Image above by Kevin from The Beginning at Last
Many and strange are the universes that drift like bubbles in the foam upon the River of Time—first sentence of Wall of Darkness by Arthur C. Clarke, 1949.
What is Time? What is the arrow of time? Does entropy define an arrow of time? Is there a past and a future? Has time always existed as, for example, in the eternal inflation cosmological model in which universes continuously pop into existence via Big Bangs like the bubbles on the River of Time in the Arthur C. Clarke quote above. Does time have a beginning as a recent Big Bang model by Stephen Hawking imply. If time came into existence with the universe itself then there is no place for creation, just as in an infinitely existing universe. There cannot be anything north of the north pole, and there cannot be anything before time itself.
In the theories of relativity time is relative. The speed of clocks as well as the order of events differ from observer to observer. The presence of energy or mass will bend time. There is no universal flow of time. There is no universal time.
The goal of this blog is to create a list of what I call super facts. Important facts that we know to be true and yet they are surprising, shocking or disputed among non-experts. It is a type of myth busting. However, I also create posts that are not super facts but that feature other interesting information, such as this book review and book recommendation.
About Time: Einstein’s Unfinished Revolution by Paul Davies
The book I am about to present focuses a lot on relativity. This is not strange since the theories of relativity shed a lot of light on time. Yes, pun intended. I’ve come across a lot of people who make various claims about time, and even consider themselves philosophers of time, and yet they do not even understand the special theory of relativity. Because of this they say a lot of profound sounding things about time that ultimately are nonsensical. There is no way around it. If you want to say profound things about time and expand human knowledge on this topic you need to first have some understanding of relativity as well as other related physics such as thermodynamics and entropy. This book will provide that.
I should say that the book is somewhat outdated, being written in 1995 and 1996. However, most of it is still relevant and I know of no other book that approaches the topic in such an honest and rigorous way. The book comes in two formats hardcover and paperback. I bought the paperback version.
- Hardcover – Publisher – Simon & Schuster; First Edition (March 13, 1995), ISBN-10 : 0671799649, ISBN-13 : 978-0671799649, 316 pages, item weight : 1.3 pounds, dimensions : 6.25 x 1.25 x 9.5 inches, it costs $18.09 on US Amazon. Click here to order it from Amazon.com.
- Paperback – Publisher – Simon & Schuster; First Edition (April 9, 1996), ISBN-10 : 0684818221, ISBN-13 : 978-0684818221, 316 pages, item weight : 0.704 ounces according to Amazon but I think that should be 0.704 pounds, dimensions : 9.21 x 6.14 x 0.8 inches, it costs $12.28 on US Amazon. Click here to order it from Amazon.com.
Amazon’s Description of About Time: Einstein’s Unfinished Revolution
An elegant, witty, and engaging exploration of the riddle of time, which examines the consequences of Einstein’s theory of relativity and offers startling suggestions about what recent research may reveal.
The eternal questions of science and religion were profoundly recast by Einstein’s theory of relativity and its implications that time can be warped by motion and gravitation, and that it cannot be meaningfully divided into past, present, and future.
In About Time, Paul Davies discusses the big bang theory, chaos theory, and the recent discovery that the universe appears to be younger than some of the objects in it, concluding that Einstein’s theory provides only an incomplete understanding of the nature of time. Davies explores unanswered questions such as:
* Does the universe have a beginning and an end?
* Is the passage of time merely an illusion?
* Is it possible to travel backward — or forward — in time?
About Time weaves physics and metaphysics in a provocative contemplation of time and the universe.
My four-star review for About Time: Einstein’s Unfinished Revolution
The link above will take you to my original review for About Time: Einstein’s Unfinished Revolution. Below is a slightly modified version of the review.
Our Evolving Concept of Time
Science, particularly physics, has revealed to us some profound insights about time, and yet it remains a mysterious topic. In the first chapter of the book “A Very Brief History of Time” the author describes how the concept of time has evolved throughout human history. The ancient philosophers had a very fuzzy notion of time, and they often dismissed both motion and time as illusions. The author tells us about “cyclic time”, and the “linear time” concept from Judeo-Christian thinking, and how it was incorporated into science as a “time variable”. This made it possible to solve the paradoxes created by such Greek thinkers as Zeno, who based on apparent paradoxes concluded that motion and time cannot really exist. Those “false” paradoxes were solved with the concept of linear physical time.
Physical time also made Calculus and Physics possible, and it became clear that there was a difference between physical time, which is a measurable entity used to sequence events, and experienced time, which is the subjective human feeling of a past, present, and a future.
Most of the rest of the book is focused on the Special Theory of Relativity and the General Theory of Relativity. The theories of relativity revolutionized how we view time, and they enabled a much deeper understanding of time. Special relativity refuted the concept of universal absolute time. Not only do clocks in different systems run at different speeds, but there is no universal “Now”.
However, the theories of relativity are not all there is to know about time, and we are not even done drawing conclusions about time based on the theories of relativity. This is why the book is called “About Time Einstein’s Unfinished Revolution”. The book also discusses quantum time, the arrow of time, worm holes, neuroscience and modern psychological experiments.
The book contains a lot of information and yet it scratches only on the surface. Time is a quite complex concept when you start digging into it. Take, for example, the discussion on the arrow of time. The conclusion of the books seems to be that there really is an arrow of time. Time has direction. The author is presenting both “sides” of the issue and to really get a grasp of the issue you need to clarify and look at the physics. Time certainly seems to have a direction if you look at the concept of entropy. The Cosmos is filled with irreversible processes. Our memory, which is essential for our experience of a self, is another example.
However, time has a direction even on the most fundamental level in subatomic particles. Kaon, a type of meson, decays in a way that is not time symmetric. The same may be true for the neutron. These particles “know” the difference between the past and the future. One could easily imagine how this chapter could be turned into a several thousand pages long book by just digging deeper into the related physics.
“About Time Einstein’s Unfinished Revolution” covers a lot of interesting topics related to time and it is often quite informative. The book is also well written, well organized, it has a good pace, and it is very interesting. It strikes a good balance between depth and breadth, and it does not overwhelm its readers. However, I do have some critique of the book, which prompted me to give the book four stars instead of five stars.
To understand some of the discussions in the book you should have a decent understanding of the theories of relativity, in my opinion. The author is explaining the theories of relativity to some degree, but the explanations did not seem to be that good. I did not have a problem with understanding these explanations since I already studied these topics, but I don’t think I would have understood what I needed to understand had I encountered the theories of relativity for the first time while reading this book.
Another criticism I have of the book is that he introduces ugh Everett’s many-worlds interpretation of quantum mechanics and in my opinion promotes it. This interpretation is in my opinion both strange and implausible and is not necessary for the discussions in the book. In short, it proposes that every quantum measurement creates new universes, each corresponding to a different possible outcome of that measurement. In essence, our Universe is just one of many, and each quantum event splits the universe into multiple versions, where each version experiences a different outcome. The problem with this interpretation is not so much that you get multiverses, but that you an infinite number of new fully evolved universes every nanosecond, which in turn create an infinite number of universes, which in turn create an infinite number of universes, and so on infinitely, and there is no way to empirically verify their existence. It is a so-called solution to a problem that is fictitious in my opinion and is derived from an old naïve interpretation of quantum waves. It is “hip” and “cool” interpretation, but I don’t see how it is useful. I should add that I have no problem with, for example, the multiverse idea stemming from string theory.
Anyway, except for my two complaints I think this is a pretty good book that I can recommend.
About Paul Davis
Paul Davies is an internationally acclaimed physicist, cosmologist, and astrobiologist at Arizona State University, where he runs the pioneering Beyond Center for Fundamental Concepts in Science. He also chairs the Search for Extraterrestrial Intelligence Post-Detection Taskgroup, so that if SETI succeeds in finding intelligent life, he will be among the first to know.
The asteroid 1992OG was officially renamed Paul Davies in his honor. In addition to his many scientific awards, Davies is the recipient of the 1995 Templeton Prize–the world’s largest annual prize–for his work on science and religion. He is the author of more than twenty books, including The Mind of God, About Time, How to Build a Time Machine, and The Goldilocks Enigma. He lives in Tempe, Arizona.
Other Relativity Related Posts
- Book Review : Relativity Visualized by Lewis Carroll Epstein
- Book Review : The Special Theory of Relativity by David Bohm
- The Speed of Light In Vacuum Is a Universal Constant
- Two events may be simultaneous for some but not for others
- Time Dilation Goes Both Ways
- The Pole-Barn Paradox and Solution
To see the Super Facts click here
Newstrade
Time is a tricky concept. Does this book answer the three questions it poses–
* Does the universe have a beginning and an end?
* Is the passage of time merely an illusion?
* Is it possible to travel backward — or forward — in time?
I’ve begun to consider time less linear than I used to so these answers would help. I might even buy the book! Thanks for the intriguing review.
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That’s an excellent question I only vaguely answered it/them because the book only vaguely answers them too. For the first question, he describes cosmological models for which the Universe (and time) has a beginning and cosmological models for which there are many universes and time has existed infinitely. The book is quite dated, so it is leaning towards the first option whilst recent models and research is leaning towards the latter (as I understand). But reasonable minds disagree.
The second question is that it depends on what you mean by illusion but in general, time is not an illusion. You can maybe say that the universe and all of the time exists all at once as an unchangeable entity and our evolving memories, which is a part of that entity gives the feeling of moving time. But that is a philosophical viewpoint. The arrow of time definitely exists (irreversible processes), so in that sense you cannot say that time is an illusion. However, it should be noted that time does not exist for massless particles like photons.
The answer to the third question is that you can travel forward in time, in fact we already are, but not likely backwards in time. If you can travel backwards in time, then you cannot affect the universe in any way.
Thank you so much Jacqui
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Great piece, as always, and a wonderful read. Thank you.
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Thank you so much Luisa for your kind words.
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You’re more than welcome 🌹
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