Hide this

Results from Google Books

Click on a thumbnail to go to Google Books.

The Hidden Reality: Parallel Universes and…

The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos

by Brian Greene

MembersReviewsPopularityAverage ratingMentions
8812610,055 (3.91)11
  1. 00
    Why Does the World Exist? An Existential Detective Story by Jim Holt (CGlanovsky)
    CGlanovsky: Touching on similar concepts, including Nozick's "Ultimate Multiverse" (there's isn't something rather than nothing, there's both).

Sign up for LibraryThing to find out whether you'll like this book.

No current Talk conversations about this book.

» See also 11 mentions

English (24)  Swedish (1)  German (1)  All languages (26)
Showing 1-5 of 24 (next | show all)
This, the third major popular physics book by Brian Greene, focuses on the utterly fascinating question of whether this universe is the only one. In great detail and honestly covering many complexities and theoretical holes or flaws,The Hidden Reality begins with the relatively easy multiverses: maybe space is just infinite, in which case everything happening right now might well happen in an identical way, or maybe slightly differently, somewhere else in this universe. Then there is the theory of inflation, which posits possibly infinite bubble universes, of which we are just one. Things start to get more complicated - and strange - when you bring in superstring theory where we may be just one membrane amongst trillions, some of which may be hardly recognisable as the universe we see in front of us (and the same may go for those bubble universes too). Quantum mechanics adds its own multiverse strangeness, where any subatomic option that occurs in this universe yields another universe with a different option, and therefore potentially infinite parallel universes splitting off from our own. The holographic principle gets into even weirder territory, where information is the key and the physical state of our 3-D universe is somehow recorded as data on a 2-D surface somewhere else. Perhaps the most baffling suggestion is that our universe is merely a computer simulation, perhaps within another simulation, in turn inside another, many steps removed from an ultimate reality.

There is no question that all these ideas are thrilling and groundbreaking. My worry at times was just how intensely speculative and removed from evidence these ideas are. Greene doesn't shy away from admitting the problems of speculation and carefully and cleverly debates the question of whether these ideas really constitute science or not. Still, although I find the multiverse is of quantum mechanics and inflation theory to be quite plausible, even likely, for superstring multiverses and simulation universes I found it a strain to read such detail about ideas that have so many layers of speculation to build them up, and they may never be able to be verified experimentally.

I must admit, having recently read Max Tegmark's book, The Mathematical Universe, where much of the same ground is covered, I much preferred that book, for its somewhat more grounded approach to multiverses, its greater clarity in general, and fewer sections that get heavily bogged down in details.

Still though, reading this book is like an incredible adventure, and an immense feat of creativity, all rolled into one. And just the fact that scientists are debating such wild ideas is one I find utterly thrilling, and there are few better authors than Brian Greene to guide us laypeople through such territory. ( )
  RachDan | Jan 25, 2016 |
I found this book to be a very good explanation of the theories of multiple universe that are being bounded about by M-theorists and other modern quantum physicists. This book sets the clear tone that has to be answered by Christians and others who believe in absolutes. But reading this book, one has to remember that physics research/conclusions changes. Books written about black holes in the 1980s, for example, have to be scrapped in light of modern math being worked out.

The book closes with a long diatribe by Greene on how nothing in our world may actually be real, we could all be living in a simulated multiverse. After all, we see how video games like The Sims and research into artificial intelligence are evolving quickly; it's not hard to think about how our grandchildren may be manipulating simulated life, so maybe we're actually living in such a scenario and everything we do is more or less dictated by a game player. And what about the world the game player lives in? It could also be simulated, and he could be a simulation himself! You end up with an infinite loop of simulations...until what? Greene doesn't say. Greene doesn't even think to mention DesCartes "I think, therefore I am." If I'm doubting what Greene is saying then I must necessarily be thinking, and I reject the notion that my myriad of doubts are simply simulated by someone running my life like The Sims. It's clear why Stephen Hawking can say that modern philosophy hasn't kept up with physics (The Grand Design). Modern physics would move philosophy back a thousand years.

But I give this book 5 stars for clearly elucidating the theories of the multiverse and explaining where the most modern physics are.

Research into inflation-- the rapid expanse of the universe from proton-sized to the holder of galaxies in the blink of an eye-- has important implications for how we view our world and philosophy. Assumptions that the universe is finite and began at a specific instant in time are being challenged by M-theory. If the universe is infinite, then it has always existed and there are also multiple universes. If the universe is finite, then there are not. Greene writes that experiments with the Hadron collider are basically trying to find out whether we're living on a brane universe. If it can be determined we live on a brane, then it is much more likely that our universe is one of many. Greene states at the outset that he is not sure, and that much cannot be proven. But how you look at cosmology has deep implications for how you view your own humanity. 7 billion years ago, universe sped up its expansion and it's still rapidly expanding. So, what happened 7 billion years ago needs to be explained.

The particals called "inflatons" necessary to explain the process of inflation are theoretical. That's a problem with physics that Greene addresses- is any of this theoretical speculation on things that cannot be actually proven still be classified as "science?" Science means testable hypotheses, can any of these be tested? A hypothesis simply sets conditions that can later be tested (at least in theory), which means that the various ideas thrown about by cosmologists are science, according to Greene.

Greene goes through all the various possibilities for multiverses:

Table 11.1 Summary of Various Versions of Parallel Universes
1. Quilted Multiverse: Conditions in an infinite universe necessarily repeat across space, yielding parallel worlds.
2. Inflationary Multiverse: Eternal cosmological inflation yields an enormous network of bubble universes, of which our universe would be one.
3. Brane Multiverse: In string/M-theory's braneworld scenario, our universe exists on one three-dimensional brane, which floats in a higher-dimensional expanse potentially populated by other branes - other parallel universes.
4. Cyclic Multiverse: Collisions between braneworlds can manifest as big bang-like beginnings, yielding universes that are parallel in time.
5. Landscape Multiverse: By combing inflationary cosmology and string theory, the many different shapes for string theory's extra dimensions give rise to many different bubble universes.
6. Quantum Multiverse: Quantum mechanics suggests that every possibility embodied in its probability waves is realized in one of a vast ensemble of parallel universes.
7. Holographic Multiverse: The holographic principle asserts that our universe is exactly mirrored by phenomena taking place on a distant bounding surface, a physically equivalent parallel universe.
8. Simulated Multiverse: Technological leaps suggest that simulated universes may one day be possible.
9. Ultimate Multiverse: The principle of fecundity asserts that every possible universe is a real universe, thereby obviating the question of why one possibility - ours - is special. These universes instantiate all possible mathematical equations.

The theoretical universe where absolutely nothing exists would exist the set of universes contained in #9 above. (Wrap your head around that.) There is much history on research attempting to determine whether or not the cosmological constant equals zero. The size of the cosmological constant matters greatly for the formation of galaxies and such. Putting it in the equation makes a difference, as does its magnitude. So, a physicists' assumption on the magnitude of the cosmological constant has huge implications for how you look at the universe and humanity. How many universes needed to exist for it to be reasonably possible that one containing our exact cosmological constant could exist? Greene works that out.

Cyclical cosmology purports that the universe had no beginning or end, it exists in an infinite loop. This conflicts with the law of entropy, which is observed in our universe, that things are moving from order to disorder-- necessitating a beginning point. Greene explains how modern views combine the theory of relativity with cyclical cosmology to find a way around the need for a big bang. It's complicated, and he at least explains what the math looks like at some points.

There is plenty on Calabi-Yau shapes, and Calabi-Yau spaces. I don't get it, honestly.

Greene takes a long look at the math's implications for the anthropic principle - the philosophical consideration that observations of the physical universe must be compatible with the conscious and sapient life that observes it. Some proponents of the anthropic principle reason that it explains why the Universe has the age and the fundamental physical constants necessary to accommodate conscious life. As a result, they believe it is unremarkable that the universe's fundamental constants happen to fall within the narrow range thought to be compatible with life (wikipedia). In other words, the universe is as it is because we're here. But Greene explains the multiverse with the analogy of a shoe store-- there are plenty of pairs of shoes and one of them must match your feet. The Milky Way is one of an infinite number of galaxies, and happens to be just the one that can sustain us, which we shouldn't find remarkable.

Also from wikipedia:
The anthropic idea that fundamental parameters are selected from a multitude of different possibilities (each actual in some universe or other) contrasts with the traditional hope of physicists for a theory of everything having no free parameters: as Einstein said, "What really interests me is whether God had any choice in the creation of the world." In 2002, proponents of the leading candidate for a "theory of everything", string theory, proclaimed "the end of the anthropic principle"[33] since there would be no free parameters to select. Ironically, string theory now seems to offer no hope of predicting fundamental parameters, and now some who advocate it invoke the anthropic principle as well.

In the end, Greene hypothesizes that we're all in a simulation. Perhaps even the laws of physics we experience in this world are programmed into the simulation and may not hold in other simulated universes. Perhaps they are also accidents or unsolved problems in the code of the program being run that we inhabit (seriously, this is the best physics can do).

I read a recent interview with Greene that faith and a belief in a Creator are not incompatible with physics (though he rejects any literal interpretation of Genesis) but it's clear that an infinite universe-- with no beginning or end-- needs no creator or creation point. I do not think Greene explained well how to reconcile what we know about a Big Bang -- that there was a beginning of the universe-- with the inflationary infinite loop. Much less how we can pinpoint the increase in the speed of the expansion 7 million years ago when such measurements are pointless if the timeline is infinite in both directions.

Greene makes an interesting point that the human eye only evolved to see certain types of radiation-- like light, which contains information (his only foray into biology). Other types of radiation and information remain hidden to the naked eye. I've never seen an atheist explain how the light came to hold that information, except for Greene's simulated universe explanation. How did the eye know that the information was there to be processed? This is a problem for biologists, much less physicist-philosophers like Greene and Hawking. If Greene's infinite universe with infinite multiverses is correct, then we are all just a random compilation of molecules (as stated by Greene). At this juncture, it would appear physics is incompatible with evolutionary biology. Biologists purport that everything evolved in response to the results of trial-and-error processes that necessitate cells understanding information and responding accordingly (Richard Dawkins & company don't explain where that information came from, either). In the Greene/Hawking philosophy, it was purely random. Yet, they both agree that life is dependent upon information. This seems, to me, to be quite a contradiction (rather than just a paradox).

This book is important because Greene alludes to the implications modern physics has for philosophy, and therefore ethics, human rights, theology, etc. Every Christian should read it as well as every atheist and respond with their own coherent philosophical critiques. I hope to read physicist Lee Smolin's The Trouble with Physics for a critique of Greene's string theory/M-theory from some of his own colleagues. ( )
  justindtapp | Jun 3, 2015 |
While it was a good survey of current scientific thinking on physical reality, the explanations often remain unclear and protracted. ( )
  inasrullah64 | Sep 26, 2014 |
Brian Greene really is one of the best popular science writers. His books give you a real sense of being guided by someone who genuinely knows what they're talking about, who uses metaphors effectively, and who effectively weaves the traditional material in with the new points he is making. He also approaches science with curiosity untainted by dogmatism. He is very much open to speculation, but equally open to the speculation not panning out.

This book is about different concepts of the Multiverse. Greene devotes a chapter to each of what he defines as the major types and then has one or two additional chapters on questions like whether these theories are testable and broader implications.

The multiverse's he consider include the quilted multiverse (which is just our universe extending out infinitely, leaving the possibility of endless accidental repetition -- which follows from some cosmological theories that follow the big bang), the inflationary multiverse (a product of repeated episodes of inflationary expansion, which follows from the addition of inflation to the previous theories), three multiverses that come from different versions of string theory (brane, cyclic and landscape), a quantum multiverse (which is Everett's Many Worlds interpretation, and is more conceptual), a holographic multiverse (which comes from the study of black holes and string theory), and simulated and ultimate multiverses (the last two coming from computer simulations and a deeper mathematical world).

In every case, Greene does a good job of describing the physical theories that lead, usually by accident, to the implication that there is a particular type of multiverse, discusses the scientific status of those theories, and addresses issues around testing them. In the end, Greene has some sympathy with Steven Weinberg's adage that the problem with physics is that we do not take our theories/equations seriously enough as a real description of the world. The example he cites is the Positron, which was a byproduct of Dirac's solution of a math problem that turned out to be real. Greene clearly leans towards the view that the same is true of the multiverse, but he doesn't do much to tip his hand about which one. ( )
  nosajeel | Jun 21, 2014 |
The multiverse - interviewed by Michael Krasney, KQED. ( )
  clifforddham | Mar 19, 2014 |
Showing 1-5 of 24 (next | show all)
no reviews | add a review
You must log in to edit Common Knowledge data.
For more help see the Common Knowledge help page.
Series (with order)
Canonical title
Original title
Alternative titles
Original publication date
Important places
Important events
Related movies
Awards and honors
To Alec and Sophia
First words
If, when I was growing up, my room had been adorned with only a single mirror, my childhood daydreams might have been very different.
Last words
(Click to show. Warning: May contain spoilers.)
Disambiguation notice
Publisher's editors
Publisher series
Original language

References to this work on external resources.

Wikipedia in English (1)

Book description
From the best-selling author of The Elegant Universe and The Fabric of the Cosmos comes his most expansive and accessible book to date—a book that takes on the grandest question: Is ours the only universe?

There was a time when “universe” meant all there is. Everything. Yet, in recent years discoveries in physics and cosmology have led a number of scientists to conclude that our universe may be one among many. With crystal-clear prose and inspired use of analogy, Brian Greene shows how a range of different “multiverse” proposals emerges from theories developed to explain the most refined observations of both subatomic particles and the dark depths of space: a multiverse in which you have an infinite number of doppelgängers, each reading this sentence in a distant universe; a multiverse comprising a vast ocean of bubble universes, of which ours is but one; a multiverse that endlessly cycles through time, or one that might be hovering millimeters away yet remains invisible; another in which every possibility allowed by quantum physics is brought to life. Or, perhaps strangest of all, a multiverse made purely of math.

Greene, one of our foremost physicists and science writers, takes us on a captivating exploration of these parallel worlds and reveals how much of reality’s true nature may be deeply hidden within them. And, with his unrivaled ability to make the most challenging of material accessible and entertaining, Greene tackles the core question: How can fundamental science progress if great swaths of reality lie beyond our reach?

Sparked by Greene’s trademark wit and precision, The Hidden Reality is at once a far-reaching survey of cutting-edge physics and a remarkable journey to the very edge of reality—a journey grounded firmly in science and limited only by our imagination.
Haiku summary

Amazon.com Amazon.com Review (ISBN 0307265633, Hardcover)

Amazon Best Books of the Month, January 2011: Take any of physics' major theories of the fundamental nature of the universe, extrapolate its math to the logical extreme, and you get some version of a (so far unobservable) parallel universe. And who better to navigate these hypothetical versions of the "multiverse" than Brian Greene? Normally an unflinching apologist for string theory, the bestselling author of The Elegant Universe and The Fabric of the Cosmos here treats all viable alternate realities to a laudably fair shake. For a book exploring the most far-reaching implications of bleeding-edge mathematics, The Hidden Reality is surprisingly light on math, written as it is "for a broad audience … its only prerequisite the will to persevere." Such perseverance pays off with a motley cast of potential universes featuring doppelgängers, strings, branes, quantum probabilities, holographs, and simulated worlds. The result is that rare accomplishment in science writing for a popular audience: a volume that explains the science and its consequences while stimulating the imagination of even the uninitiated.

Oliver Sacks on The Hidden Reality

Oliver Sacks was born in London and educated in London, Oxford, California, and New York. He is professor of neurology and psychiatry at Columbia University, and Columbia's first University Artist. He is the author of many books, including Awakenings, The Man Who Mistook His Wife for a Hat, and Musicophilia. His newest book, The Mind's Eye, was published in October, 2010.

Brian Greene is not only a profound cosmological thinker--a pioneer of string theory--but a writer of exceptional clarity and charm. His books--The Elegant Universe and The Fabric of the Cosmos among them--take one ever deeper into a universe stranger and more wonderful than anyone could have conceived a generation ago. The Hidden Reality takes us deeper still, and it has a special personal quality and warmth that is evident from the opening of the book, when Greene recollects how, as a boy, he was fascinated by the multiple reflections in parallel mirrors. He has never lost this childlike wonder at the world of physics, but he brings it now to examining theories of multiple universes, of the continual birth of universes, starting long before our own. . . and destined to continue, perhaps, to the end of time.

In the 1930s, as a boy myself, I read The Mysterious Universe by James Jeans. Jeans was, like Greene, a brilliant theoretical astronomer and equally mesmerizing writer. I thought Jeans's book was the most exciting, revelatory book I had ever read, and now, seventy years later, I feel the same excitement reading Brian Greene's new book, where every chapter opens level after level of previously unimaginable, mind-expanding realities.

(retrieved from Amazon Thu, 12 Mar 2015 18:08:10 -0400)

(see all 5 descriptions)

"The Hidden Reality" reveals how major developments in different branches of fundamental theoretical physics -- relativistic, quantum, cosmological, unified, computational -- have all led us to consider one or another variety of parallel universe.

» see all 5 descriptions

Quick Links

Swap Ebooks Audio
250 wanted4 pay8 pay

Popular covers


Average: (3.91)
0.5 1
1 1
2 4
2.5 1
3 24
3.5 8
4 49
4.5 2
5 32


An edition of this book was published by Audible.com.

See editions

Penguin Australia

An edition of this book was published by Penguin Australia.

» Publisher information page

Is this you?

Become a LibraryThing Author.


Help/FAQs | About | Privacy/Terms | Blog | Store | Contact | LibraryThing.com | APIs | WikiThing | Common Knowledge | Legacy Libraries | Early Reviewers | 105,891,417 books! | Top bar: Always visible