It has been long debated whether quantum mechanics is real or complex. Local experiments have been carried out confirming the complex nature of quantum mechanics in the standard formalism. Nevertheless, recent theoretical work demonstrated that in a closed universe, quantum mechanics is real. We discuss the philosophical implications of whether quantum mechanics is real or complex.

Renormalization group (RG) theory, while proposed to study particle physics, has found its usage in a large variety of topics over the years, including other physics branches like solid state physics, fluid mechanics, cosmology, machine learning and even non-physics fields like biology, epidemiology, economics, psychology, sociology and so on. The omnipresence of renormalization group theory thus raises the philosophical question of what are the common features of the systems that enable the employment of RG theory and what can be revealed (...) by using the RG method, why renormalization group theory is the naturally approach to deal with these problems and what is the essential point that leads to organizing the system according to renormalization group flow, i.e., order and disorder. These question are addressed in this paper. (shrink)

Emergence is an omnipresent phenomenon that is present in almost all subjects, including physics, other branches of natural science, languages, and even social sciences and economics. Similarities and differences can be found in these domains. We discuss the classification of emergence, which can be organized according to different rules. We also explore universal properties among different levels of emergence, and where the differences among emergence patterns in different theories come from.