Objective Bayesian Reality 2

of, relating to, or being an object, phenomenon, or condition in the realm of sensible experience independent of individual thought and perceptible by all observers : having reality independent of the mind

The idea of an objective reality is a core assumption of science and has provided much guidance for the development of science. A common theme in the development of science is its move to greater objectivity. We are progressively coming to understand, through our scientific knowledge, that we exist in an independent reality that evolved a huge amount of scientific subject matter before humans existed and that humans are only a natural extension of this reality and are in no way fundamental in shaping it.

Prior to the beginnings of science, as it is understood in a modern sense, dominant world views were largely those of the great religions; revealed through sacred texts and interpreted by a rigid bureaucracy. For the less theistically inclined Platonic philosophy with its focus on an ideal reality unseen by the senses was an alternative as were Aristotelian ideas, eventually morphing into those of the church, that were largely based on a priori ideas concerning the 'natural' state of things and came to be relied upon by reason of authority. More 'scientific' ideas, expounded by Archimedes, had little influence through the end of the middle ages as only few copies of his works existed. Much of his work was only discovered in relatively recent times.

These sources of knowledge of the reality in which we exist down-played the ability of the senses to inform our worldview. Justifications in the battle between the Church and Copernican astronomy, culminating in the prosecution of Galileo, hinged on the assertion by the Church that sensory data was not to be relied upon and that the creator could order things as he wished including the reliability of our sensory information. Of course they reserved for themselves, on the pain of death, the sole right to interpret this arbitrary divine mind.

With the advent of Newtonian scientific understanding in the 17th century a beautiful picture became available to the educated of a helio-centric solar system, accurately predictable from the law of gravitation that applied equally to planets and to objects in our everyday life. This was a giant step involving an understanding that human affairs exist in an objective reality that does not necessarily imbue their situation with special significance. Educated people gained an aesthetically pleasing alternative to believing that they were the central focus of creation and that their home planet was at the center of the universe.

In his twenties Newton became part of a small group of natural philosophers who practised science in a tradition largely established by Francis Bacon. This approach became known as the British Empirical School and stressed the importance of empirical evidence derived from experimentation in support of theoretical explanations. It was a revolutionary change from the authority centric approach which had dominated since the time of the Greeks and the beginnings of scientific speculations. Now evidence rather than authority was considered the best guide to truth.

This movement also heralded a revolutionary change in thinking about objectivity. Explanations, in the form of theories, gained support if they in turn were supported by the evidence. Further along this chain the quality of evidence was judged by its repeatability. To hold any weight observations must be repeatable. That is any individual, given the appropriate setting, must be able to make the same observation as made by any other observer. This consensus amongst a group of individuals concerning the empirical evidence they witness leads to a stronger notion of objectivity and of evidence as an objective fact free from the dictates of authority or subjective interpretation. Here was the beginnings of the understanding that ontological reality must look the same to all observers.

This small group of British investigators, practising empirical methods of investigation founded the Royal Society in 1660 and it continues today as one of the world's most prestigious scientific organizations.

Another huge blow to the remaining anthropocentric components of the scientific worldview was dealt by Darwin with his theory of Natural Selection identifying humans as only one more animal form evolved from common ancestors. This theory was seen by many as threatening human values as it awoke us from our previous shared delusion of being the central purpose of creation. Human being were revealed to be animals created by the same evolutionary process as all other life forms. Yet his views were interpreted by some as adding grandeur to our situation. We are revealed as amongst the most complex of living things. Our involvement in cultural entities is unprecedented and sets us apart from other living things. We are joined to the rest of life and to the wider universe in a natural way. Perhaps this theories greatest gift, was to reveal that the drama of life is most clearly seen in an objective context. A universal process has created us along with all other life forms, it was in full operation long before the existence of humans was even a faint possibility and it will probably continue long after the human species has ceased to exist. To gain understanding of our true situation we must give up the infantile delusion that we are 'special' in the sense of existing outside of natural processes and be open this objective world.

Philosophy, up until the late 19th century had largely been at odds with scientific understanding in general and objectivity in particular. Emmanuel Kant, perhaps the most renowned philosopher of all time, believed that the nature of reality was based on relationships between objects and that what could be known of objects could only be based on our relationship with them and that this excluded the possibility of objective knowledge.

Starting with the works of Ernst Mach in the mid 18th century a new branch of philosophy, the philosophy of science, began to take shape formed mostly from the work of scientists such as Mach who saw science as providing a philosophical vantage point. This work was expanded by the school of Logical Positivists who during the early 20th century challenged previous philosophical understanding with the notion that only those thing that could be measured should have cognitive significance.

This branch of philosophy was tremendously influential on the thinking of the great scientific works of the early 20th century including the theories of relativity and quantum mechanics.

Einstein revered Mach. He digested Mach's thinking and reaped a huge intellectual harvest. He came to understand that objectivity required constraints on scientific law in the sense that all laws must provide every observer with the same predictions regardless of their own particular circumstances. Special relativity provides common predictions for all observers regardless of their own velocity and General Relativity provides common predictions to all observers regardless of their own acceleration. Einstein was led to General Relativity largely through steadfastness to this principal.[ii] The guide of objectivity was so compelling to Einstein that he initially called his theory ‘Invariance Theory’ and only acquiesced when ‘Relativity’ became more widely adopted by Max Planck and others.[iii]

Einstein expressed his objectivity requirements by demanding that valid scientific theories must provide all observers with accurate predictions of what they would measure. This might seem quite human centric but he also made it clear that in his view objectivity extended beyond human experience and measurement. General relativity in particular predicts the behaviour of all mass and energy in response to gravity whether or not there is a human observer present.

As the baffling world of the quantum was being probed and a scientific formalism regarding it developed the dominant interpretational model came to center on the work of Niels Bohr. Bohr understood the quantum world underlying the classical world to be a distinct reality. These two realities are spanned by the process of measurement where quantum phenomena emerge in classical reality. He insisted that quantum reality could only be know through measurement and that it did not make sense to talk of quantum reality in terms other that what could be measured. In this sense his theory was epistemological, about what we can know, rather than ontological, about what is really out there.

Einstein, also one of the founders of quantum theory, had a much different point of view and insisted that any fundamental physical theory must describe an objective ontological reality. Philosopher CP Snow described the ensuing debate: 'No more profound intellectual debate has ever been conducted’.[iv] As described in more detail below perhaps the most persuasive evidence we have today serves to illuminate how they were both correct, Einstein from an ontological viewpoint and Bohr from an epistemological one.

Some variants of quantum theory have supported an anti-objective interpretation of physical reality culminating in that of Wigner’s where human consciousness was proposed as a necessary component of quantum measurement and quantum wave collapse. Even the dominant interpretation of quantum theory with its focus on measurement might seem to give special status to humans and their perspective. The paradox resulting in the requirement that a human measurement is necessary for the resolution of quantum reality was brought to the fore by Erwin Schrödinger in his famous thought experiment that has come to be known as the Schrödinger's Cat paradox. This paradox hinges on the assumption, as implied by quantum theory, that a cat can neither be considered alive nor dead until its state is measured by a human observer.

The century long confusion over the meaning of quantum mechanics, sometimes even abetted by our leading interpretations of scientific theories, concerning the nature of objective physical reality may recently have been largely resolved. The set of axioms underlying quantum theory have been revised and simplified. The most contentious ones, those requiring quantum measurements to produce classical results and that assign probabilities for the competing classical results, have been shown to be implied by the other axioms and therefore unnecessary as separate axioms. Measurement is no longer seen as a fundamental physical process but rather as just one of many types of physical interaction. At the quantum level all physical interactions between the fundamental building blocks of reality may lead to decoherence, the process where quantum effects are recorded in classical reality. Whether these interactions are initiated by a human motivated measurement or by any other natural process is irrelevant. In this sense our new understanding is entirely objective.[v]

A further recent breakthrough in our understanding of objective reality, a direct descendant of Einstein's thinking on 'invariant theory' has been made.[vi] This work details the fact that much of physical law can be derived purely from assuming an objective reality. If scientific law is to describe an objective reality a ‘point of view invariant’ reality, one where accurate predictions concerning the behaviour of all interacting matter and energy are attainable regardless of the particular circumstances of any of the participants, then this constraint is sufficient to derive many of the fundamental components of physical law including: special relativity, general relativity, quantum gauge theories and the symmetry laws.

That these components of physical law are amongst the most accurate and powerful is strong evidence that reality is objective in the sense of point of view invariance.

In some sense this theory of reality brings us full circle back to Kant. All of reality is a web of relationships. The crucial added ingredient is that this web is objective. No entity in the web has a privileged position. We can have objective knowledge of other entities contained in the web through insisting that our knowledge of other entities is no different than that experienced by any other entity. Our experience of an electron must be the same as a proton's experience of an electron; a valid scientific theory of the electron must describe both experiences. It must describe the effects of an electron in an objective reality.

If we accept that reality is at bottom this kind of objective network or web then we must also accept that it was become continuously more complex over time since the 'Big Bang'. It has evolved new hierarchies over time including chemistry, biology and culture. Still none of these newcomers is privileged over the others; each experiences the rest of the web in a common manner.

We should remember that the fundamental interactions consist of physical forces. These interactions determine some of fundamental particles' basic properties such as position, momentum and, in some theories, mass. In some sense we might think of these properties, ingrained in fundamental properties as a kind of rudimentary 'knowledge' of the outside world; that is they contain information concerning other components of the web of reality.

Isolated fundamental particles may be in situations where they seldom interact with other entities in the web. In this case they might be said to experience a limited existence. The lack of interactions experienced and the lack of internal mechanisms for information storage would indicated such particle might be said to have only very limited 'knowledge' of the world around them.

[i] Merriam Webster Online. http://www.merriam-webster.com/dictionary/objectivity

as viewed November 20, 2008

[ii] Isaacson Walter (2008), Einstein: His Life and Universe, Simon and Schuster, ISBN-10: 1416586911

[iii] Klotz Irving (1996), Postmodernist Rhetoric Does Not Change Fundamental Scientific Facts, website http://hps.elte.hu/~gk/Sokal/Sokal/KLotz.html, as viewed January 5, 2009

[iv] Isaacson Walter (2008), Einstein: His Life and Universe, Simon and Schuster, ISBN-10: 1416586911

[v] Zurek W, 2007, Relative States and the Environment: Einselection, Envariance, Quantum Darwinism and the Existential Interpretation, arXiv:0707.2832v1, http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.2832v1.pdf

[vi] Stenger V.J (2006). The Comprehensible Cosmos, 2006, New York: Prometheus Books

History of Objective Science