Monday, December 01, 2014
The Hidden Reality by Brian Greene (Book Review #112 of 2014)
The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos
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. It is an easier read than The Elegant Universe and more detailed than Hawking's The Grand Design. 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" 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.