Humans sense order in nature. Indeed, natural order is perhaps the single most pervasive theme of the history of human thought. The quality and construction of natural order, however, has not always been agreed on by people. The second law of thermodynamics, for instance, predicts that entropy, destructive disorder, will sooner or later overcome any system. Steven Strogatz rejects the universal application of this law in favor of an overarching natural order. Exactly what is the essence of natural order, however, remains a primary question of philosophers and scientists to this day. Storgatz is one of a long line of such philosophers and scientists to essay an answer to that question in his impressive book, Sync. Moreover, Strogatz has added to his difficulties by aiming his book at the lay reader. Although an applied mathematician by profession, Strogatz has eschewed relying on mathematics and turns instead to writing that is at once clear and lucid and to metaphors that are apt and charming. Consequently, not only is Sync a book dealing with complex and significant scientific theory, but it is also a true pleasure to read.
Strogatz begins with the rivers of Southeast Asia, along whose banks huge collections of fireflies blink in unison throughout the night. This endless synchronous display has delighted tourists and perplexed scientists for more than three hundred years. It is perhaps the most celebrated of nature’s instances of spontaneous rhythmic unity but certainly not the most pervasive nor the most significant. For humans, as Strogatz observes, synchronous rhythm is the very essence of beauty, as in the performance of a fine symphony orchestra or in the choreography of a world-class ballet company.
The very synchronous order which informs most performing arts is deeply related to the rhythm which keeps people alive and aware of the world all around. One depends on the mysterious beating pattern of one’s heart to keep one supplied with blood and breath. Indeed, once the underlying synchronization of heart muscles is better understood, people will be better able to prevent sudden heart failure that leads to unannounced attacks and death. More than vessels to contain a rhythmic heart muscle, people are able to arrange incoming sensory messages into thoughts and ideas, a process based upon the ability of the neurological system to fire in sync in patterns even more intricate than the beating of the heart.
As cardiac rhythms might suggest, synchrony—which may be defined as rhythmic patterns in time as opposed to the spatial patterns of classical physics—is a basic attribute of human beings. It has long been known that women who live together, as in sorority houses, tend to establish similar menstrual cycles. Some of this synchrony is based on certain senses, such as smell, but all humans, as well as other animals, share brain waves that tend toward the cyclic. Indeed, the cycles of a computer are a mechanical reproduction in many ways of the more subtle biological cycle of the brain wave. Hence it is no surprise that computers, like humans, tend to get involved in traffic jams or information “gliches” or in strange, riotous activities not unlike human mob violence. Both animate and inanimate phenomena are composed of oscillators. When and how these oscillators become spontaneously coupled and what results follow is the basis of the new science of synchrony.
Having laid out the fundamentals of his subject, Strogatz spends a chapter exploring one of the most fundamental rhythms of the human condition: the cycle of sleep versus waking. Called the circadian cycle (based on the Latin terms for “about a day”), the sleep-wake pattern is one engaged in by almost every human. Humans are not the only creatures who possess such a cycle, but they are among the most interesting to investigators. To be sure, most people are aware that they follow a regular pattern of sleep and wakefulness, but because sleep is such a personal and private experience, a thorough scientific study with closely controlled parameters of sleep cycles is difficult and elaborate. Strogatz presents interesting details from several such studies, such as the difficulty of keeping the study subjects from knowing the actual time of day so that the effect of sunlight or the imposition of prior habits can be eliminated. Indeed, in one such study where subjects were kept in a sealed environment, male researchers shaved every time they entered the study area so that the subjects could not be tipped off as to time of day by the...
(The entire section is 1855 words.)