From Niels Bohr to John Wheeler to QBism: The trajectory of an interpretation of quantum mechanics

John Wheeler summarized in a popular science book his path to an informational “world-view”: “I think of my lifetime in physics as divided into three periods. In the first period… I was in the grip of the idea that Everything is Particles… I call my second period Everything is Fields… Now I am in the grip of a new vision, that Everything is Information” (WHEELER, 1998, p. 63).

It's usually attributed to Wheeler the view that the physical domains are conclusively informational. As he would put it himself, we should replace “it” for “bit” in our physical picture of the universe, to which the quantum computer pioneer David Deutsch added a further remark: “it” for “qubit” (CALUDE, 2015, p. 228). And as it is well known Wheeler studied under Niels Bohr in Copenhagen between 1934-35. I will then follow in my talk the development of Wheeler’s own understanding of the Copenhagen interpretation of quantum mechanics from this time to his “it for bit” concept and from thereafter up to the current interpretation advanced nowadays by physicist Christopher Fuchs (a former student of Wheeler) and one of the main proponents of QBism. This lecture will be based on primary and secondary literature, as well as on an interview with Christopher Fuchs and our work together while I was (among other colleagues physicists, historians and philosophers of physics) a visiting researcher (invited by Fuchs) at the Stellenbosch Institute for Advanced Study (STIAS) in 2018 in a project named “Is It Autonomy All the Way Down? The Search for a QBist Metaphysic”.

Bibliography:

CALUDE, Cristian S (Org.). The Human Face of Computing. (2016). Imperial College Press. London, UK.

FUCHS, Christopher A. (2011). Coming of Age with Quantum Information: Notes on a Paulian Idea. Cambridge, UK, Cambridge University Press.

GOLDSTINE, H. H. (1980). The Computer from Pascal to von Neumann. Princeton University Press. Princeton, USA.

WHEELER, J. A.; FORD, Kenneth. (1998). Geons, Black Holes & Quantum Foam: A Life in Physics. W. W. Norton & Company, Inc. New York, NY.

YEANG, Chen-Pang. (2011). “Engineering Entanglement, Conceptualizing Quantum Information”. Annals of Science, 68:3, 325-350.