Modelling Under Risk and Uncertainty: An Introduction to Statistical, Phenomenological and Computational Methods

10.3 Annex 3 – Introductory Reflections on the Sources of Macroscopic Uncertainty

A large variety of causes or phenomena give rise to uncertainty in the state of a system at a macroscopic decision-making scale. Brief introductory reflections will be made on the sources of such uncertainty, zooming out from the smaller to the larger scales of reality. It should be seen as an incentive to study further the fruitful relationship of a macroscopic uncertainty modelling to quantum and statistical physics or complex system dynamics. A thorough theoretical discussion of the complex concepts involved, not exempt from on-going interpretational controvery, is completely beyond the scope of this book.

It is essential first to estimate the underlying intrinsic variability of reality.

Starting with the fundamental constituents of matter and energy, a set of associated phenomena generate intrinsic variability: the atomic or particular nature and the quantum behaviour of reality, epitomized, for instance, by the discrete nature of radioactive emissions or of photon fluxes, accompanied by energy fluxes varying random-like in time between discrete values; the fundamental indeterminacy in the states of a system (and its dependence to observation) as reflected in Heisenberg principle of indeterminacy (or uncertainty principle). The latter concept reflects the intertwined particular and wave natures of matter, energy or light; it involves a series of relations specifying an irreducible lower bound ...