Solar power has been the next big thing for forty years
Philosophically, a realist is someone who holds that our theories are descriptions of how the world really is. Yet realist explanations of the behaviour of elementary particles face a fundamental challenge. Although electrons, for example, would seem to be simple entities – they have no internal structure – a satisfactory description of their behaviour in classical Newtonian terms, as if they were little balls, proved impossible. Theorists therefore turned to building mathematical models which could predict electron behaviour rather than explain electrons in realist terms.
Instrumentalism is this view that theories are useful for explaining and predicting phenomena, rather than that they necessarly describe the world. Yet the mathematical apparatus underpinning such instrumentalism, such as Dirac’s use of infinite-dimensional Hilbert [abstract mathematical] spaces, and Feynman’s sums-over-all-possible-histories, are so powerful, and so beautiful, that the lack of a convincing realist alternative has so far not proved to be a significant handicap in the development of quantum physics and its technological applications. In fact, quantum theory in its instrumental form has provided the most successful explanation of all time, by being the most powerful of all scientific theories. But Deutsch wants a realist quantum theory.
artwork { Olaf Brzeski, Dream, Spontaneous Combustion, 2008 }
