Preface of the Special Issue Probing the Limits of Quantum Mechanics: Theory and Experiment, Volume 1

The quantum information revolution significantly increased the interest in the foundations of quantum mechanics. Nowadays this topic is no longer only a business of philosophers and historians of science, but also of practicing physicists and of physical practice, theoretical and even experimental. While complemented by the more traditional philosophical analysis, foundational studies are now basedmuchmore firmly on complex theoretical models, advanced mathematics and numerical simulations, very closely related to experiments. The intensive development of quantum information and quantum technologies continuously generates novel foundational problems. One such topic is foundational justification of the project on quantum random generators. Foundationally, this project is based on von Neumann’s claim concerning the irreducibility of quantum randomness, conceived in an unconditional opposition to classical randomness. However, some among recent developments of quantum information theory brings new dimensions to this question, specifically in relation to the problem of violation of Bell type inequalities. In general the field of quantum information is a great playground for testing various interpretations of quantum mechanics—especially of the information nature, such as operational approaches to quantum theory or, more recently QBism (Quantum Bayesianism) based on the subjective interpretation of probability.