The Game of Prediction and Retrodiction: A Radical-Constructivist Perspective on the Notion of Time in Physics

Abstract

The notions of prediction and retrodiction, and the role they play in the natural sciences, are discussed. These notions derive from our perception of the fundamental category of time, as an ordering scheme for our experiential world. The issue of philosophical determinism vs. human free will is examined from a perspective of radical constructivism, and contrasted with the issue of solipsism vs. shared experience; and it is argued that both philosophical determinism and solipsism may be rejected, on the same (existential, not logical) grounds. Both prediction and retrodiction are discussed, in the context of some sciences (notably, classical and quantum physics), and are shown to be realisable only to a very limited extent. Some consequences of this, for the ability of science to forecast what will happen in the future, or to infer what has happened in the past, are reviewed. It is concluded that scientific knowledge, of both the past and the future, is (and must be) constructed in the present, based on presently observed data and theoretical arguments. Hence there can be no conception of true knowledge, either of the future or of the past.