Customer Reviews

Cosmic Evolution: The Rise of Complexity in Nature

5 star:		(4)
4 star:		(1)
3 star:		(1)
2 star:		(0)
1 star:		(0)

 

 

Professor Chaisson has succeeded in providing a narrative of the Universe, one that is elegant and satisfying, and at the same time based on a rock-solid, quantitative approach.

This book has finally reconciled for me the vexing question of how complexity and disorder (entropy) can increase simultaneously. I knew that total entropy must increase, per the 2nd law of thermodynamics. What I did not realize is that the maximum POSSIBLE entropy of the Universe is increasing even faster, due to the expansion of the Universe. So now I have a way of visualizing the amount of complexity in the Universe - it is the difference between these two entropies.

One of my favorite aspects of the book is the clear identification of the phases of the Universe: Radiation Era->Matter Era->Life Era. The idea that we, as intelligent life, can give birth to a thriving, universal Life Era is visionary and uplifting (and part of the basis for Reason for the Common Good).

Cosmic Evolution is extremely well-researched, quantitative, and most of all, illuminating.

This is an enjoyable big-picture examination of evolution in light of thermodynamics, i.e. how can order increase despite the 2nd law of thermodynamics? You will need to recall some calculus and some basic physics in order to follow the thread of the discussion. Chaisson does an excellent job of laying out the subject, looking at the evolution of complicated structures, e.g. the universe, stars, galaxies, planets, life, brains, societies. He actually works through the numbers on several examples in order to give you a better feel for the subject of evolution, and for thermodynamics. If you have an interest in things cosmological, I strongly recommend this book.

Chaisson's book is an exploration of the consequences of an expanding universe - an exploration that leads to the conclusion that it is the very expansion of the universe that is (almost literally) the engine of creation.

First, Chaisson provides an introduction to the nature of change. He starts out simply enough looking at time and quantum probability, but then turns toward open systems and the "spontaneous order" (or "dissipative structure") consequences of gradients (both thermal and otherwise) in such systems when the second law of thermodynamics kicks in and attempts to drive the system toward equilibrium. This review of the basics sets the stage for Chaisson's ultimate contribution.

Chaisson then moves on to the history of the universe. Taking things a bit out of order, he starts with what he terms the "Matter" period. Here, he covers the cosmology of matter, discussing topics such as the material evidence for an expanding universe, what this tells us about the age of the universe, and so on.

From there, Chaisson reverses field to an earlier period that he calls the "Radiation" period. This period starts with the big bang and revolves around what happens to energy at different densities. For example, at the highest possible densities, energy is just a homogeneous blob. At lower densities, fundamental particles begin precipitating out forming a plasma. At lower densities still, the precipitation stops and these particles begin collecting together into atomic structures and such. And given that the universe is expanding, energy runs through the entire range of these densities - thus it is the very expansion of the universe that drives the evolution of energy and matter.

At this point we jump forward into the "Life" period. This is where Chaisson makes the best use of that introduction on dissipative systems. At this point in its history, the universe is filled with two fundamental components: radiative energy and matter. As the universe expands, the thermal density of these components decreases; however, these densities decrease at different rates. Using equations that could fit on the back of a napkin, Chaisson shows that the expansion of the universe is happening quickly enough that thermal gradients build up between the radiative energy of the universe and the matter of the universe. These gradients cause dissipative structures to form as the second law of thermodynamics kicks in to try to drive the universe toward equilibrium. And, as discussed in the intro, such dissipative structures are the sediment from which more complex dissipative structures can form as these gradients vary and persist. Spontaneous order occurs and becomes more complex without violating any of the laws of thermodynamics. Given enough time, there can arise metabolic dissipative structures - that is, life itself. And all due to the simple fact that the universe expands.

If Chaisson is right, he has unveiled a mind-blowingly simple reason regarding why the total complexity and total entropy of the universe should be able to increase at the same time even if the universe turns out to be a closed system. The reason no-one ever discovered this simple reason before could be that no-one ever thought there was a need to look for one. That is, in our own little corner of the universe it is often thought that if you consider the Earth as an open system that all you need to explain the increasing complexity of the biosphere is the massive energy influx from the Sun. That may be true, but Chaisson may have just shown that ever-increasing complexity is not simply a local phenomenon of relatively small open systems at the expense of the rest of the universe but rather is a general principle of the universe as a whole.

This book was not written for the lay reader of science, such as myself. At times the writer sounds as if, chalk in hand, he is giving a lecture to astrophysics third-year students - the only thing missing is the pronunciation of the equations. Those uncomfortable with formulas will find the middle of the book slow going.

The payoff, for those who persevere, is two or three new ideas. And that's why we read books like this.

This book contains great ideas, and some of them definitely true and correct - they have to be, lest the fundamental laws of physics are violated. In a nutshell: The universe is expanding; the expanding of the universe causes a gap between the maximum possible level of entropy and the actual amount of entropy within the universe - hence disquilibrium is possible; this gap is the foundation of the flow of free energy and thus the seed of the formation of organized structures (such organized structures have low entropy by definition); the process of generating progrssively more & more complicated stuctures is therefore possible and consistent with the laws of the universe (viz. the second law of thermodynamics); our human existence, behavior and even cultures fit within this scheme coherently.

The first two-thirds of the book is excellent - with equations and mathematical analysis to prove and demontrate the aforementioned thesis convincingly and conclusively. A lot of effort (perhaps slightly too much) is spent on explaining in great length and depth the concept of free energy rate density - with slightly detailed derivation and estimation.

The last third of the book is, to my humble opinion, not as good as the first two thirds. I feel that the author is stretching the concept of disequilibrium engendering complexity too far. It is difficult to pinpoint (as in this part of the book he is comparatively vague) but it seems that he is trying to explain biological evolution and even sentience using the same ideas; and more than once he suggests that the boundary between life and "non-life" is blurred if not non-existent. To be fair, he admits frankly that there are limitations and uncertainties, but the urge and temptation to be encompassing (perhaps too ambitiously) is easily palpable.

So, overall it is a book with very important ideas; but towards the end it tends to philosophize a bit too much and detracts a bit from the initial clarity. Four stars.

I quote: "life likely differs from the rest of clumped matter only in degree, not in kind. We admit no vitalism, no special life force that would set animate beings manifestly apart from all other forms of inanimate complexity [p.122...] a 'life force' [...] something akin to vitalism or vis vitae [p.149...] no one has ever discovered anything akin to an elan vital, or special life force, that would truly set aside life from all other organized systems [p.217]." This is in keeping with the perspective of modern biology as concerns 'the stuff of life:' until there is evidence to support the idea, vitalism is merely an archaic, superstitious figment.