Quantum Foundations Podcast

Quantum theory appears to allow some kind of connection between entangled particles, but not enough to send messages. Antony Valentini argues this is a conspiracy: there must be something deeper than quantum, where nonlocality can actually be used to send messages, but it is hidden from view in standard quantum experiments. In this episode of the Quantum Foundations Podcast, Valentini uses Pilot-wave theory to explain the physics of the nonlocal subquantum world. He discusses various ways that the theory could be experimentally tested, by looking for signatures of violations of the Born rule in extreme environments, such as the early universe. He also discusses the radical technological implications of subquantum physics, if we were able to harness it.

 

Valentini recently released a book for a general audience explaining these ideas, "Beyond the Quantum: A Quest for the Origin and Hidden Meaning of Quantum Mechanics".

What if quantum particles have no gravity? In this episode of the Quantum Foundations Podcast, Professor Gerard Milburn explains how this radical idea could solve open problems in quantum theory and lead towards a theory of quantum gravity. It comes with extreme consequences for quantum measurements; the formation of black holes; and even the beginning of the universe. From a new understanding of Bell experiments to a cosmological arrow of time, find out if dropping gravity from the equation could be the start of transforming the field of quantum science and technology.

If there really is a quantum reality for every possible outcome of a measurement, then where do measurement probabilities come from? Dr Tony Short at the University of Bristol has used a set of intuitive assumptions to derive probability in a quantum multiverse. In this episode we discuss his motivations for exploring the many-worlds interpretation; what his assumptions are and how they lead to the Born rule for measurement probabilities; and how these ideas fit within the broader landscape of research in quantum foundations, probability and the many-worlds interpretation.

The notion of true quantum nonlocality is absurd. Prof Tim Palmer from the University of Oxford suggests that there is a hidden assumption in standard quantum mechanics, and dropping it will save us from this absurdity. Namely, the reality of counterfactuals: the physics of what could have happened but did not. Inspired by chaos theory and the fractal structure widespread in atmospheric physics, Palmer has developed a new underlying structure for quantum theory, with radical implications for our fundamental principles of quantum physics; the limits of quantum computation; and perhaps even the search for quantum gravity.

What if you could put an observer in superposition on a quantum computer? Dr Will Zeng suggests that this experiment could stretch standard quantum theory so far that it might break — and radically update our understanding of physical reality. However, today's proof-of-principle experiments on quantum computers use single qubits to model observers. Zeng explains how a new programme of research aims to quantify "observer-ness" and conduct experiments with increasingly realistic observers, pushing quantum computers to the limits until they can run actual quantum Artificial General Intelligence experiments.