En présentiel : Amphithéâtre Charpak sur le campus Pierre-et-Marie Curie à Jussieu, le 21 octobre 2021 à 17H30

You can’t always get what you want. (A simondonian interpretation of quantum entanglement)

The understanding of QM is obscured by a twofold “epistemological obstacle” (Bachelard 1938) that has taken quite different and apparently opposed forms in the interpretation of the theory: substantialism and instrumentalism. While substantialism is the ontological assumption that reality is entirely composed of individuals with permanent unity and identity (Bontems & de Ronde 2011), instrumentalism is the anti-realist assumption that science is just a procedure to make predictions about measurement outcomes (‘clicks’ in detectors). Instead of searching for new concepts that would explain what QM is really talking about, the Bohrian ‘solution’ that prevailed was, on the contrary, to subvert realism by retaining classical substantialist concepts as fictions embedded in paradoxical story-tellings illustrating experimental procedures with essential gaps bridged by irrepresentable notions such as ‘quantum particles’ and ‘quantum jumps’. One of the kernel notions of QM is entanglement, originally designed by Einstein as a « spooky action at a distance » to demonstrate the inconsistency of ‘quantum jumps’ in a substantialist framework. Even though entanglement, considered as a spooky philosophical notion, was completely erased from physics for half a century, during the 1990s it was included –due to its pragmatic possibilities– once again within the still orthodox contemporary Borhian narrative. After recalling the conceptual bases of a Simondonian interpretation of QM (Bontems & de Ronde 2019) – the hypothesis of preindividuality and the postulate of a realism of relations – we discuss the inconsistencies present in the orthodox definition of entanglement. Our claim is that the Bohrian narrative is biased by the fact that it presupposes the existence of individuated particules, while Simondon’s realism of relations shifts the focus on preindividuality and the processes of individuation that may (or may not) generate such individuals. This allows us to sketch a realist but non-substantialist understanding of entanglement that leaves behind both the mere instrumentalist reference to measurement outcomes and substantialism: “You can’t always get what you want… but why did you want particles in the first place?”