Es­say The cre­ativ­ity of chaos

In con­tin­gency, par­tially tamed chaos re­veals all its cre­ativ­ity, show­ing us how far the real is a sub­set of the pos­si­ble

Domus - - CONTENTS - Text by Telmo Pievani

Our minds are used to as­so­ci­at­ing chaos with things that have no ra­tio­nal ex­pla­na­tion. In­tu­itively we equate chaos with dis­or­der, lack of con­trol and a con­fu­sion of facts, ideas and feel­ings. Where chaos reigns, we feel there are no laws, uni­for­mity, pat­terns or emerg­ing forms. This in­ter­pre­ta­tion of chaos as be­ing un­in­tel­li­gi­ble is sup­ported by the fact that the same word is used with the same mean­ing in both clas­si­cal myths and the science that stud­ies the ori­gins of the uni­verse. Ac­cord­ing to the an­cient sto­ries, in the be­gin­ning there was a pri­mor­dial chaos from which a cos­mos — hence or­der — popped into ex­is­tence. Anal­o­gously, 21st-cen­tury par­ti­cle physics sees the cos­mogo­nic ad­ven­ture as start­ing with an in­fin­i­tes­i­mal and ran­dom phys­i­cal anom­aly, a con­tin­gent fluc­tu­a­tion, a sub­tle im­per­fec­tion in the prim­i­tive quan­tum void. Con­se­quently Lu­cretius’s cli­na­men (“swerve”) is re­vised in the light of con­tem­po­rary science, in the guise of a small sub­atomic de­vi­a­tion that lit­er­ally gave rise to ev­ery­thing. As for what­ever ex­isted “be­fore”, it is un­known. On closer in­spec­tion, how­ever, there is no stark in­com­pat­i­bil­ity be­tween chaos and or­der. Chaotic sys­tems can spawn ex­tremely orderly be­hav­iours, as oc­curs in chem­i­cal clocks. The to­tally chaotic col­li­sions of gas par­ti­cles in a box gen­er­ate such re­li­able fore­casts of the vol­ume and pres­sure of the gas that they can be de­scribed with ex­tremely el­e­gant phys­i­cal laws. Wa­ter in a ket­tle on a hob moves chaot­i­cally un­til it reaches a cer­tain tem­per­a­ture, con­vec­tion cells form and the wa­ter starts to boil in an orderly way. What is chaos on one level is or­der on an­other. There is also a dia­lec­tic be­tween the two poles. The most com­plex and cre­ative sys­tems in na­ture, from ecosys­tems to cells and genomes, are de­scribed as be­ing on the “edge of chaos” be­cause, although they never fall into the chasm of pure dis­or­der, they are self-or­gan­ised net­works so densely in­ter­con­nected that they ex­hibit non­lin­ear be­hav­iour. In­deed, many slight per­tur­ba­tions may have no ef­fect on such net­works since they are ab­sorbed by the sys­tem’s neg­a­tive con­trol cir­cuits. But an­other seem­ingly in­signif­i­cant per­tur­ba­tion may trig­ger a rev­o­lu­tion­ary restruc­tur­ing of the sys­tem if it touches a pos­i­tive feed­back loop. In sys­tems pos­sess­ing self-or­gan­ised crit­i­cal­ity, the avalanche seems stable as flake after flake of snow falls, but then just one more flake (who knows why that flake) is enough to send the whole mass hurtling down. So for­tu­nately it is not true that every flap of a but­ter­fly’s wing in Brazil trig­gers a hur­ri­cane in Ja­pan, be­cause sys­tems on the edge of chaos are highly re­silient yet un­pre­dictable. The bio­sphere, for in­stance, has so far en­dured our in­sane and self-ob­sessed dis­rup­tions of it very well, but we’d be well ad­vised not to count on its tol­er­ance in the medium term. An­other wide­spread mis­un­der­stand­ing is that Dar­winian evo­lu­tion — of which we are all the off­spring — sweeps us along in a flow of merely ran­dom changes. This is not the case. Ran­dom­ness does play an im­por­tant part in evo­lu­tion, of course. Ge­netic mu­ta­tions, i.e the sources of vari­a­tion that drive any evo­lu­tion­ary process, are called “ran­dom” as we are un­able to know all their causes (even if they ex­ist) and be­cause they emerge spon­ta­neously with­out any con­nec­tion to the ef­fects — mostly neg­a­tive, of­ten in­dif­fer­ent and some­times pos­i­tive — that they bring to their bear­ers. In the first sense, there­fore, ran­dom­ness is sim­ply a mea­sure of our ig­no­rance of the causes. Other sig­nif­i­cant ran­dom mech­a­nisms are gen­er­ated when, for ex­am­ple, a small pop­u­la­tion sep­a­rates from a larger one, tak­ing with it a ran­dom sam­ple of the ini­tial ge­netic vari­abil­ity. This “ge­netic drift” is called ran­dom even though it, too, pro­duces very el­e­gant fore­casts. Since it re­duces the ge­netic vari­abil­ity of pop­u­la­tions in a reg­u­lar way, we can, for ex­am­ple, use it — as did the great, re­cently de­ceased Ital­ian ge­neti­cist Luigi Luca

Cavalli-Sforza — to re­con­struct the mi­gra­tory routes out of Africa of the Homo sapi­ens species, the em­i­grant an­ces­tors from whom we are all de­scended. Again, this ran­dom ma­te­rial nur­tures or­der, or rather the se­lec­tive fil­ter­ing pro­cesses that gen­er­ate adap­tive struc­tures. In some cases these struc­tures are for­mi­da­bly com­plex and ef­fi­cient. The 2018 No­bel Prize for Chem­istry has just been awarded to three sci­en­tists who learned to ap­ply this dia­lec­tic be­tween ran­dom vari­a­tions and se­lec­tion to the di­rected evo­lu­tion of pow­er­ful en­zymes in the lab­o­ra­tory, en­abling us to syn­the­sise new drugs or pro­duce bio­fu­els. It is there­fore in­cor­rect to state that by virtue of Dar­winian evo­lu­tion we are all chil­dren of “pure chance”. Rather, we are each the unique re­sult of an in­ter­weav­ing of ran­dom­ness and eco­log­i­cal pro­cesses that gen­er­ate or­der. This ex­plains why two an­i­mals not closely re­lated end up de­vel­op­ing sim­i­lar func­tional struc­tures if ex­posed to the same ex­ter­nal se­lec­tive pres­sures (for ex­am­ple the ap­pear­ance of forms of sonar in var­i­ous mam­mals and cer­tain birds). Ob­vi­ously evo­lu­tion starts from the ex­ist­ing ma­te­ri­als, con­straints and vari­a­tions that make these an­i­mals dif­fer­ent, just as the in­tel­li­gence distributed through the body of the oc­to­pus is rad­i­cally dif­fer­ent from our mam­malian in­tel­li­gence that is con­cen­trated in a cen­tralised brain. All these im­per­fec­tions that func­tion, or “frozen ac­ci­dents”, are the re­sult of evo­lu­tion­ary paths that could have eas­ily taken a dif­fer­ent di­rec­tion and led to dif­fer­ent out­comes. As the palaeon­tol­o­gist Stephen J. Gould posited, if we were to rewind the tape of life end­lessly, we would get an end­less num­ber of dif­fer­ent sto­ry­lines and end­ings. Here chance and or­der, the op­por­tu­ni­ties and con­straints, are both su­per­seded in the con­cept of con­tin­gency. The as­teroid that led to the cat­a­strophic ex­tinc­tion of al­most all the di­nosaurs (ex­cept birds, which are thero­pod di­nosaurs still alive and kick­ing) did not con­tra­vene any phys­i­cal law. In fact it was pre­dictable on the ba­sis of the in­ter­sec­tions be­tween the or­bits of the so­lar sys­tem’s plan­ets and those of ob­jects fur­ther out, which oc­ca­sion­ally en­croach on the plan­ets. In short, it was a per­fectly orderly event on the as­tro­phys­i­cal plane. How­ever, the ex­plo­sion it caused in the midst of a Cre­ta­ceous world, where life was go­ing on in the usual way (some di­nosaurs de­clin­ing, oth­ers chang­ing, our mam­mal an­ces­tors rel­e­gated to mar­ginal noc­tur­nal niches, etc.) ir­re­versibly and un­pre­dictably de­flected the course of his­tory, re­vers­ing for­tunes and open­ing an un­ex­pected win­dow of op­por­tu­nity for cer­tain hairy in­sec­tiv­o­rous rats of the Me­so­zoic Era. This is not pure chance ei­ther, be­cause in ret­ro­spect ev­ery­thing can be ex­plained as a strict se­quence of cause and ef­fect. But this ne­ces­sity is, in fact, a pos­te­ri­ori. A pri­ori, how­ever, no one would have bet a penny on the ap­pear­ance of a large, talk­a­tive and med­dle­some biped pri­mate. We owe to con­tin­gency our most im­per­fect and suc­cess­ful adap­ta­tions: ar­tic­u­late lan­guage, in­creas­ing the risk of suf­fo­ca­tion yet en­abling us to com­mu­ni­cate, or­gan­ise our thoughts and de­velop ab­stract ideas; a big­ger brain, a mag­nif­i­cent tan­gle of an­cient and mod­ern parts reused many times with dif­fer­ent func­tions; the very ex­pen­sive and pro­longed child­hood of our help­less off­spring, which has given us play, imi­ta­tion, flex­i­bil­ity and learn­ing, in short ed­u­ca­tion and cul­ture. Hence con­tin­gency is not an­ar­chy or emo­tiv­ity gone hay­wire. Rather it is a mod­u­la­tion of prob­a­bil­i­ties (or rather of lesser im­prob­a­bil­i­ties that ac­tu­ally hap­pen). In con­tin­gency, par­tially tamed chaos re­veals all its cre­ativ­ity, show­ing us how far the real is a sub­set of the pos­si­ble, and our present only one of the many counter-fu­tures that the past held within it­self. With one in­ter­est­ing con­se­quence: if this is the case, the fu­ture is then ope­nended, and it de­pends on our de­sign choices. Telmo Pievani (1970) is pro­fes­sor at the De­part­ment of Bi­ol­ogy, Uni­ver­sity of Padua, where he cov­ers the first Ital­ian chair of Phi­los­o­phy of Bi­o­log­i­cal Sciences. At the same de­part­ment he also teaches Bioethics and Nat­u­ral Science Com­mu­ni­ca­tion. His re­cent pub­li­ca­tions in­clude Lib­ertà di mi­grare (with Va­le­rio Cal­zo­laio, Ein­audi, Turin 2016) and Come saremo. Sto­rie di uman­ità tec­no­logi­ca­mente mod­i­fi­cata (with Luca De Bi­ase, Codice Edizioni, Turin, 2016). www.tel­mopievani.com

Left: Land­scape with Hand Grenade by Cliff McReynolds, 63.5 x 66.04 cm, oil on ma­sonite, 1972 Op­po­site page, bot­tom: Cre­ation with Nat­u­ral Phe­nom­ena by Cliff McReynolds, 1971

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