24.4 Selections: new physics?

In Chapter 5 and in this chapter, I talked about the actualizing or selection events that make the bottom line of the whole multi-level world. I implied that such events are the same as the measurement events that are known in quantum physics, but this is not strictly true. There is still much debate in physics concerning whether there really are such events. Physicists do not yet have evidence for whether what is called the ‘reduction of the wave packet’ in measurements really occurs or not.

Many physicists, especially those in quantum cosmology who are used to thinking far from everyday life, claim that there is only ever the appearance of such actual selections, and that, really, they do not exist. Maybe, they say, the multiple options that are supposed to be selected from still continue to exist in ‘worlds of their own’ that can never interact with each other. Since, for all practical purposes, we are stuck in just one world, we therefore approximately exist (they claim) as if we made the selection that defines that world. The ‘many worlds’ interpretation of quantum mechanics by Everett (1957), or the ‘decoherent histories’ interpretation by Gell-Mann and Hartle (1993) and Halliwell (1995), offer such views. These approaches have the feature of keeping only the Schrödinger dynamics and avoiding anything beyond that. In theistic science, this would be to advocate keeping only the propensity fields of degree 3.32 but without them ever being propensities for anything. The result of such interpretations is that each would-be-choice results in a set of multiple worlds, in which each possible outcome is manifested in each of the corresponding possible worlds. From any reasonable viewpoint (as Bell (1990) eloquently argues), this must be considered an extraordinarily baroque speculation to avoid adding even the simplest formalism to allow precise outcomes, here the actualizations of propensities.

Theistic science must therefore go along with those who make some extension to quantum mechanics in order to allow and describe the actual selection between the multiple outcomes predicted by quantum mechanics. It is essential to the theory of this book that there are specific selection events made in physics. Only then can humans decide and can the resulting actions constitute the ultimate foundation of the theistic universe.

There are a number of proposals for the selection mechanism in quantum mechanics. These are often called ‘collapse’ or ‘reduction’ mechanisms because the range of propensities existing before the selection is collapsed after the event to those compatible with which event actually occurred. I have investigated many of these proposals in Chapter 12 of Thompson (2010), but I find no conclusive argument or evidence for a definitive conclusion on which is best. Within theoretical physics, the mathematics necessary to describe reduction events is plausibly given as some stochastic Schrödinger equation or an equivalent semi-group master equation with Lindblad operators: for details see the review by Bassi and Ghirardi (2003) and references therein. The best known specific hypothesis is the proposal of Ghirardi et al. (1986), where fields are localized to narrow Gaussians. The GRW proposal has been criticized by Lewis (1997) as not a true selection because of finite tails of the Gaussians, and indeed it does not give a strict selection between spatial regions. What is needed in the theistic account, however, is not necessarily a strict spatial selection but a strict selection between alternative outcomes, or histories as these are usually called.^24.7

The prediction of theistic science is therefore that some actualizing or collapse events do occur, and so physicists should still be trying to find out where, when and how they happen. The present thesis states that there must be at finite time intervals some events in which these become exactly decoherent, but the thesis leaves open the precise conditions for such events. These actualization events are in addition to the results of environmental influence on quantum superpositions and will result in even fewer effects of superpositions, entanglement or interference effects than are predicted by Schrödinger dynamics. It is predicted that one day these will be observable effects in experimental physics.

A weighty objection to the possibility of actualizing events is based on how quantum mechanics fits into Einstein’s special theory of relativity. That is because actualizing events may alter the causing field of propensity in one step, even if it is spread out over very large distances, possibly over light-years (say) for an intergalactic photon. This is one of many possible effects of quantum non-locality. It is not yet certain that these are forbidden.^24.8Relativity theory is commonly taken as forbidding all communications faster than the speed of light, since, in that case, the order of transmission and reception events would be different according to different observers in relative motion. That would appear to contradict one principle of causality, namely that a cause always comes before its effect. In our theistic science we do keep that property of causality: we never allow future events to influence what happens now. So does relativity forbid non-locality over spatial intervals within times less than the propagation time for light? (These are called ‘space-like’ intervals in relativity theory.) Should we follow relativity in its ‘conventionality of distant simultaneity’ by not allowing space-like separated events to have no intrinsic order?^24.9

Theistic science, in reply, affirms that actual events must have an actual order. This response is based on the correspondence between non-local propensity fields and the non-locality of minds that follows because they are not themselves located in physical space-time (only their effects are). I surmise that any mind of a being has a complete ordering of its internal changes since since all events are ‘seen’ in the mind as they happen. Thus, if a non-local mind observes changes of propensity fields spread over space-like intervals, these observations will have some determinate order and so will the propensity-actualizing events that were observed.

What is not necessary is that the actual order of collapse events be determined by quantum mechanics, that is, by the Schrödinger equation. It is quite possible that actualizing events, since they occur probabilistically from their propensities, may also have a probabilistic actual order. This is to say, two space-like actualizing events will not have a predetermined order, but some order will be established as they occur. Only afterwards will it be clear that one event occurred before the other, when we see in which order changes were made to their common propensity field.^24.10This theory is equivalent to making Lorentz invariance apply strictly to deterministic field propagations (the virtual fields of level 3.22 and the Schrödinger wave field of level 3.23) and to apply only statistically to indeterministic field actualizations (the actual events of level 3.33). That seems entirely fitting.