The personal world is by no means a new idea. Interpretations of this nature began to appear in the 1970s. As they show, this kind of world is the solution to great paradox of quantum theory. In this light the physics works perfectly. This is described in later sections. But although these types of theories solve fundamental problems, they have been generally ignored and sidelined.
The main problem is there is no ‘ontology’, no fundamental explanation. This is the breakthrough claimed in Avant Garde Science. The basis of this explanation is explored in this section of the site.
The Relative World
It is fundamental to quantum theory that there are two competing descriptions of the real physical world. Physicist Lev Vaidman, a specialist in the foundations of quantum mechanics, puts clear definitions to the two types. The first is the ordinary world, as we generally understand it:
A world is the totality of macroscopic objects: stars, cities, people, grains of sand, etc. in a definite classically described state. (2008)
In other words, ordinary real stuff. This is the concept of the world we are all used to. This is called the ‘classical’ view. The other type of world is the personal world, which he calls the ‘relative world’:
In this world, all objects which the sentient being perceives have definite states, but objects that are not under her observation might be in a superposition of different (classical) states. (2008)
In other words, objects not observed are ‘indeterminate’, unreal. It is called the relative world because the world is only defined relative to the individual.
The great debate has been which type of world is the real one. The resolution is that both are real. This is the breakthrough presented in Avant Garde Science.
Many Worlds
Hugh Everett’s famous Many-Worlds interpretation (1957) of quantum theory means that all possible ordinary worlds exist. Half a century later, the multiplicity of reality is increasingly accepted. David Deutsch, a renowned physicist who works on fundamental issues, states this is without question correct:
The point that theorists tend to miss is that the multiplicity of reality is not only, or even primarily, a consequence of quantum theory. It is quite simply an observed fact. (1996)
The great debate is about what these worlds are like.
Copies
The existence of all possible worlds gives rise to some remarkable implications. One of these is the identical copies. In the many worlds, there are a great many identical copies of a specific individual. This is described by prominent cosmologist Max Tegmark in his paper Parallel Universes (2003).
As Deutsch states, these are without question all the same person. Given there are multiple identical copies of me, he asks, which one am I?:
I am, of course, all of them. Each of them has just asked that question, ‘which one am I?’, and any true way of answering that question must give each one of them the same answer. (1997, 279)
The key point is that all the ‘copies’ are just one individual.
In the quantum universe, the many worlds all exist in the same place at the same time, superposed. This is fundamental to quantum theory. So all the identical copies of me are in the same place at the same time. And that would seem to mean that there is actually only one of me.
Superposition
So, all the copies of me are actually me. So I exist in all of these worlds at the same time. And that means that my reality is all of those worlds at the same time. In other words, for me, all those worlds are superposed.
The first question is how can this possibly work? How can worlds be superposed? This is just how quantum systems work.
The superposition principle is fundamental to all physics. A common example is the way waves superimpose, and the result is the sum of the different waves. This image on the Wikipedia page about the superposition principle illustrates the idea very nicely.
The principle simply means that when systems are superposed, the resulting system operates like the sum of those systems.
Quantum Superposition
We can see immediately why this applies to waves on water. But reality itself? It all sounds a bit absurd. But the logic is very simple. At the quantum level, all physical reality is defined by a wave of probability. This image from Wikidoc shows what electrons actually look like. They are tiny waves of probability.
This means that when physical systems are superposed, it works just like the waves on the water. The result is that the real objects are added together, just like multiple slides on an overhead projector.
Firstly, this explains why there is only one of me. If you add two identical images together, you just get the one image.
The same is true of physical objects in the quantum universe.
The Superworld
This principle explains what the world is actually like for me when I am in all those worlds at the same time. This is illustrated with the images of the butterfly with its wings in different positions. The last image is the superposed sum of all the possible wing positions. In this superposition, only the body of the butterfly is the same in all the images, so only the body is solid and definite. The wings are the superposed sum of all the possible variations, so the image of the wings is indefinite.
This is what happens with all the worlds I am in. All the objects and events that I have observed are the same in all the worlds. So when these worlds are superposed, all these objects are determinate, real and solid, like the body of the butterfly. But for everything else, everything that has not been observed, the opposite is true. Every possible variation of how things could be is included in the superposition. So all the things unobserved are indeterminate, like the wings of the butterfly. This is the explanation of the relative world.
In my world, the result of the superposition of all the worlds I am in, the reality is literally the superposition of different (classical) states, just as Vaidman describes. The superposition of worlds gives rise to a world where objects not under my observation are in a superposition of different states.
This is the ontology of the relative world, meaning this is what it is ‘made of’. This is the missing concept that makes sense of the relative world. The relative world is made of ordinary worlds superposed. It is a ‘superworld’.
This has very different properties to the ordinary world. And this is what explains the great paradoxes of the quantum theory, as will be described further on. The next question is who exactly is this me who exists in all those worlds. The answer is described in The World Hologram.