forming a measurement apparatus.

Experimental physicists are undoubtedly able to build detection apparatuses allowing microscopic entities to temporarily acquire a spatial localization, in specific places, and even though these apparatuses could in principle localize in space a certain number of microscopic entities at a time, as far as I know a device which can localize an entire macroscopic structure doesn’t exist, and perhaps is not even conceivable. The possibility remains, of course, that the process of spatial localization could occur even in the absence of macroscopic structures playing the role of detection devices, as is suggested in some interpretations of quantum theory, like the so-called objective collapse theories [@Ghirardi2011], the transactional interpretation of quantum physics [@Ruth2013], and others, the discussion of which, however, would go beyond the scope of the present article.

Among the factors that we have not taken into account in the estimation of ${\cal P}_{\rm body}$, there are of course also those that could slightly increase the value of the probability. For example, we have implicitly assumed that all the atomic components have to re-localize at exactly the same instant. However, nothing prevents us from admitting a small time-delay in the localization process of the individual atoms, 