Timeline for If superposition is possible in QM, why do we often assume systems are already in their eigenstates?

3 events

when toggle format	what		by	license	comment
Nov 15, 2012 at 14:05	comment	added	Andrew		A small nitpick: there are ensembles of systems in superposed states that can't be replaced with an equivalent ensemble of systems in energy eigenstates. For example, any ensemble that was all in the same superposition of ground and first excited state and all having the same relative phase between these two states. However, any ensemble of systems in energy eigenstates can be indistinguishably replaced with an ensemble of systems in superposition states, but with random relative phases.
Nov 14, 2012 at 6:01	comment	added	WP-		No one told me an electron can't be in a superposition of states, or anything like that. I just assumed that a superposed state would have properties different than those of its constituent eigenstates -- and therefore the physical behavior of the superposed state would differ somehow. At the very least something would be lost by not considering superposition. That potential omission bothered me. But Andrew's answer points out my misconception: an ensemble of systems in superposed states is essentially indistinguishable from a properly constructed ensemble of systems in eigenstates.
Nov 12, 2012 at 21:03	history	answered	Mark Eichenlaub	CC BY-SA 3.0