on 27 June 1999
In this book Paul Davies provides a comprehensive, brilliant discussion of the nature of time. Beginning with Einstein's revolution which abolished the classical view of absolute time and space, Davies ranges widely into the scientific and philosophical ramifications of relativity. The bottom line is that our "common sense" notions of past, present, and future and our perception of time as flowng from present into future are distortions of reality. Instead of a flowing time that moves from present to future, time is actually a block of past, present, and future that is simply "there." The common sense notion of past, present, and future must be discarded if we are to understand the nature of time.Davies' discussion of time is exhaustive. And, while the book is difficult, particularly to a non-scientist like me, Davies has a gift for explaining very complex ideas in a way that a layperson can comprehend (but with effort; this is not casual reading!). Davies' prose is elegant and clear. He provides interesting insights into the lives of major scientific figures, particularly Einstein. And, he has a likable sense of humor. This book was a JOY TO READ.
on 8 July 2002
Time has become a huge subject, particularly since Hawking set pen to paper, and raised the popular science bar. Davis's book shows just how many aspects of time can be considered, and how many unanswered questions remain after Einstein and others blew the concept apart early in the 20th century.
Each chapter is largely self-contained, is intelligent and accesible, and manages not to patronise - a flaw of so much of the popular science genre. The scientist biographies are there of course, as are the obligatory Feynman diagrams, but what sets this apart from similar books are the chapters on perception. "What time is now" is superbly thought-provoking, as it explores how our minds perceive each moment of time... novel and just a little frightening
on 19 November 1998
If you've ever wondered what is time, where did it come from, does it flow, why does it seem to go in one direction, will it have an end, or is it slowing down, you'll not find your answers in Paul Davies' book "About Time." Neither are you likely to find your answers anywhere else. For me, the most profound knowledge that came from reading Davies' book is the reminder that we really don't know what time is. We live in it, experience it, but really - on a fundamental level - fail to comprehend it.
Davies has subtitled his book "Einstein's unfinished revolution," and he does an excellent job of exposing the reader to some of the unexpected (from a common-sense point of view) conclusions we draw about time from the special and general theories of relativity. He offers an interesting historical perspective on the life of Einstein, and how he developed his theories. Davies also provides some interesting background on experiments that have validated Einstein's space-time, reviewing the qualitative results from some of the more important experiments.
After this introduction to the non-universal time of relativity, Davies takes us to the ultimate time machine: black holes. He offers some interesting explanations about what an imaginary traveler to a black hole might see looking out, and how we - looking in - might view the hapless victim as she neared the event horizon.
As the book progresses, conclusions and examples become less and less concrete. Relative time is a proven fact, and most physicists consider black holes a foregone conclusion. From there, Davies takes us to the very root of some of the biggest issues in cosmology: the origin of time and the age of the universe. Davies clearly believes there are problems with the current Big-Bang theory of the universe, and proposes Einstein's cosmological constant as one possible solution.
Things get weirder still. From cosmology he moves to quantum time and the implications of tunneling and EPR experiments. There is some brief mention of Hawking's imaginary time and, of course, no book on time would be complete without a chapter on possible time travel. Davies looks at all the possibilities, and some of the discussions and speculation runs wild.
For the most part I really enjoyed this book. It is well written, and clear, but sometimes the author fails to define terms properly. He appears to use the term "timewarp factor" synonymously with "time-dilation factor" but the formula on page 58 disagrees with the top figure on page 61. Also, in his discussions about problems with the Big Bang theory, I felt the author failed to give sufficient coverage to inflationary models of the universe that might resolve some of the issues he raised.
Overall, Davies' book is worth the time to read it. It may not answer all the deepest questions about time, but it will help you appreciate how little of the subject we truly comprehend. I'd also recommend his book "The Last Three Minutes."
on 23 August 1999
As an A-level student I found this book a great insight into the world of theoretical physics - expressed in lay terms. It doesn't take a great deal of scientific knowledge to understand the principles that Davies tries to convey, making this a very enjoyable and fascinating read.
His explanations of Einstein's Special and General Theories of Relativity are concise and explained rigorously using conceivable scenarios. I enjoyed this very much and hope that others will enjoy this book as much as I did.
on 15 February 1999
This is a masterpiece. I have read all of the relativity/time books by Hawking, Feynman, Rohrlich, etc., and this is the best by far. It is extremely easy to understand, plus Davies presents ideas that most authors leave out (such as Wheeler's single particle universe). If you have any interest in relativity or the nature of time, read this one.
on 27 May 1998
Davies has managed to capture the very essence of physics, and at the same time explains it so clearly that it feels like reading a novel. I bought this book in December of 1996, I was 17 at the time, because I have laways had a flair for the dramatic and seemingly immposible like time travel. Davies not only convinced me that it is actually possible to accomplish time travel and how it can be held in our hands to mold it, but also kept me thinking that in time and with technology constantly increasing, we will soon capture the universe itself. Davies introduces to the reader the bigger picture, how we are so insignificant in our own universe and how we must prevail to understand it like Einstein did. "About Time" is so gracefully and fluidly written that anyone with interest for science or physics can understand even the most complex situations such as the Theory of Relativiy. I highly recomend this book to anyone, it is one of the best books written in the field.
on 14 June 1999
My only criticism with this book is that the first chapter is a bit too long and philosopihical, so it takes a while to get into, but if you enjoy philosophy then it is not a problem, and if you don't then you can just skip it without losing any of the understanding of the theories that come later. He presents loads of different and amazing theories from different areas of physics and brings them all together near the end, and has one of the best explanations of the Twins Paradox and relativity that I have seen so far in a popular science book. It's impossible to put down, and your perspective of the universe will be completely different after reading it - it is amazing.
on 27 May 1996
Have you ever asked what time is it? Paul Davies takes 300
pages to answer this question and leaves you wanting 300 more.
From Einstein's theory of relativity to the time dilemmas
of today, this book offers startling insight on a subject many
mistakingly believe conclusive. You'll learn why time travels
faster at heights, whether or not time travel is possible, and
of mystical particles known as tachyons. Presented in a clear
and readibly understandable tone, About Time will make looking
at your watch a whole new experience!
on 10 March 2002
Out of the 4 Paul Davies books I have read, while they all have been enjoyable this is probably his best. It is not a good place for new comers in popular physics to start but those with some basic knowledge will really enjoy this book.
It deals mostly with trying to explain Einstein's concept of time and space and the importance it has on understanding our world. It does, however, deal a lot with time in the quantum world, which is where the book is at its best, this is of course seperate from Einstein's own dislike for many of the concepts (such as total randomness) used in Quantum physics. That said it is Davies' intention to show the importance of spacetime in all aspects of the universe.
For anyone interested in what exactly is meant by spacetime, and what this implies, this is definately the book for you.
Unfortunately, though cosmology is only the crudest projection of their abstractions by some physicists on the cosmos, it has become a staple of pop philosophy. From black holes to the big bang, cosmologists have created a new vocabulary that pops in the unlikeliest of places today, far outside of their original and strictly qualified scientific domains.
Davies is a rarity amoung popular science writers. Not only does he stick to hard science without over-simplifying, but he avoids the excesses in speculative claims that boosters foist on the uninformed public. In clear and concise prose, he examines the cutting edge of the field of time, as framed by Einstein and extended by recent research and observations, with grace and humor. It is a masterly performance.
While he does not avoid the fantastical worlds that may be beckoning, such as a black hole being a gateway to the end of time, Davies never neglects the flip side of such phenomena: any ship that went into a black hole would probably be crushed or would be unable to communicate what it had found, as not even light can escape.
THis also means that, while Davies explains the building blocks of the new cosmology with unusual clarity, he also exposes the flimsiness of its foundations. We do not know, for example, what constitutes 9/10s of the mass of the universe! Nor can we explain many of the oberservations of the Hubble telescope, such as the discovery of stars that appear to be older than the universe itself. Now THAT more is exciting than off-the-wall speculation! Our theories, Davies demonstrates, are far from complete.