Newton's Clock: Chaos in the Solar System

A best-selling author shows how the model of the solar system has changed from Newton's mechanistic theory, predicting clocklike precision and infallibility, to modern chaos theory, which allows for the possibility a planet may one day leave its orbit.

Peterson ( The Mathematical Tourist ) is well-suited to wean the general reader away from one of everyday science's most comforting and tenacious illusions--namely, that the solar system operates on a giant stable clockwork system. As this historical treatment demonstrates, some 300 years before the development of the computer, mathematical astronomers offered theories in line with today's current chaos and dynamic systems theories. Even in astronomy's earliest days, perturbations of some planetary bodies defied Newton's mechanics; centuries of interaction between astronomical theory and observation have demanded that serious stargazers take account of complexity and chaotic phenomena. In Peterson's long view, this is a mathematically meaty story. The few (and insufficient) basic calculus formulas included are presented in sidebars; many of the illustrations depict historical models or manuscripts. Readers grounded in number theory will most fully appreciate the progression of the astronomical issues covered here.
Copyright 1993 Reed Business Information, Inc.

Peterson (math-and-physics editor at Science News) tells how science has unlocked the secrets of celestial motion. The puzzle is as ancient as cave men peering at the night sky: how to explain the weird (sometimes seemingly backwards) movements of moons and planets? Peterson anoints two scientists as patron saints in the quest: Johannes Kepler, who established physics as the basis for astronomy and demonstrated that planets travel in elliptical, not circular, orbits; and Isaac Newton, whose three laws of movement and study of gravity established a practical understanding of planetary orbits. In fact, to Newton and his heirs, cosmic motion was as reliable as the tick-tock of a clock. But is the solar system really God's windup toy? Mathematicians and scientists like Henri Poincar‚ discarded that idea through the development of chaos theory. Chaotic systems are not, emphasizes Peterson, truly random: Inexorable physical laws still apply. But in chaotic systems, such an enormous number of factors are involved that a tiny variation can lead to enormous, unpredictable changes down the road. Observations of planetary rings, asteroid placement, and the like seem to indicate that our solar system is indeed chaotic. And while computer models project no major disruptions in the next trillion years or so, one never knows: We live, says Peterson, not in a clockwork world but in one ``constantly changing, infinitely complex.'' A very tough subject made lucid. Not for science illiterates, but astronomy and physics buffs will lap it up. (B&w illustrations--115--not seen) -- Copyright ©1993, Kirkus Associates, LP. All rights reserved.

This is a history of human efforts to understand the mechanics of the solar system, reaching from classical Greece to the present. By the time of Isaac Newton, there was reason to hope that the stability of the solar system could be proven and that its mechanics could be reduced to the precision of clockwork. However, it gradually became clear that the basic equations could not be solved with absolute precision; we are still not assured that the orbits of the Earth and the other planets are stable. Further, there is a fundamental indeterminancy in solar system mechanics that cannot be avoided. Peterson, a science journalist, has told his story in a lively and very readable fashion. Necessarily, he has included a modest amount of technical detail, but the volume should be fully intelligible to lay readers with a bit of background in the physical sciences. Recommended for academic and public libraries.
- Jack W. Weigel, Univ. of Michigan Lib., Ann Arbor
Copyright 1993 Reed Business Information, Inc.