Time moves forward, not backward---everyone knows you can't unscramble an egg. In the hands of one of today's hottest young physicists, that simple fact of breakfast becomes a doorway to understanding the Big Bang, the universe, and other universes, too. In From Eternity to Here, Sean Carroll argues that the arrow of time, pointing resolutely from the past to the future, owes its existence to conditions before the Big Bang itself---a period of modern cosmology of which Einstein never dreamed.
Increasingly, though, physicists are going out into realms that make the theory of relativity seem like child's play. Carroll's scenario is not only elegant, it's laid out in the same easy-to-understand language that has made his group blog, Cosmic Variance, the most popular physics blog on the Net. From Eternity to Here uses ideas at the cutting edge of theoretical physics to explore how properties of space-time before the Big Bang can explain the flow of time we experience in our everyday lives. Carroll suggests that we live in a baby universe, part of a large family of universes in which many of our siblings experience an arrow of time running in the opposite direction. It's an ambitious, fascinating picture of the universe on an ultra-large scale, one that will captivate fans of popular physics blockbusters like Elegant Universe and A Brief History of Time.
©2009 Sean Carroll (P)2010 Tantor
Carroll writes with verve and infectious enthusiasm, reminding readers that science is a journey in which getting there is, without question, much of the fun.(Publishers Weekly)
The reader's biggest challenge is to understand the complex material. If you're a lay person who's curious about time and the universe and also willing to accept that you're unlikely to comprehend all of the highly technical concepts being presented, then this book is probably for you. I enjoyed it and am glad I bought it.
If you're a hard-core scientific type who believes that scientists have no right to engage in speculative thought about the ultimate nature of the universe, then the predictions in the last few chapters may rub you the wrong way. Traditional scientific wisdom treats speculation unsupported by data as belonging to the domain of naïve amateurs. Accepted scientific thought is that such speculation should be avoided at all costs by 'real' scientists. To my mind though, the author (Dr. Sean Michael Carroll, Ph.D.) is to be commended for engaging in just this type of speculation. To a lay person like myself, it is intriguing to hear a well-respected theoretical physicist make specific "predictions" about the ultimate nature of our universe. ("Predictions" is a word Dr. Carroll chooses carefully.)
Even though Dr. Carroll does a fantastic job of formulating his explanations using everyday language rather than mathematical formulas, the challenge to the reader's intellect is still substantial. These include concepts such as Boltzmann brains, Maxwell's demon, de Sitter space, white holes, the Planck length, Schrodinger's Cat, the Heisenberg uncertainty principle, Poincaré's recurrence theorem and many, many more. Thought experiments are high on Dr. Carroll's list of epistemological techniques.
One of the most rewarding aspects of Dr. Carroll's writing is that he goes to great lengths to distinguish between what is known fact, what is unproven theory and what is speculation. He is equally at ease admitting what is not known about our universe as he is with explaining what is known. The book also follows a very orderly progression of thought processes. Entropy and its entanglement with the arrow of time is introduced early on and remains the central theme throughout the book. Initially entropy is explained in the context of the second law of classical thermodynamics. The reversibility or irreversibility of physical processes is considered next. Then comes general relativity, quantum mechanics and quantum gravity.
If this book were a work of non-fiction, this paragraph would probably be labeled as a 'spoiler'. So consider yourself warned. Throughout the book, Dr. Carroll shows how the arrow of time always points in the direction of increasing entropy. He leaves the reader with the idea that this is the number one clue to the ultimate nature of our universe. Likewise, he leaves the reader with the feeling that the number two clue is the unlikely fact that our currently observable universe is in a low entropy state that was even lower at the 'big bang'. Using these two observations as stepping stones, he goes on to predict that our observable universe is merely a bubble, or "baby universe" that has pinched off from a parent universe. Collectively, Dr. Carroll calls the parent universe and all the baby universes a "multiverse". In this context, he describes how the multiverse is compatible with all the principles of entropy, thermodynamics, relativity, quantum mechanics ad quantum gravity that he has already described in the rest of the book.
In summary, this book is not for the faint of heart. If you're not prepared for a cerebral workout, don't buy it. If you like an intellectual challenge and enjoy musing about the nature of time and space, then this book is probably for you.
Two closing observations: On the 'upside', the narration by Erik Synnestvedt is very well done. On the 'downside' the narrative often refers to graphs and tables that are not accessible from the audio book file. This can be rather frustrating. The graphics should be bundled into the audio file download or a web page containing these images should be created for people who have purchased the audiobook.
Ponderous, yes. Comprehensive, yes, yes. Up to date--wow. Carroll is a genius at seeing the links between critical ideas. I have heard him lecture on physics through the Teaching Company, and this book is far superior. But it is hard going, and sadly the publisher has not provided the figures to go with it, so it is difficult to follow some of Carroll's arguments. I recommend the first section to get your feet under you, the last section to review, and in between just listen and be amazed. This book will change your perspectives on both time and the universe. And you will get lots of exercise in the process.
l'enfer c'est les autres
He states Dark Energy comes from the vacuum energy. He completely delves into the 2nd law of thermodynamics (entropy) and explains it historically and with superb analogies. The expansion of the universe is finally starting to make sense to me. I read Brian Greene's books before this one and Carroll brings with him another useful set of analogies to explain the physics of the universe. At the end of the book Carroll gives a plausible explanation for why we are one universe in a mega-verse of universes.
I eagerly await his next book, and I will listen to it as soon as it's published. I like the author that much.
I focus on fiction, sci-fi, fantasy, science, history, politics and read a lot. I try to review everything I read.
This book deserves a high rating simply because of the sheer quantity of interesting information and questions it clearly presents along with the pleasant narration. Most of the book focuses on the facts and questions related to our understanding of time followed by some relatively brief speculations. When speculation occurs it is clearly labeled as such. It is unfortunate that a PDF is not available for the figures discussed. There were, however, a few weaknesses. The book is largely from a general relativity point of view, only mildly addressing quantum effects. Particularly in the description of the hints we see in experiments regarding time, Carroll focuses a lot on the unexpectedly low entropy of the recent past (which is important) but then glosses over several other equally important hints such as the Bell/EPR results, Space and Time not being fundamental, and the information density enigma, he also speaks about the wave function as if it is fundamental while there are very good reasons to believe it is not.
The author basically admits although space and time being non-fundamental increasingly appears to be the case, he is unable to say anything interesting about this, so instead proposes solutions to the low entropy problem in a fundamental space-time context. This is a bit like looking for your keys under the streetlight because the light is better over there. Although speculation is an important aspect of science, successful speculation will illuminate by addressing several of the outstanding hints before us. Although the speculation was mildly interesting, the focusing on just one of the outstanding enigmas along with non-testability left it ultimately un-illuminating.
The author also indicates his preferred interpretation of quantum mechanics is the Multi-World interpretation. Although Carroll seems to point out QM having so many interpretations is odd (and likely another hint) instead of rejecting all the interpretations he seems to settle for one.
The key benefits of this book are the enigma and questions it raises. The author highlights most of the important enigmas giving us hints towards a fuller understanding of time; unfortunately he does follow most of the hint presented. For example the author points out the strong correspondences between information and entropy, even seeming to conclude that the information viewpoint is clearer and more fundamental, yet then proceeds to ignore the information viewpoint for the rest of the book.
Although the author does a pretty good job describing how classical entropy works, I am not sure I would have fully understood it without having listened to Penrose???s (long, detailed and daunting) description in Cycles of Time.
I had recently purchased a DVD set from the teaching company by Sean Carol and felt pretty content and that's the reason behind purchasing this book. No regrets here. Well written by Prof. Carol. I felt that the narration could have been better, but taking into consideration the material presented in the book it wasn't a big compromise to make. Overall a ***** i.e., a 5 STAR book.
I love written books but I also love listenning to audio books while doing the mundane tasks required in the day to day grime. This book is great for the listener since hardly any math is mentioned and when it is required you dont feel overwhelmed.
Carroll has the best grasp of the meaning of
The part I enjoyed most was the many descriptions of how time was defined throughout history. The author made each insight as clear as a cloudless summer day sky. This was also helped by having it read aloud by a very firm and warm voice.
The book gave me a new view on the universe and how it came to be.
I highly recommend this book to anyone who wants a scientific view of what time really is. The reader needs only a basic grasp of science to enjoy the views carroll lays out. I am studying quantum mechanics and while I knew many of the theories he took time to describe I still felt as though much of it was a better way to see how it all works without the use of mathematics.
This is a difficult book to follow because cosmology is difficult. It requires close attention and the occasional retreat and repeat. I'll probably reread it next year to see if I get more out of it.
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