The Personal World


The Relative World

The personal world is by no means a new idea. 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 all used to. 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 defined relative to the individual.

Bizarre as it sounds, this has now been demonstrated in a recent leading-edge physics experiment.

Wigner’s Friend

Eugene Wigner was a modest genius who received the Nobel Prize in Physics in 1963. His famous thought experiment became known as the Wigner’s Friend Paradox. Wigner’s friend carries out a quantum experiment, and observes the result. Quantum theory tells us that for Wigner, who is elsewhere, the outcome is not just unknown but physically indeterminate. This has now been confirmed. As physicist Alexander Poltorac writes, Massimiliano Proietti and his colleagues tested the Wigner’s Friend Paradox:

They proved that two contradictory realities could coexist. Eugene Wigner was right; the quantum reality is observer-dependent. (2019)

Observer-dependent means the world is a relative world. But even though this is simply conforming to the fundamentals of quantum theory, the whole idea has been given very little attention. The reason is that it makes no sense, and there is no ‘ontology’, no basic explanation of how this could be. This is the new concept presented here.

The Superworld

The resolution arises in the context of Hugh Everett’s famous many worlds theory. He demonstrates that the great paradox of quantum theory, the ‘measurement problem’, is resolved if all possible worlds exist. This is increasingly accepted.

One of the direct implications of the many worlds is that there are a great many copies of a specific observer in the many worlds. The new idea is very simple. From the subjective perspective of this observer, present in all these worlds all at once, the world is the superposed sum of all of them. This automatically has the properties of a relative world. This is the ontology of the personal world.

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 Wikipedia illustrates the idea very nicely.

Waves on water are superposed
Waves on water are superposed

The principle means that when systems are superposed, the resulting system operates like the sum of the whole. This applies even to solid physical systems because at the quantum level all physical reality is defined by a wave of probability, the ‘wave function’.

So when physical states are superposed, it works just like slides on a projector. This is illustrated with the images of the butterfly below. 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. The same is true of the superposition of worlds. Only what is the same in all the worlds is solid and real.

Superposition of different wing positions
Superposition of different wing positions

This explains the ontology of the relative world. All the objects that the individual perceives are the same in all the worlds in which she exists. So when these worlds are superposed, all these objects are determinate. But for all the objects that have not been observed the opposite is true. Every possible variation of how they could be is included in the superposition. So the net result is the superposition of different (classical) states. In other words, all these objects are all indeterminate.

It is not quite as simple as that which is why this idea has not surfaced before. The individual, the sentient being, is not the same thing as the physical body. Which is why this whole concept has been invisible in physics. The full explanation of this is given in the next section, The World Hologram.