Water in a frigidaire cools down; in a freezer it turns to ice - becomes solid; in a boiler, water converts to steam - a gas. The best way to beat swords into plowshares is to melt (which happens at a suitably high temperature) and subsequently mold them into proper shapes - which takes some cooling. Such processes are known as phase transitions; phases or states describe matter with uniform properties. Phase transitions are abrupt: metal gets warmer, then hotter, but remains in solid state while temperature raises to a melting point. When that is reached metal turns liquid.
Phase transitions are associated with certain values of parameters that characterize specific material near which small changes in parameters lead to big changes in the properties of the material.
Some events in human society are deftly described as phase transitions. Until the moment in July 21, 1969 when Neil Armstrong set foot on the lunar surface the possibility of man walking on the Moon was at best in the minds and folklore of humankind, but then came his famous sentence "That's one small step for man, one giant leap for mankind." What was just possible became a reality, a given fact for the generations that came afterwards.
Samuel Arbesman in his new book The Half-Life of Facts writes,
The iPhone appeared so rapidly in the world technology that executives from a rival company thought many of its claimed specifications were lies, and Mark Andreessen has argued that it's as if it appeared from the future, incredibly ahead of its time. One day there was a certain understanding of how we thought the world works, and the nest day humanity's factual environment had undergone a fundamental change.
The appearance of iPhone marked a phase transition not only of the world of technology but of the entire way of life and thinking. Curiously, the quote relates - without pointing it out - to another societal phase transition that took place a decade and a half earlier. The first iPhone was released on June 29, 2007. The first internet browser - Mosaic - was released in 1993. Mosaic popularized the World Wide Web, turning it in a short time into a household commodity. Mark Andreessen - at the time a student at University of Illinois - was responsible for the development of Mosaic and later on of the Netscape Navigator. Arbesman quotes Mark assuming that the reader would know who that was.
Our knowledge is also subject to state transitions. Two 1995 papers by Andrew Wiles and Richard Taylor marked the end of a 300 years long search for a proof of Fermat's Last Theorem. Interestingly and surprisingly, there are other laws - expressed pretty much mathematically - that govern the rate with which knowledge accrues and spreads, and how long it remains current. The latter is reflected in the title of the book, but the book covers a much greater territory.
Growth of scientific output obeys exponential laws; naturally, the rate depends on specific field: doubling time in medicine is about 87 years, in mathematics 63, in genetics 20, etc. However, knowledge is not only being accumulated; some undergoes modifications, some of it becomes obsolete entirely. In medical circles the fact is well known:
As the saying among doctors goes, "Hurry up and use a new drug while it sill works."
Arbesman expertly tells his engaging story, with no noticeable effort, sprinkling his narration with humorous tidbits. I very much enjoyed reading the book and plan to tell about it to my friends and mention it to my family; I placed this review in a blog and will be tweeting about it when finished. This is how humans are organized: in multiple networks, with clusters of strong links, and weaker links joining the clusters. "... social networks spread information." Which links are most responsible?
Ultimately it's the medium-strength ties that are most important. They are that happy medium between ties that are too weak to spread anything and those too strong to be found in anything but socially (and informationally) inbred groups.
Social networks are as good in spreading false information, and also may fail to pass information between clusters. Modern technology comes in handy in strengthening (or even discovering) links between clusters. For example, MEDLINE, an online database run by the National Library of Medicine, has been used to reveal hidden knowledge, links between medical facts that escaped experts' attention.
It is very likely that a review of a book hides more than it reveals about the book because in a review it is impossible to mention every idea and concept discussed in the book. Arbesman's book is wonderfully informative. If I knew of its contents before I read it, I would have characterized it as an eye-opener. Now that I finished reading it I think it would be a better recommendation to say that it caused a phase transition in my personal worldly outlook. We do live in an information society. We learn that information - the crucial component of the modern world - obeys certain laws. Abersman's book helps the reader understand how the world of information works.