I propose a simple thpught experiment; A scientist A measure the spin of an electron and finds it "up". After that he removes all evidence of his experiment and goes away, only to die in a road accident. Another scientist, obviously unaware of the experiment done by A come and measures the spin of the same electron. Will B find the spin necessarily "up" or he will measure just any value "up" or "dpwn" with equal probability? If the wave function collapsed by A is an objective reality, B should also measure the same value of the spin (up). Otherwise the experiment of B will be unaffected by the experiment of A, because he does not know anything about it. Will anybody please enlighten me?