The only way to collapse the wave function (and retroactively force the isotope to have decayed or to have not decayed) is to open the box and find out. This is pretty embarrassing.

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The fuzzy quantum shape that describes the speed or location of a single particle, its wave function, has now been directly measured in the laboratory, giving this mathematical concept a small ...

If the wave function is real, then a single experiment should not be able to determine its polarisation – it can have both until you take more measurements. Alternatively, ...