1 - The Treatment of Uncertainty in the Physical Sciences

Abstract

This chapter discusses the uncertainty in the physical sciences with the observation that complete certainty about anything in the world is an unattainable goal. Modern science is preoccupied with themes such as chaos, quantum indeterminacy, fuzzy logic, and semantic analysis. The current paradigms tend to embrace uncertainties rather than the alleged certainties of the past. Certainty comes in two major varieties: primitive certainty and derivative certainty. Primitive certainty derives directly from the human senses. It is the kind of certainty experienced when one perceives objects or events in the immediate environment. Derivative certainty pertains to knowledge that is deduced or inferred from observations or occurrences that may not have been perceived. Uncertainty was formally admitted into science over 300 years ago when studies began to be made on the outcomes of games of chance. Since that time, probability arguments have remained with us and have been employed in the description and characterization of myriad scientific systems. Around the turn of the century, several totally unexpected developments in the physical sciences occurred—the founding of the quantum mechanics, the discovery that even deterministic systems could exhibit chaotic behavior, and the realization that traditional Aristotelian logic had its limitations when applied to real-world systems. Starting with the quantum-theoretical concepts, fuzzy reasoning quickly manifested its suitability for the description of physicochemical concepts.