Improving on Newton Dealing with the Views of the Anti-Scientific Writers Such As Heidegger and Koestler

Home , Oliver Penrose

NA ;,.::.c:..:...11.J:..:..:RE=--V.....,:;O=--L.3:..:..:IO.....,:;26:....:JU..:..;L:..:..:Y...:..:.I984.:..:...... -______BOOK REVIEWS------'-"'341

centuries. For me the most interesting section in this part of the book was the one Improving on Newton dealing with the views of the anti-scientific writers such as Heidegger and Koestler. Oliver Penrose Part II is devoted to phenomena which seem outside the Newtonian view because Order out of Chaos: Man's New Dialogue with Nature. they are unpredictable or time-asymmetric By IIya Prigogine and Isabelle Stengers. or both; it includes examples from a variety Bantam, New York: 1984. Pp.349. Pbk $8.95. of branches of science where irreversible To be published in the UK on 6 A ugust by William Heinemann, hbk £9.95. processes, taking place far from equilibrium, do indeed generate "order out WHEN Galileo and Newton formulated of the many interesting quotations in the of chaos" rather than the degradation of the laws of classical mechanics, they book under review) can be discerned the order into chaos which the second law revolutionized man's understanding of the determinist's belief that past, present and of thermodynamics would lead one to Universe and his power to predict and con future are logically equivalent: anyone of expect. In particular, it is here that bio trol the behaviour of small parts of it. them determines the other two. (Though logical systems make their first appearance Nevertheless two aspects of Newtonian not every determinist would accept in the book. mechanics have puzzled people who Einstein's inference that the distinction The final part investigates what post looked at the world about them and won between past, present and future is there Newtonian mechanics, particularly dered whether Newtonian mechanics was fore illusory). Likewise, relativistic quantum mechanics and statistical sufficient to explain its behaviour. One of mechanics offers us no more than Newton mechanics, can do to improve on the these aspects is its determinism - the fact in the way of an explanation of time Newtonian picture. It includes a non that the laws of motion, taken together asymmetry: its laws are just as symmetrical technical description of Prigogine's own with the dynamical state of the Universe as those of Newton. work in this area. The motivation for this (the positions and the velocities of all the Quantum mechanics was a more far work appears to be a dissatisfaction with particles in it) at some arbitary instant, reaching revolution; like relativity, it the "Newtonian" features of the conven completely determine the entire past and stresses the role of the observer, but, unlike tional formalism of statistical mechanics as future of the Universe. This is, to say the relativity, it also stresses the uncontrollable developed by its founding father, Willard least, somewhat humiliating to us human and non-deterministic character of his Gibbs. The Gibbs formalism, based on beings who do not like to think that the interaction with the system he observes. time-dependent probability distributions actions and decisions we agonize over, the Nevertheless, the puzzlement remains. The in phase space, is symmetrical under time immortal flashes of creative inspiration, time evolution of an unobserved system is reversal; it contains no criterion for dis have' 'in reality" been predetermined since still governed by a deterministic law - tinguishing a physically possible non the world began. Somehow, it seems, Schr~dinger's equation - and so if we equilibrium probability distribution from human beings have been left out of the pic choose to regard the entire Universe as a the physically impossible one that would be ture. In the words of Jacques Monod, cited single system there is no outside observer to obtained from it by time reversal. Despite on page 3 of the book under review: interfere uncontrollably, and the deter many attempts, both by Prigogine and minism is still there. Quantum mechanics others, for "breaking the time-reversal Man must. . . at last realize that, like a gypsy, he lives on the boundary of an alien world. A world also fails to remove our puzzlement about symmetry" (that is, for inserting that is deafto his music, just as indifferent to his time asymmetry. Schrodinger's equation unsymmetric elements into the theory hopes as it is to his suffering or his crimes. has a time-reversal symmetry similar to which would enable us to distinguish the that of Newton's equations; so the only physical from the non-physical probability The other puzzling aspect of Newtonian answer quantum mechanics has to offer to distributions), I believe that the definitive mechanics is its symmetry under time the time-asymmetry puzzle is that we as answer to this problem has not been given. reversal: for every possible motion of a observers may be inserting the time Some readers may be irritated by the dynamical system there is another in which asymmetry into the systems we study. It is rather effusive style, which in places reads the same sequence of dynamical states is hard to accept this explanation since one almost like advertising copy ("It is hardly traced out in precisely the opposite order. believes that there are irreversible processes an exaggeration to state that one of the The behaviour of real physical systems, on taking place in systems such as the centres greatest dates in the history of mankind the other hand, is rarely symmetrical under of stars which have never been directly was April 28, 1686, when Newton time reversal; and so Newtonian mechanics observed and never will be. presented his Principia to the Royal Society alone is not sufficient to explain their In their new boo k Order out ojChaos (in of London") or by some minor imper behaviour. effect a new edition of their earlier La fections in the English (the word "model The twentieth century has seen two Nouvelle Alliance, published by Gallimard ization", for example, is not part of the further revolutions in the science of mech in 1979), Isabelle Stengers and IIya language as I know it). More serious, anics, but neither has totally overcome the Prigogine make a new assault on these well perhaps, are a certain lack of logical focus misgivings aroused by Newtonian entrenched perplexities. Their thesis is that in the writing and a few inaccuracies of fact mechanics. Relativity theory, with its a further revolution in science is now taking (one is in the sentence cited above; only emphasis on the role of the observer, seems place in which the sterile view of the world Part I of Principia was presented on April at first sight to bring human beings into the provided by mechanics is being replaced by 28, 1686, Parts II and III appearing later picture; but the resulting picture is no less a more complicated and fruitful one; but on). In a mathematical passage even such a deterministic than Newton's. Indeed this time the revolution consists not in yet small inaccuracy can easily make the text Einstein himself, on the occasion of the another advance in the science of almost unintelligible. But the book death of his close friend, Michele Besso, mechanics but in an increased emphasis on contains plenty of interesting information wrote: irreversible (time-asymmetric) aspects of and has much to offer readers with inter Michele has left this strange world just before nature. disciplinary interests in physics, chemistry, me. This is of no importance. For us convinced The book is in three main parts. Part I is biology or the history and philosophy of physicists the distinction between past, present a scholarly examination of the Newtonian science. 0 and future is an illusion, although a persistent world view and of the comments which a one. large array of philosophers and other Oliver Penrose is Professor of Mathematics at Underlying this poignant passage (another savants have made about it over three the Open University.