Penrose (2004: 516):
But now another question looms large. How do we know what physical circumstance it is that constitutes a ‘measurement’? Why, after we have been happily using this wavefunction description of a particle as a wave spread out in two quite different directions through the reaches of space, should we suddenly revert to a description of it as a localised particle as soon as the detection of it is performed?
This same curious kind of picture of a quantum particle appears also to be appropriate for detection at the screen in our two-slit experiment, just as it was with the (unspecified) ‘detectors’ used by my far-flung colleagues.
In my descriptions so far, it certainly seems that the wavelike aspects must be maintained right up until we choose to ‘perform a measurement’ to detect the particle, but then we suddenly revert to a particle-like description, where there is an awkward discontinuous (and non-local) change of the state — a quantum jump — as we pass from the wavefunction picture to the ‘reality’ presented by the measurement. Why? What is it about the detection process that demands that a different (and highly non-local) mathematical procedure should be adopted, in the event of a ‘measurement’, from the standard quantum-evolution procedure provided by Schrödinger’s equation?
Blogger Comments:
From the perspective of Systemic Functional Linguistic Theory, a 'measurement' is an observation, and an observation is a mental process mediated by a Senser.
From this perspective, the wavefunction measures the potential meaning that can be construed of experience by the Senser. It is only when the Senser makes an observation that one instance of this potential is made actual as a particle. It is this process of instantiation that constitutes a 'quantum jump'.
In this view, the description above misconstrues the potential as actual, and misconstrues the potential–instance relation as an actual before–after relation.
No comments:
Post a Comment