A few months ago I was invited by Prof. Miroljub Dugic (Institute of Physics, University of Kragujevac, Serbia) to take part in a poll on the future of quantum science and technology. Below I report the questions together with my answers. The complete paper can be downloaded from this link.

Do you find the quantum measurement problem worth striving?

I really have no idea if or how the quantum measurement problem may be solved. Quantum theory itself has nothing to say about a putative solution, so, if I must pick one, I would say that any genuine resolution of the measurement problem, if it exists at all, would have to come from new physics for which we currently have neither hints nor any operational need, in a sense. For the moment, the problem seems to tell us more about the limits of our preferred narratives than about the limits of formalism itself.

Which research directions do you find prominent in theory and applications?

I believe we should more decisively push toward an observer-dependent perspective, not only in quantum theory but in science as a whole, including cosmology. This idea is not new; it is as old as science itself. From time to time it resurfaces, and when it does it sheds new light on physics, yet it is quickly overshadowed again by the powerful illusion that we call “objective reality”. In this spirit, I expect research directions that put center stage what an observer can infer and learn, and how such inferences are constrained or enabled by physical theory, to become increasingly prominent. Such an approach may guide both theoretical developments and quantum technologies.

What would you expect of the future post-quantum theory?

If a future post-quantum theory ever emerges, to deserve that name, it would have to depart from quantum theory at least as radically as quantum theory departed from classical physics. It is worth recalling that the inadequacy of classical theory was made evident by relatively simple, low-energy experiments at the end of the nineteenth and the beginning of the twentieth century. By contrast, and this is an important methodological point, we currently have no experimentally demonstrated situations in which quantum theory is inadequate. The open issues we do have are conceptual or theoretical rather than empirical. The regimes where quantum theory might conceivably fail lie at extreme scales not yet accessible to experiment. Without concrete empirical hints, imagining a genuinely new framework becomes exceedingly difficult. In this sense, talk of a post-quantum theory today feels uncomfortably close to “armchair philosophizing”, carried out without the observational footholds that historically guided genuine theoretical revolutions.