, space is just as real and necessary. This, of course, is what scientific discussion is all about. Good book

  21. 5 out of 5

    Kian

    Smolin always has its own special assumption like everyone else but what he wants to achive in general seems more noble let's say. Here he tries to show why time is real and a fundamental element to the reality of the universe and maybe the only one and not a concept which we preceive based on preconditioned illusion of us.

  22. 5 out of 5

    Allan Olley

    This book is an extended exploration of time in physics especially cosmology with a to my mind somewhat controversial thesis. Time has been largely if not wholly excised from modern physics and this is an impediment to physics making progress in fields like cosmology that attempt to understand the universe as a whole. The first part of the book explores how physics has removed most if not all of time from its description of the world. The innovations of Galileo and Newton described physical pheno This book is an extended exploration of time in physics especially cosmology with a to my mind somewhat controversial thesis. Time has been largely if not wholly excised from modern physics and this is an impediment to physics making progress in fields like cosmology that attempt to understand the universe as a whole. The first part of the book explores how physics has removed most if not all of time from its description of the world. The innovations of Galileo and Newton described physical phenomenon in terms of timeless mathematical expressions, curves and equations. Already the future and past are described all as a piece of a block with time functioning like space, now is no more an objective quality of a moment then here is an objective quality of a place. Also gone is the sense that the future is not yet fixed and that the past is gone. Smolin then extends his discussion into the picture given by Relativity where one loses even the sense that there could be a single agreed upon present for different observers distant in space and traveling at different rates. Finally there is a speculative theory that attempts to apply quantum mechanics to the whole universe and calls into question whether there is time at all. In the second half of the book Smolin sets out why he thinks a return to the reality of time. A view where there is an objective meaning and difference about the present moment and the arrow of time (the way the past and future are different and the past flows into the future). He tries to lay out principles for developing a cosmological theory chief among these the concept that we must explain the laws of nature as themselves the result of a process of evolution (change) rather than as fixed timeless mathematical forms. Much of the book is concerned with suggesting how to make sense of that notion. Another principle he returns to is the need for scientific theories to make empirically testable predictions, he finds much modern theorizing bereft of contact with the world in this regard. In has no fully concrete proposals but gives a few suggestions. For example, he sketches his suggestion that we view are universe as the product of a process by which each black hole is the instance for the generation of a new universes and these universes composition and laws are variations on the universe they arose from. Thus we would expect an ensemble of universes where the properties (laws and initial conditions) that lead to universes with lots of black holes will be common. Since through a kind of cosmological analogy to natural selection those will be the kind favoured to produce lots of successors. This will then suggest probable properties of universe that can be tested for. Smolin has many other suggestions. He suggests that an approach called shape dynamics allows us to specify a universal present in relativity theory. How theories that suggest how space might have emerged from something more fundamental might suggest a kind of universal time. He talks about how cyclic views of cosmology where the current period of expansion is in fact a bounce back not from a singularity but a previous period of collapse and that the current period of expansion will be followed by another collapse and another bounce and so on in an endless cycle. He also tries to illustrate how he thinks alternatives that he thinks of as timeless are untenable implying multiverses where anything is possible and notions of empirical verification break down because anything can be explained. In the epilogue Smolin extends his consideration to economic, social and environmental theory and suggests that here to time has been insufficiently payed respect to and needs to be restored. He thinks economics is in the thrall of theories that posit timeless equilibrium rather than looking at the messy interconnected reality and proposes that the reintroduction of the working of what he takes as time will be helpful in understanding what we need to do to confront challenges like global warming. I find the book engaging and somewhat persuasive in laying out its issues. The proposed solutions are interesting and engaging for their novelty and the passion behind them, however I am not really convinced by Smolin's interpretations of the problems or the solutions. In terms of the removal of time from physics and the equating of physical reality to abstract mathematical forms. I think in fact time is real and even things like the present are an integral part of actual physical theory. We can not know the future, changes the past, directly effect things that are not presently happening and so on and this is all understandable in terms of physical descriptions like those given by Newton. The fact that in some abstract sense past people and events still exist on the timeless view, is not as Smolin (and apparently some of the people he criticizes) a comfort because the same view that tells me they exist tells me no less definitely that they will remain forever beyond my ability to know, communicate or interact with, I can do them no favours and they can do me no kindnesses. There are some tricky conceptual issues at play likewise. If only the present exists as Smolin suggests at least once then there could be no meaning to predicting the future or knowing the past. If the past does not exist in the same sense that unicorns do not exist then everything and nothing can be true of it (consider a story where all unicorns are white and another where all are pink, both are equally false or true) and so that past theories predicted present conditions becomes difficult to analyze. If the past does not exist but existed and so what existed was a definite set of events then you can have a closed future (the series presented as having existed) that has all the properties of the present where the future is open, so is what makes the future open or closed really the existence or not of a series of events that follow? Indeed even mathematics is not quite the timeless realm Smolin suggests, what is more mathematical then that model of a computer the Turing Machine, but many see the Turing machine as exemplifying aspects of time, the famous halting problem says there is no general method to predict the halting of such a machine. Smolin often equates the timelessness of mathematical laws with some transparency by which they imply knowledge of their outcomes, but in fact such descriptions are not always transparent and so to know whether the machine will halt may not exist in principle to our knowledge even if it is in some other it is determined. In some sense even mathematical truths are not intrinsic in their initial description but must be worked through to some other state. I would also quibble with things like how he sees shape dynamics or the cosmic microwave background radiation as setting a standard of what constitutes the present in relativity. These standards might get everyone to agree on a time standard, but they would not get everyone to agree on seeing distant events as happening in the same reconstructed order. Likewise I am not sure how is cosmological natural selection of universes generated by black holes would imply a global standard of time as he suggests. At one point he distinguishes between a Leibnizian universe where things are always different, changing and evolving with a Boltzman universe which tends to a stable recurrent equilibrium. However he admits that in a Boltzman world things need never exactly recur. Likewise in his imagined Leibnizian world events might get arbitrarily close to recurring and never actually recurring and meet his strict definition. I think his distinction here is best understood as loose and heuristic. He believes attempts to model the universe as a one where the features we see like the arrow of time are posited as fundamental and dramatically at work will be more fruitful for science then models where those properties are accidental and fading, I wish he had said it that way is all. Ultimately I think he fails to confront to big tensions in his views of what will work in physics. The first tension is between his view that the future is open (and so unpredictable) on the one hand and the demand that theories are only when they can be tested (and so yield predictable results). Ultimately only that the future is predictable is fully testable, so if Smolin is right either science must fall short of offering a full theory of things (not all that could be predicted will be) or the future is not open. I am not sure the prospect of what Smolin considers as closed future is quite as dire as he does (for reasons already suggested but also for others about the nature of responsibility and free will), but I also don't think this tension is avoidable. There is almost certainly a limit to our knowledge and yet in order to find it we must never stop demanding to know more these impulses are in tension. The other tension is Smolin's demands for an explanation of why things are the way they are? Why does the universe have a low entropy beginning? why do the laws seem so fine tuned for life? Against this consider his admission that questions like, why is there something rather than nothing? May just not be appropriate questions to ask there could never be an answer. Yet that is just the most general form of the questions about why these improbable initial conditions or laws, that he keeps asking. Again the tension between what it is possible and impossible to know suggests itself and the need to push on what it is possible to know to reach an answer. Science almost always explains at least some things, it makes some seemingly improbable thing make more sense, but only so long as we are willing to assume other improbable things. If most of the major planets are spaced according to an integer set of distances (the Titus-Bode law) this is improbable but may be made probable by adducing some principle about the gravitational interactions between them, thus the Titus-Bode Law may have evolved, in much the way Smolin wants to imagine the Standard Model of Physics evolved. The question becomes where do we draw a line and say this regularity this fact will not be explained further or do we. Smolin's book is a challenge to those who think we are at or near the limit of what can be explained by science and certainly provoked me to think about what we can explain and what we should explain with science.

  23. 5 out of 5

    Hilmi Uysal

    Kitabın orijinal adı “Time Reborn: From the Crisis in Physics to the Future of the Universe” ve ilk basımı 2013 yılında. Benim okuduğum baskı, “Zamanın Yeniden Doğuşu” adıyla TUBİTAK Yayınları’ndan çıkan Türkçe çevirisi. Kitabın çevirmeni Bilge Tanrıseven'i özellikle kutlamak istiyorum çünkü çok başarılı bir iş çıkarmış. Lee Smolin’in daha önce herhangi bir kitabını okumamıştım. ZYD (Zamanın Yeniden Doğuşu) ilk okuduğum kitabı oldu. Sonuncusu da olmayacak; “Fiziğin Krizi: Sicim Kuramının Yükseli Kitabın orijinal adı “Time Reborn: From the Crisis in Physics to the Future of the Universe” ve ilk basımı 2013 yılında. Benim okuduğum baskı, “Zamanın Yeniden Doğuşu” adıyla TUBİTAK Yayınları’ndan çıkan Türkçe çevirisi. Kitabın çevirmeni Bilge Tanrıseven'i özellikle kutlamak istiyorum çünkü çok başarılı bir iş çıkarmış. Lee Smolin’in daha önce herhangi bir kitabını okumamıştım. ZYD (Zamanın Yeniden Doğuşu) ilk okuduğum kitabı oldu. Sonuncusu da olmayacak; “Fiziğin Krizi: Sicim Kuramının Yükselişi, Bilimin Düşüşü ve Sonrası” ile devam etmeyi planlıyorum. ZYD’nin birinci kısmında, evrensel zaman fikrinin bir yanılsama olduğunu kabul eden günümüzün bilimsel bakışı anlatılmış. Fizikte zamanın bir yanılsama olarak kabul görmesinin arkasındaki fikirler okuyucuya verilmiş. Burada yazar çok başarılı. Klasik fizikte zamanın doğasının nasıl ele alındığını bu kadar güzel açıklayan bir popüler bilim kitabı okumamıştım. ZYD’nin ikinci kısmı, kitabın ana savını açıklamaya ayrılmış. Zamanın yanılsama olarak kabul görmesinin, açıklayıcı gücü yüksek bir kozmoloji kuramının oluşturulmasına nasıl engel teşkil ettiği ve bu nedenle kozmolojinin bir kriz yaşadığı ve zamanın da dahil edildiği bir kurama ihtiyaç olduğu savı açıklanmış. Kitabın ana savları bunlar. Smolin, evrensel zaman fikrini barındıran yeni bir kozmoloji kuramı sunmuyor kitapta. Zaten, anladığım kadarıyla henüz ortada böyle bir kuram da yok. Smolin’in kitabında yaptığı şey, evrensel zamanın varlığı kabul edilerek yeni bir kozmoloji kuramının çalışılması gerektiğine yönelik bir öngörüsü olduğunu ilan etmekten ibaret. Fizikçilerin evrensel zaman kavramını ortadan kaldırmış olan temel fizik kuramlarını kullanarak bir kozmoloji kuramı inşaa etmeye çalışmaya son vermeleri gerektiğini söylüyor. Kozmolojide ilerlemek isteniyorsa ve krizden çıkılsın isteniyorsa, fizikçilerin zamana bakışlarını kökten değiştirmesi gerektiğini anlatıyor. Bu kitabı okurken bazı kişisel deneyimlerimi de hatırladım. 20 yıl önce kendi kendime Özel Görelilik’i öğrenmeye çalışıyorken, konuyu birazcık anlamaya başladığımda yaşadığım aydınlamadan büyük haz duymuştum. Newtoncu fizikte eşzamanlılığın yanlış yorumlanışına ve herkese göre sabit tik-tak’larla akan evrensel zaman fikrinin bir yanılsama olması gerektiğine dair Einstein’ın düşünce deneylerine kafa patlatmıştım. İşte o zamanlar deneyimlediğim aydınlanma anlarından aldığım hazları unutamam. Fizikle ilgilenen herkes benzer deneyimler yaşamıştır, kitap beni o anlarıma da götürüp mutlu etti. Smolin’in iddialarını temellendirmek için kitabında yaptığı bazı yorumları zorlama buldum. Buna rağmen, bu kitabın düşünme ve öğrenme isteğinizi kamçılayacak harikulade bir kitap olduğunu düşünüyorum. Kozmoloji konuları beni her zaman insan zihni ile dış gerçeklik arasındaki ilişkinin doğasına ve epistemolojinin ana tartışmalarına götürür. Bu kitabı okurken zihnimde yine oralara gittim. Belki siz de gidersiniz...

  24. 4 out of 5

    Jonathan Hockey

    Very good book, a lot of important ideas in it, and always nice to see some attempts being made to get out of the consensus dogma in mainstream science. He criticises some of these perspectives, such as those who support the multiverse idea and those who are attached to string theory, with a combination of rightfully pointing out that these theories become too flexible to the point where there is no observation that could empirically falsify them, alongside referring to principles of reason and Very good book, a lot of important ideas in it, and always nice to see some attempts being made to get out of the consensus dogma in mainstream science. He criticises some of these perspectives, such as those who support the multiverse idea and those who are attached to string theory, with a combination of rightfully pointing out that these theories become too flexible to the point where there is no observation that could empirically falsify them, alongside referring to principles of reason and a relational view of basic metaphysics of space and time to suggest an alternative perspective from within which the laws of nature can evolve within and over time. He gives arguments to support how this can be a theory with good empirical content, with a kind of natural selection idea applied to the universe as a whole, in which universes are created in black holes. At the same time he develops the notion of the reality of time and the value of taking it as a primary notion. He criticises a lot of theoretical physics for its over reliance on a timeless approach to solving problems, whereby it tends to end up confusing it's timeless mathematical model of reality, with reality itself. The issue here is that these timeless models are only approximations that work on local scales. When it comes to the scale of the universe, the author argues that they engage in the cosmological fallacy in applying this approach. Various difficulties and dead ends are mentioned such as the problem of how to choose the initial conditions, the inadequacy and non-empirical nature of appeals to the anthropic principle or to multiple universes, where we are left with no data that can be falsified so that wild speculations not grounded in any solid data can proliferate. Another example he gives is how the standard approach of the mainstream view in cosmology requires that life be an aberration, a statistical anomaly. But if this is the case, there is never going to be a coherent explanation for its emergence, and the example of the Boltzmann brain problem is referred to, to illustrate how this idea becomes reduced to absurdity. In his alternative Leibnizian approach he recommends we stick to some of Leibniz' core principles of reasoning such as the principle of sufficient reason and the identity of indiscernibles, to ensure our view is not reduced to a kind of absurdity that Leibniz himself did warn about all that time ago, when he urged people to avoid the notion of absolute space and time, as it leads to difference without any ground of distinction to represent that difference. Hence, a difference without reason. All in all, a great attempt to bring solid reasoning and empirical science back into an area of theoretical physics that had begun, in my opinion to languish in a cul-de-sac of yes men parroting a consensus doctrine for the sake of saving form, to give the impression of certitude, and in the process closing their theories off from the independent confirmation of the surrounding empirical world. By bringing time as lived and felt back to the heart of physical science, it may be a rebirth not just for time but for free and open enquiry and speculation about the fundamental nature of reality.

  25. 4 out of 5

    Jafar

    I think Smolin has been hanging out with too many theoretical physicists and philosophers who say funny things like: time doesn’t exist, or, time is an illusion. For the rest of us mortals, a thinning hair is enough proof for the reality of time. Smolin is not happy with the fact that, starting from Newton, time lost its centrality in physics. It simply doesn’t appear in many representations and formulations of the laws of physics. Even when it does, it doesn’t really do anything other than move I think Smolin has been hanging out with too many theoretical physicists and philosophers who say funny things like: time doesn’t exist, or, time is an illusion. For the rest of us mortals, a thinning hair is enough proof for the reality of time. Smolin is not happy with the fact that, starting from Newton, time lost its centrality in physics. It simply doesn’t appear in many representations and formulations of the laws of physics. Even when it does, it doesn’t really do anything other than move things along. Physical laws have become like computer algorithms. Output is determined by the input, and time is not really relevant. Relativity tells us that there is no absolute time. Cosmology tells us that time came into existence with the universe and it’s meaningless to talk about time before the Big Bang. Smolin wants to change physics and put time back at the center. Time, instead of being an obedient servant of the laws that sit outside time, becomes their master. There are a lot of fascinating discussions in the book. You probably won’t be able to make up your mind and take side in the debate, but it’s fascinating nonetheless.

  26. 5 out of 5

    Joseph Schrock

    As a non-physicist, I must say that I was quite intrigued by Lee Smolin’s considerably deep and abstruse discursion into highly speculative aspects of theoretical physics. This book, “Time Reborn”, as the title indicates, is mainly devoted to a discussion of time as a truly-existing phenomenon – not a mere illusion conjured up by human consciousness. I very much appreciate Smolin’s commitment to rendering time as an objective reality. Ever since I became aware that many of modern physicists, inc As a non-physicist, I must say that I was quite intrigued by Lee Smolin’s considerably deep and abstruse discursion into highly speculative aspects of theoretical physics. This book, “Time Reborn”, as the title indicates, is mainly devoted to a discussion of time as a truly-existing phenomenon – not a mere illusion conjured up by human consciousness. I very much appreciate Smolin’s commitment to rendering time as an objective reality. Ever since I became aware that many of modern physicists, including Einstein, considered time to be a mere illusion, I found that idea distressing and disturbing. Is it credible to describe the universe as an eternally (non-temporally) existing “block” that is unchanging? To my mind, this is about as great an absurdity as one can well manufacture. Can time be understood as an objective reality? Even though the human intellect encounters insuperable barriers when seeking to decipher the nature of time, my own philosophical sentiments (not to say LOGIC) lead me to almost conclude that Smolin’s efforts to “resurrect” time as a genuine reality are quite definitely defensible and are a step in the right direction – with regard to physics, astronomy, and cosmology. Regarding Smolin’s concept of an evolving set of laws of nature and even the evolution of mathematics (as opposed to unchanging and inviolable “laws”), I find it conceivable that laws of nature could evolve, but my mind cannot quite tackle any concept to the effect that mathematics (the fundamental axioms, theorems, etc.) can possibly evolve such that what is true (seeming indubitably true and provable in mathematics) could become falsehoods in billions of years hence. Now, geometry is, as I see it, to be distinguished from pure mathematics. As mathematicians came to realize in the nineteenth century, one can construct geometries that are consistent, just as logical as Euclidean geometry, and (apparently, based on General Relativity) sometimes applicable to our very universe. Yet, aspects of those “alternative” geometries are incompatible with Euclidean geometry. Presumably, even the great German philosopher, Immanuel Kant, had regarded the geometry of his day (strictly Euclidean) to be infallible and inviolable. He was proven wrong by the non-Euclidean geometries that were generated, including Riemannian geometry, which was applied directly to Einstein’s theory of general relativity. I am, admittedly, merely an amateur (philosopher, mathematics hobbyist, and “logician”), but I confess to being somewhat disturbed by Smolin’s suggesting that even the “laws” and axioms of mathematics can evolve – not merely our APPLICATIONS of mathematics, but the very structure of mathematics. I could fail to correctly understand Smolin when he declares on page 246: “Math comes after nature….” If he merely means that mathematical descriptions of nature are derived from observations of nature, I would reservedly agree. Of course, Smolin rejects mathematical Platonism, and I confess to being fairly solidly favorable toward Platonism. Although our knowledge of logical “laws” will evolve, logic itself, I firmly believe, is inviolable and eternally unchanging. Smolin rejects that, but I see no reason why time cannot exist objectively, with change being a prominent feature of physical and mental realities, while certain timeless “laws” prevail unchangingly. I see no obvious conflict in that supposition. I confess to being a quite devout theist, and it is thus perfectly in line with my worldview to subscribe to a Platonist mathematics and logic. After all, I feel compelled to ascribe to the Divine Realm some fundamental, indubitable, unchanging, and eternal principles and “laws”. Let us suppose that the Divine operates in a world of time, participates in time and changes, but still exists with infallible commitment to certain principles and rules by which reality is to be conducted. The Divine might well be capable of both transcendent and immanent existence, whereby aspects of the Divine remain unchanging and eternally infallible, while operations and “thoughts”, including creative activities, all function in temporal and changing realms. Let me use an analogy to a human being. Let’s, for the moment, suppose that I were a spiritually perfect person (I am not so, by the way) who had subscribed unerringly to certain principles of conduct, including a strict determination to never treat any sentient being unfairly or unjustly. Even if I were to live eternally, it is perfectly reasonable to argue that I would eternally subscribe to (and infallibly practice) the principle of refusing any conduct that would ever render any injustice or unfairness to any sentient being. In principle, I would operate by eternally unchanging “laws”, even if my thinking and my behaviors were continuously in flux. The same sort of principle, it seems to me, could be applied to a universe that evolves and (possibly) has “laws of nature” that evolve, but undergirding all that evolution would be immovable and unchanging rules or principles – including unchanging logical and mathematical laws. Admittedly, Smolin wouldn’t buy this – his worldview is quite clearly (I gather from reading his book) either atheistic or agnostic. It does, by the way, need to be at least acknowledged that science is NOT NECESSARILY the ONLY path to knowledge of reality. To deny this fact is to engage in unjustifiable dogmatism – the very dogmatism that many scientists aver that they deplore. At any rate, I found Lee Smolin’s “Time Reborn” to be a fantastically challenging and engaging read. I would highly recommend it to scientific and philosophical thinkers of almost all varieties. Smolin freely confesses to speculating far beyond the currently available data, but he indicates that his cosmology (cosmological natural selection) can make predictions and generate hypotheses that are testable and potentially falsifiable. When one gets into physics at that level, my highly limited expertise tends to meet its conceptual defeat. Yet, this book was certainly readable and comprehensible enough for me to find it a joy to read.

  27. 4 out of 5

    Troy Blackford

    This was an interesting book, but I feel like it makes it quite clear why concepts in physics the author doesn't endorse - namely string theory - are more popular with the public than the ideas expressed here: the ideas presented are frequently impenetrable and the writing seems to jump from topic to topic without making it very clear what is meant. I mean, it would probably help if I understood physics better, but that's precisely what I'm saying: it's been easier for me to at least feel like I This was an interesting book, but I feel like it makes it quite clear why concepts in physics the author doesn't endorse - namely string theory - are more popular with the public than the ideas expressed here: the ideas presented are frequently impenetrable and the writing seems to jump from topic to topic without making it very clear what is meant. I mean, it would probably help if I understood physics better, but that's precisely what I'm saying: it's been easier for me to at least feel like I am understanding what authors like Brian Greene and Michio Kaku are saying when they discuss their ideas about physics than it was for me to understand Lee Smolin. Still, I'm glad I read this book.

  28. 5 out of 5

    keith koenigsberg

    Weak book. His writing is wandering and opaque; he often states as the plain-truth ideas which are actually far from obvious; he often states that he has shown you something ("We have seen") yet it is not clear that he has; and he could have used a good editor. The book is *way* too long with lots of fluff (he spends a lot of time telling you what he's going to tell you); although he thanks two dozen people for proofreading the book for him, I found several errors (errors of logic and errors of Weak book. His writing is wandering and opaque; he often states as the plain-truth ideas which are actually far from obvious; he often states that he has shown you something ("We have seen") yet it is not clear that he has; and he could have used a good editor. The book is *way* too long with lots of fluff (he spends a lot of time telling you what he's going to tell you); although he thanks two dozen people for proofreading the book for him, I found several errors (errors of logic and errors of fact) in it. I must ascribe the errors to bad and hasty writing, as I'm sure Mr Smolin knows his physics. But, such sloppy writing makes for a laborious and unrewarding read.

  29. 5 out of 5

    Christy

    Follow me to LibraryThing, where this review now lives. I'm not an unpaid content provider for Amazon any more. My account is public, look for CSRodgers.

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