Summaries and Customer Reviews are supplied by Amazon.com
Summary:
As Chaos explained the science of disorder, Nexus reveals the new science of connection and the odd logic of six degrees of separation.
"If you ever wanted to know how many links connect you and the Pope, or why when the U.S. Federal Reserve Bank sneezes the global economy catches cold, read this book," writes John L. Casti (Santa Fe Institute). This "cogent and engaging" (Nature) work presents the fundamental principles of the emerging field of "small-worlds" theory—the idea that a hidden pattern is the key to how networks interact and exchange information, whether that network is the information highway or the firing of neurons in the brain. Mathematicians, physicists, computer scientists, and social scientists are working to decipher this complex organizational system, for it may yield a blueprint of dynamic interactions within our physical as well as social worlds.
Highlighting groundbreaking research behind network theory, "Mark Buchanan's graceful, lucid, nontechnical and entertaining prose" (Mark Granovetter) documents the mounting support among various disciplines for the small-worlds idea and demonstrates its practical applications to diverse problems—from the volatile global economy or the Human Genome Project to the spread of infectious disease or ecological damage. Nexus is an exciting introduction to the hidden geometry that weaves our lives so inextricably together.
Customer Reviews:
Average Customer Rating:
An Important Idea and and Entertaining Book
Customer Rating:
In this book, I think Buchanan makes a fairly convincing case that the natural, human, and technological worlds naturally tend to organize themselves into networks consisting of (a) clusters of strongly connected elements and (b) a relatively small number of weak links which fairly randomly connect the clusters. Such networks are "small worlds" because the shortest path from any element to any other is usually quite short, typically on the order of six steps or less, even for networks as large as the entire global human population of 6 billion people.
When all the elements in a small-world network have a comparable number of links, they are called "egalitarian," but some "aristocratic" small-world networks also have hub elements which are more highly linked (according to a power law or "fat tail" relationship). Either way, small-world networks tend to be efficient and robust, although they are also vulnerable to disfunction or complete collapse if a significant percentage of their weak links or hub elements are lost.
The above summarizes the basic concept, which Buchanan fleshes out with many examples spanning many fields (biology, economics, physics, epidemiology, information technology, business, politics, etc.), and he also adds a human-interest element by telling us about specific researchers and their working relationships. Buchanan is a top-notch science writer, and so he relays all of this in an effective and entertaining manner.
The only downside is that the book format gives it more of the feel of a novel rather than a textbook, so key points are not highlighted and it's difficult to go back and find information. I think this is a significant downside because it hinders the serious reader who wants to use the book as a reference and explore the topic further, so I'm giving the book a four-star rating instead of five. However, I still highly recommend the book to readers who are interested in general popular science, and especially network theory. This topic has an important place in the broader and increasingly important subject of complexity theory.
Fascinating
Customer Rating:
Nutshell review - The topic of this book, small-world networks, is fascinating and the author does a great job of covering the material in an easy to absorb and understand manner for us laymen. Well written, entertaining and thought provoking.
Extremely frustrating
Customer Rating:
The subject that Mark Buchanan addresses is, in itself, significant and fascinating. And Mr. Buchanan knows his stuff. He provides excellent visuals and thorough notes that many readers will find useful.
Why, then, do I find it so frustrating? Simply put, Mr. Buchanan may be a first-class editor, but he is not a very good writer. Not that he can't write a grammatical sentence. He just has trouble structuring one that leads unambiguously from one idea to another.
Thus, as interesting as I find the subject, it took me three years to force myself to finish the book. I am quite willing to reread something if, ultimately, I learn it. But I hate to be fighting constantly with the writer, trying to understand which of three possible concepts he's trying to convey.
And then there's the minor annoyance of the cover stock (paperback edition). It was curling before I left the bookstore, and it will never uncurl.
Good High-Level Overview
Customer Rating:
Nexus is a book that delves into network theory, specifically the implications of so-called "small-world" networks. Small-world networks are signified by low degrees of separation and clustering, yielding the "six-degrees" phenomena that connects a person to Kevin Bacon (or anyone else) within approximately six links, all the while most connections are maintained amongst close groups of friends or colleagues.
Research into small-world networks is a new and rapidly advancing field of complexity theory. Written in 2002, Nexus outlines the impact of small-world networks on many topics, including biology, ecology, economics, and technology. However, the cutting-edge nature of the field, combined with the now somewhat dated year of publication, limits the scope of the book.
In my opinion, while the book was interesting as a high-level overview, it lacked the level of detail that I would have preferred. While I have not yet read Linked or Six Degrees, I'm hoping that those books dive into the topic a bit further.
Very interesting!
Customer Rating:
A really interesting book. It's not hard to read and open your eyes on a new approach in understanding how real things go.
Select button not working? 
