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.
on 24 May 2013
Lee Smolin has truly made a book that does make you think very differently about time. His arguments are provocative and perhaps controversial but that is a good thing. I love that his emphasis is always on making his theories as amenable to experiment as possible. Having read the book I am especially swayed by his arguments about trying to build a cosmological theory that is not based on what he calls the "physics in a box" theories which always involve boundary conditions. The most important thing about this book is that it is easy to read and engaging. Another reviewer was horrified that he was promoting a nonlocal hidden variables theory, but at least he has made a justification for it and his focus is always in trying to build such a justification for a new theory that will be experimentally falsifiable. I also rather like his ensemble-interpretation of quantum physics because it at least is trying to make the theory based on real-ensembles. Almost throughout the book this falsifiability is his main commitment, and if it was throughout the whole book then I would have given it 5 stars. However, he recapitulates in the epilogue and claims that there are things that are probably "intrinsic" and "essence-like" and seems to hark back to dualist and unfalsifiable theories of consciousness. Though this is a tiny section of the book it scares me that he would build such a wonderful relational justification for the universe and then discard it because he can't "see" how consciousness would fit into it. He drives a difficult path through the mire and then seems to jump on an easy one at the end for a bit of light relief! It is difficult to imagine a relational and heterophenomenological theory of consciousness, but just because it is difficult to imagine is no argument against it, and certainly should justify believing in essences! He was admittedly coy about even delving into this topic and I just wish he hadn't. It seemed to come out of nowhere. In the rest of the book he argues very well that people have been stuck in a rut and think about physical theories in a dubious way, and I think is argument is important and should be well-read. I also like his arguments for things having an actual history and evolving being a very important criteria in science - as else we are effectively presuming timelessness. His main thesis is certainly very palatable, and deserves serious attempts to falsify it. One of the most exciting sections of the book is the section on shape dynamics - theories which are equivalent to general relativity but in which size is not absolute, but relative, yet which also has a preferred time slicing. A wonderful idea. In summary: read this book, just be careful with the epilogue!
on 21 December 2014
Physics has encountered a tough problem in explaining why the fundamental constants which define the masses, charges and interactions of particles have the values they do. This impasse, decades in duration, was analysed by Lee Smolin in his 2006 book, "The Trouble with Physics".
Foremost among attempts at its resolution are schemes containing a plethora of universes, possibly an infinitude, of which our local one just happens to be the way it is; if it weren't we would not be here to wonder about these things. Hardly a falsifiable proposition, and therefore not scientific, as Smolin points out.
Mind you, his preferred scenario is also replete with universes, though in his universes a selection mechanism is at work which zones in on our particular cosmic environment as a fruitful one for propagation of more universes via black holes. Cosmic "genes" (fundamental constants, initial conditions) that are good for production of black holes are good also for galaxies, stars, planets and, ultimately, us. This theory is at least capable of making predictions which are falsifiable (or not) using available data sources.
Time is implicit in his hypothetical process. But universal time is associated with the concept of simultaneity which is ruled out by relativity. Smolin and his associates are working on a resolution of this conflict which might, as a bonus, explain non-local aspects of quantum entanglement without invoking the notorious hidden variables which have themselves been pretty well ruled out by clashes with Bell's theorem.
So far, nothing has come of this approach, though the reality of time is supported by the emergence of complexity in a universe which should by rights be heading for equilibrium. The discussion of how this happens through the intervention of gravity and the effective re-setting of entropy's clock when stars light up is fascinating and rewarding to read.
But, apart from a few such illuminating insights, this book makes tedious reading. It suffers from poor style, lack of conciseness in presentation of ideas, sloppy diagrams and a great deal of repetition. The epilogue is a rambling discourse upon life, the universe and everything, including subjects as diverse as ecology, economics, moral values, the origin and nature of consciousness - even global warming. Read this section first and you might save yourself an awful lot of time.
on 16 January 2014
Lee Smolin is a researcher at the Perimeter Institute in Canada and considers low level issues in physics like why it's so hard to formulate gravity in a quantum framework. He's also a bit of an outsider because he thinks modern physics hasn't really progressed in 30 years. Sure we have light emitting diodes and smartphone but there's been no change in fundamental physics. For example, the theoretical under-pinnings of the recently discovered Higgs boson were written down 50 years ago.
So in the book Smolin advances his view of a possible alternative formulation of fundamental physics which he believes will allow progress to be made. Core to this alternative formulation is our perception of time as an eternal, outside constant. This is why the book has the name it does. He's not proposing to rewrite general relativity or quantum mechanics he's just suggesting looking at these pillars from a different perspective.
If you are into physics and want a non-establishment view of current ideas and research in physics this will be a good read for you.
on 6 October 2014
In this remarkable book Lee Smolin carefully builds the case for adopting time rather than space as the fundamental property of the universe. The principal models which describe the physical behaviour of material, Newtonian, relativistic and quantum mechanics agree very well with experiment but do not give completely consistent accounts of experimentally observed reality because they model isolated systems. A truly fundamental description of physical reality must take into account the rest of the universe in which we exist. By considering the dynamic behaviour of material in an unbounded universe Professor Smolin concludes that there is good reason to expect that a consistent account of reality can be achieved if we accept the reality of absolute time and space as an emergent property. The case for this approach is beautifully made without recourse to mathematics and the author shows that it leads to experimentally testable conclusions. Despite the absence of maths the book is not an easy read because the arguments are detailed, but the writing is lucid. I find the book both enjoyable and exciting because it offers the hope of progress in deepening our understanding of reality.
on 16 April 2015
A boy writes his telephone number on a tennis ball and throws it to a stranger, who catches it. If you want to know more, you'll need to buy the book. The story exemplifies Smolin's easy fluent narrative style. This is a book with no formulae, and the easiest way into special relativity that I've seen in a pop science book. At the same time, Smolin is generally true to science, and he lets you know when his ideas are reaching into conjecture and metaphysics.
The parable of the tennis ball elegantly shows the two views of time that Smolin contrasts in this book. The flight of the ball follows a parabola, following Newton's laws of motion, which Einstein's General Relativity generalises. These laws treat time as another static dimension. There is no "now" or flow of time, or even a direction -- a movie of a tennis ball in flight would look the same run forwards or backwards. This static timeless view of the world is what this book is arguing against.
What happens at the ends of the ball's flight exemplify the other view of time, which Smolin is trying to bring back into physics, a view that gives time direction and flow, and cannot simply be treated as another dimension. The boy who writes the phone number is deciding to change his future, and is transmitting information forward in time.
Conventional physics has only the second law of thermodynamics to offer, that disorder increases, but this law leaves many questions unanswered, such as why everything was so well-ordered in the first place, or the apparent direction of causality, or the strange time-asymmetric "collapse" of the wavefunction in quantum mechanics. In particular, if there is such a concept as "before the big bang", time has to be more than just some emergent property of the known universe.
Smolin does not so much answer these questions as pose them, but I think he does well to do so. He criticises the multiple universes or Goldilocks theory on the grounds that it is unverifiable. However, some of his own conjectures strike me as being metaphysical in the same way. Surely the way to determine whether the universe is finite or closed is through experiment, rather than metaphysical argument.
I find Smolin rather too vague about the detail of what he means by time that is independent of space -- a time that can exist before the Big Bang, and which could define the ordering of the two ends of a EPR experiment. (I do not think it is necessary to define an ordering in that case, and the concept of direction of causation is all he needs in general. But what do I know.)
Smolin's theory of the evolution of universes via black holes, though contentious, does have the benefit of being testable. If it proves true, it surely wins Smolin a Nobel prize, and also confirms him as one of the most visionary physicists of our generation.
on 19 April 2015
This is a deep and thought provoking book by an expert in the subject who is also something of a heretic (since he has doubts about certain implications of General Relativity). At the same time I found it lacking in certain respects. Smolin does not really go into what (our notion of) time is and in particular does not distinguish sharply between time as succession and time as duration.
The disappearance of time in modern physics is alarming from the human point of view since it endangers the very concept of personal liberty and choice (because In the GR block-universe model everything that can happen has in some sense already happened). But Lee Smolin deliberately skips these aspects and implications, precisely those that would interest the general reader the most. The book is a wide ranging non-mathematical but nonetheless strictly scientific study. There is little questioning of science itself as the one and only path to firm knowledge. It is dreadful to think we are in some sense dependent on a small elite of mathematical physicists for what we can know about reality (including the 'future' which is no longer the future). The implications of General Relativity are even worse than those of Quantum Mechanics, almost I prefer the latter since there is at least uncertainty. But while registering some reservations, Lee Smolin does not really show what's wrong with the GR block universe picture which I can only hope to God is not completely true. Galada
on 14 March 2015
The concept that "Time is real" is not completely original to Smolin and his collaborators. The idea was central to the thought of the philosopher Henri Bergson, and I'm amazed Bergson goes unmentioned in the book, especially since Smolin prides himself on the breadth of his philosophical studies.
There are superficial flaws which make the book average. The prose frequently loses focus, as when Smolin attempts to enliven his writing with personal anecdotes in the manner of Nassim Taleb's popular works, but Smolin lacks Taleb's gift for discursive narrative. The excursion into climate change and economics theory towards the end adds little to the book and it comes across as an exercise in scientific megalomania.
The author also continually asserts that his thesis undermines the need for metaphysics. Yet the tradition he is writing against shares the same disdain for metaphysics too; Smolin is confused on this issue, assuming that the idea that Time is an illusion is inherently Platonic and supportive of traditional ideas of God and the ideal as Timeless. However, there has been a great deal of work in theology in recent years which opens up the concept of God as being involved in Time - such as Keith Ward's work on the Trinity. Henri Bergson understood that Time is real yet he also wrote metaphysics.
Overall, I was disappointed by the quality of the book, but the central concept is important.
on 26 April 2013
Professor Lee Smolin argues that we need to move away from 'timeless' theories of physics and put 'now' back where it belongs, at the centre of our theories, just as it is at the centre of our experience. This, he maintains, will allow progress in quantum theories beyond the discomfiting and untestable notion that we live in an infinite multiverse, where anything that can happen does happen, an infinite number of times. Exciting stuff, presented in a non-mathematical way that does not presume an extensive knowledge of physics. Einstein found 'now' puzzling... I guess he might approve of this approach.
on 22 January 2015
I thought that Lee Smolin's "The Trouble With Physics" was a timely and important critique of string theory's dominance of the research agenda in fundamental physics, given that it has failed to deliver - or even progress towards - testable predictions about reality. I was looking forward to his new book, which purports to offer some new approaches which might start to bring theory back on an intercept course with experiment.
Central to Smolin's proposed new approach is the idea that time is "real", in the sense that there is such a thing as "the present moment", which is qualitatively different from the future and the past, independently of any observer perceiving it to be so. The fact that pretty much all scientific advances since Gallileo have suggested the contrary (that all moments are equally real and it is a subjective experience that the present moment is fundamentally different from those that have gone before or are yet to come) is, Smolin suggests, a mistaken notion that is holding scientific progress back.
Smolin offers no data or experiment to support this conclusion, but merely a set of logical and linguistic arguments - Time Reborn should therefore really be classed more as philosophy than science. Unfortunately, Lee Smolin is not a good philosopher, and his arguments turn out to be a house of cards built on flimsy foundations.
Things start off badly when Smolin hints at a sympathy for platonism - a 2400 year old metaphysical system basically expressing Plato's inability to comprehend the concept of an abstraction. Much ink is dedicated to what Smolin calls the Newtonian Paradigm of science - experiments performed repeatedly on isolated systems from which conclusions are drawn about the underlying laws that are operating. Smolin suggests that because a system can never be truly isolated (it is always at least gravitationally affected by its environment), anything we conclude from such experiments can be at best an approximation to a fundamental "law" because there will always be other factors at play. He seems either not to understand or to be skeptical of the idea that what remains true across multiple repetitions and in many environments is deduced to be an underlying law, even though any specific experiment is always going to be affected by other factors. This is reminiscent of Plato's failure to understand that an abstraction is basically just grouping objects by their commonalities and ignoring their differences. It cannot and does not try to capture every single detail of specific concrete objects. Similarly, scientific "laws" do not purport to capture every aspect of a system, but hopefully to model what is common between them. To conclude (as Smolin does) that there can be no such thing as a universal law because there is never a perfectly isolated system that embodies it seems to rather miss the point.
Smolin further suggests that physics has hit a roadblock because it tries to apply the Newtonian Paradigm to cosmology (the study of the whole universe), but fails because the universe cannot be isolated (from the observer, at least) or repeated. Smolin criticises scientists for trying to apply a method which works on small parts of the universe to the universe as a whole, but then repeatedly commits the equivalent philosophical error - many of his arguments boil down to logical arguments constructed in domains where the words used cannot reasonably be assumed to apply - broadly what would be called a "category error". Just because we can ask "What was happening before time began?" it does not mean there must be an answer, for instance (Smolin's arguments are not so crude, but often resolve to a similar misuse of logic).
It is Leibniz that gets the most name checks in the book though, with Smolin citing several of the philosopher's principles as guides. The Principle Of Sufficient Reason is the first pillar on which Smolin attempts to construct his cosmology, though I am not sure Leibniz would condone Smolin's interpretation of it. Starting from his Principle of Sufficient Reason and through dubious logical gymnastics Smolin deduces a series of principles which he believes a valid cosmological theory must embody. At each step he seems to try to make the case that reconceiving time as fundamental and "real" both implies and is implied by his arguments, though I don't think he ever makes a convincing case for it either way.
Time Reborn starts off pretty unconvincing and gets even more so as it goes on. By the midpoint it had become a real slog to get through, as Smolin deduces new conclusions and principles from arguments he has failed to convincingly make earlier. It all comes across as sophomoric philosophical speculation with little or no connection with scientific experiment. By the time Smolin is basing his arguments on things like a "Principle of no unreciprocated action" that he basically pulls from nowhere (just the observation that it worked for Einstein - I don't think it was a major motivation for General Relativity, to be honest) he might as well just be filling the page with the word "bibble". At one point he suggests that a new understanding of quantum mechanics might be based on a "principle of precedence" - essentially that the universe makes up the results to any given experiment as it goes along, constrained only by the rule that it must be consistent with the results of previous experiments. How such consistency is enforced is never even speculated about, and no method by which we could prove that the result of an experiment we have never performed was undetermined before we performed it is suggested. It seems basically to be motivated by a desire to show that the future is "open", in that novel events can happen which are not determined by the history of the system, and therefore that humans might have "free will", because that would be nice. Maybe, but it's not science.
I do agree that string theory has taken physicists on a detour down what is looking increasingly like a blind alley, and that fresh new ideas are needed to get the discipline back on a productive course. Those ideas have to be driven by the data though - theories which can explain the data we already have better than existing theory, or ideas for novel experiments that might yield fresh leads. Second rate philosophy and speculation ain't going to do it.