Cover Image: The Janus Point

The Janus Point

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Member Reviews

On the Solstice, I think a lot about time. Why time's arrow only points in one direction, for example. I am always bothered by the implication inherent in the laws of physics that we presently understand that this is an observational artifact, not part of the structure of physics.

While I sit and ponder the strange dichotomies between what we observe and what theory tells us is possible, Author Barbour sets himself the task of learning the why, and questioning the how, of all the factors in physics that determine this issue's boundaries. That is an immense task.

It is also one well beyond most people's educational, vocational, and experiential capacities. The author isn't writing an academic paper in this book. He is, however, presupposing a lot of knowledge on the reader's part...if you don't know what a Boltzmann brain is, for example, this book will be lost on you...and even for those with the requisite grounding in at least the people who created the outlines of the Standard Model of particle physics, the need for frequent research breaks, aka "fallings down the many rabbit holes", is ever-present.

Very much not a Wikipedia-level treatment of an immensely important topic being argued, studied, researched, and pondered by some of the best-furnished minds in the field of physics today; yet it does not repel boarders with its case-shot loaded cannons of erudition. Author Barbour is quippy and quotable. The problem is quoting him won't help. This is someone with a very broad grasp of physics, history, cultural anthropology, etc. He lays out arguments that I suspect I only dimly grasp for his new model of endlessly repeatable order, ie creation of matter instead of its inevitable and complete decay, grounded in all the currents of thought there are.

Not, as you'd expect, a mere bagatelle to be consumed of an evening. Took me two years to read it, and I regret not a page or a minute of it. I was rewarded with a greatly expanded idea of what the science of physics is reaching for in its quest for a unified theory.

At this #Booksgiving moment, self-gifting this immensely challenging and deeply absorbing book is a great way to invest in your brain's expansion in entirely new ways and directions. It will be a Project. It is also well worth your eyeblinks.

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Dnf at 65%
Thanks to NetGalley for an earc of this. I ended up listening to the audiobook.
In short, the book is overly esoteric. It's honestly hard to imagine this is actually intended for the lay reader. The basic idea is fascinating: the big bang as imagine it, actually occurred in both directions of time, but on the other side of the big bang, matter evolves with entropy (i.e., the arrow of time) opposite of our own. I was interested in learning about this, but he spends too much time trying to prove it (I feel like a lot of is better fitting a peer reviewed paper) than actually communicating the basic idea. You can hear my thoughts in a couple vlogs, my Washington trip (pretty much just this first clip) and my moving vlog.

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I appreciate the publisher allowing me to read this book. This one really makes you think.I had to read some portions more than once.

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Julian Barbour describes his book as "the song of thanks to the cosmos." Whilst no doubt thought provoking and stimulating, "Janus Point" poses a veritable challenge to the uninitiated and rustic when it comes to the Science of Big Bang Theory and Astrophysics. At the nub of Barbour's book is the contention that there is no concept such as the 'beginning of time.' The Big Bang represents a unique configuration of the elementary building blocks of the Universe. These building blocks takes the shape of what the author terms, the 'Janus Point.' The further one moves from such a point, more the altered nature of the shape. Since this movement could be in any direction with reference to the passage of time, the nomenclature of Janus. Janus, in Roman mythology represents a two-faced God.

The book gets incredibly complex when Barbour elucidates to his readers a model known as the "three-body problem". Under the three body problem, a Janus Point is reached when all three masses momentarily occupy the same point - a total collision. The peculiar shape at such a collision point, takes the form of an equilateral triangle, which is his model’s version of the Big Bang.

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"The Janus Point" by Julian Barbour posits that there is a point at which time runs in reverse for the universe. We think as time as running forward from the Big Bang on, but Barbour believes that time also runs in reverse from that point, although we cannot experience that.

Barbour knows his stuff, but throws a lot of less-comprehensible material at the reader. Richard Feynman, a famous physicist, after trying to explain a topic, once said, "“I couldn’t do it. I couldn’t reduce it to the freshman level. That means we don’t really understand it.” I think Barbour understands the high points of his theory, but has difficulty translating it for non-physicists. The general reader will struggle with the concepts and math, and also with Barbour's general verbosity. It's a fascinating topic and a great theory about which I'd like to know more, but it was a slog to get through.

Slightly recommended.

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This is a lovely and very readable book. I very much enjoyed "The End of Time" some years ago when it came out in hardback, so I was excited to see a follow-up from Barbour. Although I read quite a lot of not-for-specialists physics books, the beginning of this one was almost entirely new to me in terms of the history it presented of how the laws of thermodynamics were revealed. Barbour is a clear writer and strikes a good balance between avoiding equations and oversimplifying.

I received an advanced e-copy from #NetGalley in exchange for my honest review.

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In a universe filled by chaos and disorder, one physicist makes the radical argument that the growth of order drives the passage of time -- and shapes the destiny of the universe. Time is among the universe's greatest mysteries. Why, when most laws of physics allow for it to flow forward and backward, does it only go forward? Physicists have long appealed to the second law of thermodynamics, held to predict the increase of disorder in the universe, to explain this. In The Janus Point, physicist Julian Barbour argues that the second law has been misapplied and that the growth of order determines how we experience time. In his view, the big bang becomes the "Janus point," a moment of minimal order from which time could flow, and order increase, in two directions.

The Janus Point has remarkable implications: while most physicists predict that the universe will become mired in disorder, Barbour sees the possibility that order -- the stuff of life -- can grow without bound. A major new work of physics, The Janus Point will transform our understanding of the nature of existence. This is a fascinating, life-altering and accessible read, which is deeply informative and rich in intricate detail. I've read several books that cover this topic but none were as absorbing and engaging as Barbour manages to make this narrative. It is a book I cannot recommend highly enough to those with an interest in our universe, the concept of time and its impact on the way we live our lives, and our philosophical outlook.

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Reading The Janus Point is like picking raisins out of a bowl of porridge – a few interesting ideas bogged down in a bowl of unwieldy prose, philosophical and literary ruminations.

The author explores the concept of time in physics. For some actions, time can be symmetric, if you rewind a movie for instance, the actions are unchanged only in the reverse order, However, for some things, actions cannot be easily reversed; for example, particles moving in an electro-magnetic field. To reverse the direction of the particles, the field itself has to be reversed. Based on simple physics, the author suggests that there was a ‘close to zero’ time, just after the Big Bang when the universe started expanding, and on the other side, there is also a symmetrical time when the universe contracted to the ‘close to zero’ point. This is the Janus point.

The author makes a very valid point that some of the basic rules of Physics have persisted through history but have lost the connection to the initial conditions under which they were held. For example, some theories which were based on a closed system (such as the steam engine) have been interpolated to larger open systems such as the universe and these historical ‘inheritances’ need to be rigorously re-appraised to ensure that the conditions on which they are based are relevant to the actual system under consideration.

In addition to the idea of the Janus Point as two ‘cones’ of universal time and space, the author also argues that the universe is not going from low entropy and high order to increasing ‘disorder’ but instead it is to increasing complexity. He cites biological evolution as a proof of this. He also claims that it isn’t the entropic disorder that makes the arrows of time fly in one direction only, but the increase in this complexity.

The physics would be familiar to anyone with a physics background, and this book does have few ‘food for thought’ moments; however, I found it had too many confusing assertions and was too sparse on actual proofs – for example, interpolating evolution as an argument increasing complexity in the universe seems quite a leap of faith.

In addition, there were too many irrelevant asides such as pages of the history of some of the early discoveries (which is already familiar to most physicists) and long-winded treatise on philosophy and Shakespeare. Although, I too am a fan of the Bard, I don't enjoy quotes being sprinkled on everything I read. I wish the author had given more thought to the audience he wants to read this this book is - if fellow physicists, then omit the basic physics and history and literary distractions and focus on real proofs; if a layman, then simplify the ideas and again remove the distractions.

Thank you to NetGallery for providing an e-copy of this book in exchange for an unbiased review.

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Intriguing Theoretical Astrophysics. If it wasn't clear from the description of this book, this book is *all about* theoretical astrophysics and the author's new theory of the origins and nature of time. If words like Newtonian and General Relativity and Leibniz and thermodynamics are part of your every day lexicon, you'll probably enjoy reading this. For the rest of us... at least there isn't much math involved in the actual text here? Specifically of the Calculus variety, which gives even many math-oriented people the heebie jeebies? Truly an intriguing work, but I'll be the first to say that I didn't fully follow or comprehend all of it - it is simply that high level. Even though Barbour tries to use narrative examples and structures designed to allow most anyone to have some idea of what is going on, at the end of the day this is still advanced theoretical astrophysics, of the kind that even Stephen Hawking wrestled with. While others more learned in the actual science may find fault here, for what it is I could find none. Very much recommended.

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