David Peat

200 From Certainty to Uncertaintygun to set aside the blinders it has been wearing for the past 200 yearsto view the world in terms of complexity, ambiguity, and uncertainty.If the material world appeared simpler in the past it was because wewere looking at it through the perspective of classical physics. Whenwe choose to direct our sight only toward simple systems (for example,those close to equilibrium or that are acted on by small forces, and thatbehave in regular ways) then naturally the world appears simple. It is alittle like those travel brochures produced several decades ago by theapartheid government of South Africa. A naive reader could be seducedinto believing that the population was overwhelmingly white becauseonly white faces were seen in the carefully posed photographs of shops,bars, and beaches.Similarly, classical physics created a travel brochure of the cosmos,one that emphasized regularity and simplicity. Galileo idealized hisobservations of the way a ball rolls downhill by ignoring, or bracketingout, the effects of bumps and friction. Newton asked how an apple fallsin the absence of air resistance. Chemists investigated reactions whereeverything was close to equilibrium. Scientists were interested in whatthey termed “closed systems,” systems insulated from the perturbationsof the outside world. When it came to the study of solids, such as metalsand crystals, they developed theories about tiny disturbances, smallvibrations, and gentle heat flows. In each case science was filtering theworld. And because theories of closed systems, reactions close to equilibriumand small disturbances, worked so well, scientists naturallyconcentrated on investigations within the context of those particularconditions. Carefully designed experiments, well insulated from thecontingencies of the external world, provided clear data that would fiteasily onto a graph without too much scatter or experimental error.The world of classical physics was free from uncertainty, ambiguity,and chaos. In turn, scientists set up their experiments in ways thatconfirmed these basic assumptions about the world. This is what ThomasKuhn calls a scientific paradigm. Science always works withinparadigms, which means that new knowledge is always gathered fromwithin a particular context and by making assumptions that are heldlargely unconsciously. The result is that such knowledge naturally fallswithin the established scheme of things. It is only when science comes