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CONSCIOUSNESS, BIOLOGY AND FUNDAMENTAL PHYSICS

INTRODUCTION

In writing something of this kind, it is difficult know what level to pitch it at and what degree of detail to bring in. On the one hand, experts in particular fields may ridicule the superficial nature of the description and arguments here, while at the other extreme some would-be readers may find even the opening sentences baffling. I have two recommendations for dealing with these problems. Firstly, I would advocate a pick and mix approach to the offerings here. For instance, those not particularly inclined to wade through user-unfriendly material relative to physics, biology and neuroscience might prefer to go straight to the final section, rather arrogantly entitled 'a theory of consciousness'. This gives the main conclusions as how consciousness arises and its function. If this looks at all interesting it is then possible to go back and see how I have attempted to substantiate the proposals I have made in this section.

The same general approach can be applied to the other chapters, in skipping over things that are either too difficult, or are too well known to need revisiting. There is perhaps a word of caution relative to this approach. The section on physics emphasises the problem areas in quantum physics, which may be played down in more mainstream discussion. The sections on both quantum biology and neuroscience emphasise research work in very recent years that can be argued to have reversed some assumptions that are still common in science and in consciousness studies.

The main inspiration for this attempt at consciousness theory is the ideas of Roger Penrose (1.&.2.) Unfortunately, I have over more than twenty years come to form the opinion that the vast majority of modern consciousness studies is profoundly misguided, and that in time Penrose may come to be seen, as being alone as a deep thinker on the subject, in our rather benighted period.

This book attempts an amendment and simplification of the Orch OR scheme, and also to some extent an updating in line with very recent developments in biology. It is tentatively suggested that a less complex approach to the function of consciousness than that provided by the Gödel theorem can be attempted, and similarly that in the brain, quantum consciousness might be based on shorter-lived quantum coherence in individual neurons, rather than the longer-lived and spatially distributed proposal put forward by Hameroff. The possible need to amend the original concepts are the reason from merely commenting on quantum consciousness topics to outlining a version of the theory.

SECTION 1

THE HARD PROBLEM

Definition: Consciousness is defined here as our subjective experience of the external world, our physical bodies, our thinking and our emotions. Consciousness is also defined in terms of 'being like something' to have experiences. It is like something to be alive, like something to have a body and like something to experience the colour red. In contrast, it is assumed to be not like something to be a table or a chair. Further to being like something conscious also gives us the experience of choice. In philosophy, this opens up the controversial topic of freewill, but at a more mundane level we have the something it is like to choose types of beer, or between a small amount of benefit now or a more substantial benefit in the future. A special characteristic of subjective consciousness is privacy, in the sense that we have no way of knowing that our experience of the colour red is the same as someone else’s, and no way of conveying the exact nature of our experience of redness. These subjective experiences are referred to as qualia. The problem of qualia or phenomenal consciousness is here viewed as the sole problem of consciousness and the whole of the problem of consciousness.

The problem we have to address here is how consciousness, subjective experience or qualia arise in the physical matter of the brain. Even this simple question raises some queries as to whether consciousness does in fact arise from the brain, although the arguments in favour of this position do in fact look strong. The classic argument is that things done to the brain such as particular injuries or the application of anaesthetics can remove consciousness.

The main challenge to the ‘brain produces consciousness’ hypothesis is dualism, or the idea that there is a separation between a spirit stuff and a physical stuff that together make up the universe, with consciousness being part of the spirit stuff, but inhabiting a physical brain and body. This had probably been the most popular idea since ancient times, but it was formalised by Descartes in the seventeenth century. The idea has a certain beguiling simplicity, since at a stroke it gets rid of the need to worry about how the physical brain can produce consciousness, or all the difficulties this gives rise to in terms of biology and physics.

Unfortunately, the problems of dualism appear to be of the serious kind. This is principally the question of how the physical stuff and the spirit stuff can interact. If the spirit stuff is to interact with the physical stuff it would appear to need to have some physical qualities, in which case it would not be true spirit stuff. The same applies in the opposite direction in that the physical stuff would seem to need some spirit qualities to interact with the spirit stuff, and would therefore not conform to conventional physics.

We are thus left with the problem of how the physical stuff as described by science can produce consciousness. The philosopher, David Chalmers (3.), labelled this the ‘hard problem’. The problem here is really a problem of specialness. The brains of humans and possibly animals are the only places in the universe where consciousness has been observed, so the question really is as to ‘what is special about the brain’, and the answer to this tends to be that there’s nothing special about the brain, because it’s made of exactly the same type of stuff and obeys the same physical laws as the rest of the universe. The brain comprises the same carbon, oxygen, hydrogen and other atoms that are found in the stars and planets and the objects of the everyday world around us.

At first sight this might not seem too much of a problem. The brain is considered to be the most complex thing in the universe, and surely something in such a system can manage to produce consciousness. Unfortunately, this does not appear to be the case. In a conventional neuroscience text book, which will emphasise the fluctuation of electrical potential in the neurons (brain cells) and the resulting movement of neurotransmitters between neurons, we are presented with a causally closed information system, which does not require consciousness in order to function, and offers no physical mechanism by which consciousness could be produced.

Since consciousness ceased to be a taboo subject for academic research twenty-or-so years ago, several theories that seek to explain consciousness arising within the confines of classical/macroscopic physics have been advanced. It would take many hundreds of pages to discuss these adequately, so I will here summarise the main ideas, and where they look to fail. For those who find any of them plausible, there is a huge and expanding literature out there working to reinforce these theories.

1.1: CONSCIOUSNESS AS AN EMERGENT PROPERTY
Possibly the most plausible attempt to explain how the brain could produce consciousness within the concepts of classical and macroscopic physics is the idea that consciousness is an emergent property of the brain’s physical matter. Emergent properties are an established concept in physics. The classic example is that liquidity is an emergent property of water. The individual hydrogen and oxygen atoms or their sub-atomic components do not have the property of liquidity. However when the atoms are combined into molecules and a sufficient number are brought together, within a particular temperature range, the property of liquidity emerges.

The problem with the emergent property idea, when it comes to dealing with consciousness, is that where emergent properties do arise in nature, physics can trace them back to the component particles and the forces that bind them. Thus the liquidity of water can be explained by the electromagnetic force acting on hydrogen and oxygen atoms. But in many years of the emergent property idea being promoted by parts of the conventional consciousness studies community, no one has been able to propose a micro scale emergent mechanism in the brain comparable to the explanation of how liquidity emerges from water.

1.2: FUNCTIONALISM
In much of the late twentieth century consciousness studies was dominated by functionalism. This theory proposes that consciousness is a function of the brain's information processing system, and that the biological matter of the brain is irrelevant to consciousness. This means that any system that processes information in the same way as the brain will be conscious regardless of what it is made of. Therefore a silicon computer of sufficient complexity would flip into consciousness at some point, and future systems using still other materials would do likewise. This is because the system, rather than the stuff from which it is made, is seen as being the thing that produces consciousness. The underlying weakness of functionalism is that it does not actually explain the mechanism of how consciousness arises in the brain's systems in the first place, nor how it might physically arise from silicon computers or other machines.

This is a crucial problem regardless of whether the brain or system in question is made of biological tissue, silicon or anything else. It is generally agreed that the computer on the desk is not conscious, but that brains are conscious. The question we are left with is what changes between the computer on the desk and the brain, and similarly between the computer on the desk and any future super computer that might actually become conscious. There may be a vague assumption that more and more of the same initial complexity does it. But the physical world doesn't work like that. The problem of butter not cutting steel is not resolved by adding lots more butter, but by finding something with different properties from butter.

1.3: IDENTITY THEORY
Identity theory is similar in tone to functionalism. It says that consciousness is identical to the brain or at least parts of it. The problem with an identity theory is that it needs to specify a particular object, or more plausibly a particular process in the brain that is physically identical to consciousness. It is not enough to show that the axons of neurons spike, or that there is a gamma oscillation between the cortex and the thalamus, when conscious processing occurs. These things are correlated to consciousness, but that is another thing from saying they are identical to consciousness. The distinction between identity and correlation is crucial here. Thunder and lightning are correlated, but they are not the same physical process, even though they have the same ultimate cause. In contrast, the morning star and the evening star are identical, because they are both names given to the planet Venus, a single physical object. Astronomy has conclusively demonstrated this identity, because the behaviour of a point of light in the morning and evening sky can be completely explained by the behaviour of the planet Venus. However, neuroscience has not demonstrated that the behaviour of any particular physical process in the brain that is identical to, or can completely explain the behaviour of consciousness, as opposed to being merely correlated to it.

In addition to this, more recent neuroscience has at least qualified identity theory. Expositions of identity theory tended to be rather simplistic in applying to the whole brain, while recent neuroscience has demonstrated consciousness as correlated to both particular neuronal assemblies and to single neurons, albeit on a temporary basis with activity correlated to consciousness shifting from place to place in the brain.

1.4: HIGHER ORDER (HOT) THEORIES
The basic idea here appears to be that a level or perhaps levels of the brain observe another level or levels, and the interaction of the two somehow generates consciousness. We are also asked to believe that because one system monitors another it will become conscious. This suggestion bears little relation to the technological world where it is common place for one non-conscious automated system to monitor another and have some automatic response to changes in it, without any requirement for or evidence of consciousness.

1.5: EMBODIMENT AND CONSCIOUSNESS
In the present century, the concept of conscious embodiment has come to the fore. It is suggested that a brain or a computer by itself cannot be consciousness, but the brain and possibly the computer can become conscious when attached to a body or some comparable extension. The recognition of the fact that brain and body are interactive was in itself an advance on twentieth century notions of the brain as an isolated computer, and the body as an automaton incapable of being uninfluenced by the mind. That said, there appear to be two problems with this approach as an explanation of consciousness. Firstly, it carries the rather implausible notion that the body has some consciousness generating process that does not exist in the brain. There is a complete absence of explanation as to what this might actually be. Admittedly, most touch and pain are transmitted from the body to the brain, and visual and auditory inputs to the brain are fed forward to the viscera, but this does not explain why signals going through the body should generate something different from incoming signals through the brain. This theory looks difficult to square with what has now become known about the organisation of brain processing. While the bodily touch and pain can certainly be seen to play a role, it is hard to see why all visual, auditory inputs, and the results of cognitive processing should have to wait on the laborious responses of the viscera, especially as it is the reward assessment areas of the brain that signal the viscera in the first place. If bodily generated emotion were the whole story, the emotional evaluation regions of the orbitofrontal and amygdala would seem to be in a state of suspended activity between sending a signal to the autonomic system and getting signals back from the viscera. In the specific case of rapid phobic reactions in the amygdala, the idea fails completely. Recent expositions of the theory indicate an over emphasis on the body's movement and relations to the external world, perhaps because they are more compatible with this theory, at the expense of the other senses and more especially at the expense of thinking and emotion-related evaluation.

A further objection to this theory is that bodily arousal does not provide a sufficient range of responses to match the range of human emotional responses. Emotional research, which often means animal research, has tended to focus on the easy target of fear, which produces very definite bodily responses, whereas cognitive processing or visual and auditory sensations, not related to immediate danger, can produce a much less marked bodily response, and a wider and subtler range of emotional responses. The more plausible view is that visceral responses are one aspect of many responses that are integrated in the orbitofrontal and other evaluation processes.

Further to this, evolution seems to have altered the response system to visceral inputs when it came to primates. The visceral inputs no longer go via the pons structure in the brain stem, and this is argued to suggest a less automatic response to visceral inputs in humans and primates. It seems more likely that in line with most brain processes, there is a complex feed-forward and feedback between all parts of the system including the viscera and the orbitofrontal. The body-only theory looks to depend on a simple feed-forward mechanism, which is alien to how brain processing functions.

1.6: INFORMATION THEORY AND CONSCIOUSNESS
Attempts to classify consciousness as a form of information can be seen as another attempt to explain consciousness in classical terms. This idea also looks to encounter insuperable problems. There are innumerable examples of information processing and communication that does not involve consciousness, especially when we look at modern technologies. Further to this, we lack a description of a physical process that would distinguish conscious information from non-conscious information.

There is a core difference between information and reality, in that information involves only what we happen to know about something, while a knowledge of reality requires a full description of its make up and a full explanation of its behaviour. The only information available to a hunter gatherer in ancient Africa glancing up at the sun is the intensity of glare and heat and changes in position in the sky of light. It required the complexities of modern science to unravel everything that is involved in the sun producing light, the light getting to our eyes, and the brain states this produces.

1.7: EPIPHENOMENALISM
This theory proposes that consciousness is a by-product of neural processing, which has no function or significance. There are three main problems here. In the first place like some other modern consciousness theories, it is actually a non-explanation. Even if consciousness has no function, we still need to know how it is physically instantiated, and this is never attempted when this theory is proposed. The suspicion is that the proponents of this theory are unconsciously closet Cartesians, with an underlying assumption that consciousness is ‘non-physical’ or ‘immaterial.’ If it can be categorised in this surprising manner it can be dismissed as non-functional, and relegated to a smallest possible footnote in any scientific study. This is contradictory in that the proponents are invariably non-dualists, who believe that there is no such thing as the non-physical.

The second problem is that consciousness has to be linked to the rest of the brain and the physical universe, because the very fact of conscious experience indicates that we are dealing with the reception of some form of incoming signal, and anything receiving incoming signals is likely to be able to emit them in some form of response, which will have physical consequences. Some writers have suggested an escape route here, which allows consciousness a trivial influence. This is feasible up to a point, but hints at problems in defining what is trivial, and would erode the position of the modern orthodoxy that argues for complete determinism and no freewill at all in behaviour.

A further problem for epiphenomenalism is that it conflicts with evolutionary theory. If this by-product consciousness is physical as the scientific paradigm demands, it needs energy to produce and maintain it, and given that the brain is very energy intensive, this could involve quite a large amount of energy. It would be maladaptive for evolution to select for something that ties up energy with no benefit to the organism. It might be argued that neural processing was such that some by-product was essential, but this would require a demonstration that neural processing produces this something else. However, in the physical description of the matter and energy involved in the brain, as described by standard neuroscience, there is no sign of such a process.

1.8: NEW MYSTERIANS
New mysterians or sometimes just mysterians take the view that just as dogs cannot understand calculus, humans will never be able to understand consciousness. This may in the end turn out to be true, but to accept this view as final at this stage in the proceedings seems unduly defeatist. The human mind has proved capable of understanding the mechanisms of the physical universe so far, and it is reasonable to hope that the rather narrow scope of thinking in conventional consciousness studies may not have exhausted all possible explanatory routes.

Where the mysterian approach is advocated there is usually a 'no nonsense' implication that having established this point, consciousness is no longer a threat to a view of the mind that is dominated by classical physics and slightly old fashioned text book neuroscience. On further reflection however the exact opposite is true. Humans have been able to understand the physical law. If they cannot understand consciousness, then consciousness lies outside the physical law or any logical extension to it. This, if anything ever does, opens the sluice gates to the dark tide of the occult, necessitating that consciousness is something akin to a spirit stuff lying outside of, and able to act outside of the physical law.

1.9: IS THE PROBLEM WITH CONSCIOUSNESS STUDIES CULTURAL RATHER THAN SCIENTIFIC?
Much of the scientific, philosophical and psychological community never internalised the revolution in physics that produced quantum theory early in the last century. There seems to be an assurance that this was an abstruse special case that need not bother day-to-day thinking. The theory was more or less censored out of general education and even basic scientific education. In mainstream consciousness studies, there is an apparent determination not to move beyond nineteenth century macroscopic physics, which proposes a billiard ball world, where everything is explained in terms of objects bumping into one another. This is despite the fact that it has been known for a century that this is a convenient approximation for studying the human-scale world, but is not how the underlying physics works.

Neuroscience’s approach to consciousness is even more mired in nineteenth century concepts. The discovery of individual neurons and their connections at the end of that century allowed the idea of the neuron as a simple switch with no further complications to become entrenched. Not long after this discovery, what is sometimes called ‘the long night of behaviourism’ descended on consciousness studies, decreeing that consciousness was irrelevant to behaviour and not a proper subject of study. Although behaviourism as such dropped out of favour in the latter decades of the twentieth century, subsequent theories have sought to justify the same general conclusion by marginalising consciousness. Behaviourism is dead. Long live behaviourism.

In fact, one curious consequence of the functionalist and identity approaches is that much of consciousness studies has paid remarkably little attention to the brain or to advances in neuroscience in recent decades. The assumption has been that all that was needed was a particular system that could run on any material, and there was no need to inquire any further into the detailed biology of the brain. Information about binding and the gamma synchrony or consciousness in individual neurons and the distinction between conscious and non-conscious neural area are footnotes, while the functional role of subjectivity in orbitofrontal valuation is never mentioned, or perhaps not even known about.

1.10: Why 21st century consciousness studies will fail
Consciousness studies has gone off in a different direction from neuroscience. Much of it is dominated by philosophers or psychologists who deal more in abstractions than what is going in the physical brain. In addition, they have tended to see themselves as under-labourers supporting a nineteenth century Newtonian world view, while at the same time discussing consciousness in very abstract terms that take limited account of advances in neuroscience research. Neuroscientists, meanwhile, seem to have been persuaded to treat consciousness as not really part of their remit, and defer to philosophers whenever they felt it necessary to mention consciousness, even when the views of the philosophers appeared to conflict with the neuroscientists recent findings. For this reason, it seems possible to predict that consciousness studies will come to the end of the 21st century without having achieved consensus on a theory that has any useful explanatory value.

1.11: CONSCIOUSNESS AS A FUNDAMENTAL PROPERTY
The above discussions might seem to bring us to an impasse, where we don’t think that consciousness can derive either from separate spirit stuff nor from the material that comprises the brain, the body and the universe. Luckily, there is an escape route from this. Physics does not explain everything. The arrow of explanation heads for ever downwards, but it does at last strike bottom. There is a level beyond which there is no further reduction or explanation. The quanta or sub-atomic particles have properties of mass, charge and spin and are bound by the particular strengths of the forces of nature. These are fundamentals, primitives or given properties of the universe that have to simply be accepted.

If we ask what is the charge on the electron, not what does it do, but what is it, the answer is a resounding silence, because it is a given property of the universe, and comes without explanation. If we had a scientific culture that did not accept that quanta could be electrically charged, and that other quanta could intermediate the electromagnetic force, this might develop into another hard problem like the one we have with consciousness. We would go round and round trying to stick electrical charge on to other and probably macroscopic physical features, or we might even decide, as happens sometimes in consciousness studies, that charge did not really exist, that it was a product of something else or an illusion. No doubt experimental psychologists could devise cunning tests that showed how subjects confabulated the idea of electrical charge.

If we accept that fundamental properties do exist, and that they cannot be explained by other means, and also that it is impossible to explain consciousness in terms of classical physics, then it would seem reasonable to suggest that consciousness is one of this small group of fundamentals. Thinkers such as David Bohm (4.) and Roger Penrose have made such proposals, but the response has been generally hostile, although the reasons for this may be cultural or even metaphysical rather than scientific.

SECTION 2

QUANTUM PROBLEMS & THE NATURE OF SPACETIME

Just having a concept of consciousness as a fundamental of physics is not by any means enough. Fundamental physics may be a possible gate to consciousness, but to substantiate this we need some concept of how consciousness might be integrated into what is known about fundamental physics. In the first place, it might help to have at least a very simplified idea of quantum theory and some recent ideas about spacetime.

Quantum theory is the fundamental theory of energy and matter as it exists behind the appearances of the classical or macroscopic world. Suppose one were to ask for a scientific description of your hand. Biology could describe it in terms of skin, bone, muscles, nerves, blood etc., and this might seem a completely satisfactory description. However, if you were just a bit more curious, you might ask what the muscle and blood etc. were made of. Here you would descend to a chemical explanation in terms of molecules of protein, water etc. and the reactions and relations between these.

If you were still not satisfied, then beyond this you would have to descend into the quantum world. At this level, the solidity and continuity of matter dissolves. The molecules of protein etc. are made up of atoms, but the atoms themselves are mainly vacuum. Most of the mass of the atom lies in a small nucleus, comprised of protons and neutrons, which are themselves made up of smaller particles known as quarks. The rest of the mass of the atom resides in a cloud of electrons around the nucleus.

2.1: THE FORCES OF NATURE
The fundamental particles are bound together by the four forces of nature, which are electromagnetism, the strong and the weak nuclear forces and gravity. The quanta can be divided into two main classes, the fermions, which possess mass and the bosons which convey energy or the forces of nature. In contrast to the nuclear forces, gravity and electromagnetism are conceived of as extending over infinite distance, but with their strength diminishing according to the inverse square law. That is, if you double your distance from an object, its gravitational attraction will be four times as weak. The strong nuclear force binds together the particles in the nucleus of the atom, and acts only over the very short range. Gravity is a long-range force that mediates the mutual attraction of all objects possessing mass. The electromagnetic force, also a long-range force, is perhaps the force most apparent in everyday life. We are familiar with it in the form of light, radio, microwaves and X-rays. It holds together the atom through the attraction of the opposite electrical charges of the electron and the proton. It also governs the interactions between molecules. Van der Waals forces, a weak form of the electromagnetic force is vital to the conformation of protein and thus to the process of life itself.

2.2: Quantum waves, superpositions and a problem of the serious kind.
The quantum particles or quanta are unlike any particles or objects that are encountered in the large-scale world. When isolated from their environment, they are conceived as having the property of waves, but when they are brought into contact with the environment, there is a process referred to as decoherence or wave function collapse, in which the wave form collapses into a particle located in a specific position.

The wave form of the quanta is different from waves of matter in the large- scale world, such as the familiar waves in the sea. These involve energy passing through matter. By contrast, the quantum wave can be viewed as a wave of the probability for finding a particle in a specific position. This probability wave also applies to other states of the quanta such as momentum. While the quanta remain in wave form, they are described as being in a superposition of all the possible positions that the particle could occupy. At the peak of the wave, where the amplitude is greatest, there is the highest probability of finding a particle. However, the choice of position for each individual particle is completely random, representing an effect without a cause. This acausal result comprises the first serious conceptual problem in quantum theory.

2.3: THE TWO-SLIT EXPERIMENT
The physicist, Richard Feynman, said that the two-slit experiment contained all the problems of quantum theory. In the early nineteenth century, an experiment by Thomas Young showed that when a light source shone through two slits in a screen, and then onto a further screen, then a pattern of light and dark bands appeared on the further screen, indicating that the light was in some places intensified and in others reduced or eliminated. Where two waves of ordinary matter, for instances waves in water, come into contact an interference pattern forms, by which the waves are either doubled in size or cancelled out. The appearance of this phenomenon in Young's experiment demonstrated that light had the characteristics of a wave.

2.4: The experiment refined
Later, the experiment was refined. It could now be performed with one or two slits open. If there was only one slit open, the photons or light quanta, or any other quanta used in the experiment behaved like particles. They passed through the one open slit, interacted with the screen beyond, and left an accumulation of marks on that screen, signifying a shower of particles rather than a wave. But once the second slit was opened, the traditional interference pattern, indicating interaction between two waves, reappeared on the screen. The ability to generate the behaviour of either particles or waves, simply according to how the experiment was set up, showed that the quanta had a perplexing wave/particle duality.

It could seem that the best way to understand what was happening here was to place photon counters at the two slits in order to monitor what the photons were up to. However, as soon as a photon is registered by a counter, it collapses from being a wave into being a particle, and the wave-related interference pattern is lost from the further screen. The most plausible way to look at it may be to say that the wave of the photon passes through both slits, or possibly that it tries out both routes.

2.5: There was worse to come
The wave/particle duality was shocking enough, but there was worse to come. Technology advanced to the point where photons could be emitted one-at-a-time, and therefore impacted the screen one-at-a time. What is remarkable is that with two slits open, but the photons emitted one-at-a-time, the pattern on the screen formed itself into the light and dark bands of an interference pattern. The question arose as to how the photons emitted later in time 'knew' how to arrange themselves relative to the earlier photons in such a way that there was a pattern of light and dark bands. The ability of quanta to arrange themselves in this non-random way over time, despite initially choosing random positions, could be considered to be the second big problem of quantum theory.

2.6: QUANTUM ENTANGLEMENT
Einstein disliked the inherent randomness involved in the collapse of the wave function. This was despite himself having contributed to the foundation of the quantum theory. He sought repeatedly to show that quantum theory was flawed, and in 1935 he seemed to have delivered a masterstroke in the form of the EPR (Einstein, Podolsky, Rosen) experiment. At the time this was only a 'thought experiment', a mental simulation of how a real experiment might proceed, but in recent decades, it has been possible to perform this as a real experiment.

Two quanta that have been closely connected can be in a state where they will always have a particular relationship to one another. This is known as being entangled. For instance, electrons have a property of spin, and can have a state of spin-up or spin-down. Two entangled electrons can be in a state where their spin will always be opposite. This applies however distant they become from one another. However while the electrons (or other quanta) are in the form of the wave both electrons are superpositions of spin-up and spin-down, so entanglement only really manifests itself when there is decoherence or wave function collapse.

The EPR experiment proposed that two quanta, which have remained sufficiently isolated from their environments to be conceived as waves or superpositions, are moved apart from one another. This could be a few metres along a laboratory bench or to the other side of the universe. The relevant consideration is that the two locations should be out-of-range of a signal travelling at the speed of light, within the timescales of any readings that are taken.

Both particles are a superposition of two possible states, but if an observation is made on one of the particles, its wave function collapses, and it acquires a defined spin, let's say spin-up in this case. Now when an observation is made on the other particle, it will always be found to have the opposite spin. This defies the normal expectation of classical physics that a random choice of spins would produce approximately 50% the same spin and 50% different. Therefore, there is seen to be some non-local connection between the two particles, although it is not possible to describe or detect this in terms of a physical transfer of energy or matter. In fact, the entanglement influence is shown to be instantaneous, whereas energy and matter are thought to be constrained by the speed of light. This quantum relationship between particles is called entanglement, and can be regarded as the third big problem in quantum theory.

2.7: QUANTUM INTERPRETATIONS
Recent debate suggests that the different interpretations of quantum theory are becoming more distinct and more entrenched, rather than showing any sign of moving towards any kind of consensus (5.). In particular, six types of approach are distinguished, [1.] Everett many-world theories [2.] Post-Copenhagen theories based only on our information about quantum states.[3.] Coherence remains with hidden superposition within macroscopic objects. [4.] Bohmian type pilot-wave theories, [5.] wave function collapse theories. [6.] The suggestion that none of these are satisfactory, and that quantum theory will only be explained in terms of a deeper level of physics.

The interpretation of quantum theory has an unhappy history. In the 1920s there was for a short time a unity of purpose in trying to both understand and apply quantum theory. Thereafter a premature notion that the interpretative debates had been settled took hold, and in the period after World War II academic institutions discouraged foundational research. The physicist, AntonyValentini, argues that quantum theory got off to this bad start, because it was philosophically influenced by Kant's idea that physics reflected the structure of human thought rather than the structure of the world. The introduction of the observer into physics allowed a drift away from the idea of finding out about what existed and also how what existed behaved. It was not until the 1970s and 1980s that new interpretations of quantum theory started to become academically acceptable.

The philosopher, Tim Maudlin, contrasts two intellectual attitudes in the approach to quantum theory. Einstein, Schrödinger and Bell wanted to understand what existed and how it worked, while many who came after them were more incurious, and happy with a calculational system that worked, giving the so-called 'shut up and calculate' approach. Maudlin suggests that what is traditionally referred to as the 'measurement problem' in quantum theory is really the problem of what is reality. He sees the aim of physics as being to tell us what exists and the laws governing the behaviour of what exists.

Maudlin argues that quantum theory describes the movement of existing objects in spacetime, while the wave function plays a role in determining how objects behave locally. He suggests that there are many problems for theories that deny the existence of real objects or the reality of the wave function. Lee Smolin, a physicist at the Perimeter Institute, remarks that bundles of ideas in quantum theory and related areas tend to go together. Believers in Everett many worlds tended to also support strong artificial intelligence, allowing classical computers to become conscious, and also support the anthropic principle. Disagreement with these three ideas also seems to go together.

2.8: Everett many-worlds
The philosopher, Arthur Fine, puts the fashionable 'many worlds' theory, originally proposed by Everett, at the bottom of 'anyone's list of what is sensible'. He criticises proponents of the theory for concentrating on narrow technical issues rather than thinking about what it means for universes to split. I think the difficulty of many worlds is even greater than Fine's suggests. The splitting of worlds demands that huge number of new universes are coming into existence all the time, thus apparently suggests that the energy of entire new universes is being created the whole time. Explanations never seem to go beyond asserting that this is, for some reason, not a problem. Christopher Fuchs, another Perimeter Institute physicist, criticises philosophers who support the Everett theory for not looking for some physical explanation. The theory did not receive much support when it was originally propounded in the 1960s. The current popularity may look like an attempt to preserve classical assumptions, even at the cost of asserting a fantastical sci-fi idea.

Continued in Online Book 2