Leonard Susskind, a specialist in quantum cosmology, describes the strange reality of the holographic universe:
The three-dimensional world of ordinary experience––the universe filled with galaxies, stars, planets, houses, boulders, and people––is a hologram, an image of reality cited on a distant two-dimensional (2D) surface. (2008, 410)
This seems utterly ridiculous. This is deeply at odds with everything we intuit about the world. But this is what the physics tells us without question. It seems to mean we are actually like cardboard cutouts of zero thickness. We just think we are three-dimensional.
As stated by the influential theoretical physicist Jacob Bekenstein:
Our innate perception that the world is three-dimensional could be an extraordinary illusion. (2003)
The puzzle of the holographic universe is longstanding. All attempts to find an alternative explanation of the physics have failed. As stated by Lee Smolin, a theoretical physicist and philosopher who specialises in the subject, this is for sure:
… an idea which at first seems too crazy to be true, but which survives all our attempts to disprove it. (2000, 178)
The 2D World
However extraordinary, something major seems to have passed unnoticed in all this. This is exactly the nature of the personal, relative world. So the bizarre paradox that seems so incomprehensible is fully explained.
Only what is observed is determinate, which means that only the observed surface is defined. In other words, the mysterious two-dimensional surface is simply the observed surface, the outer limit of perception. It is not distant, except when one looks up at the stars. But it is two-dimensional. It has no thickness. And it defines the physical reality.
So there is no question the definition of the relative world conforms exactly to the definition of the holographic universe. In other words, the holographic universe is actually the cosmology of the relative world. This is the nature of each personal parallel reality. Here again, this is what has been discovered but not recognised.
The major paradox of the holographic universe is that there is not even such a thing as volume. As Bekenstein describes:
The holographic principle states … that volume itself is illusory and the universe is really a hologram which is isomorphic to the information “inscribed” on the surface of its boundary. (2003, 59)
In other words, there is nothing really there. Whatever the physical reality is, it has no depth. It is just a surface, a two-dimensional artefact. So it is literally unreal in any ordinary physical sense. This is the extraordinary but inevitable implication. As stated by Kostas Skenderis, Professor of Applied Mathematics & Theoretical Physics:
The idea is similar to that of ordinary holograms where a 3D image is encoded in a 2D surface, such as in the hologram on a credit card. However, this time, the entire Universe is encoded. (Beall, 2017)
And this seems like the whole story because nothing more is required to explain the physics that has been discovered. As Bekenstein states:
… physical theory defined only on the 2-D boundary of the region completely describes the 3-D physics. (2003, 63)
2D But Real
But in the relative world there is no mystery. The net effect is a reality with zero depth. But the actuality is the superposition of many ordinary worlds. And each world is a three-dimensional volume of matter and energy. So the personal world has volume because it is ‘made of’ these real ordinary worlds. It is all these worlds at the same time, so, naturally, this superposition is a domain that has volume.
In this light, the holographic universe is fully explained by existing concepts. This is the cosmology of the relative, personal world, determinate only where observed. In other words, determinate only where defined by this 2D surface. This is the nature of the physical environment in which we each find ourselves. And the personal nature of each world is also confirmed by this physics. As cosmologist Raphael Bousso explains:
… for physics to make sense, you must restrict your description of the universe to what a single observer can see (Gefter, 2010)
All this may well be considered as strong evidence for the relative world.
Finally, there is evidence from the precise fit the world hologram makes with The Missing Subject.