Physics Without Building Blocks (Scholar's Award)

University Of Arizona, Tucson AZ

Investigators

Abstract

This project on the foundations of quantum mechanics is supported by the Science, Technology, and Society program. It is also supported by the joint initiative with Mathematical and Physical Sciences Directorate: Research at the Interface of the Mathematical and Physical Sciences and Society. One goal of the project is to provide a critical scrutiny of one perspective on fundamental science so as to make way for an alternative. A widely prevalent image of science, which has influenced the thinking of many scientists and the general public, pictures scientific knowledge as hierarchically organized. At the base of the hierarchy is physics, applicable to objects and processes at all length and energy scales. The other sciences, which concern themselves with kinds of system (chemical, biological, psychological, social, economic) that become manifest only in special circumstances, are regarded as being based on "fundamental" physics. The traditional hierarchy based on "fundamental" physics is organized in accordance with three principles: (1) Everything is composed of basic microphysical elements, (2) All properties of objects are wholly determined by the basic intrinsic properties and relations of these basic microphysical elements, and (3) All laws and/or theories governing the behavior of composite objects ultimately reduce to the fundamental laws/theories governing the behavior of their microphysical constituents. Taken together, these principles would warrant the belief that the basic laws that govern the behavior of the ultimate constituents of matter are in fact responsible for the behavior of everything. They provide an image of the physical world as constructed out of basic building blocks?basic objects, basic properties and basic laws. This research subjects each of these organizing principles of the traditional hierarchy to critical examination and explores ways of getting along without that hierarchy. The current project builds on previous research undermining the principle that the properties of all objects are determined by those of their ultimate constituents. Physicists commonly talk of elementary particles and their associated quantum fields. But it turns out that there are strong reasons to doubt these could play the role of ultimate constituents of matter. Even if such objects were available to serve as building blocks, they do not compose the objects of condensed matter physics in any simple way. Though quantum (field) theories are extremely predictively successful, it has proved extraordinarily hard to interpret them as offering a self-contained description of the world at a fundamental level. If this is not possible, then the laws of fundamental physics as currently conceived cannot be responsible for the behavior of everything. This suggests a revised image of physics (if not all of science) as successfully modeling structures in various domains by a network of theories, loosely connected by diverse and domain-specific logical and ontological relations.