It seems to me to be clear that the wavefunction must be something a good deal more ‘real’ than would be the case for merely ‘a probability wave’. The Schrödinger equation provides us with a precise evolution in time for this entity (whether it is charged or not), an evolution that depends critically upon how the phase indeed varies from place to place. But if we ask of a wavefunction ‘where is the particle?’, by performing upon it a position measurement, we must be prepared to lose this phase-distribution information. In fact, after the measurement, we have to start all over again with a new wavefunction. If the result of the measurement asserts ‘the particle is here’, then our new wavefunction has to be very strongly peaked at the position ‘here’, but then it rapidly disperses again, in accordance with Schrödinger evolution. If our position measurement were absolutely precise, then the new state would be ‘infinitely peaked’ at that location;
Blogger Comments:
From the perspective of Systemic Functional Linguistic Theory, probability is an assessment of potential. So the 'reality' that a probability wave assesses is potential 'reality'.
The reason why 'performing a position measurement' loses the 'phase-distribution information' of the wavefunction is that making such an observation actualises just one instance of the total potential.
The reason why a new wavefunction is required after 'performing a position measurement' is that the potential of the quantum system has changed after making an observation.
In this view, the notion that a wavefunction "disperses" misconstrues potential as actual. It is only the particle that is actual, and 'actual' in the sense of being an instance of the potential specified by the wavefunction.
No comments:
Post a Comment