Quantum reality is real

Graham P. Smetham

As we shall illustrate in this paper, it appears that quantum ‘particles’ might be thought to have aspects of both reality and unreality, and this is a paradoxical viewpoint which leads us in the direction of some dramatic claims about the nature of reality made by Buddhist metaphysicians such as Dharmakirti and Nagarjuna, claims which move towards providing an answer to Penrose’s quandary: “can real objects be constructed from unreal constituents?” According to Nagarjuna: “everything is real and not real, both real and not real, neither real nor not real which is the Lord Buddha’s teaching”. The resolution of the apparent paradox will become clear as we explore the relationship between the implications of quantum theory and the Buddhist doctrine of the ‘two truths’, or ‘two realities’, in detail. In fact we will discover that an appreciation of the Buddhist perspective throws significant light onto quantum conundrums. We shall discover that Dharmakirti’s philosophical analysis, alongside other Buddhist insights, which lead to the ‘ultimate’ realm of ‘empty’ Mindnature, prefigures modern quantum discoveries, particularly the notion of an ‘Epiontic Universe’ which derives from the ‘quantum Darwinism’ perspective suggested by Wojciech H. Zurek.

Marcello Cini

Guolin Wu

Understanding the nature of reality has been a central theme in philosophy for centuries. Classical science presented a well-defined, deterministic view of reality as objects are governed by clear laws. However, quantum mechanics introduced a radically different perspective that suggests a “quantum reality” where particles exhibit wave-like behavior and defy classical intuitions. This chapter delves into the evolution of reality, exploring its characteristics in classical physics and its transformation in the face of quantum mechanics. One key aspect of quantum reality is the wave function, as in whether the wave function is of reality. The Copenhagen interpretation posits that the wave function is a probabilistic tool, rather than a description of the real state of microscopic particles. However, the fundamental principles of quantum control and the very objects it manipulates challenge this view. By directly or indirectly influencing the wave function, quantum control techniques provide compelling evidence for its quantum reality. The PBR theorem suggests that the wave function reflects a real physical state, not merely a mathematical tool. This chapter argues that the wave function is of the “reality of relative entity-structure”. In addition, the “quantum Cheshire cat” experiment further highlights the unusual nature of quantum reality, which shares some connections with the concept of “Tao” in Chinese Taoism that suggests that everything arises from a fundamental nothingness that itself is real. Quantum technology brings forth a “quantum technological reality” characterized by new properties and applications.

Marcello Cini

Wu-zhong Guo, Song He, Yu-Xuan Zhang

Abstract As a generalization of entanglement entropy, pseudo entropy is not always real. The real-valued pseudo entropy has promising applications in holography and quantum phase transition. We apply the notion of pseudo-Hermiticity to formulate the reality condition of pseudo entropy. We find the general form of the transition matrix for which the eigenvalues of the reduced transition matrix possess real or complex pairs of eigenvalues. Further, we find a class of transition matrices for which the pseudo (Rényi) entropies are non-negative. Some known examples which give real pseudo entropy in quantum field theories can be explained in our framework. Our results offer a novel method to generate the transition matrix with real pseudo entropy. Finally, we show the reality condition for pseudo entropy is related to the Tomita-Takesaki modular theory for quantum field theory.