[[ PDF / Epub ]] ☃ The Hidden Reality: Parallel Universes and the Search for the Deep Laws of the Cosmos Author Brian Greene – Rvtrek.info
This is a pretty dense book Some of the footnotes have footnotes I m sure it must be very difficult for an author of a popular science book to walk the line between, on the one hand, providing enough technical information to make the arguments cogent, and on the other, miring the reader in a bog of difficult concepts and facts My hat s off to Dr Greene for giving it a try on some of the most out there ideas that can be imagined Some very interesting ideas, but ultimately, for me this was all a little difficult to chew and swallow.My own theory unencumbered by fact or mathematics is that the universe is infinite in all directions Our atoms and subatomic particles are someone or something else s galaxies and universes, and likewise, that our galaxies are atoms and molecules to some other beings And, boy, are those beings big For some reason I also think that the hierarchy that I just described doesn t recurse infinitely in a fractal manner Instead, it s all circular, so that if you start here and go up to galaxies or down to atoms or down to gehanna or up to the throne , or, for that matter, out to the edge of our universe, and bringing it back to the topic of this book to other universes in the multiverse, you would eventually end up here again Weird.Not light reading, but recommended if you re interested in some of the current thinking in the fields of cosmology and physics. Outstanding update of the current status of modern physics and the projections of parallel universes from various advances I would have loved to have Greene for a teacher in college The tour is suitable for laymen with some understanding of physics, as he provides plenty of concrete examples to explain challenging concepts and gives an opportunity to skip technical sections For the knowledgeable reader, a copious appendix is available, replete with the relevant math equations Greene works his way through the history and logic behind eight different models of parallel universes and their status in terms of development and progress toward potential verifiability The only one that I was really familiar with, from a college course on quantum physics 40 years ago, Everett s 1956 Many Worlds Hypothesis, is the only one that really bothers me, with its continual splitting off of parallel realities at every point where uncertain outcomes like the position of an object is resolved Greene makes it clear how the interpretation is simpler and elegant than Bohr s interpretation The latter calls for the probability wave of a particle to mysteriously collapses when it is detected or interacted with, effectively throwing out Schroedinger s equations out whenever a measurement is made and restricting their applicability only to very small objects Despite Occam s Razor favoring Everett s hypothesis the quantum mechanics equations apply deterministically at all times , the interpretation of possible alternative states as each being somehow real has always been too absurd to be true to me It s a relief then that there is still scientific resistance to the notion and demonstrations of problems with the theory Greene notes I don t expect theoretical or experimental consensus to come in my lifetime concerning which version of reality a single universe, a multiverse, something else entirely quantum mechanics embodies The other theories are fascinating and do not call for my alternative choices to have an existence in parallel universes It was great to get a perspective on the excitement and challenges with string theory and its promise for helping unify the gravitational force with the other forces already in the fold of quantum field theory The discovery that our universe is undergoing an acceleration in its expansion, and the need for some kind of anti gravity force dark energy was a shock to me, so the recent successes of the theory of empty space having an inflaton field was satisfying to read about Greene s coverage of recent work on the meaning of entropy and information in physical systems was also a pleasure for me.For a sense of the content of this book, here is a thumbnail sketch of the seven other parallel universe theories covered, as laid out in Greene s summary chapter Quilted Multiverse Conditions in an infinite universe necessarily repeat across space, yielding parallel worlds Inflationary Multiverse Eternal cosmological inflation yields an enormous network of bubble universes, of which our universe would be one 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 Landscape Multiverse By combining cosmology and string theory, the many different shapes for string theory s extra dimensions give rise to many different bubble universes Holographic Multiverse The holographic principle asserts that our universe is exactly mirrored by phenomena taking place on a distant boundary surface, a physically equivalent parallel universe Simulated Multiverse Technological leaps suggest that simulated universes may one day be possible Ultimate Multiverse The principle of fecundity asserts that every possible universe is a real universe These universes instantiate all possible mathematical equations.The summary chapter was also satisfying to me in attempting to address the following questions Is the Copernican pattern fundamentalFollowing the 500 year trend that the we understand, the less central we appear , we now approach the perspective that our universe itself may not be central to any cosmic order Can scientific theories that invoke a multiverse be testedThe worry is that by invoking a multiverse, we enter the domain of theories that can t be tested He argues that well founded multiverse theories should be able to make predictions which are likely to be testable in our own universe, and hence falsifiable How does the multiverse affect the nature of scientific explanationTraditional approaches for physics aims to use mathematical expressions of physical laws and a set of constants and initial conditions to project what measurable things will be like at a subsequent time Multiverse theories usefully explore variability in these conditions and laws which must be accepted as a given in a single universe theory Should we believe mathematicsBased on past progress, mathematical theories have had a huge impact on guiding science toward hidden truth Despite problems in testing the multiverse theories, pushing on them is likely to lead to progress. Awakeel 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 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. It took me 8 months to read this book My system is to read until my head is ready to explode, then stop for a month, then restart at the beginning On the 4th attempt, I made it to the last page or rather, Kindle location no guarantee of how much was actually understood This is a book that pried open my mind The brain is sore and ecstatic from the experience.From the last chapter,Table 11.1 Summary of Various Versions of Parallel Universes1 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.Kindle location 6079 6106.scientific discovery has shifted humankind s perspective on its place in the cosmic order Over the course of nearly five centuries, the Copernican progression has been a dominant theme experience abounds with clues suggesting that we re a central hub around which the cosmos revolves But the objective methods of scientific discovery have steadily corrected this perspective At nearly every turn, we ve found that were we not here, the cosmic order would hardly differ We ve had to give up our belief in earth s centrality among our cosmic neighbors, the sun s centrality in the galaxy, the Milky Way s centrality among the galaxies, and even the centrality of protons, neutrons, and electrons the stuff of which we re made in the cosmic recipe There was a time when evidence contrary to long held collective delusions of grandeur was viewed as a frontal assault on human worth With practice, we ve gotten better at valuing enlightenment The trek in this book has been toward what may be the capstone Copernican correction Our universe itself may not be central to any cosmic order The idea that reality based on a multiverse extends the Copernican pattern and perhaps completes it is cause for curiosity But what elevates the multiverse concept above idle speculation is a key fact that we ve now repeatedly encountered Scientists have not been on a hunt for ways to extend the Copernican revolution Instead, scientists have been doing what they always do using data and observations as a guide, they ve been formulating mathematical theories to describe the fundamental constituents of matter and the forces that govern how those constituents behave, interact, and evolve Remarkably, when diligently following the trail these theories blaze, scientists have run smack into one potential multiverse after another Kindle location 6109 6128 Brian bae Definitely one of the accessible cosmology writers of today Any book discussing quantum field theory and string theory is going to require your undivided attention, of course, but it s much readable than many others, especially if you re fond of analogies Turns out, there s lots of theories that give rise to the possibility of alternate realities Theory 1, aka Quilted Multiverse If the universe is infinite it might not be, but if it is then at some point in the distant, distant universe, there are worlds where there is a human named Annie just like me, typing on Goodreads, except she typed GR instead of Goodreads And there s another world with an Annie whose life is exactly like mine except she s allergic to red wine I would have to kill myself because there would be no point in living In some, the worst things I ve ever imagined happening have happened In others, my wildest dreams have been fulfilled Somewhere, there is an Annie who can write like Kafka, DH Lawrence, and Kundera combined Theory 2 aka Swiss Cheese If the universe is expanding hint, it almost definitely is then there would be places which expansion would create which would have to have lowered rates of expansion, and those are like holes in Swiss cheese The number of cheese holes, as the cosmos continues to expand, continues to increase, and each one of those is adorably termed a bubble universe, or pocket universe Including our own This also brings in the Quilted Multiverse idea from inside a bubble universe, the bubble s space is infinite, but from outside the bubble universe, it s finite What appears as endless time to an outsider appears as endless space, at each moment of time, to an insider And if it s infinite to an insider, then there have to be infinite worlds with infinite repetitions and variations, as in Theory 1 Theory 3 aka String Theory aka Bread Loaf aka Cyclic Multiverse Strictly speaking there are five types of string theory, no one Type I, Type IIA, Type IIB, Heterotic O, and Heterotic E, which all sound like sexually transmitted diseases to me, and anyway they all get subsumed into the grander M theory String theory particles are vibrating loops of filaments, and the way it vibrates determines what particle it is how it behaves and corresponding M theory predict that there are ten dimensions of space and the eleventh dimension of time Seven than the ones we re aware of length, width, height, and time But maybe that s not an issue, because the four dimensions we re used to extend over massive maybe infinite distances, but maybe the other seven are curled up at the other end of the cosmos and we can t find them and they don t extend far enough to reach into our reality For analogy Greene gives the example of a straw, normal sized, except it s as tall as the Empire State building It s three dimensional up close, but from the other side of the river, it would just look like a vertical line two dimensional Here comes the multiverse idea pretend the world has just two dimensions it s a flat plane called a two braneworld Line up a couple of these flat planes slices of bread and you can add on other parallel universes, other braneworlds, as many as you like just add slices to the cosmic loaf as Greene memorably says Of course, we have three spatial dimensions, but looking at 2 dimensions makes it easier to wrap our 3D heads around It s also possible that different braneworlds would bounce into each other and restart the cosmological clock, so that, rather than one big bang, things are a gigantic bumper car game and universes are constantly though very slowly, from our perspectives getting remade and unmade and remade Theory 4 aka Landscape Multiverse pretty much the idea that the cosmological constant density of energy in space, creating certain gravitational values might be necessary for life, and so what are the odds it happened to happen Well, you d need an infinite number of universes to make it likely that at least one of them just happened to have the exact necessary cosmological constant to make life happen.Theory 5 aka the Quantum Multiverse all the possibilities of our reality are realized in another reality, another multiverse All possible histories and all possible futures are real One of them is the reality we live in the basically infinite rest exist in some way True reality is like a tree than a line Theory 6 aka Everything is a Hologram The event horizon of a black hole point of no return is the surface of a black hole in some ways, and fluctuations in the surface of the event horizon contains all the information the black hole sucks in Similarly, our 3D world may be a rendering of 2D encoded information on some cosmological event horizon type thing which creates reality as we know it.Theory 7 aka Virtual Reality we can create other universes virtually and, someday, could probably create reactions in the potentially sentient actors in those universes which could make it feel like reality, every bit as much as it does to us If everything s infinite see theory 1 with infinite numbers of beings creating infinite numbers of virtual universes whose inhabitants can also create infinite numbers of infinite universes and so forth, doesn t it seem like odds are good that we re just one of those games Could we even tell if we were in a simulation Depends on your Simulator and if they want to reveal themselves are you there, God It s me, Annie Other interesting things Dark energy might be the answer to Einstein s unproven cosmological constant that he retracted after he suggested it because he couldn t account for it There s some some shit out there, and we can t see it, describe it, or know of its existence other than through a few methods of measurement The mind boggling idea that if the universe is infinite, and you shrunk infinity, everything would be closer together but the universe would still be infinite Rationally I understand that you can t reduce infinity infinity divided by two is still infinity but my brain doesn t want this to be a thing About 1 percent of the snow on a television that s tuned to a non working channel is due to reception of the big bang s photons aka background radiation. This was a good book For a popularization, this had some pretty heavy science in it I m a pretty smart guy and will have to re read it to really have a better understanding Greene really is a good writer, because even when you don t quite understand what he s talking about, he gives you enough of the broad overview so that you can go to the next section and feel that you haven t missed anything critical.The section on quilted multiverses was pretty straightforward and I can claim to have understood it The next few parallel universes were a bit trickier, but I was with the program When I got to multiple dimensions and the landscape multiverse with so many possible shapes to the extra dimensions that kazillions doesn t even begin to cover the number, this was something I wasn t quite so sure that I could explain to my wife I m not sure I want to challenge Brian Greene on any scientific question, but the one point I would have some questions about were the simulated multiverses as in the movie The Matrix I think he may be shortchanging Goedel and Turing I m not convinced that a simulated multiverse sufficient to model all the creatures on our planet would not consume so much energy that it would be in effect less probable than an actual universe My experience as a programmer is that the complexity of programs and the resources needed to design them go up exponentially with the size of the program If that is the case, creating a universe might actually take less energy than modeling one We would need to automate the process of computer design, but this essentially can t be done, and that s the point of Turing s thesis There may be a practical upper limit on the size of simulated universes that we or future super intelligent beings in our universe could ever design This may be my confusion, but I d like just a little explanation here So, this book is recommended, and I hope to come back to it One final thing though the book never utters a word about it, Brian Greene is a vegan That anybody this smart is a vegan says something, I think, about where we should be headed as a species. The first book I had by Brian Greene was The Fabric of the Cosmos I got it not long after it was releases and a friend asked me if he could borrow it not long after I received it in the mail, before I d read it I said yes.I didn t get the book back for several years, Dr Greene had written by then Oh well.This book as is Dr Greene s wont is an attempt to take highly technical and advanced ideas and make them understandable to us , we , the great unwashed , the masses I suppose in all truthfulness it only succeeds to a point.I mean, I know I don t have the math to grasp the heart of what he s talking about and even I can see the imprecision Still, he does take the difficult, sugar coats it and lays it out there I kept seeing that scene from Big Bang Theory where they have a cameo from Dr Greene and Sheldon s reaction to him.If you re a physicist theoretical or experimental I suspect this book will probably be hopelessly imprecise and simple, if your like me, it s fairly interesting Even though I know that what I m getting is at best a broad outlined picture where the multiverse is compared to a large Swiss Cheese with the bubbles pictured as the universes The book is laid out largely in the format of here it is, here s what we think know and here s why It assumes that those reading it won t really be in a position to challenge it and tries to be as simple as possible.In short not a bad book and manages to lay things out in a relatively get it relatively simple way when dealing with a difficult set of subjects or subject if it s unified Enjoy If it interests you I recommend it. I ve now read three books about the multiverse in rapid succession the first two were Rees s Before The Beginning 1996 and Davies s The Goldilocks Enigma 2007 This one came out just a few months ago, so I m hopefully up to date for the moment.Well I m starting to feel quite familiar with the arguments, but each book has an interestingly different slant Rees concentrates on presenting the experimental evidence for the existence of other universes basically, the physical constants of our own universe appear to be tuned exactly right for life to be possible, it s unlikely that this is just chance, so we re probably one of many universes and explicitly avoids philosophical speculation Davies recapitulates Rees s arguments, but then goes overboard on philosophy whatever he says, it s clear that he very much wants there to be a spiritual dimension to the story Greene is similar to Davies, but his obsession is with string theory He s spent his life working on it, and he desperately wants it to be part of the final explanation Despite Greene s exaggerated love for all things stringy, I liked this book and found it well worth reading The author presents nine different theories which in one way or another involve multiple versions of the universe Most of these I had already seen in Davies, but I found Greene s exposition clearer and detailed In particular, I thought his chapter on inflation was the best account I had read of this mysterious process, which got our universe started by exponentially blowing it up, in a minute fraction of a second, from the size of a proton to a macroscopic scale People now seem to understand inflation moderately well, and there are mathematical models which can be checked against the detailed maps of the cosmic background radiation which have been constructed over the last 10 years I also thought the chapter on the Many Worlds interpretation of quantum mechanics was excellent I hadn t understood that it s just a historical accident that the Copenhagen interpretation is the mainstream one As Greene points out, it s actually conservative to think of quantum processes as continually splitting off new universes, each of which is equally real The Copenhagen interpretation, with its notion of the collapse of the wavefunction, is the one which involves hand waving and mystical invocations of the privileged role of the observer If you just look at the underlying mathematics, the Schr dinger equation, the Many Worlds interpretation is the straightforward way to translate the numbers into words.As already noted, Greene wants string theory to be in there, so there are chapters on brane worlds our universe is floating in a higher dimensional space , the Cosmic Landscape there is a multitude of universes reflecting different flavors of string theory and the Holographic Universe we are the projection of a lower dimensional process on a distant boundary surface Like Davies, he also speculates about the possibility that our universe is a simulation running in some gigantic computer, or that we live in a Platonic Universe , where mathematical theories exist simply by virtue of being consistent, and there is no other reality All of these ideas were fun to read about, but I felt they were somewhat beside the point I was surprised not to see him focussing on what, at least to me, seems like the obvious account As he says, the Many Worlds interpretation of quantum mechanics is perfectly respectable, and inflation has accumulated a great deal of credibility as a theory of how the universe got started Inflation starts at a scale where quantum processes are all important We can actually see the fossils of those quantum processes in the unevenness of the background radiation.Putting those two things together, we already have a multiverse theory that s mainstream to the point of being conservative The quantum realities which split off during the very early history of the universe will be substantially different from each other The question is whether they re going to be different enough, since we want them to differ with respect to things including settings of the physical constants This part is still speculative But you need it anyway in order to make most of the other theories work, and there seem to be moderately well worked out accounts of how it could happen I am sure people must be exploring in this direction It sounds incredible when you write it down, but we appear to be on the edge of constructing a coherent scientific theory of Life, The Universe and Everything I m really curious to see what happens next. If you re into stuff like this, you can read the full review.Blood Farts The Hidden Reality Parallel Universes and the Deep Laws of the Cosmos by Brian Greene Original review, 2011 The Multiverse is awesome.We all look, we find what we may, but we all have to choose what we look at deeply than we will look at the rest of what there is Yes, I refuse to spend much time on multiverse hypotheses I used to spend a lot of time looking at quantum field theory instead and doing QFT, thinking about it, developing a feel for and making choices about what I think is important or not, and changing my mind endlessly, and becoming intimate with it as much as my abilities will let me, all of which takes time than anyone has.