Can a 3d holographic universe exist in 3d?

[Suekdccia]

In a holographic universe model, could our 3D universe be encoded in 3D and still be a holographic universe, instead of 3D information encoded in 2D space? Or is the standard model (non-holographic) of the universe already 3d information encoded into 3d space?
https://en.wikipedia.org/wiki/Holographic_principle
https://news.ycombinator.com/item?id=8227177

 

[.Scott]

In a holographic universe model, could our 3D universe be encoded in 3D and still be a holographic universe, instead of 3D information encoded in 2D space? Or is the standard model (non-holographic) of the universe already 3d information encoded into 3d space?

You are calling it a "holographic model". In black holes, maximum entropy scales with the square of the radius. Since the "holographic model" takes this to be a real and inherent limit, it is a model. But really, it is an interpretation. In other words, it is another way of looking at physics that is compatible with other ways - and those other ways are mainstream physics.

The answer to your question is in that first link - the wiki article. It describes where the 2D vs. 3D comes from:

The holographic principle was inspired by black hole thermodynamics, which conjectures that the maximal entropy in any region scales with the radius squared, and not cubed as might be expected. In the case of a black hole, the insight was that the informational content of all the objects that have fallen into the hole might be entirely contained in surface fluctuations of the event horizon. The holographic principle resolves the black hole information paradox within the framework of string theory.

Of course, you can create a 3D holographic interpretation as well. But interpretations are only as good as they are useful.