THE ARROW OF TIME

It is the ambition of all research, the authors quote 19th- century scientist Willard Gibbs, ``to find the point of view from which the subject appears in its greatest simplicity.'' However, it is the ambition of these same authors (Coveney: Physical Chemistry/Univ. of Wales; Highfield: science editor of the London Daily Telegraph) to demonstrate that simplicity doesn't get you very far in the real (macroscopic) world of time and space. Thus, the die is cast. The authors' aim in this not-so-easy treatise is to find objective bases for the irreversibility of time. Rather than discourse on varying interpretations of time in the manner of Stephen J. Gould in Time's Arrow, or assume the positivist stance of Stephen W. Hawking in A Short History of Time- -where he dismisses time as subjective—the authors make a case for uncertainty and ``dynamical'' chaos. Their approach is historical, pointing out that Newton's laws of motion, Einstein's relativity theory, and quantum mechanics all treat time as symmetrical—time can move forward and backward in the equations. But we know otherwise and so did 19th-century formulators of the second law of thermodynamics—entropy increases and isolated systems move inexorably toward thermal equilibrium. It is only with Prigogine and colleagues, recent computer modeling, and theories of chaos and catastrophe that the authors arrive at a state of the science in which they believe time's arrow is objectively demonstrated. All this may not mean a lot to people who take life, death, and decay as a given. However, for the intellectually curious there is much food for thought. In addition, the authors provide some fascinating examples of biorhythms and patterning in chemical and biological clocks, and in self-organizing systems from slime molds to the mammalian embryo. (Color and b&w photographs—not seen.)