Strong emergence in condensed matter physics

TL;DR

This paper argues that condensed matter physics exhibits strong emergence, where macroscopic properties cannot be fully reduced to microscopic quantum laws, highlighting the importance of top-down causation and practical modeling approaches.

Contribution

It challenges reductionist views by providing arguments and practical examples that support the existence of strong emergence and top-down causation in condensed matter physics.

Findings

Condensed matter theories often rely on phenomenological models rather than microscopic laws.

There are fundamental differences between microscopic quantum theories and practical condensed matter models.

Arguments are presented in favor of strong emergence and top-down causation in physics.

Abstract

This paper argues that the physics of condensed matter cannot be fully reduced to the supposedly fundamental quantum mechanical theory for all the atoms of which the system consists. In fact, there are many reasons to reject the idea that the world of physics is causally closed with everything being determined bottom-up by fundamental microscopic laws. This is illustrated by considering how condensed-matter theory is done in practice. It is never done by starting with a microscopic theory for the interaction of all the atoms of the system. Instead, approximations, plausible assumptions, intuitive models, and phenomenological theories are used to mathematically describe and explain the properties of systems that consist of a macroscopic number of particles. I argue that this is not merely a matter of convenience, but that there are fundamental and qualitative differences or even contradictions between the microscopic theory and the theory that is used in practice. The paper includes a list of arguments in favor of strong emergence and top-down causation within the realm of physics, and a response to several widespread objections against this view.