Swapping something real

Experiments demonstrating entanglement swapping have been alleged to challenge realism about entanglement. Seevinck (2006) claims that entangle- ment “cannot be considered ontologically robust” while Healey (2012) claims that entanglement swapping “undermines the idea that ascribing an entangled state to quantum systems is a way of representing some new, non-classical, physical relation between them.” My aim in this paper is to show that realism is not threatened by the possibility of entanglement swapping, but rather, it should be informed by the phenomenon. I argue—expanding the argument of Timpson and Brown (2010)—that ordinary entanglement swapping cases present no new challenges for the realist. With respect to the delayed-choice variant discussed by Healey, I claim that there are two options available to the realist: (a) deny these are cases of genuine swapping (following Egg (2013)) or (b) allow for existence of entanglement between timelike separated regions. This latter option, while radical, is not incoherent and has been suggested in quite different contexts. While I stop short of claiming that the realist must take this option, doing so allows one to avoid certain costs associated with Egg’s “orthodox” account. I conclude by noting several important implication of entanglement swapping for how one thinks of entanglement generally