Introduction This paper provides a new context for an established metaphysical debate regarding the problem of persistence. Namely, how can it be said that one and the same physical object persists through time while changing over time? I contend that a popular view about persistence which maintains that objects persist by perduring-that is, by having temporal parts-receives a particularly neat formulation in quantum mechanics due to the existence of a formal analogy between time and space. I

more »

... gue, however, that on closer inspection this analogy fails due to a 'no-go' result which demonstrates that quantum systems can't be said to have temporal parts in the same way that they have spatial parts. Therefore, if quantum mechanics describes persisting physical objects, then those objects cannot be said to perdure. This argument serves two aims. The first is to continue the recent tradition of addressing the problem of persistence in the context of specific physical theories: Balashov (2010); Gilmore (2008) consider special relativity; Butterfield (2005 Butterfield ( , 2006 considers classical mechanics. The second aim is to provide a novel interpretation of the no-go result mentioned above, which is well-known in the quantum foundations literature but rarely discussed by philosophers of physics. The result is often phrased like this: There exists no time observable