Interpretations of quantum mechanics
Where  is the superposition of the various wavefunctions. This idea implies that a particle occupies every possible wavefunction it can. This implies that a particle occupies more than one position at the same time. In other words, a particle exists in at least two different positions simultaneously. When an observer comes and actually measures the position of the particle, something called the wavefunction collapse occurs. So when someone observes the particle, the following happens: