Shan Gao

Shanxi University
  • Shanxi University
    Research Center For Philosophy Of Science And Technology
    Professor
University of Sydney
Department of Philosophy
PhD, 2013
Areas of Interest
Philosophy of Mind
  •  11
    In collapse theories of quantum mechanics, there exist quantum observers who are observers being in a superposition of different result branches. In this paper, I analyze the mental state of a quantum observer. First, I argue that the mental state of a quantum observer is not the usual state of recording one of the results in the superposition, but it is definite. Second, I argue that the mental state of a quantum observer is determined by both the amplitudes and relative phases of the result br…Read more
  •  9
    Psychophysical supervenience requires that the mental properties of a system cannot change without the change of its physical properties. In this paper, I argue that the Everett interpretation of quantum mechanics or Everett's theory seems to violate the principle of psychophysical supervenience. In order to be consistent with our experience, the theory assumes psychophysical supervenience in each world, including our world. However, this permits the possibility that under certain unitary time e…Read more
  •  23
    Psychophysical supervenience requires that the mental properties of a system cannot change without the change of its physical properties. In this paper, I argue that the Everett interpretation of quantum mechanics or Everett's theory seems to violate the principle of psychophysical supervenience. In order to be consistent with our experience, the theory assumes psychophysical supervenience in each world, including our world. However, this permits the possibility that under certain unitary time e…Read more
  •  21
    Recently the first protective measurement has been realized in experiment [Nature Phys. 13, 1191 ], which can measure the expectation value of an observable from a single quantum system. This raises an important and pressing issue of whether protective measurement implies the reality of the wave function. If the answer is yes, this will improve the influential PBR theorem [Nature Phys. 8, 475 ] by removing auxiliary assumptions, and help settle the issue about the nature of the wave function. In…Read more
  •  24
    The role of the light postulate in special relativity is reexamined. The existing theory of relativity without light shows that one can deduce Lorentz-like transformations with an undetermined invariant speed based on homogeneity of space and time, isotropy of space and the principle of relativity. However, since the transformations can be Lorentzian or Galilean, depending on the finiteness of the invariant speed, a further postulate is needed to determine the speed in order to establish a real …Read more
  •  16
    It is argued that if the relative configuration of Bohmian particles represents the measurement result, then the predictions of Bohm's theory may be inconsistent with the Born rule in some situations.
  •  13
    Everett's theory assumes the completeness of the description by the wave function, the linearity of the dynamics for the wave function, and multiplicity. In this paper, I argue that these three assumptions of Everett's theory may lead to the violation of psychophysical supervenience.
  •  91
    The meaning of the wave function has been a hot topic of debate since the early days of quantum mechanics. Recent years have witnessed a growing interest in this long-standing question. Is the wave function ontic, directly representing a state of reality, or epistemic, merely representing a state of knowledge, or something else? If the wave function is not ontic, then what, if any, is the underlying state of reality? If the wave function is indeed ontic, then exactly what physical state does it …Read more
  •  10
    The existing psi-ontology theorems are based on a simplified assumption of the ontological models framework, according to which when a measurement is performed the behaviour of the measuring device is determined by the ontic state of the measured system immediately before the measurement. In this paper, I give an argument for the reality of the wave function in terms of protective measurements under a more reasonable assumption, according to which the behaviour of the measuring device during a m…Read more
  •  40
    Protective Measurements and the Reality of the Wave Function
    British Journal for the Philosophy of Science 73 (3): 777-794. 2022.
    It has been debated whether protective measurement implies the reality of the wave function. In this article, I present a new analysis of the relationship between protective measurements and the reality of the wave function. First, I briefly introduce protective measurements and the ontological models framework for them. Second, I give a simple proof of Hardy’s theorem in terms of protective measurements. Third, I analyse two suggested ψ -epistemic models of a protective measurement. It is shown…Read more
  •  16
    Quantum Nonlocality and Reality: 50 Years of Bell's Theorem (edited book)
    with Mary Bell
    Cambridge University Press. 2016.
    A collaboration between distinguished physicists and philosophers of physics, this important anthology surveys the deep implications of Bell's nonlocality theorem.
  •  28
    Can Chinese Philosophy Embrace Wilderness?
    Environmental Ethics 39 (2): 147-159. 2017.
    Because of rapid industrialization and urbanization, many natural resources in China have increasingly been degraded. In response to this situation, China haslearned from the United States about one of its best ideas, national parks. This idea triggers many philosophical questions. How is wilderness interpreted in theUnited States? What are the philosophical foundations for the concept of intrinsic value in wilderness? Can Chinese philosophy accept wilderness? To answer these questions, the idea…Read more
  •  19
    Collapse of the Wave Function: Models, Ontology, Origin, and Implications (edited book)
    Cambridge University Press. 2018.
    An overview of the collapse theories of quantum mechanics. Written by distinguished physicists and philosophers of physics, it discusses the origin and implications of wave-function collapse, the controversies around collapse models and their ontologies, and new arguments for the reality of wave function collapse.
  •  30
    On Uffink's criticism of protective measurements
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 44 (4): 513-518. 2013.
    Protective measurement is a new measuring method introduced by Aharonov, Vaidman, and Anandan, with the aim of measuring the expectation value of an observable on a single quantum system, even if the system is initially not in an eigenstate of the measured observable. According to these authors, this feature of protective measurements favors a realistic interpretation of the wave function. These claims were challenged by Uffink. He argued that only observables that commute with the system's Hami…Read more
  •  41
    Science has made a mighty advance since it originated in ancient Greece more than 2500 years ago. Yet we still live in Plato's cave today; we think everything around us moves continuously, but continuous motion is merely a shadow of real motion. This book will lead you to walk out the cave along a logical and comprehensible road. After passing Zeno's arrow, Newton's inertia, Einstein's light, and Schrodinger's cat, you will reach the real world, where every thing in the universe, whether it is a…Read more
  •  45
    We discuss a new realistic interpretation of quantum mechanics based on discontinuous motion of particles. The historical and logical basis of discontinuous motion of particles is given. It proves that if there exists only one kind of physical reality---particles, then the realistic motion of particles described by quantum mechanics should be discontinuous motion. We further denote that protective measurement may provide a direct method to confirm the existence of discontinuous motion of particl…Read more
  •  116
    Quantum collapse, consciousness and superluminal communication
    Foundations Of Physics Letters 17 (2): 167-182. 2004.
    The relation between quantum collapse, consciousness and superluminal communication is analyzed. As we know, quantum collapse, if exists, can result in the appearance of quantum nonlocality, and requires the existence of a pre- ferred Lorentz frame. This may permit the realization of quantum superluminal communication (QSC), which will no longer result in the usual causal loop in case of the existence of a preferred Lorentz frame. The possibility of the existence of QSC is further analyzed under…Read more
  •  108
    We study the possible connection between self-consciousness and quantum process. It is shown that the self-consciousness function can help to measure the collapse time of wave function under some condition, while the usual physical device without self-consciousness can't. Furthermore, we show that the observer with self-consciousness can distinguish the definite state and the superposition of definite states under some stronger condition. This provides a practical physical method to differentiat…Read more
  •  36
    In this paper, we propose an ontological interpretation of the wave function in terms of random discontinuous motion of particles. According to this interpretation, the wave function of an N-body quantum system describes the state of random discontinuous motion of N particles, and in particular, the modulus squared of the wave function gives the probability density that the particles appear in every possible group of positions in space. We present three arguments supporting this new interpretati…Read more
  •  958
    We analyze the possible implications of spacetime discreteness for the special and general relativity and quantum theory. It is argued that the existence of a minimum size of spacetime may explain the invariance of the speed of light in special relativity and Einstein’s equivalence principle in general relativity. Moreover, the discreteness of spacetime may also result in the collapse of the wave function in quantum mechanics, which may provide a possible solution to the quantum measurement prob…Read more
  •  684
    This article analyzes the implications of protective measurement for the meaning of the wave function. According to protective measurement, a charged quantum system has mass and charge density proportional to the modulus square of its wave function. It is shown that the mass and charge density is not real but effective, formed by the ergodic motion of a localized particle with the total mass and charge of the system. Moreover, it is argued that the ergodic motion is not continuous but discontinu…Read more
  •  19
    It is a fundamental and widely accepted assumption that a measurement result exists universally, and in particular, it exists for every observer, independently of whether the observer makes the measurement or knows the result. In this paper, we will argue that, based on an analysis of protective measurements, this assumption is rejected by the many-worlds interpretation of quantum mechanics, and worlds, if they indeed exist according to the interpretation, can only exist relative to systems whic…Read more
  •  64
    It has been argued that the existence of a minimum observable interval of space and time is a model-independent result of the combination of quantum field theory and general relativity. In this paper, I promote this result to a fundamental postulate, called the MOIST postulate. It is argued that the postulate leads to the existence of a maximum signal speed and its invariance. This new result may have two interesting implications. On the one hand, it suggests that the MOIST postulate can explain…Read more
  •  46
    The physical origin of holographic dark energy is investigated. The main existing explanations, namely the UV/IR connection argument of Cohen et al, Thomas' bulk holography argument, and Ng's spacetime foam argument, are shown to be not satisfactory. A new explanation of the HDE model is then proposed based on the ideas of Thomas and Ng. It is suggested that the dark energy might originate from the quantum fluctuations of spacetime limited by the event horizon of the universe. Several potential …Read more
  •  689
    The remarkable connections between gravity and thermodynamics seem to imply that gravity is not fundamental but emergent, and in particular, as Verlinde suggested, gravity is probably an entropic force. In this paper, we will argue that the idea of gravity as an entropic force is debatable. It is shown that there is no convincing analogy between gravity and entropic force in Verlinde’s example. Neither holographic screen nor test particle satisfies all requirements for the existence of entropic …Read more
  •  22
    It is widely accepted that continuity is the most essential characteristic of motion; the motion of macroscopic objects is apparently continuous, and classical mechanics, which describes such motion, is also based on the assumption of continuous motion. But is motion really continuous in reality? In this paper, I will try to answer this question through a new analysis of the cause of motion. It has been argued that the standard velocity in classical mechanics cannot fulfill the causal role requi…Read more
  •  26
    Energy nonconservation is a serious problem of dynamical collapse theories. In this paper, we propose a discrete model of energy-conserved wavefunction collapse. It is shown that the model is consistent with existing experiments and our macroscopic experience.
  •  34
    The ontological model framework provides a rigorous approach to address the question of whether the quantum state is ontic or epistemic. When considering only conventional projective measurements, auxiliary assumptions are always needed to prove the reality of the quantum state in the framework. For example, the Pusey-Barrett-Rudolph theorem is based on an additional preparation independence assumption. In this paper, we give a new proof of psi-ontology in terms of protective measurements in the…Read more
  •  116
    It is shown that Uffink's attempt to protect the interpretation of the wave function against protective measurements fails due to several errors in his arguments