When Do Fields Collapse?

A notable question in physics now concerns collapse of the "wave-function": When does it occur? There have been many speculations (see, e.g., Ghirardi-- Rimini-- Weber theory, Penrose Interpretation, Physics forum) and experiments (e.g., "Towards quantum superposition of a mirror") about this. The most extreme viewpoint is the belief that Schrödinger's cat is at the same time alive and dead, although Schrödinger proposed this particular thought-experiment (like Einstein's less-well-known bomb experiment) to demonstrate how silly this type of an idea is.

The concern arises because Quantum Mechanics can only calculate probabilities until an observation happens. But Quantum Field Theory, which deals in real field intensities-- not probabilities, delivers a practical indisputable answer. Unfortunately, Quantum Field Theory in its authentic sense of "there are no particles, there are only fields" (Art Hobson, Am. J. Phys. 81, 2013) is ignored or misinterpreted by a large number of physicists. In QFT the "state" of a system is illustrated by the field intensities (technically, their expectation value) at every point. These fields are real properties of space that behave deterministically depending on the field equations-- with one exception.

The exception is field collapse, but in Quantum Field Theory this is an incredibly different thing from "collapse of the wave function" in QM. It is a physical event, not a change in chances. It occurs when a quantum of field, regardless of how spread-out it may be, suddenly deposits its energy into a single atom and vanishes. (There are also other kinds of collapse, such as scattering, coupled collapse, internal change, and so on) Field collapse is not explained by the field equations-- it is an independent event, but just because we don't possess a theory for it doesn't imply it can not take place. The fact that it is non-local bothers some physicists, but this non-locality has been demonstrated in many experiments, and it does not result in any disparities or paradoxes.

So once field collapse happens, the ultimate "decision"-- the climax-- is reached. This is QFT's answer to when does collapse occur: when a quantum of field colapses. In the case of Schrödinger's cat, this is when the radiated quantum (perhaps an electron) is grabbed by an atom in the Geiger counter.

Right before a field quantum finally collapses, it may have interacted or entangled with numerous other atoms along the way. These interactions are described (deterministically) by the field equations. However the quantum can not have indeed collapsed into any of those atoms, because collapse can transpire only once, so whatever you refer to it as-- interaction, entanglement, perturbation, or just "diddling"-- these initial interactions are undoable and do not bring about macroscopic changes. Then, when the last collapse takes place, those atoms become "undiddled" and return to their undisturbed state.

To sum up, in QFT the "decision" is developed when a quantum of field deposits all its energy into an absorbing atom. In addition to replying to this inquiry, QFT additionally explains why time dilates in Special Relativity and settles the wave-particle duality issue of Quantum Mechanics. One can simply wonder the reason that this particular concept hasn't already been embraced and made the grounds for our awareness of nature. I think it is truly time for physicists to WAKE UP AND SMELL THE QUANTUM FIELDS.
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