Last Updated on May 8, 2015, by eNotes Editorial. Word Count: 408
Ever since Albert Einstein and the Theory of Relativity, time has been described as the fourth dimension of the universe, on an equal footing with height, width, and depth. Research in recent years (since Einstein) has extended the understanding of this basic force to realms beyond the physical. Jeremy Campbell, a correspondent for the London STANDARD and author of the well-received GRAMMATICAL MAN (1982), explores philosophy, history, physics, biology, music, cybernetics, and psychology in an attempt to synthesize the effects of time in our lives.
In the physical world, he covers theories of time from the ancients (Plato and Aristotle), the Renaissance and the Scientific Revolution (Galileo Galilei and Isaac Newton), to the twentieth century (Einstein). In the post-Einstein world, time is not an absolute constant, integrally linked to space, as it had been under the earlier world philosophies.
Biological organisms exhibit marked time-dependent behaviors. Circadian rhythms are reflected in changes in body temperature and blood pressure, as well as levels of production of certain hormones, over roughly a twenty-four-hour period. It is these changes which wake us up in the morning and make us sleepy at night. Winston Churchill liked to take a nap after lunch and before Cabinet meetings because he was taking advantage of a “window of sleepability” which allows us to fall asleep in the afternoon. Other cycles are longer than twenty-four hours. Bird migration, mammal hibernation, and mating seasons are all regulated by the seasonal changes in length of daylight. Some drugs are more effective when given at certain times of day or at certain points in a cell life cycle.
In the psychological realm, time is perceived in a variety of ways: It flies when one is having fun, but it drags when one is doing something unpleasant. Perception of music essentially consists of following sound patterns in a temporal sequence. The ear will often fail to perceive tricks in composition, such as a previous phrase played in reverse, although they are apparent to the eye looking at the printed score. Perceptions of time can even be altered to synchronize with another person’s perceptions, as among members of a synchronized swim team or players in an orchestra.
The biological mechanisms which control all these changes are extraordinarily subtle and complex and are not fully understood. Campbell does a remarkable job of explaining these theories, without speculating about how the actual mechanisms might have evolved. Many readers will find this wide-ranging inquiry fascinating.
Last Updated on May 8, 2015, by eNotes Editorial. Word Count: 1679
The computer is to chronobiology, Jeremy Campbell suggests, as the microscopes of the seventeenth century were to biology—it lets scientists see complexities and structures that were previously unsuspected, thus opening new areas of research that may have important consequences for medicine and psychiatry. The discoveries about rhythms, cycles, and time-sense assembled and explained in Winston Churchill’s Afternoon Nap: A Wide-Awake Inquiry into the Human Nature of Time also provide a fascinating commentary on human nature in the broadest sense of the term. Although much of the material is highly technical, Campbell skillfully uses analogies, metaphors, anecdotes, and narratives to make the book not only intelligible but also very interesting.
Chronobiology—a word not yet in most dictionaries—is the study of variations in biological function over time. Most people are aware, subjectively, of certain internal rhythms: cycles of body temperature that lead to a feeling of chill when staying up past bedtime, peak times for mental activity during the day, alternating periods of deep sleep and dreaming at night. Those in search of good news want both their weight and their blood pressure measured first thing in the morning, and pulse rates can differ by as much as ten beats per minute depending on time of day. As these and other physiological rhythms became increasingly evident, scientists until the 1970’s accepted the concept of a fixed body time and searched for a “master clock,” perhaps in the brain or endocrine system, which regulated physiological functions in tune with a regular period that encompassed roughly twenty-four hours but did not depend on the external cues of light and dark. (Bodily cycles are more stable than the timing of sunrise and nightfall in those latitudes where seasons change.)
With the computer, however, it became possible to make and plot the multiple readings that track a great many more biological processes and to discover previously unsuspected periodicities. Almost everything in the body, it was discovered, fluctuates rhythmically: the secretion of adrenaline and other hormones, the manufacture of proteins, the operation of organs such as the kidneys and liver, the presence of various chemical neurotrans-mitters in the brain. White blood cells increase and decrease by as much as 50 percent, an observation which may lead to important ways of understanding—and manipulating—the body’s ability to fight infection.
Furthermore, the computer has revealed regular rhythms that span periods shorter or longer than the simple twenty-four-hour daily clock provided by the Earth’s rotation. One major surprise comes with the discovery that many cycles have a seven-day pattern. In humans, weekly rhythms have been found in pulse, heartbeat, temperature, the number of red blood cells, and the fluctuation of several chemicals and hormones. From a medical standpoint, the seven-day rhythms in the body’s response to certain bacteria and other foreign materials are highly significant. Before penicillin, doctors knew that the crisis in pneumonia came on the seventh or ninth day; malaria has a seven-day curve; and in patients with kidney transplants the immune system is most likely to reject the new organ at regular intervals that come one week, two weeks, three weeks, and four weeks after the operation.
This discovery is intriguing because it challenges received knowledge about the construction of the calendar. The year and the lunar month arose from astronomical observation, but shorter subdivisions of time varied widely in the ancient world. Yet it cannot be that human bodies have simply become accustomed to the workweek/weekend rhythm of the past few centuries and adapted to it; seven-day cycles are much older than human beings and appear in some of the most primitive organisms that have been examined. It is possible, then, that the Jewish calendar which established the seven-day week was an intuitive externalizing of internal rhythms: the sole example of a standardized time measurement based on the human body rather than the solar system.
On the evidence Campbell presents, however, it would seem that another familiar measure of time—the division of a calendar day into twenty-four sixty-minute hours—is arbitrary and unnatural. Human bodies have a number of ninety-minute cycles: the waves of rapid eye movement (REM) and non-REM sleep at night, corresponding periods of waking fantasy in the daytime (which seem to exist although they are much obscured by conscious activity), stomach contractions, the fluid balance of the kidneys—and the rhythm of peak performance at demanding work. A more “natural” method of time-keeping would probably divide the day into sixteen ninety-minute hours.
In order to avoid raising this sort of speculation in a breezy and superficial fashion, Campbell presents a considerable amount of information about classical astronomy, relativity, statistics, harmonics, wave theory, evolution, the working of the senses and the brain, existential philosophy, artificial intelligence, and basic biology. By and large, he achieves clarity through intelligent writing and helpful examples. Although discussions of the evolutionary function of certain mechanisms are necessarily speculative and Campbell’s observations about the varying effects of chemotherapy administered at certain times of day have been disputed by some specialists, the book not only assembles virtually everything currently known about the science of chronobiology but presents it in ways that will allow readers to understand the results of new research when it is reported in the news.
One central theme of the book is the effect of human temporal structure on human nature. Campbell distinguishes between two sorts of “human time”: biological time, expressed in the rhythms and periodicities of bodily functions, and psychological time, or the experience of past, present, future, and time’s passage that is constructed in the brain. Freedom from external timekeepers such as seasons is to a certain extent a human advantage. Primates can mate at any time of year; the human will can override bodily cues that tell it to sleep; and the mind’s ability to remember episodes (as well as skills) and to imagine the future may explain modern consciousness.
For the majority of species-centric and egocentric humans, Winston Churchill’s Afternoon Nap is probably most interesting for its nuggets of useful information. There are indeed “morning people” and “evening people.” Campbell calls them “larks” and “owls,” explains the difference in the relationship of their internal timekeeping mechanisms to the twenty-four-hour external clock, and suggests some implications for core personality and for work patterns. The complex relationship of various systemic rhythms to the efficiency of the brain could also have practical consequences. Simple tiredness does not explain all the variations in mental acuity over the course of a day. Recent research suggests that the ability to reason and to apply rules and formulas peaks early in the day, that perplexing and challenging intellectual tasks are best done around midday, and that material is most effectively stored in long-term memory during the afternoon—a schedule which might have promising results if applied to school days. Furthermore, it is not merely the need to relax after a day’s mental effort that makes many people choose the hours after work to crochet or paint bookshelves; routine manual exercises are most successfully carried out late in the day, when body temperature is at its highest.
There are also practical implications in the explanation of “entraining,” which is the process by which bodily clocks are reset to match external timekeepers such as the sun. Examined in detail, entraining provides a physiological rationale for the “Monday-morning blahs” that people tend to blame on mental states (such as dislike for their jobs or their employers). Entraining also explains why jet lag is worse when flying from Chicago to London than on the London-Chicago trip (not simply because it is easier to come home). The airlines, in fact, could take many practical steps that would help control jet lag for crews as well as passengers. One of the more frightening revelations, from a safety standpoint, is that mental acuity (and the impression that one is in control) recovers more quickly than manual dexterity.
The complex relationship of internal and external clocks is sometimes startling. For example, parents (and store managers who run “back-to-school” sales) have long known that most children grow rapidly in the spring and late summer—but apparently the cause is not just fresh air, exercise, and the freedom to raid the refrigerator several times a day. Children who are blind do not exhibit seasonal variations in their rate of growth. There must be, then, some connection between the hours of daylight, the eye, the brain, and the release of growth hormones. Many kinds of artificial light fail to suppress the hormone melatonin, which is normally produced only at night and may act as a sedative: It is possible that some workplaces actually do put employees to sleep. Many animals have a limited breeding season which results in the birth of young at the most favorable time of year, and there is some evidence that humans in very harsh climates also exhibit seasonal variations in conception.
A deeper understanding of human dependence on internal as well as external controls may therefore require rethinking the concepts of freedom and will. There are also significant implications for understanding and treating various mental disorders. The disruption of bodily clocks has well-defined emotional consequences—and hospital intensive-care units are among the places that cause such disruption. Depression itself may be an abnormal biological rhythm. Campbell suggests the possibility of an exciting research frontier in the use of chemicals which could control and shift some or all of the body’s timekeeping mechanisms for therapeutic purposes.
The science of chronobiology, it is clear, has about as much connection with the concept of “biorhythms” as astrophysics does with astrology. Yet both continue to fascinate, not only in tabloid newspapers but also in the presumably more sophisticated world of those who buy programs for home computers. Winston Churchill’s Afternoon Nap has solid and sound information that should interest biologists, medical professionals, teachers, shift workers, travelers, philosophers, phychologists, literary critics involved with the implication of time in narrative theory, and curious human beings who are intrigued by information about their bodies and minds.
Last Updated on May 8, 2015, by eNotes Editorial. Word Count: 47
Choice. XXIV, July, 1987, p. 1716.
Kirkus Reviews. LV, February 1, 1987, p. 185.
Library Journal. CXII, May 1, 1987, p. 74.
Los Angeles Times. February 24, 1987, V, p. 4.
The New York Times Book Review. XCII, March 8, 1987, p. 14.
Psychology Today. XXI, January, 1987, p. 77.
Publishers Weekly. CCXXXI, January 16, 1987, p. 66.
The Washington Post Book World. XVII, March 1, 1987, p. 4.
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