The superposition of worlds is a completely different kind of thing to the ordinary world of the current paradigm, and the concept of logical type enables us to understand this clearly. The principle of logical type was discovered by Bertrand Russell (1908). It was the solution he discovered to a certain type of paradox in logic now known as Russell’s Paradox. Most of the existing articles about logical type focus on this rather obscure aspect of formal logic, but the principle itself is very simple. It is just that a set of things is a completely different kind of entity to any one of those things, the elements of the set.
A movie film is simply a sequence of still images, but a movie is of course a completely different kind of thing to the still image of a single frame. The frame is of the first primitive logical type, and the movie, the set of frames, is of a second logical type. The movie projector is a different kind of thing again. It iterates the frames of any and all movies. It is thus of the class of all possible sets of frames, of a third logical type. As Russell showed, ignoring this kind of difference inevitably leads to paradox and nonsense results. This is essentially the problem with the great paradoxes of the new physics.
QBism resolves the paradoxes of quantum theory, but leaves the fundamental question unanswered. Why is the world of each individual determinate only where observed? In the reality of the superposition of worlds the answer is self-evident, as explained in World Superposition. Once this is established, the other great paradoxes of the new physics dissolve. In quantum theory the great paradox of the measurement problem is simply explained. The collapse dynamics is a process taking place at a different level of logical type to the ordinary physical world. Collapse happens on observation, as originally maintained by the pioneers of quantum theory, because the making of an observation changes the basis on which the world is defined. This alters which worlds are included in the superposition of worlds defining the physical reality of the subject.
In principle the reality of the world of each person works exactly like a movie. Each version of the world hologram is one frame that gets experienced at that specific moment. The sequence of these experiences is the experience of reality, but the crucial point is that each one exists in a different moment, meaning a different version of the physical world. That is what gives rise to the effective collapse of the wave function.This is a phenomenon of a completely different logical type to anything in an ordinary physical world. Nothing like this can possibly happen in an ordinary physical reality, which is why it all makes no sense in the current paradigm.
When it comes to the paradoxes of relativity, logical type is absolutely central. Weyl states that consciousness passes from moment to moment in the static layout of space-time. This is how the frame of reference of experience passes from one moment to the next and the next in the static four-dimensional block universe defined by modern physics. He is essentially saying that consciousness is to physical reality as the projector is the movie. This is necessarily a phenomenon of the third level of logical type, the iterator of all possible sets of moments in all possible worldlines. This is logically required by the experience of the passage of time and the phenomenon of the Now. This is simply what reality is like in the moving frame of reference of consciousness.
In quantum theory, the second logical type is required, both to explain the surreal significance of observations, and how the collapse dynamics actually comes about in effect. QBism states that only what is observed is determinate, but in the current paradigm this is just nonsense because it cannot make sense. The world is defined by physical reality, and physical reality is an ordinary world. So things getting observed and experienced can only be a subsidiary property of the physical world. Therefore observation cannot define the physical world – it is the physical world that defines observations, not the other way around. This is the simple truth of the outside view. But of course the inside view is completely different. This is a truly massive leap because the thing that is different is the definition of the matter and energy of the world. As explained in World Superposition, the world of the inside view is the product of the superposition of a great number of ordinary worlds. It is a second logical type phenomenon, and quite outside the standard ontology. In relativity, the moving frame of reference can only be a property of the universe as a whole, a completely different kind of thing again. As explained in Universe Consciousness, it is a phenomenon of the third logical type. Thus there are three fundamental ontological categories, not just one. It is a vast leap, a conceptual revolution of epic proportions once the implications are added in as well.
Given all this, it is very easy to understand why the new paradigm has been invisible. The world-view of modern science addresses only one fundamental category of existence because this seems obviously the primal essence of the real world. In physics, perfectly naturally, there is only what exists as matter and energy. And this is the fundamental category, the ontology, out of which all is built and from which all properties of the real physical world are derived. But in order to make sense of the reality that is actually encountered, three fundamental categories have to be addressed.
The great paradox of quantum theory is automatically resolved. As Everett states, there is only the appearance of the ‘collapse of the state vector’. What is happening is that as each observation is made, this alters the record of observations, which is what defines the indeterminacy of the physical world of this individual. So as this changes, effectively, the determinacy of the physical world of this individual changes. But this happens, can only happen, at the second level of logical type. All the matter and energy of the world, all the primitive first logical type components of physical reality, cannot change in this way. There can be no change of the quantum state. The only way for change to be encountered is for the frame of reference of the perceiving subject to change. Which is what happens – in experience. The great paradox of relativity is solved by the third-logical-type phenomenon, the consciousness that is to the moments of reality as the projector is to the frames of the movie film. This not only explains the passage of time and the now. It explains how the quantum mechanical dynamics come to be enacted, again, in experience and there alone. This is what breathes fire into the equations to echo Hawking’s famous quote.