Time’s Direction and Orthodox Quantum Mechanics: Time Symmetry and Measurement

It has been argued in various places that measurement-induced collapses in Orthodox Quantum Mechanics yields a genuine structural (or intrinsic) quantum arrow of time. In this paper, I will critically assess this proposal. I begin by distinguishing between a structural and a non-structural arrow of time. After presenting the proposal of a collapse-based arrow of time in some detail and discussing some criticisms it has faced, I argue, first, that any quantum arrow of time in Orthodox Quantum Mechanics cannot be defined for the entire universe and, second, that it requires non-dynamical information to be established. Consequently, I deliver that any quantum arrow of time in Orthodox Quantum Mechanics is, at best, local and non-structural, deflating the original proposal.