The standard interpretation of QM (Copenhagen) states that an event is not real until it is observed. How does this work for building a magnet whenever it was formed (supposingly billions of years ago)? Begining with two atoms with magnetic moments, they must have two orientations parallel and antiparalell, which is a projection of the spin of one of them on the spin direction of the other. As these spins are oriented randomly there would be a superposition of up and down. As far as I see there would be two vectors rotating at Larmour frequency one for z and other for -z building a superposition. In order one to be prefered an observation is needed. While there was not such billion years ago then the superposition survived! Then many other atoms in the magnet have the same faith and everything stayed in a complex form of multipole superposition, maybe until the time the magnet was not digged out and taken in the hand of a man? Then the proccess of spin allignment took place immidiately?

  • $\begingroup$ Something must have forced the projection to take place. The Ghirardi–Rimini–Weber theory seems most appropriete. Or the variant of Penrose. $\endgroup$ – Mercury Oct 28 at 12:23