Early in his career, the author received some unorthodox career advice from Richard Feynman. Feynman noted that in physics, as in all sciences, there were a large number of things that most professional scientists believed which nobody had been able to prove or demonstrate experimentally. Feynman's insight was that, when considering one of these problems as an area to investigate, there were two ways to approach it. The first was to try to do what everybody had failed previously to accomplish. This, he said, was extremely difficult and unlikely to succeed, since it assumes you're either smarter than everybody who has tried before or have some unique insight which eluded them. The other path is to assume that the failure of numerous brilliant people might indicate that what they were trying to demonstrate was, in fact, wrong, and that it might be wiser for the ambitious scientist to search for evidence to the contrary.
Based upon the author's previous work and publications, I picked up this book expecting a discussion of the problem of time in quantum gravity. What I found was something breathtakingly more ambitious. In essence, the author argues that when it comes to cosmology: the physics of the universe as a whole, physicists have been doing it wrong for centuries, and that what he calls the “Newtonian paradigm” must be replaced with one in which time is fundamental in order to stop speaking nonsense.
The equations of general relativity, especially when formulated in attempts to create a quantum theory of gravitation, seem to suggest that our perception of time is an illusion: we live in a timeless block universe, in which our consciousness can be thought of as a cursor moving through a fixed, deterministic spacetime. In general relativity, the rate of perceived flow of time depends upon one's state of motion and the amount of mass-energy in the vicinity of the observer, so it makes no sense to talk about any kind of global time co-ordinate. Quantum mechanics, on the other hand, assumes there is a global clock, external to the system and unaffected by it, which governs the evolution of the wave function. These views are completely incompatible—hence the problem of time in quantum gravity.
But the author argues that “timelessness” has its roots much deeper in the history and intellectual structure of physics. When one uses Newtonian mechanics to write down a differential equation which describes the path of a ball thrown upward, one is reducing a process which would otherwise require enumerating a list of positions and times to a timeless relationship which is valid over the entire trajectory. Time appears in the equation simply as a label which causes it to emit the position at that moment. The equation of motion, and, more importantly, the laws of motion which allow us to write it down for this particular case, are entirely timeless: they affect the object but are not affected by it, and they appear to be specified outside the system.
This, when you dare to step back and think about it, is distinctly odd. Where did these laws come from? Well, in Newton's day and in much of the history of science since, most scientists would say they were prescribed by a benevolent Creator. (My own view that they were put into the simulation by the 13 year old superkid who created it in order to win the Science Fair with the most interesting result, generating the maximum complexity, is isomorphic to this explanation.) Now, when you're analysing a system “in a box”, it makes perfect sense to assume the laws originate from outside and are fixed; after all, we can compare experiments run in different boxes and convince ourselves that the same laws obtain regardless of symmetries such as translation, orientation, or boost. But note that once we try to generalise this to the entire universe, as we must in cosmology, we run into a philosophical speed bump of singularity scale. Now we cannot escape the question of where the laws came from. If they're from inside the universe, then there must have been some dynamical process which created them. If they're outside the universe, they must have had to be imposed by some process which is external to the universe, which makes no sense if you define the universe as all there is.
Smolin suggests that laws exist within our universe, and that they evolve in an absolute time, which is primordial. There is no unmoved mover: the evolution of the universe (and the possibility that universes give birth to other universes) drives the evolution of the laws of physics. Perhaps the probabilistic results we observe in quantum mechanical processes are not built-in ahead of time and prescribed by timeless laws outside the universe, but rather a random choice from the results of previous similar measurements. This “principle of precedence”, which is remarkably similar to that of English common law, perfectly reproduces the results of most tests of quantum mechanics, but may be testable by precision experiments where circumstances never before created in the universe are measured, for example in quantum computing. (I am certain Prof. Smolin would advocate for my being beheaded were I to point out the similarity of this hypothesis with Rupert Sheldrake's concept of morphic resonance; some years ago I suggested to Dr Sheldrake a protein crystallisation experiment on the International Space Station to test this theory; it is real science, but to this date nobody has done it. Few wish to risk their careers testing what “everybody knows”.)
This is one those books you'll need to think about after you've read it, then after some time, re-read to get the most out of it.
Enjoy fast, FREE delivery, exclusive deals and award-winning movies & TV shows with Prime
Try Prime
and start saving today with Fast, FREE Delivery
Amazon Prime includes:
Fast, FREE Delivery is available to Prime members. To join, select "Try Amazon Prime and start saving today with Fast, FREE Delivery" below the Add to Cart button.
Amazon Prime members enjoy:- Cardmembers earn 5% Back at Amazon.com with a Prime Credit Card.
- Unlimited Free Two-Day Delivery
- Instant streaming of thousands of movies and TV episodes with Prime Video
- A Kindle book to borrow for free each month - with no due dates
- Listen to over 2 million songs and hundreds of playlists
- Unlimited photo storage with anywhere access
Important: Your credit card will NOT be charged when you start your free trial or if you cancel during the trial period. If you're happy with Amazon Prime, do nothing. At the end of the free trial, your membership will automatically upgrade to a monthly membership.
Buy new:
$18.90$18.90
FREE delivery: Friday, Aug 18 on orders over $25.00 shipped by Amazon.
Payment
Secure transaction
Ships from
Amazon
Sold by
Returns
Eligible for Return, Refund or Replacement within 30 days of receipt
Buy new:
$18.90$18.90
FREE delivery: Friday, Aug 18 on orders over $25.00 shipped by Amazon.
Payment
Secure transaction
Ships from
Amazon
Sold by
Returns
Eligible for Return, Refund or Replacement within 30 days of receipt
Buy used: $8.68
Buy used:
$8.68
Have one to sell?
Other Sellers on Amazon
Added
Not added
$18.87
& FREE Shipping
& FREE Shipping
Sold by: SKMG
Sold by: SKMG
(395 ratings)
92% positive over last 12 months
92% positive over last 12 months
Only 1 left in stock - order soon.
Shipping rates and Return policy Added
Not added
$18.89
FREE Shipping
on orders over $25.00
shipped by Amazon.
FREE Shipping
Get free shipping
Free shipping
within the U.S. when you order $25.00
of eligible items shipped by Amazon.
Or get faster shipping on this item starting at $5.99
. (Prices may vary for AK and HI.)
Learn more about free shipping
Sold by: GLOBALIXIR
Sold by: GLOBALIXIR
(344 ratings)
100% positive over last 12 months
Shipping rates and Return policy 100% positive over last 12 months
Added
Not added
$18.93
FREE Shipping
on orders over $25.00
shipped by Amazon.
FREE Shipping
Get free shipping
Free shipping
within the U.S. when you order $25.00
of eligible items shipped by Amazon.
Or get faster shipping on this item starting at $5.99
. (Prices may vary for AK and HI.)
Learn more about free shipping
Sold by: markable
Sold by: markable
(2463 ratings)
100% positive over last 12 months
100% positive over last 12 months
Only 1 left in stock - order soon.
Shipping rates and Return policy 
See Clubs
Loading your book clubs
There was a problem loading your book clubs. Please try again.
Not in a club? Learn more
Join or create book clubs
Choose books together
Track your books
Bring your club to Amazon Book Clubs, start a new book club and invite your friends to join, or find a club that’s right for you for free.
Download the free Kindle app and start reading Kindle books instantly on your smartphone, tablet, or computer - no Kindle device required. Learn more
Read instantly on your browser with Kindle for Web.
Using your mobile phone camera - scan the code below and download the Kindle app.
Flip to back Flip to front
Audible sample Sample 
Time Reborn: From the Crisis in Physics to the Future of the Universe Hardcover – April 23, 2013
by
Lee Smolin
(Author),
Henry Reich
(Illustrator)
{"desktop_buybox_group_1":[{"displayPrice":"$18.90","priceAmount":18.90,"currencySymbol":"$","integerValue":"18","decimalSeparator":".","fractionalValue":"90","symbolPosition":"left","hasSpace":false,"showFractionalPartIfEmpty":true,"offerListingId":"xxCqd957Hi89q7xApSWaT%2FtPKfUydsXKWVGzRXx0ngyQM63%2B00sqJiI652LPR550nLsFwx3aKRO8t%2BkpP7xBxDTnjDeODoMu10P3fJQ2dbf897DwP%2FepdwTyNGCBqVZfqGSWTeVQHBaXVPnOIoJvnwg%2BLp3Sx8bdhnKm1DL36zDjW0vtf%2BBUaw%3D%3D","locale":"en-US","buyingOptionType":"NEW","aapiBuyingOptionIndex":0}, {"displayPrice":"$8.68","priceAmount":8.68,"currencySymbol":"$","integerValue":"8","decimalSeparator":".","fractionalValue":"68","symbolPosition":"left","hasSpace":false,"showFractionalPartIfEmpty":true,"offerListingId":"xxCqd957Hi89q7xApSWaT%2FtPKfUydsXKx9XehSDhAzXbClHGkQAdQvM0PZ2XoOfG4qhKiyvvB%2BYiqoXN%2B2jFxO8XUeCAJ9aqhJcTbD6EN3GHoPMyUzn6ReSrZik3qhwySHDNdi%2Bpwqit05nzxYXoOPFWC%2B5EQKgI4PfWb0vz6PvRtzH1FvGL6HAojZQ4ljAY","locale":"en-US","buyingOptionType":"USED","aapiBuyingOptionIndex":1}]}
Purchase options and add-ons
From one of our foremost thinkers and public intellectuals, a radical new view of the nature of time and the cosmos
What is time?
This deceptively simple question is the single most important problem facing science as we probe more deeply into the fundamentals of the universe. All of the mysteries physicists and cosmologists face—from the Big Bang to the future of the universe, from the puzzles of quantum physics to the unification of forces and particles—come down to the nature of time.
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, from Newton to Einstein to today’s quantum theorists, have seen things differently. The scientific case for time being an illusion is formidable. That is why the consequences of adopting the view that time is real are revolutionary.
Lee Smolin, author of the controversial bestseller The Trouble with Physics, argues that a 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 possibilities. There are few ideas that, like our notion of time, shape our thinking about literally everything, with huge 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.
What is time?
This deceptively simple question is the single most important problem facing science as we probe more deeply into the fundamentals of the universe. All of the mysteries physicists and cosmologists face—from the Big Bang to the future of the universe, from the puzzles of quantum physics to the unification of forces and particles—come down to the nature of time.
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, from Newton to Einstein to today’s quantum theorists, have seen things differently. The scientific case for time being an illusion is formidable. That is why the consequences of adopting the view that time is real are revolutionary.
Lee Smolin, author of the controversial bestseller The Trouble with Physics, argues that a 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 possibilities. There are few ideas that, like our notion of time, shape our thinking about literally everything, with huge 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.
- Print length352 pages
- LanguageEnglish
- PublisherHoughton Mifflin Harcourt
- Publication dateApril 23, 2013
- Dimensions6.5 x 1.5 x 9.5 inches
- ISBN-100547511728
- ISBN-13978-0547511726
Book recommendations, author interviews, editors' picks, and more. Read it now
Frequently bought together
This item: Time Reborn: From the Crisis in Physics to the Future of the Universe
$18.90$18.90
Get it as soon as Friday, Aug 18
Only 1 left in stock - order soon.
+
$19.84$19.84
Get it as soon as Friday, Aug 18
Only 1 left in stock - order soon.
Total price:
To see our price, add these items to your cart.
Try again!
Added to Cart
These items are shipped from and sold by different sellers.
Choose items to buy together.
What do customers buy after viewing this item?
Page 1 of 1 Start overPage 1 of 1
- Most purchased | Highest rated | Lowest Pricein this set of products
A Brief History of TimeStephen HawkingPaperback
Editorial Reviews
From Booklist
*Starred Review* Was Einstein wrong? At least in his understanding of time, Smolin argues, the great theorist of relativity was dead wrong. What is worse, by firmly enshrining his error in scientific orthodoxy, Einstein trapped his successors in insoluble dilemmas as they try to devise timeless laws explaining the origins and structure of the cosmos. How, Smolin asks, can such laws account for the highly improbable set of conditions that triggered the big bang jump-starting the universe? How, Smolin further wants to know, can scientists ever empirically test their timeless cosmic hypotheses? With rare conceptual daring, Smolin beckons toward a new perspective for doing cosmological theory, a perspective allowing Leibniz’s principle of sufficient reason to open surprising possibilities. This horizon not only readmits time as a reality; it enshrines time as the reality, the indispensable point of flux allowing everything else, including the laws of matter and energy, to evolve and change. Embracing time as real, Smolin asserts, will allow cosmologists to convert laws once regarded as timeless into the contingent data they need to develop testable new theories of galactic evolution. More immediately, Smolin anticipates that this paradigm shift will help climatologists understand global warming and economists to ameliorate financial turbulence. A thrilling intellectual ride! --Bryce Christensen
Review
"[Smolin’s] book, a mix of science, philosophy and science fiction, is at once entertaining, thought-provoking, fabulously ambitious and fabulously speculative." —The New York Times"Provocative, original, and unsettling." —The New York Review of Books"Brilliant…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." —Popular Science"Smolin provides a much-needed dose of clarity about time, with implications that go far beyond physics to economics, politics, and personal philosophy. An essential book for physicists and non-physicists alike, Time Reborn offers a path to better theory and potentially to a better society." —Jaron Lanier, author of You Are Not a Gadget and The Fate of Power and the Future of Dignity"Applying his deep mastery of cosmology, quantum mechanics, general relativity and all the diverse attempts at quantum gravity, in Time Reborn Lee Smolin weaves a convincing and entirely new view of reality. He shows us how contemporary physics eliminates time and argues persuasively that any adequate cosmology rests on making time and ‘now’ fundamental." —Stuart Kauffman, University of Vermont, author of At Home in the Universe"Smolin is an excellent writer, a creative thinker and is ecumenical in the way he covers so many different branches of thought. Even as I mentally argued with this book, I kept on ploughing through to see how Smolin dealt with the objections. I would love to sit down with him over a drink and debate the ins and outs of his theory. And that is how this book should be read: as an account that makes you ask questions." —Nature"An entertaining, head-spinning and, yes, timely blend of philosophy, science, and speculation to put the Now back into physics." —The Telegraph "An energetic case for a paradigm shift that could produce mind-boggling changes in the way we experience our world." —Publishers Weekly"A thoughtful, complex re-evaluation of the role of time in the universe…A flood of ideas from an imaginative thinker." —Kirkus
"With rare conceptual daring, Smolin beckons toward a new perspective for doing cosmological theory…A thrilling intellectual ride!"—Booklist (starred review)
From the Inside Flap
From one of our foremost thinkers and public intellectuals, a radical new view of the nature of time and the cosmos
What is time?
This deceptively simple question is the single most important problem facing science as we probe more deeply into the fundamentals of the universe. All of the mysteries physicists and cosmologists facefrom the Big Bang to the future of the universe, from the puzzles of quantum physics to the unification of forces and particlescome down to the nature of time.
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, from Newton to Einstein to todays quantum theorists, have seen things differently. The scientific case for time being an illusion is formidable. That is why the consequences of adopting the view that time is real are revolutionary.
Lee Smolin, author of the controversial bestseller The Trouble with Physics, argues that a limited notion of time is holding physics back. Its 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 possibilities. There are few ideas that, like our notion of time, shape our thinking about literally everything, with huge implications for physics and beyondfrom climate change to the economic crisis. Smolin explains in lively and lucid prose how the true nature of time impacts our world.
What is time?
This deceptively simple question is the single most important problem facing science as we probe more deeply into the fundamentals of the universe. All of the mysteries physicists and cosmologists facefrom the Big Bang to the future of the universe, from the puzzles of quantum physics to the unification of forces and particlescome down to the nature of time.
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, from Newton to Einstein to todays quantum theorists, have seen things differently. The scientific case for time being an illusion is formidable. That is why the consequences of adopting the view that time is real are revolutionary.
Lee Smolin, author of the controversial bestseller The Trouble with Physics, argues that a limited notion of time is holding physics back. Its 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 possibilities. There are few ideas that, like our notion of time, shape our thinking about literally everything, with huge implications for physics and beyondfrom climate change to the economic crisis. Smolin explains in lively and lucid prose how the true nature of time impacts our world.
About the Author
LEE SMOLIN has made influential contributions to the search for a unification of physics. He is a founding faculty member of the Perimeter Institute for Theoretical Physics. His previous books include The Trouble with Physics, The Life of the Cosmos, and Three Roads to Quantum Gravity.
Excerpt. © Reprinted by permission. All rights reserved.
INTRODUCTION The scientific case for time being an illusion is formidable. That is why the consequences of adopting the view that time is real are revolutionary.
The core of the physicists’ case against time relies on the way we understand what a law of physics is. According to this dominant view, everything that happens in the universe is determined by a law, which dictates precisely how the future evolves out of the present. The law is absolute and, once present conditions are specified, there is no freedom or uncertainty in how the future will evolve.
As Thomasina, the precocious heroine of Tom Stoppard’s play Arcadia, explains to her tutor: “If you could stop every atom in its position and direction, and if your mind could comprehend all the actions thus suspended, then if you were really, really good at algebra you could write the formula for all the future; and although nobody can be so clever as to do it, the formula must exist just as if one could.”
I used to believe that my job as a theoretical physicist was to find that formula; I now see my faith in its existence as more mysticism than science.
Were he writing lines for a modern character, Stoppard would have had Thomasina say that the universe is like a computer. The laws of physics are the program. When you give it an input — the present positions of all the elementary particles in the universe — the computer runs for an appropriate amount of time and gives you the output, which is all the positions of the elementary particles at some future time. Within this view of nature, nothing happens except the rearrangement of particles according to timeless laws, so according to these laws the future is already completely determined by the present, as the present was by the past.
This view diminishes time in several ways.1 There can be no surprises, no truly novel phenomena, because all that happens is rearrangement of the atoms. The properties of the atoms themselves are timeless, as are the laws controlling them; neither ever changes. Any feature of the world at a future time can be computed from the configuration of the present. That is, the passage of time can be replaced by a computation, which means that the future is logically a consequence of the present.
Einstein’s theories of relativity make even stronger arguments that time is inessential to a fundamental description of the world, as I’ll discuss in chapter 6. Relativity strongly suggests that the whole history of the world is a timeless unity; present, past, and future have no meaning apart from human subjectivity. Time is just another dimension of space, and the sense we have of experiencing moments passing is an illusion behind which is a timeless reality.
These assertions may seem horrifying to anyone whose worldview includes a place for free will or human agency. This is not an argument I will engage in here; my case for the reality of time rests purely on science. My job will be to explain why the usual arguments for a predetermined future are wrong scientifically.
In Part I, I will present the case from science for believing that time is an illusion. In Part II, I will demolish those arguments and show why time must be taken to be real if fundamental physics and cosmology are to overcome the crises they currently face.
To frame the argument of Part I, I trace the development of the concepts of time used in physics, from Aristotle and Ptolemy through Galileo, Newton, Einstein, and on to our contemporary quantum cosmologists, and show how our concept of time was diminished, step by step, as physics progressed. Telling the story this way also allows me to gently introduce the material the lay reader needs for an understanding of the argument. Indeed, key points can be introduced by ordinary examples of balls falling and planets orbiting. Part II tells a more contemporary story, since the argument that time must be reinserted into the core of science arose as a result of recent developments.
My argument starts with a simple observation: The success of scientific theories from Newton through the present day is based on their use of a particular framework of explanation invented by Newton. This framework views nature as consisting of nothing but particles with timeless properties, whose motions and interactions are determined by timeless laws. The properties of the particles, such as their masses and electric charges, never change, and neither do the laws that act on them. This framework is ideally suited to describe small parts of the universe, but it falls apart when we attempt to apply it to the universe as a whole.
All the major theories of physics are about parts of the universe — a radio, a ball in flight, a biological cell, the Earth, a galaxy. When we describe a part of the universe, we leave ourselves and our measuring tools outside the system. We leave out our role in selecting or preparing the system we study. We leave out the references that serve to establish where the system is. Most crucially for our concern with the nature of time, we leave out the clocks by which we measure change in the system.
The attempt to extend physics to cosmology brings new challenges that require fresh thinking. A cosmological theory cannot leave anything out. To be complete, it must take into account everything in the universe, including ourselves as observers. It must account for our measuring instruments and clocks. When we do cosmology, we confront a novel circumstance: It is impossible to get outside the system we’re studying when that system is the entire universe.
Moreover, a cosmological theory must do without two important aspects of the methodology of science. A basic rule of science is that an experiment must be done many times to be sure of the result. But we cannot do this with the universe as a whole — the universe only happens once. Nor can we prepare the system in different ways and study the consequences. These are very real handicaps, which make it much harder to do science at the level of the universe as a whole.
Nonetheless, we want to extend physics to a science of cosmology. Our first instinct is to take the theories that worked so well when applied to small parts of the universe and scale them up describe the universe as a whole. As I’ll show in chapters 8 and 9, this cannot work. The Newtonian framework of timeless laws acting on particles with timeless properties is unsuited to the task of describing the entire universe.
Indeed, as I will show in detail, the very features that make these kinds of theories so successful when applied to small parts of the universe cause them to fail when we attempt to apply them to the universe as a whole.
I realize that this assertion goes counter to the practice and hopes of many colleagues, but I ask only that the reader pay close attention to the case I make for it in Part II. There I will show in general, and illustrate by specific example, that when we attempt to scale up our standard theories to a cosmological theory, we are rewarded with dilemmas, paradoxes, and unanswerable questions. Among these are the failure of any standard theory to account for the choices made in the early universe — choices of initial conditions and choices of the laws of nature themselves.
Some of the literature of contemporary cosmology consists of the efforts of very smart people to wrestle with these dilemmas, paradoxes, and unanswerable questions. The notion that our universe is part of a vast or infinite multiverse is popular — and understandably so, because it is based on a methodological error that is easy to fall into. Our current theories can work at the level of the universe only if our universe is a subsystem of a larger system. So we invent a fictional environment and fill it with other universes. This cannot lead to any real scientific progress, because we cannot confirm or falsify any hypothesis about universes causally disconnected from our own.
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. These are presented in chapter 10. In the chapters that follow it, I will illustrate how the principles can inspire new hypotheses and models of the universe that point the way to a true cosmological theory. The central principle is that time must be real and physical laws must evolve in that real time.
The idea of evolving laws is not new, nor is the idea that a cosmological science will require them.2 The American philosopher Charles Sanders Peirce wrote in 1891:
To suppose universal laws of nature capable of being apprehended by the mind and yet having no reason for their special forms, but standing inexplicable and irrational, is hardly a justifiable position. Uniformities are precisely the sort of facts that need to be accounted for. . . . Law is par excellence the thing that wants a reason.
Now the only possible way of accounting for the laws of nature and for uniformity in general is to suppose them results of evolution.”3
The contemporary philosopher Roberto Mangabeira Unger has more recently proclaimed:
You can trace the properties of the present universe back to properties it must have had at its beginning. But you cannot show that these are the only properties that any universe might have had. . . . Earlier or later universes might have had entirely different laws. . . . To state the laws of nature is not to describe or to explain all possible histories of all possible universes. Only a relative distinction exists between lawlike explanation and the narration of a one-time historical sequence.”4
Paul Dirac, who ranks with Einstein and Niels Bohr as one of the most consequential physicists of the 20th century, speculated: “At the beginning of time the laws of Nature were probably very different from what they are now. Thus, we should consider the laws of Nature as continually changing with the epoch, instead of as holding uniformly throughout space-time.”5 John Archibald Wheeler, one of the great American physicists, also imagined that laws evolved. He proposed that the Big Bang was one of a series of events within which the laws of physics were reprocessed. He also wrote, “There is no law except the law that there is no law.”6 Even Richard Feynman, another of the great American physicists and Wheeler’s student, once mused in an interview: “The only field which has not admitted any evolutionary question is physics. Here are the laws, we say, . . . but how did they get that way, in time? . . . So, it might turn out that they are not the same [laws] all the time and that there is a historical, evolutionary, question.”
In my 1997 book, The Life of the Cosmos, I proposed a mechanism for laws to evolve, which I modeled on biological evolution.8 I imagined that universes could reproduce by forming baby universes inside black holes, and I posited that whenever this happens, the laws of physics change slightly. In this theory, the laws played the role of genes in biology; a universe was seen as an expression of a choice of laws made at its formation, just as an organism is an expression of its genes. Like the genes, the laws could mutate randomly from generation to generation. Inspired by then-recent results of string theory, I imagined that the search for a fundamental unified theory would lead not to a single Theory of Everything but to a vast space of possible laws. I called this the landscape of theories, taking the language from population genetics, whose practitioners work with fitness landscapes. I will not say more about this here, as it is the subject of chapter 11, except to say that this theory, cosmological natural selection, makes several predictions that, remarkably, have held up despite several opportunities to falsify them in the years since.
Over the last decade, many string theorists have embraced the concept of a landscape of theories. As a result, the question of how the universe chooses which laws to follow has become especially urgent. This, I will argue, is one of the questions that can be answered only within a new framework for cosmology in which time is real and laws evolve.
Laws, then, are not imposed on the universe from outside it. No external entity, whether divine or mathematical, specifies in advance what the laws of nature are to be. Nor do the laws of nature wait, mute, outside of time for the universe to begin. Rather the laws of nature emerge from inside the universe and evolve in time with the universe they describe. It is even possible that, just as in biology, novel laws of physics may arise as regularities of new phenomena that emerge during the universe’s history.
Some might see the disavowal of eternal laws as a retreat from the goals of science. But I see it as the jettisoning of excess metaphysical baggage that weighs down our search for truth. In the coming chapters, I will provide examples illustrating how the idea of laws evolving in time leads to a more scientific cosmology — by which I mean one more generative of predictions subject to experimental test. To my knowledge, the first scientist since the dawn of the Scientific Revolution to think really hard about how to make a theory of a whole universe was Gottfried Wilhelm Leibniz, who, among other things, was Newton’s rival, famously in the matter of which of them was the first to invent the calculus. He also anticipated modern logic, developed a system of binary numbers, and much else. He has been called the smartest person who ever lived. Leibniz formulated a principle to frame cosmological theories called the principle of sufficient reason, which states that there must be a rational reason for every apparent choice made in the construction of the universe. Every query of the form, “Why is the universe like X rather than Y?” must have an answer. So if a God made the world, He could not have had any choice in the blueprint. Leibniz’s principle has had a profound effect on the development of physics so far, and, as we will see, it continues to be reliable as a guide in our efforts to devise a cosmological theory.
Leibniz had a vision of a world in which everything lives not in space but immersed in a network of relationships. These relationships define space, not the reverse. Today the idea of a universe of connected, networked entities pervades modern physics, as well as biology and computer science.
In a relational world (which is what we call a world where relationships precede space), there are no spaces without things. Newton’s concept of space was absolute: He saw atoms defined by where they are in space but space in no way affected by the motion of atoms. In a relational world, there are no such asymmetries. Things are defined by their relationships. Individuals exist, and they may be partly autonomous, but their possibilities are determined by the network of relationships. Individuals encounter and perceive one another through the links that connect them within the network, and the networks are dynamic and ever evolving.
As I will explain in chapter 3, it follows from Leibniz’s great principle that there can be no absolute time that ticks on blindly whatever happens in the world. Time must be a consequence of change; without alteration in the world, there can be no time. Philosophers say that time is relational — it is an aspect of relations, such as causality, that govern change. Similarly, space must be relational; indeed, every property of an object in nature must be a reflection of dynamical relations between it and other things in the world.
Leibniz’s principles contradicted the basic ideas of Newtonian physics, so it took some time for them to be fully appreciated by working scientists. It was Einstein who embraced Leibniz’s legacy and used his principles as major motivation for his overthrow of Newtonian physics and its replacement by general relativity, a theory of space, time, and gravity that goes far to instantiate Leibniz’s relational view of space and time. Leibniz’s principles are also realized in a different way in the parallel quantum revolution. I call the 20th-century revolution in physics the relational revolution.
The problem of unifying physics and, in particular, bringing together quantum theory with general relativity into one framework is largely the task of completing the relational revolution in physics. The main message of this book is that this requires embracing the ideas that time is real and laws evolve.
The relational revolution is already in full swing in the rest of science. Darwin’s revolution in biology is one front, manifested both in the notion of a species being defined by its relation to all the other organisms in its environment and in the concept that a gene’s action is defined only in the context of the network of genes regulating its action. As we are quickly coming to realize, biology is about information, and there is no more relational concept than information, relying as it does on a relationship between the sender and receiver at each end of a communications channel.
In the social sphere, the liberal concept of a world of autonomous individuals (conceived by the philosopher John Locke as analogous to the physics of his friend Isaac Newton) is being challenged by a view of society as composed of interdependent individuals, only partly autonomous, whose lives are meaningful only within a skein of relationships. The new informational halo within which we are so recently enmeshed expresses the relational idea through the metaphor of the network. As social beings, we see ourselves as nodes in a network whose connections define us. Today the idea of a social system made up of connected, networked entities increasingly crops up in social theories formulated by everyone from feminist political philosophers to management gurus. How many users of Facebook are aware that their social lives are now organized by a potent scientific idea?
The relational revolution is already far along. At the same time, it is clearly in crisis. On some fronts, it’s stuck. Wherever it is in crisis, we find three kinds of questions under hot debate. What is an individual? How do novel kinds of systems and entities emerge? How are we to usefully understand the universe as a whole?
The key to these puzzles is that neither individuals, systems, nor the universe as a whole can be thought of as things that simply are. They are all compounded by processes that take place in time. The missing element, without which we cannot answer these questions, is to see them as processes developing in time. I will argue that to succeed, the relational revolution must embrace the notion of time and the present moment as a fundamental aspect of reality.
In the old way of thinking, individuals were just the smallest units in a system, and if you wanted to understand how a system worked you took it apart and studied how its parts behaved. But how are we to understand the properties of the most fundamental entities? They have no parts, so reductionism (as this method is called) gets us no further. The atomic viewpoint has no place to go here; it, too, is truly stuck. This is a great opportunity for the nascent relational program, for it can — and indeed must — seek the explanation for properties of elementary particles in the network of their relations.
This is already happening in the unified theories we have so far. In the Standard Model of Particle Physics, which is the best theory we have so far of the elementary particles, the properties of an electron, such as its mass, are dynamically determined by the interactions in which it participates. The most basic property a particle can have is its mass, which determines how much force is needed to change its motion. In the Standard Model, all the particles’ masses arise from their interactions with other particles and are determined primarily by one — the Higgs particle. No longer are there absolutely “elementary” particles; everything that behaves like a particle is, to some extent, an emergent consequence of a network of interactions.
Emergence is an important term in a relational world. A property of something made of parts is emergent if it would not make sense when attributed to any of the parts. Rocks are hard, and water flows, but the atoms they’re made of are neither solid nor wet. An emergent property will often hold approximately, because it denotes an averaged or high-level description that leaves out much detail.
As science progresses, aspects of nature once considered fundamental are revealed as emergent and approximate. We once thought that solids, liquids, and gases were fundamental states; now we know that these are emergent properties, which can be understood as different ways to arrange the atoms that make up everything. Most of the laws of nature once thought of as fundamental are now understood as emergent and approximate. Temperature is just the average energy of atoms in random motion, so the laws of thermodynamics that refer to temperature are emergent and approximate.
I’m inclined to believe that just about everything we now think is fundamental will also eventually be understood as approximate and emergent: gravity and the laws of Newton and Einstein that govern it, the laws of quantum mechanics, even space itself.
The fundamental physical theory we seek will not be about things moving in space. It will not have gravity or electricity or magnetism as fundamental forces. It will not be quantum mechanics. All these will emerge as approximate notions when our universe grows large enough.
If space is emergent, does that mean that time is also emergent? If we go deep enough into the fundamentals of nature, does time disappear? In the last century, we have progressed to the point where many of my colleagues consider time to be emergent from a more fundamental description of nature in which time does not appear.
I believe — as strongly as one can believe anything in science — that they’re wrong. Time will turn out to be the only aspect of our everyday experience that is fundamental. The fact that it is always some moment in our perception, and that we experience that moment as one of a flow of moments, is not an illusion. It is the best clue we have to fundamental reality.
The core of the physicists’ case against time relies on the way we understand what a law of physics is. According to this dominant view, everything that happens in the universe is determined by a law, which dictates precisely how the future evolves out of the present. The law is absolute and, once present conditions are specified, there is no freedom or uncertainty in how the future will evolve.
As Thomasina, the precocious heroine of Tom Stoppard’s play Arcadia, explains to her tutor: “If you could stop every atom in its position and direction, and if your mind could comprehend all the actions thus suspended, then if you were really, really good at algebra you could write the formula for all the future; and although nobody can be so clever as to do it, the formula must exist just as if one could.”
I used to believe that my job as a theoretical physicist was to find that formula; I now see my faith in its existence as more mysticism than science.
Were he writing lines for a modern character, Stoppard would have had Thomasina say that the universe is like a computer. The laws of physics are the program. When you give it an input — the present positions of all the elementary particles in the universe — the computer runs for an appropriate amount of time and gives you the output, which is all the positions of the elementary particles at some future time. Within this view of nature, nothing happens except the rearrangement of particles according to timeless laws, so according to these laws the future is already completely determined by the present, as the present was by the past.
This view diminishes time in several ways.1 There can be no surprises, no truly novel phenomena, because all that happens is rearrangement of the atoms. The properties of the atoms themselves are timeless, as are the laws controlling them; neither ever changes. Any feature of the world at a future time can be computed from the configuration of the present. That is, the passage of time can be replaced by a computation, which means that the future is logically a consequence of the present.
Einstein’s theories of relativity make even stronger arguments that time is inessential to a fundamental description of the world, as I’ll discuss in chapter 6. Relativity strongly suggests that the whole history of the world is a timeless unity; present, past, and future have no meaning apart from human subjectivity. Time is just another dimension of space, and the sense we have of experiencing moments passing is an illusion behind which is a timeless reality.
These assertions may seem horrifying to anyone whose worldview includes a place for free will or human agency. This is not an argument I will engage in here; my case for the reality of time rests purely on science. My job will be to explain why the usual arguments for a predetermined future are wrong scientifically.
In Part I, I will present the case from science for believing that time is an illusion. In Part II, I will demolish those arguments and show why time must be taken to be real if fundamental physics and cosmology are to overcome the crises they currently face.
To frame the argument of Part I, I trace the development of the concepts of time used in physics, from Aristotle and Ptolemy through Galileo, Newton, Einstein, and on to our contemporary quantum cosmologists, and show how our concept of time was diminished, step by step, as physics progressed. Telling the story this way also allows me to gently introduce the material the lay reader needs for an understanding of the argument. Indeed, key points can be introduced by ordinary examples of balls falling and planets orbiting. Part II tells a more contemporary story, since the argument that time must be reinserted into the core of science arose as a result of recent developments.
My argument starts with a simple observation: The success of scientific theories from Newton through the present day is based on their use of a particular framework of explanation invented by Newton. This framework views nature as consisting of nothing but particles with timeless properties, whose motions and interactions are determined by timeless laws. The properties of the particles, such as their masses and electric charges, never change, and neither do the laws that act on them. This framework is ideally suited to describe small parts of the universe, but it falls apart when we attempt to apply it to the universe as a whole.
All the major theories of physics are about parts of the universe — a radio, a ball in flight, a biological cell, the Earth, a galaxy. When we describe a part of the universe, we leave ourselves and our measuring tools outside the system. We leave out our role in selecting or preparing the system we study. We leave out the references that serve to establish where the system is. Most crucially for our concern with the nature of time, we leave out the clocks by which we measure change in the system.
The attempt to extend physics to cosmology brings new challenges that require fresh thinking. A cosmological theory cannot leave anything out. To be complete, it must take into account everything in the universe, including ourselves as observers. It must account for our measuring instruments and clocks. When we do cosmology, we confront a novel circumstance: It is impossible to get outside the system we’re studying when that system is the entire universe.
Moreover, a cosmological theory must do without two important aspects of the methodology of science. A basic rule of science is that an experiment must be done many times to be sure of the result. But we cannot do this with the universe as a whole — the universe only happens once. Nor can we prepare the system in different ways and study the consequences. These are very real handicaps, which make it much harder to do science at the level of the universe as a whole.
Nonetheless, we want to extend physics to a science of cosmology. Our first instinct is to take the theories that worked so well when applied to small parts of the universe and scale them up describe the universe as a whole. As I’ll show in chapters 8 and 9, this cannot work. The Newtonian framework of timeless laws acting on particles with timeless properties is unsuited to the task of describing the entire universe.
Indeed, as I will show in detail, the very features that make these kinds of theories so successful when applied to small parts of the universe cause them to fail when we attempt to apply them to the universe as a whole.
I realize that this assertion goes counter to the practice and hopes of many colleagues, but I ask only that the reader pay close attention to the case I make for it in Part II. There I will show in general, and illustrate by specific example, that when we attempt to scale up our standard theories to a cosmological theory, we are rewarded with dilemmas, paradoxes, and unanswerable questions. Among these are the failure of any standard theory to account for the choices made in the early universe — choices of initial conditions and choices of the laws of nature themselves.
Some of the literature of contemporary cosmology consists of the efforts of very smart people to wrestle with these dilemmas, paradoxes, and unanswerable questions. The notion that our universe is part of a vast or infinite multiverse is popular — and understandably so, because it is based on a methodological error that is easy to fall into. Our current theories can work at the level of the universe only if our universe is a subsystem of a larger system. So we invent a fictional environment and fill it with other universes. This cannot lead to any real scientific progress, because we cannot confirm or falsify any hypothesis about universes causally disconnected from our own.
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. These are presented in chapter 10. In the chapters that follow it, I will illustrate how the principles can inspire new hypotheses and models of the universe that point the way to a true cosmological theory. The central principle is that time must be real and physical laws must evolve in that real time.
The idea of evolving laws is not new, nor is the idea that a cosmological science will require them.2 The American philosopher Charles Sanders Peirce wrote in 1891:
To suppose universal laws of nature capable of being apprehended by the mind and yet having no reason for their special forms, but standing inexplicable and irrational, is hardly a justifiable position. Uniformities are precisely the sort of facts that need to be accounted for. . . . Law is par excellence the thing that wants a reason.
Now the only possible way of accounting for the laws of nature and for uniformity in general is to suppose them results of evolution.”3
The contemporary philosopher Roberto Mangabeira Unger has more recently proclaimed:
You can trace the properties of the present universe back to properties it must have had at its beginning. But you cannot show that these are the only properties that any universe might have had. . . . Earlier or later universes might have had entirely different laws. . . . To state the laws of nature is not to describe or to explain all possible histories of all possible universes. Only a relative distinction exists between lawlike explanation and the narration of a one-time historical sequence.”4
Paul Dirac, who ranks with Einstein and Niels Bohr as one of the most consequential physicists of the 20th century, speculated: “At the beginning of time the laws of Nature were probably very different from what they are now. Thus, we should consider the laws of Nature as continually changing with the epoch, instead of as holding uniformly throughout space-time.”5 John Archibald Wheeler, one of the great American physicists, also imagined that laws evolved. He proposed that the Big Bang was one of a series of events within which the laws of physics were reprocessed. He also wrote, “There is no law except the law that there is no law.”6 Even Richard Feynman, another of the great American physicists and Wheeler’s student, once mused in an interview: “The only field which has not admitted any evolutionary question is physics. Here are the laws, we say, . . . but how did they get that way, in time? . . . So, it might turn out that they are not the same [laws] all the time and that there is a historical, evolutionary, question.”
In my 1997 book, The Life of the Cosmos, I proposed a mechanism for laws to evolve, which I modeled on biological evolution.8 I imagined that universes could reproduce by forming baby universes inside black holes, and I posited that whenever this happens, the laws of physics change slightly. In this theory, the laws played the role of genes in biology; a universe was seen as an expression of a choice of laws made at its formation, just as an organism is an expression of its genes. Like the genes, the laws could mutate randomly from generation to generation. Inspired by then-recent results of string theory, I imagined that the search for a fundamental unified theory would lead not to a single Theory of Everything but to a vast space of possible laws. I called this the landscape of theories, taking the language from population genetics, whose practitioners work with fitness landscapes. I will not say more about this here, as it is the subject of chapter 11, except to say that this theory, cosmological natural selection, makes several predictions that, remarkably, have held up despite several opportunities to falsify them in the years since.
Over the last decade, many string theorists have embraced the concept of a landscape of theories. As a result, the question of how the universe chooses which laws to follow has become especially urgent. This, I will argue, is one of the questions that can be answered only within a new framework for cosmology in which time is real and laws evolve.
Laws, then, are not imposed on the universe from outside it. No external entity, whether divine or mathematical, specifies in advance what the laws of nature are to be. Nor do the laws of nature wait, mute, outside of time for the universe to begin. Rather the laws of nature emerge from inside the universe and evolve in time with the universe they describe. It is even possible that, just as in biology, novel laws of physics may arise as regularities of new phenomena that emerge during the universe’s history.
Some might see the disavowal of eternal laws as a retreat from the goals of science. But I see it as the jettisoning of excess metaphysical baggage that weighs down our search for truth. In the coming chapters, I will provide examples illustrating how the idea of laws evolving in time leads to a more scientific cosmology — by which I mean one more generative of predictions subject to experimental test. To my knowledge, the first scientist since the dawn of the Scientific Revolution to think really hard about how to make a theory of a whole universe was Gottfried Wilhelm Leibniz, who, among other things, was Newton’s rival, famously in the matter of which of them was the first to invent the calculus. He also anticipated modern logic, developed a system of binary numbers, and much else. He has been called the smartest person who ever lived. Leibniz formulated a principle to frame cosmological theories called the principle of sufficient reason, which states that there must be a rational reason for every apparent choice made in the construction of the universe. Every query of the form, “Why is the universe like X rather than Y?” must have an answer. So if a God made the world, He could not have had any choice in the blueprint. Leibniz’s principle has had a profound effect on the development of physics so far, and, as we will see, it continues to be reliable as a guide in our efforts to devise a cosmological theory.
Leibniz had a vision of a world in which everything lives not in space but immersed in a network of relationships. These relationships define space, not the reverse. Today the idea of a universe of connected, networked entities pervades modern physics, as well as biology and computer science.
In a relational world (which is what we call a world where relationships precede space), there are no spaces without things. Newton’s concept of space was absolute: He saw atoms defined by where they are in space but space in no way affected by the motion of atoms. In a relational world, there are no such asymmetries. Things are defined by their relationships. Individuals exist, and they may be partly autonomous, but their possibilities are determined by the network of relationships. Individuals encounter and perceive one another through the links that connect them within the network, and the networks are dynamic and ever evolving.
As I will explain in chapter 3, it follows from Leibniz’s great principle that there can be no absolute time that ticks on blindly whatever happens in the world. Time must be a consequence of change; without alteration in the world, there can be no time. Philosophers say that time is relational — it is an aspect of relations, such as causality, that govern change. Similarly, space must be relational; indeed, every property of an object in nature must be a reflection of dynamical relations between it and other things in the world.
Leibniz’s principles contradicted the basic ideas of Newtonian physics, so it took some time for them to be fully appreciated by working scientists. It was Einstein who embraced Leibniz’s legacy and used his principles as major motivation for his overthrow of Newtonian physics and its replacement by general relativity, a theory of space, time, and gravity that goes far to instantiate Leibniz’s relational view of space and time. Leibniz’s principles are also realized in a different way in the parallel quantum revolution. I call the 20th-century revolution in physics the relational revolution.
The problem of unifying physics and, in particular, bringing together quantum theory with general relativity into one framework is largely the task of completing the relational revolution in physics. The main message of this book is that this requires embracing the ideas that time is real and laws evolve.
The relational revolution is already in full swing in the rest of science. Darwin’s revolution in biology is one front, manifested both in the notion of a species being defined by its relation to all the other organisms in its environment and in the concept that a gene’s action is defined only in the context of the network of genes regulating its action. As we are quickly coming to realize, biology is about information, and there is no more relational concept than information, relying as it does on a relationship between the sender and receiver at each end of a communications channel.
In the social sphere, the liberal concept of a world of autonomous individuals (conceived by the philosopher John Locke as analogous to the physics of his friend Isaac Newton) is being challenged by a view of society as composed of interdependent individuals, only partly autonomous, whose lives are meaningful only within a skein of relationships. The new informational halo within which we are so recently enmeshed expresses the relational idea through the metaphor of the network. As social beings, we see ourselves as nodes in a network whose connections define us. Today the idea of a social system made up of connected, networked entities increasingly crops up in social theories formulated by everyone from feminist political philosophers to management gurus. How many users of Facebook are aware that their social lives are now organized by a potent scientific idea?
The relational revolution is already far along. At the same time, it is clearly in crisis. On some fronts, it’s stuck. Wherever it is in crisis, we find three kinds of questions under hot debate. What is an individual? How do novel kinds of systems and entities emerge? How are we to usefully understand the universe as a whole?
The key to these puzzles is that neither individuals, systems, nor the universe as a whole can be thought of as things that simply are. They are all compounded by processes that take place in time. The missing element, without which we cannot answer these questions, is to see them as processes developing in time. I will argue that to succeed, the relational revolution must embrace the notion of time and the present moment as a fundamental aspect of reality.
In the old way of thinking, individuals were just the smallest units in a system, and if you wanted to understand how a system worked you took it apart and studied how its parts behaved. But how are we to understand the properties of the most fundamental entities? They have no parts, so reductionism (as this method is called) gets us no further. The atomic viewpoint has no place to go here; it, too, is truly stuck. This is a great opportunity for the nascent relational program, for it can — and indeed must — seek the explanation for properties of elementary particles in the network of their relations.
This is already happening in the unified theories we have so far. In the Standard Model of Particle Physics, which is the best theory we have so far of the elementary particles, the properties of an electron, such as its mass, are dynamically determined by the interactions in which it participates. The most basic property a particle can have is its mass, which determines how much force is needed to change its motion. In the Standard Model, all the particles’ masses arise from their interactions with other particles and are determined primarily by one — the Higgs particle. No longer are there absolutely “elementary” particles; everything that behaves like a particle is, to some extent, an emergent consequence of a network of interactions.
Emergence is an important term in a relational world. A property of something made of parts is emergent if it would not make sense when attributed to any of the parts. Rocks are hard, and water flows, but the atoms they’re made of are neither solid nor wet. An emergent property will often hold approximately, because it denotes an averaged or high-level description that leaves out much detail.
As science progresses, aspects of nature once considered fundamental are revealed as emergent and approximate. We once thought that solids, liquids, and gases were fundamental states; now we know that these are emergent properties, which can be understood as different ways to arrange the atoms that make up everything. Most of the laws of nature once thought of as fundamental are now understood as emergent and approximate. Temperature is just the average energy of atoms in random motion, so the laws of thermodynamics that refer to temperature are emergent and approximate.
I’m inclined to believe that just about everything we now think is fundamental will also eventually be understood as approximate and emergent: gravity and the laws of Newton and Einstein that govern it, the laws of quantum mechanics, even space itself.
The fundamental physical theory we seek will not be about things moving in space. It will not have gravity or electricity or magnetism as fundamental forces. It will not be quantum mechanics. All these will emerge as approximate notions when our universe grows large enough.
If space is emergent, does that mean that time is also emergent? If we go deep enough into the fundamentals of nature, does time disappear? In the last century, we have progressed to the point where many of my colleagues consider time to be emergent from a more fundamental description of nature in which time does not appear.
I believe — as strongly as one can believe anything in science — that they’re wrong. Time will turn out to be the only aspect of our everyday experience that is fundamental. The fact that it is always some moment in our perception, and that we experience that moment as one of a flow of moments, is not an illusion. It is the best clue we have to fundamental reality.
Product details
- Publisher : Houghton Mifflin Harcourt; First Edition (April 23, 2013)
- Language : English
- Hardcover : 352 pages
- ISBN-10 : 0547511728
- ISBN-13 : 978-0547511726
- Item Weight : 1.25 pounds
- Dimensions : 6.5 x 1.5 x 9.5 inches
- Best Sellers Rank: #212,781 in Books (See Top 100 in Books)
- #34 in Physics of Time (Books)
- #260 in Cosmology (Books)
- Customer Reviews:
Important information
To report an issue with this product, click here.
About the authors
Follow authors to get new release updates, plus improved recommendations.
Lee Smolin earned his Ph.D. in physics at Harvard, then went on to teach at Yale and Pennsylvania State before helping to found the innovative Perimeter Institute. He is the author of The Life of the Cosmos and Three Roads to Quantum Gravity.
Photo by Lumidek at English Wikipedia (Own work by the original uploader) [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons.
Discover more of the author’s books, see similar authors, read author blogs and more
Customer reviews
4.1 out of 5 stars
4.1 out of 5
604 global ratings
How customer reviews and ratings work
Customer Reviews, including Product Star Ratings help customers to learn more about the product and decide whether it is the right product for them.
To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyzed reviews to verify trustworthiness.
Learn more how customers reviews work on Amazon-
Top reviews
Top reviews from the United States
There was a problem filtering reviews right now. Please try again later.
Reviewed in the United States on January 19, 2020
Reviewed in the United States on May 23, 2013
Although I'm not a physicist, I loved this book. I am fortunate to have enough familiarity with the topics--the nature of time, the "finely tuned universe," the hidden-variables interpretation of quantum mechanics, and so forth--to know that the questions Smolin tackles are worth asking. I also have enough skepticism about traditional scientific thinking to entertain his suggestions for new answers.
I have been interested in the problem of time ever since reading the articles in Physics and the Ultimate Significance of Time, published in 1986. They taught me how much scientific thinking conflicts with our deepest intuitions about the unfolding of reality in time, in particular the idea that time flows from a settled past to an as-yet non-existent and indeterminate future, by way of a unique present. Einstein was uncomfortable that he couldn't find a scientific basis for such a belief. Smolin thinks that by emphasizing the timeless to the detriment of the temporal, physics has reached a kind of explanatory dead-end with regard to understanding the universe as a whole.
What scientists have been good at is "doing physics in a box." They focus on a subsystem of the universe, describe it as a configuration space of possible states, and discover laws expressible in the timeless language of mathematics that account for the changes of state. There's nothing unique or creative about the present; it's just another application of the same timeless laws. Relativity theory seems to deprive the idea of NOW of any objective meaning, since observers' frames of reference affect which events they experience as occurring simultaneously. "Observers in motion with respect to each other will reach different conclusions about whether two events are simultaneous or not when those two events are distant from each other." Without an objective NOW, we seem to lack a point at which to separate the past from the future, and all points in time become equally real in the "block universe." Some theories of quantum cosmology treat the universe as a single quantum state in which all possible configurations exist at once, and so the passage of time becomes a complete illusion.
Smolin believes that these conclusions result from the "cosmological fallacy" of trying to extrapolate the physics of subsystems to the universe as a whole. "When we attempt to scale up our standard theories to a cosmological theory, we are rewarded with dilemmas, paradoxes, and unanswerable questions. Among these are the failure of any standard theory to account for the choices made in the early universe--choices of initial conditions and choices of the laws of nature themselves." Smolin's attempts to answer questions about the universe as a whole have led him to the view that time is fundamental, and that "the laws of nature emerge from inside the universe and evolve in time with the universe they describe." Our universe must also have evolved out of some previous universe, and it may give rise to others, in his theory of "cosmological natural selection." He believes that a theory of this kind is potentially testable, since the universe can contain evidence of its past. He regards as unscientific and untestable the theory postulating a multitude of simultaneously existing universes simply in order to claim that the special conditions of our universe exist entirely by chance.
Smolin suggests that quantum mechanics is only an approximation to a larger cosmological theory, and that's why it's predictions are only probabilistic. "The missing information needed to determine what a quantum system will do might still be present somewhere in the universe, so that it comes into play when we embed a quantum description of a small subsystem into a theory of the universe as a whole." This leads him to consider a "hidden-variables" interpretation of quantum, despite its apparent contradiction of relativity theory. He argues that the theory of "shape dynamics" reformulates relativity theory to resolve this problem:
"In general relativity size is universal and time is relative, whereas in shape dynamics time is universal and size is relative. Remarkably, though, these two theories are equivalent to each other, because you can--by a clever mathematical trick...--trade the relativity of time for the relativity of size...Thus, shape dynamics achieves an accord between the experimental success of the principle of relativity and the need for a global time demanded by theories of evolving laws and hidden-variable explanations of quantum phenomena. As noted, one quantity not allowed to change when you expand and shrink scales is the overall volume of the universe at each time. This makes the overall size of the universe and its expansion meaningful, and this can be taken for a universal physical clock. Time has been rediscovered."
I'm not qualified to evaluate such a claim. But my studies in science and philosophy have convinced me that scientists are much more likely to be right about little things than about big things such as the nature of time. New ideas about big things should be welcome, especially if they help reconcile scientific knowledge with lived experience.
I have been interested in the problem of time ever since reading the articles in Physics and the Ultimate Significance of Time, published in 1986. They taught me how much scientific thinking conflicts with our deepest intuitions about the unfolding of reality in time, in particular the idea that time flows from a settled past to an as-yet non-existent and indeterminate future, by way of a unique present. Einstein was uncomfortable that he couldn't find a scientific basis for such a belief. Smolin thinks that by emphasizing the timeless to the detriment of the temporal, physics has reached a kind of explanatory dead-end with regard to understanding the universe as a whole.
What scientists have been good at is "doing physics in a box." They focus on a subsystem of the universe, describe it as a configuration space of possible states, and discover laws expressible in the timeless language of mathematics that account for the changes of state. There's nothing unique or creative about the present; it's just another application of the same timeless laws. Relativity theory seems to deprive the idea of NOW of any objective meaning, since observers' frames of reference affect which events they experience as occurring simultaneously. "Observers in motion with respect to each other will reach different conclusions about whether two events are simultaneous or not when those two events are distant from each other." Without an objective NOW, we seem to lack a point at which to separate the past from the future, and all points in time become equally real in the "block universe." Some theories of quantum cosmology treat the universe as a single quantum state in which all possible configurations exist at once, and so the passage of time becomes a complete illusion.
Smolin believes that these conclusions result from the "cosmological fallacy" of trying to extrapolate the physics of subsystems to the universe as a whole. "When we attempt to scale up our standard theories to a cosmological theory, we are rewarded with dilemmas, paradoxes, and unanswerable questions. Among these are the failure of any standard theory to account for the choices made in the early universe--choices of initial conditions and choices of the laws of nature themselves." Smolin's attempts to answer questions about the universe as a whole have led him to the view that time is fundamental, and that "the laws of nature emerge from inside the universe and evolve in time with the universe they describe." Our universe must also have evolved out of some previous universe, and it may give rise to others, in his theory of "cosmological natural selection." He believes that a theory of this kind is potentially testable, since the universe can contain evidence of its past. He regards as unscientific and untestable the theory postulating a multitude of simultaneously existing universes simply in order to claim that the special conditions of our universe exist entirely by chance.
Smolin suggests that quantum mechanics is only an approximation to a larger cosmological theory, and that's why it's predictions are only probabilistic. "The missing information needed to determine what a quantum system will do might still be present somewhere in the universe, so that it comes into play when we embed a quantum description of a small subsystem into a theory of the universe as a whole." This leads him to consider a "hidden-variables" interpretation of quantum, despite its apparent contradiction of relativity theory. He argues that the theory of "shape dynamics" reformulates relativity theory to resolve this problem:
"In general relativity size is universal and time is relative, whereas in shape dynamics time is universal and size is relative. Remarkably, though, these two theories are equivalent to each other, because you can--by a clever mathematical trick...--trade the relativity of time for the relativity of size...Thus, shape dynamics achieves an accord between the experimental success of the principle of relativity and the need for a global time demanded by theories of evolving laws and hidden-variable explanations of quantum phenomena. As noted, one quantity not allowed to change when you expand and shrink scales is the overall volume of the universe at each time. This makes the overall size of the universe and its expansion meaningful, and this can be taken for a universal physical clock. Time has been rediscovered."
I'm not qualified to evaluate such a claim. But my studies in science and philosophy have convinced me that scientists are much more likely to be right about little things than about big things such as the nature of time. New ideas about big things should be welcome, especially if they help reconcile scientific knowledge with lived experience.
Top reviews from other countries
Rob
3.0 out of 5 stars
Thought provoking
Reviewed in Australia on July 10, 2021
The first half of this book is tremendously thought-provoking, but then it kind of got a bit too philosophical for my liking. I’ve read all of Smolin’s books and if you like his style you’ll like this, but too much of it comes across as either speculative or a re-hash of stuff he’s already written in other books. So perhaps it’s more worthwhile if you haven’t read his other stuff before.
Non-Materialist
4.0 out of 5 stars
Consciousness may be the last thing to be explained for materialistic science!
Reviewed in Japan on July 8, 2017
But couldn’t be because consciousness might have come first!
I have read the author’s books: "The Trouble with Physics" (2006, Penguin Books) and "The Life of the Cosmos" (1997). Very much educative, though I don’t like the idea of “Cosmological natural selection,” because Darwin’s idea of Natural Selection seems to have been scientifically demolished according to the modern molecular biologists. See "What Darwin got Wrong" by J.A. Fodor & M. Piattelli-Palmarini (2010) & "Darwin’s Doubt" by Stephen C. Meyer (2013). Sorry, I have digressed from the subject.
Now, no need for me to explain the contents of this book, which was published 4 years ago; someone should have given a good review. Hence, I would like to place here a certain piece of information on “Consciousness” in relation with author’s writing about consciousness in Epilog.
The author writes about “consciousness” in pp. 267 – 271. Let me get to the point: The author writes (p. 269), “Here’s another way to ask it: Suppose we mapped the neural circuits in your brain onto silicon chips and uploaded your brain into a computer. Would that computer be conscious? Would it have qualia? Yet another question serves to focus our thoughts: Suppose you could do that without harming yourself. Would there now be two conscious beings with your memories whose futures diverge from there?”
So far there has been no actual case of a computer, being so manipulated as in the author’s supposition, which has “two conscious beings with a human’s memories whose futures diverge from there.” However, if we replace the computer with a living human being who has experienced a successful heart transplant from a brain-dead donor, then there have been actual cases of heart-transplanted people who have two conscious beings with donor’s memories (as well as characteristics & tastes) whose futures have definitely diverged from there.
I cite the following three references which describe the actual situations:
[1] Stephen E. Braude, “Immortal Remains – The Evidence for Life after Death,” Rowman & Littlefield, 2003, Chap. 7: Lingering Spirits.
[2] Claire Sylvia, “A Change of Heart – A Memoir,” Warner Books, 1997.
[3] Paul Pearsall, Ph.D., “The Heart’s Code,” Broadway Books, 1999.
I have read the author’s books: "The Trouble with Physics" (2006, Penguin Books) and "The Life of the Cosmos" (1997). Very much educative, though I don’t like the idea of “Cosmological natural selection,” because Darwin’s idea of Natural Selection seems to have been scientifically demolished according to the modern molecular biologists. See "What Darwin got Wrong" by J.A. Fodor & M. Piattelli-Palmarini (2010) & "Darwin’s Doubt" by Stephen C. Meyer (2013). Sorry, I have digressed from the subject.
Now, no need for me to explain the contents of this book, which was published 4 years ago; someone should have given a good review. Hence, I would like to place here a certain piece of information on “Consciousness” in relation with author’s writing about consciousness in Epilog.
The author writes about “consciousness” in pp. 267 – 271. Let me get to the point: The author writes (p. 269), “Here’s another way to ask it: Suppose we mapped the neural circuits in your brain onto silicon chips and uploaded your brain into a computer. Would that computer be conscious? Would it have qualia? Yet another question serves to focus our thoughts: Suppose you could do that without harming yourself. Would there now be two conscious beings with your memories whose futures diverge from there?”
So far there has been no actual case of a computer, being so manipulated as in the author’s supposition, which has “two conscious beings with a human’s memories whose futures diverge from there.” However, if we replace the computer with a living human being who has experienced a successful heart transplant from a brain-dead donor, then there have been actual cases of heart-transplanted people who have two conscious beings with donor’s memories (as well as characteristics & tastes) whose futures have definitely diverged from there.
I cite the following three references which describe the actual situations:
[1] Stephen E. Braude, “Immortal Remains – The Evidence for Life after Death,” Rowman & Littlefield, 2003, Chap. 7: Lingering Spirits.
[2] Claire Sylvia, “A Change of Heart – A Memoir,” Warner Books, 1997.
[3] Paul Pearsall, Ph.D., “The Heart’s Code,” Broadway Books, 1999.
Matheus Lobo
5.0 out of 5 stars
EXCELENTE!
Reviewed in Brazil on January 26, 2015
O autor argumenta muito bem sobre o que é o tempo, qual o seu papel sobre as leis da física, por meio de raciocínio apurado. Este livro ajuda bastante no fortalecimento da criatividade, da imaginação e, especialmente, da intuição física! O livro é repleto de referências para o leitor especializado que queira se aprofundar. Sou Físico Teórico, doutor em Teoria Quântica de Campos e recomendo este livro para todos os tipos de públicos. O autor apresenta assuntos abstratos, com a física subjacente, de forma clara e direta.
Takuo Yasuoka
5.0 out of 5 stars
未来への扉は時間で開かれる
Reviewed in Japan on May 12, 2013
ガリレオ、ニュートンは運動を相対化したが時計は慣性系の外に置かれ、アインシュタインにより時間は時空の中で考えられるようになったが、果たしてそれらは現実の時間と同じものであろうか？スモーリンは時間をprecedence(順序)として捉え、物理法則の共変性やネーターの定理のような対称性を仮定せず、唯ひとつの宇宙のなかで法則が進化すると考える。さらにメタ法則というナイーブな問題も扱う。数学は自然すべてを記述することができるわけではないと考えている。
時間をグローバルでリアルなものとして考え、一般相対性理論における「サイズは変わらず時間が変わる」のデュアリティーであるshape dynamicsの「時間はグローバルであり、変わるのは時間ではなく形である」の立場をとる。
量子もつれの問題について、「ガリレオ、ニュートン、アインシュタインは間違っている」といい、量子力学を統計として考え、運動や時間についてのこれまでの考え方を変えることによって解決しようとする。
創発される量子的な面積と体積をもち背景独立な理論であるループ量子重力理論には、このようなスモーリンの根本思想が潜んでいたわけである。非局所性（簡単に言えば瞬間移動）についてはスピンネットワークなどにおけるnon-local linkによって、逆問題（量子重力理論で宇宙全体を形作ることができるか）はmatrix model of string theory, causal-dynamical triangulation modelなどで解決できるという。
ボルツマン宇宙はエントロピー最大の熱平衡状態のゆらぎから生じ、出来事はポアンカレ再帰時間で（注；厳密には軌道が交わることなく近傍を通るという意味で）無数に繰り返す。これに対して、スモーリンの宇宙はライプニッツ宇宙（区別が全くできないものは同一であり我々の宇宙と同じものはふたつとない）であり、時間は非対称で重力作用のもとで複雑性が増加して構造化する開放系である。エントロピーの法則はその部分である孤立系のなかで成立する。
時間が幻想であらかじめ未来は記述できるという考えにスモーリンは警鐘を鳴らし未来は現在の上に成り立つという。経済、エコロジー、気候においても、複数の不動点が存在し経路依存的に時間発展してフィードバックを持つ複雑開放系を考える。
科学では物と物の関係を知ることはできるが、物自体とは何なのか？物が現実に存在することを確信できるのは意識やクオリアが現実に存在するからであるが、意識やクオリアとは何なのか？これらは今後の問題である。科学は冒険である。未来は予測できない。時間が鍵となり、未来は開かれている。
時間をグローバルでリアルなものとして考え、一般相対性理論における「サイズは変わらず時間が変わる」のデュアリティーであるshape dynamicsの「時間はグローバルであり、変わるのは時間ではなく形である」の立場をとる。
量子もつれの問題について、「ガリレオ、ニュートン、アインシュタインは間違っている」といい、量子力学を統計として考え、運動や時間についてのこれまでの考え方を変えることによって解決しようとする。
創発される量子的な面積と体積をもち背景独立な理論であるループ量子重力理論には、このようなスモーリンの根本思想が潜んでいたわけである。非局所性（簡単に言えば瞬間移動）についてはスピンネットワークなどにおけるnon-local linkによって、逆問題（量子重力理論で宇宙全体を形作ることができるか）はmatrix model of string theory, causal-dynamical triangulation modelなどで解決できるという。
ボルツマン宇宙はエントロピー最大の熱平衡状態のゆらぎから生じ、出来事はポアンカレ再帰時間で（注；厳密には軌道が交わることなく近傍を通るという意味で）無数に繰り返す。これに対して、スモーリンの宇宙はライプニッツ宇宙（区別が全くできないものは同一であり我々の宇宙と同じものはふたつとない）であり、時間は非対称で重力作用のもとで複雑性が増加して構造化する開放系である。エントロピーの法則はその部分である孤立系のなかで成立する。
時間が幻想であらかじめ未来は記述できるという考えにスモーリンは警鐘を鳴らし未来は現在の上に成り立つという。経済、エコロジー、気候においても、複数の不動点が存在し経路依存的に時間発展してフィードバックを持つ複雑開放系を考える。
科学では物と物の関係を知ることはできるが、物自体とは何なのか？物が現実に存在することを確信できるのは意識やクオリアが現実に存在するからであるが、意識やクオリアとは何なのか？これらは今後の問題である。科学は冒険である。未来は予測できない。時間が鍵となり、未来は開かれている。
千田太郎
5.0 out of 5 stars
ブラックホールとビッグバンをつなく゛言葉として気に入りました
Reviewed in Japan on June 5, 2014
ロジャーペンローズが「共形サイクリック宇宙論」を提唱しています。彼は熱力学第二法則から導いていますが一般相対論の時間の概念を「生まれ変わり」と表現する方法もいいのではと思います
