Many Minds

Many Minds

Overview provides a general introduction to the technical basis of the extraordinary significance of the individual. In this page the history of this kind of approach is briefly addressed.

As you might be thinking, this is way too simple an explanation to have not occurred to the physicists who work in the field, some of the smartest people in the world. It has. The seeds of such ideas have been present in our culture for at least thirty years. This is a form of ‘many minds’ theory. As the mathematician and philosopher Matthew Donald states:

Many-minds interpretation of quantum mechanics extends the many-worlds interpretation by proposing that the distinction between worlds should be made at the level of the mind of an individual observer. (1998)

Naturally, it is not difficult to see why the physics community have not been inclined to take this idea seriously. What has mind got to do with objective physical reality? Obviously nothing. On the other hand, it is true that this resolves the great paradoxes of the quantum theory. Just as the QBism world resolves all the problems, if the world is only determinate where defined by the information in the brain of the observer, the famous measurement problem does not arise. Above all, however, there has been no explanatory principle, no reason why this should be the case. But now there is. As explained in Overview, the inside view of the individual is present in a great number of worlds, and the result is the world superposition. In order to properly understand all this we need to begin with the famous many worlds theory of quantum mechanics.

Many Worlds

Hugh Everett’s famous many-worlds theory provides a solution to the longstanding difficulty at the centre of quantum mechanics, the ‘collapse of the wave function’. The wave function is the fundamental definition of the physical world. As described in The Wave Function, it defines all possibilities. This is the nature of the basis of all modern physics. As we find ourselves in one very specific version of the world, and only very specific versions of events are observed, it is clear that this is not the whole story. There has to be a ‘collapse dynamics’ also. This was the original interpretation of quantum mechanics put forward by Bohr in the early days of the theory, the Copenhagen interpretation

Everett’s theory is deceptively simple: there is no collapse; but there is the appearance of collapse. In this case, if there is no collapse, then all possible versions of events get played out. And this means that all possible versions of the world come into being. This is where the Many Worlds concept originally came from in physics. The picture below, gratis Max Tegmark, illustrates this idea with Bob asking Alice out. She may say yes or no. The Schrödinger wave equation tells us that both possibilities exist, in physical reality. She says yes in one version of reality and no in another version. If there is no collapse, then both possibilities happen. Effectively therefore, the world splits in two, and both versions exist.

quantum_cartoon

That is where the many worlds concept originally came from, but this was far too strange to be even considered at the time. The whole thing was automatically rejected. Nowadays, however, it is increasingly accepted something of this nature is inevitable. (An excellent article, 100 Years of Quantum Mysteries by John Wheeler and Max Tegmark, includes a description of this progression,)

The problems arise in the details. It has not been possible to explain exactly what is happening here. Everett essentially states that only in experience are there separate realities. Since experience cannot be relevant in physics it is assumed that he was referring to the experience of some physical process. But in that light it has not been possible to make sense of this idea, or to solve the great paradox of quantum theory, the measurement problem. The resolution in the light of logical type is given in Measurement Problem.

Making Observations

In order to see exactly what he did mean we need to go into a bit of detail about the theory. His concept centres on the technical process of making an observation. We are constantly observing all the things in reality we can see and hear. The human body uses the sensory apparatus, the eyes, ears and so on, to detect the sights and sounds of the world. And the neural system of the brain turns all this information into a visual image. Right now you are experiencing a visual image, a view of reality, specifically some words in black on a white background. That is simply the information, in the form of an image, that you are actually experiencing ‘in here’. The brain produces the visual representation ‘in here’ of the reality ‘out there’. This, of course, is simply how we formulate the world hologram, and thus get to experience the real world.
The brain records this image in memory. This is the process that Everett defines as the making of an observation: an observation is made when this sensory experience is recorded in memory.
The final, key component of his theory is the ‘state of the memory’. This is defined as the record of all of the observations that have been made. So the state of the memory is the sum total of all the sensory information that gets experienced and recorded in memory. This is the total record of one’s sensory experience. This is the world hologram described in The World Hologram.
Now for the bit that gives rise to all the difficulty. This is what he actually says in his conclusion. When the observer interacts with the environment, and an observation is made, the result:

… is a superposition of states, each element of which assigns a different state to the memory of the observer. (1957, 462)

In other words, the physical reality itself does not split as shown in the picture above. Instead, the physical reality is literally the superimposed sum of both situations at once, as in this picture.

quantum_cartoon both

That is the superposition. Nonetheless, the state of the memory – the definition of the experience of reality – is different in each element of the superposition. Thus in the experience of reality, in each element of the superposition, there is just one specific outcome, and just one version of reality, as shown in each branch of the first picture. In other words, physical reality works like picture 2, but experience works like picture 1.

This is Everett’s solution. Although in physical reality, both of the different possible outcomes are superimposed – so there is no collapse of the wave function – in each element of the superposition, it appears that the possibilities have collapsed to a single physical actuality. The problem is this seems to make no sense. How can the experience of the physical world be different to the physical world? He is saying that it is in experience, and only in experience, that different, discrete versions of the physical world exist.

In the current scientific worldview this sounds like complete nonsense. So the obvious assumption is that is not quite what he actually meant. But this is exactly what he meant; he actually states that the state of the memory is definite and specific while the physical reality in which this information is instantiated is not, as quoted above. This is the central point of his theory. And to understand his theory in this way is nothing new. This is the position of the various many-minds interpretations of quantum mechanics.

The Mind

There are two central points to be made here. The first is that the mind has to be defined in such a way as for this to make sense. The second is that an explanation has to be found of why the world of the mind should be different from the world of the body.

Nowadays the mind is considered to be simply and solely an operational property of the body. The mind is the information processing system of the neural network, the operating system of the body if you like. So this entity is here referred to as the body-mind, just as the duple space-time is now used in physics. This is the observer in physics, and Everett gives a very precise definition of the observer.  The observer is the mechanism that makes observations, taking the information from the sensory apparatus, and recording it in memory. It is the product of this process, the state of the memory, the integrated synthesis of the record of observations, that we are interested in here. This is the perceptual reality, the world hologram. This is the inside view. So mind is not a very useful term here, primarily because it lacks a proper definition in the physics. The whole situation is more correctly called a ‘many perceptions’ theory, which is exactly what it is called by physicist Don Page (2011). As he states: “I regard the basic conscious entities to be the conscious experiences themselves”.