Posted: Oct 06, 2011 11:10 pm
by Teuton
mizvekov wrote:Nice, so Teller is an example of a quantum field non-realist, a point of view not being represented on this thread.

"Teller argues that ‘quantum fields’ lack an essential feature of classical field theories so that the expression ‘quantum field’ is only justified on a “perverse reading” of the notion of a field. His reason for this conclusion is that in the case of quantum fields—in contrast to classical fields—there are no definite physical values whatsoever assigned to space-time points. Instead, the assigned quantum field operators represent the whole spectrum of possible values so that they rather have the status of observables (Teller: “determinables”) or general solutions. Something physical emerges only when the state of the system or when initial and boundary conditions are supplied. Teller's criticism of the standard gloss about operator-valued quantum fields has one justified and one unjustified aspect. The justified aspect is that quantum fields actually differ considerably from classical fields since the field values which are attached to space-time points have no direct physical significance in the case of a quantum field. However, it was not to be expected anyway that one would only encounter definite values for physical quantities in QFT since it is, like QM, an inherently probabilistic theory after all and is equally confronted with the measurement problem."