Mind and Agency in the Foundations of Quantum Physics
May 31 – June 3, Chapman University, AF211

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Conference description
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Conference description:

In contrast to classical physics, quantum physics attributes special significance to the act of “measurement”. This has led to decades of discussions in the foundations of quantum theory. Our workshop brings together scientists and philosophers who see value in exploring whether this hints at the relevance of the first person in physics – the entity that performs the measurement. We will discuss information-theoretic, mathematical, and philosophical arguments that aim at evaluating the potential relation between quantum physics and the first person.

For example, does consciousness play a crucial role in quantum physics, as von Neumann and Wigner claimed decades ago and is this testable? Or are quantum states best interpreted as agent’s subjective degrees of belief about future experiences, as QBism asserts? Or does quantum theory hint at an ontology that is more akin to an idealist worldview? And what should we make of thought experiments involving observers and quantum mechanics, such as Wigner’s friend or Bell experiments with human choices?

Our participants and organizers have very different opinions on these questions, and our workshop will make these views collide head-on, in lively but respectful discussions. We hope to find some common ground and initiate discussions across fields that have so far remained separate.

Invited speakers:

  • Larissa Albantakis (University of Wisconsin-Madison, USA)
  • Leonardo Barbosa (University of Wisconsin-Madison, USA)
  • Angelo Bassi (University of Trieste, Italy)
  • Veronika Baumann (IQOQI Vienna, Austria)
  • Eric Cavalcanti (Griffith University, Australia)
  • David Chalmers (New York University, USA)*
  • Catalina Curceanu (Istituto Nazionale di Fisica Nucleare, Italy)
  • Mauro d’Ariano (University of Pavia, Italy)
  • Lídia del Rio (ETH Zürich, Switzerland)
  • Ian Durham (Saint Anselm College, USA)*
  • Christopher A. Fuchs (University of Massachusetts Boston, USA)*
  • Lucien Hardy (Perimeter Institute for Theoretical Physics, Canada)
  • Donald Hoffman (University of California, Irvine, USA)*
  • Jenann Ismael (Columbia University, USA)
  • Bernardo Kastrup (Essentia Foundation)
  • Adrian Kent (University of Cambridge, UK)
  • Johannes Kleiner (Ludwig Maximilian University, Germany)*
  • Matt Leifer (Chapman University, USA)*
  • George Musser (Scientific American / Quanta)*
  • Jeff Tollaksen (Chapman University, USA)*
  • Howard Wiseman (Griffith University, Australia)


  • Kelvin McQueen (Chapman University, USA)*
  • Markus Müller (IQOQI Vienna, Austria)

*In person attendee.

Talk schedule:

TimeTuesday 5-31Wednesday 6-1Thursday 6-2Friday 6-3
10.00 – 10:50Angelo BassiAdrian KentMauro d’ArianoCatalina Curceanu
10:50 – 11:40Kelvin McQueen*Jenann IsmaelLídia del RioJohannes Kleiner*
11.40 – 12.00CoffeeCoffeeCoffeeCoffee
12.00 – 12.50Leonardo BarbosaChris Fuchs*Lucien Hardy
12.50 – 14.20  LunchLunchLunchLunch
14.20 – 15.10Larissa AlbantakisBernardo KastrupVeronika BaumannJeff Tollaksen*
15.10 – 16.00Ian Durham*Donald Hoffman*Eric CavalcantiDavid Chalmers*
16.00 – 16.20CoffeeCoffee
16.20 –Panel #1Panel #2
18.30 –Conference Dinner 

Panel #1: Quantum integrated information theory: can it model the observer?
Panelists: Larissa Albantakis, David Chalmers*, Ian Durham*, Johannes Kleiner*
Chair: Kelvin McQueen*

Panel #2: Wigner and Friends: what can we learn from thought experiments involving observers in superposition?
Panelists: Veronika Baumann, Eric Cavalcanti, Howard Wiseman
Chair: Matt Leifer*


Angelo Bassi

Title: Spontaneous wave function collapse models: an update

Abstract: Quantum mechanics is grounded on the superposition principle, which is the source both of its tremendous success and technological power, as well as of the problems in understanding it. The reason why superpositions do not propagate from the microscopic to the macroscopic world are subject to debate. Spontaneous wave function collapse models have been formulated to take into account a progressive breakdown of quantum superpositions when systems are large enough; they do so by modifying the Schrödinger dynamics, and therefore they are empirically testable. Deviations are tiny, and require precision measurements. I will review collapse models, their ontological stand, and the most recent experimental tests.

Kelvin McQueen*

Title: Consciousness and the collapse of the wave function

Does consciousness collapse the quantum wave function? This idea was taken seriously by John von Neumann and Eugene Wigner but is now widely dismissed. We develop the idea by combining a mathematical theory of consciousness (integrated information theory) with an account of quantum collapse dynamics (continuous spontaneous localization). Simple versions of the theory are falsified by the quantum Zeno effect, but more complex versions remain compatible with empirical evidence. In principle, versions of the theory can be tested by experiments with quantum computers. The upshot is not that consciousness-collapse interpretations are clearly correct, but that there is a research program here worth exploring. (Preprint: arxiv.org/abs/2105.02314)

Leonardo Barbosa

Title: A Measure for Integrated Intrinsic Information

Abstract: The Integrated Information Theory (IIT) of consciousness starts from essential phenomenological properties, which are then translated into postulates that any physical system must satisfy in order to specify the physical substrate of consciousness. We introduce an information measure that reflects three of these essential phenomenological properties — causality, specificity, intrinsicality—and is shown to be unique. Causality means that symbols must be transmitted with probability greater than chance. Specificity means that information must be transmitted by an individual symbol. Intrinsicality means that a symbol must be taken as such and cannot be decomposed into signal and noise. It follows that the intrinsic information carried by a specific symbol increases if the repertoire of symbols increases without noise (expansion) and decreases if it does so without signal (dilution). An optimal balance between expansion and dilution is relevant for systems whose elements must assess their inputs and outputs from the intrinsic perspective, such as neurons in a network. After introducing the new information measure, we show that it also satisfies the remaining postulates of IIT—integration and exclusion— and create the framework that identifies maximally irreducible mechanisms. These mechanisms can then form maximally irreducible systems, which in turn will specify the physical substrate of conscious experience.

Larissa Albantakis

Title: On the relationship between consciousness, the quantum, and integrated information theory

Abstract: The starting point of integrated information theory (IIT) is that consciousness (subjective experience) exists, immediately and indubitably, and that the purpose of a scientific theory of consciousness is to account for subjective experience in objective, physical terms. IIT does not presuppose that consciousness arises at the level of neurons rather than atoms, molecules, or larger brain areas, but instead predicts that consciousness emerges at the level of organization at which the intrinsic causal powers of a system are maximized. IIT thus assumes causation to be a central concept of the theory from the microphysical to the macroscopic. However, it remains to be determined whether IIT as a theory of consciousness is compatible with quantum mechanics as a theory of micro physics. Here, I will present recent efforts to extend IIT’s causal framework to quantum systems and discuss several conceptual challenges that arise around the notion of measurement, and the identification of causal entities in separate branches of the wave function. Finally, I will briefly outline how the emergent ontology implied by IIT escapes epiphenomenalism, while being agnostic about the causal closure of the physical.

Ian Durham*

Title: Autonomous Boolean networks as an ontology for integrated information

Abstract: Integrated information theory (IIT), in its present form, lacks a defined ontology. That said, in IIT version 3.0, working examples are constructed using autonomous Boolean networks. The development of a quantum IIT (qIIT) for which classical IIT is some kind of limiting case, adds additional requirements to any potential ontology such as Boolean networks. The relatively straightforward manner by which Boolean networks can be adapted to quantum inputs as well as their complex and emergent features, make them attractive in this regard. But exactly how to go about adapting these networks to the quantum case relies, at least in part, on the nature of measurement and, in particular, exactly when (or even if) it occurs. Two solutions to this problem are presented and compared within the context of IIT.

Adrian Kent

Title: Aligning Conscious Experience and Quantum Reality: possibilities and problems

Abstract: Recent proposals [Found. Phys. 42, 3 (2012); Phil. Trans. R. Soc. A 373: 20140241 (2014); Phys. Rev. A 96, 062121 (2017)] address the quantum measurement problem by defining an ontology via fictitious asymptotic late time measurements on a subsystem such as the electromagnetic field. These raise independently interesting questions about whether ontologies defined by (for example) the electromagnetic or gravitational field can be aligned with human conscious experience and perception times. They also raise the question of whether we can reasonably demand such alignment under all circumstances, or whether alignment for typical humans in typical environments suffices to make a realist theory acceptable. I will review these, discuss the connection to related questions arising in dynamical collapse models, and offer some tentative suggestions about the answers.

Jenann Ismael

Title: A Participatory Universe in the realist mode

Abstract: I will be suggesting a different way of seeing the difference between classical and quantum worlds. The fact that we act in the world that we represent makes it impossible to stabilize certain features of the world as objects of knowledge. I give some examples of this effect, distinguishing it from disturbance and ignorance. How the effects propagate depends on the way the world is connected. In the classical setting; the effects are focused and channeled into the future. In quantum mechanics they are endemic. I’ll suggest that this casts light on the sense in which the universe is participatory and explore ways of understanding this in a realist mode.

Christopher A. Fuchs*

Title: QBists Don’t Mind Being in Pure States; It’s Nothing Personal.

Bernardo Kastrup

Title: Physics without metaphysical assumptions

Abstract: Physics observes, models and predicts what we perceive. Physical quantities are descriptions of what appears on the screen of perception, even when instrumentation is used, for the output of instrumentation still needs to be perceived. Anything beyond this, including the notion that the physical world (i.e. the world ostensibly exhaustively describable in terms of physical quantities alone) has standalone existence out there, is a metaphysical assumption, not an empirical fact. In this presentation, I shall argue that these metaphysical assumptions are what create the seeming paradoxes of quantum mechanics. The physical world is but an appearance, upon measurement, of a reality that, in and of itself, isn’t necessarily physical, in the sense parenthetically defined above. As a matter of fact, we now have plenty of empirical evidence, both from foundations of quantum mechanics and neuroscience, that the world measured isn’t physical, physicality arising as a product of measurement. I shall review this evidence and argue that the physical world is akin to a dashboard of dials displaying measurements of an external world, not the external world itself. Understood this way, the paradoxes of quantum mechanics can be resolved.

Donald Hoffman*

Title: Spacetime is Doomed

Abstract: The ontology of spacetime and methodology of reductionism have been spectacularly successful assumptions of science. But quantum field theory and evolution by natural selection each entail that spacetime and reductionism are doomed (e.g., https://www.youtube.com/watch?v=Sn0W_mwA7Q0). Spacetime, with its objects, is not fundamental. Neither are Hilbert spaces. Instead physicists have found polytopes beyond spacetime, such as amplituhedra and cosmological polytopes, which create spacetime and quantum information as special projections (e.g., https://arxiv.org/abs/1709.02813). These polytopes point to an ontology, yet to be elucidated, in which objects in spacetime—such as human brains and measurement devices—are not fundamental. Coming to grips with these polytopes, and exploring their ontology, are essential steps toward understanding mind and agency in physics beyond spacetime, and their projection to the special case of quantum physics in spacetime. I explore an ontology of consciousness, as formalized by a dynamical theory of conscious agents (e.g., https://www.frontiersin.org/articles/10.3389/fpsyg.2014.00577/full), and the projection of this dynamics, via its asymptotics, to these new polytopes.

Mauro d’Ariano

Title: Hard Problem and Free Will: a quantum-informational approach

Lídia del Rio

Title: Thought experiments in a quantum computer

Abstract: We introduce a software package that allows users to design and run simulations of thought experiments in quantum theory. In particular, it covers cases where several reasoning agents are modelled as quantum systems, such as Wigner’s friend experiment. Users can customize the protocol of the experiment, the inner workings of agents (including a quantum circuit that models their reasoning process), the abstract logical system used (which may or not allow agents to combine premises and make inferences about each other’s reasoning), and the interpretation of quantum theory used by different agents. Our open-source software is written in a quantum programming language, ProjectQ, and runs on classical or quantum hardware. As an example, we model the Frauchiger-Renner extended Wigner’s friend thought experiment, where agents are allowed to measure each other’s physical memories, and make inferences about each other’s reasoning. The software can be found at https://github.com/jangnur/Quanundrum

Veronika Baumann

Title: The reasoning of agents in superposition

Abstract: Wigner’s-friend experiments exploit the fact (standard) quantum theory comprises two different dynamics, namely the collapse of the wave function, which without any ontological commitment means the application of the state-update rule, and unitary evolution. They feature regular observers — friends — who measure quantum systems, and so-called superobservers – Wigners – who perform joint measurements on the quantum systems, the friends and potentially other relevant degrees of freedom. If both the friends and Wigners can reason about the measurement results in their setup they might arrive at a contradiction, if they use different formal descriptions for a quantum measurement. In some instances these predictions can be compared at some point, making the disagreement between observers and superobservers empirically accessible. Moreover, the friend alone can produce contradicting records when reasoning about her perceived measurement results before and after Wigner’s measurement. But even without such records one can derive an interesting, counterintuitive no-go theorem for the probability assignments for the results observed by Wiger’s friend. There is no joint probability distribution for the friend’s perceived measurement outcomes before and after Wigner’s measurement, that depends linearly on the initial state of the measured system and whose marginals reproduce the predictions of unitary quantum theory. This means that one must either propose a nonlinear modification of the Born rule for two-time predictions, sometimes prohibit the use of present information to predict the future or deny that unitary quantum mechanics makes valid single-time predictions for all observers. Which of these reactions to the no-go theorem one is most likely do endorse, will depend on one’s interpretation of quantum theory.

Markus Müller

Title: You may be unembedded structure

Abstract: What does Wigner’s friend see in a quantum experiment? If we simulated an agent on a computer, would it be conscious? In discussing questions like these, we typically think of the agent (or other structure unrelated to humans or consciousness) as being instantiated or realized by some physical system, i.e. as being embedded in a concrete way into the physical world as part of its definition. In this talk, I argue that this tacit assumption rests on a lack of imagination: there is a simple class of mathematical models that describes agents (including “you”) as unembedded structure, while predicting that things typically look approximately for the agent as if it was embedded into an external world. I argue that approaches of this kind are methodologically necessary to address some conceptual puzzles of physics and philosophy, they are broadly consistent with our physical observations, and they suggest counterintuitive but consistent options to think about the world and our place in it.

Eric Cavalcanti

Title: Experimental metaphysics with observers and thinkers

Catalina Oana Curceanu

Title: Testing Quantum Mechanics Underground: Sneaking a look at God’s cards

Abstract: We are experimentally investigating possible departures from the standard quantum mechanics’ predictions at the Gran Sasso underground laboratory in Italy. In particular, with radiation detectors we are searching signals predicted by the collapse models (spontaneous emission of radiation) which were proposed to solve the “measurement problem” in quantum physics and signals coming from a possible violation of the Pauli Exclusion Principle. I shall discuss our recent results which ruled out the natural parameter-free version of the gravity-related collapse model and the implications for Orch OR models. I shall then present more generic results on testing CSL (Continuous Spontaneous Localization) collapse models and discuss future perspectives. Finally, I shall briefly present the VIP experiment with which we look for possible violations of the Pauli Exclusion Principle by searching for “impossible” atomic transitions and comment the impact of this research in relation to Quantum Gravity models. Borrowing the title of a beautiful book of Giancarlo Ghirardi – I shall tell you the story of how we are sneaking a look at God’s cards in the cosmic silence!

Johannes Kleiner*

Title: Collapse and the Closure of the Physical

Abstract: We investigate the implications of the closure of the physical in the context of models and theories of consciousness. We prove that if and only if a model of consciousness does not describe the physical as closed, the induced physical evolution of that model is, to leading order in time, that of a dynamical quantum collapse model. This result sheds new light on the question of why and how consciousness and quantum theory are related. It contributes to the exploration of what consciousness does, independently of assumptions about what consciousness is. Our analysis is made possible by powerful theorems in quantum mathematical physics. From a mathematical perspective, the main achievement is to overcome the Markov requirement in these theorems.

Lucien Hardy

Title: Proposal to use Humans to switch settings in a Bell experiment

Abstract: In this talk I will discuss how we might go about performing a Bell experiment in which humans are used to decide the settings at each end. To get a sufficiently high rate of switching at both ends, I suggest an experiment over a distance of about 100km with 100 people at each end wearing EEG headsets, with the signals from these headsets being used to switch the settings. The radical possibility we wish to investigate is that, when humans are used to decide the settings (rather than various types of random number generators), we might then expect to see a violation of Quantum Theory in agreement with the relevant Bell inequality. Such a result, while very unlikely, would be tremendously significant for our understanding of the world (and I will discuss some interpretations). Possible radical implications aside, performing an experiment like this would push the development of new technologies. The biggest problem would be to get sufficiently high rates wherein there has been a human induced switch at each end before a signal as to the new value of the setting could be communicated to the other end and, at the same time, a photon pair is detected. It looks like an experiment like this, while challenging, is just about feasible with current technologies.

Jeff Tollaksen*

Title: A New Approach to Time

David Chalmers*

Title: Wrap-up talk: Dualism and idealism in the foundations of quantum mechanics