A note on measurement

Abstract

Grounded on the quantum measurement riddle, a general argument against the universal validity of the superposition principle was recently put forward by Bassi and Ghirardi. It is pointed out that this argument is valid only within the realm of the philosophy of ``objectivistic realism'' which is not a necessary part of the foundations of physics, and that recent developments including decoherence theory do account for the appearance of macroscopic objects without resorting to a break of the principle.