I just have to comment on a recent article in the Independent entitled, ‘Reality doesn’t exist until you look at it, pioneering quantum physics experiment finds’ ,( http://www.independent.co.uk/life-style/gadgets-and-tech/news/reality-doesnt-exist-until-you-look-at-it-pioneering-quantum-physics-experiment-finds-10305047.html). Firstly what terrible English, but much more importantly this is a prime example of the media’s unbalanced and ill-informed presentation of what physics is really about. I also think that physicists are partly to blame because they have a very naive view of realities that lacks rigorous definition. So the question for me is which reality is the journalist talking about?
In my article on physical reality I try to distinguish between two physical realities; the first is the reality that we perceive through our interaction with the universe of which we are part. This is the universe that physics is probing though experimentation and measurement, or more fundamentally interaction. Physics is all about using symbolic methods to predict the perceived effects of interactions between aspects of the complex system that is our universe. Fortunately the universe seems to be homogeneous and isomorphic, at least locally, so this perceived internal reality can be a commonly shared model. In the last hundred years or so we have come to realise that the internal reality is split into two and we have models and methods that predict behaviour on scales that are larger than atoms (classical physics) and another set of methods and models to predict behaviour on smaller scales (quantum mechanics).
The second reality is what I term objective physical reality. Objective reality is whatever exists if the earth was hit by a comet and no humans were around to interact with it. Unless you believe, and it is a well-documented philosophical stance, that you are the universe and the rest of us are some kind of unconscious zombies that in some way are generated as part of the universe from your consciousness, then this objective universe must exist in some form. Whether you believe Max Tegmark’s view that objective reality is a pure mathematical object or that our internal reality is a holographic projection of an objective reality at the edge of our universe, or you take R Cahill’s view that reality is some kind of abstract self-referential nodal network, the overriding common position seems to be that there is a complex system that we can term an objective reality and from whose interactions a scale of pattern has emerged of which we are part and from which, though internal interactions we have developed a physics that infers the behaviour of this scale of patterns and its emergent rules.
The truth is that physics tells us very little about this objective reality and it can’t because physics is based upon us interacting with the system from within. The objective universe would have to be viewed from the outside. So the uncertainty and randomness that drops out of quantum mechanics may just be an indication that our intellectual theories and experimentation have reached a scale below which we cannot interact with the objective universe. Don’t take my word for it; many of the top physicists believe that quantum mechanics is only an approximation to a deeper understanding.
Another pertinent point is that looking at something or measuring it is only one type of interaction at quantum mechanical scales. At atomic scales everything is interacting with its environment and there is a quantum mechanical process called quantum decoherence which is akin to the environment surrounding every atom looking at it all of the time; so from a quantum mechanical viewpoint a tree does exist in some form of reality even if we are not looking at it.
The journalist went for a headline and completely missed the conclusion of this experiment, which re-enforces the view that the science underlying our two views of internal reality are mutually exclusive, and that combining these views to explain experimental observations in the hinterland between them leads to incomprehensible results, meaning we are either missing something, or this is as deep as we can go.
So what of the headline; does reality exist even if we are not looking at it? Sure does; and at least two of them!