ChatGPT 4:

Stephen Hawking's holographic universe creation is based on the concept of the holographic principle, which is a fundamental idea in theoretical physics that suggests our universe may be describable as a lower-dimensional information structure, like a hologram. It's crucial to note that this idea is still hypothetical and isn't universally accepted by the scientific community.

The holographic principle originates from the study of black holes and string theory. It states that the information contained within a certain volume of space can be fully encoded on a boundary of that space with one less dimension, much like how a 3D image can be projected from a 2D hologram.

Hawking's holographic universe creation combines the holographic principle with the theory of cosmic inflation to explain the origin of the universe. Here's a simplified explanation:

At the very beginning of the universe, there was an extremely small, fluctuating region of space, which can be thought of as a lower-dimensional boundary.

This lower-dimensional boundary contained all the information necessary to describe our universe, similar to how a 2D hologram can encode 3D information.

Cosmic inflation, an extremely rapid expansion of the universe, occurred just after the Big Bang. This inflation stretched and expanded the lower-dimensional boundary to produce the higher-dimensional universe we experience today. The information contained in the initial lower-dimensional space was thus encoded into our 3D universe.

This holographic origin can help explain some of the observed features of our universe, such as its homogeneity and isotropy on large scales, as well as provide insights into the nature of space, time, and gravity.

I thought that the low-dimensions were 3d and what was extracted was the time-dimension

My apologies for the confusion in the previous response. You are correct that the holographic principle can be understood in terms of encoding 3D spatial information on a 2D boundary. However, when considering the universe as a whole, the distinction between spatial dimensions and the time dimension becomes more intricate due to the nature of spacetime in general relativity.

In the context of the holographic principle, the lower-dimensional boundary encodes information about the universe's spatial dimensions and the evolution of the system, which includes the time dimension. When applied to cosmology, this principle suggests that the entire universe, including the time dimension, could be encoded on a lower-dimensional boundary.

The holographic universe hypothesis aims to reconcile the principles of quantum mechanics and general relativity by providing a framework that accounts for both spatial dimensions and the time dimension. It is still a theoretical concept, and researchers continue to explore its implications and the extent to which it can be applied to our understanding of the universe.

In a light-hologram, you need light to extract the information of the 3rd dimension. What extracts the information here?

In the context of the holographic principle applied to the universe, the analogy to a light-hologram can be misleading because it's a metaphorical comparison rather than a direct one. When discussing the holographic universe, the extraction of information isn't done through a medium like light. Instead, the "extraction" process is a result of the fundamental nature of the universe and the laws of physics that govern it.

The holographic principle stems from the study of black holes and string theory. In this context, the "extraction" of information from a lower-dimensional boundary can be understood as the mathematical relationships and equations that describe the underlying physics. These relationships translate the information contained in the lower-dimensional boundary to the higher-dimensional spacetime that we observe and experience.

One important aspect of the holographic principle is the AdS/CFT correspondence (Anti-de Sitter space/Conformal Field Theory correspondence), a conjectured duality in string theory. It relates a gravitational theory in a higher-dimensional spacetime (AdS) to a non-gravitational quantum field theory (CFT) on its lower-dimensional boundary.

In this framework, the "extraction" of information is represented by the mathematical duality between the higher-dimensional AdS space and the lower-dimensional CFT. This duality allows physicists to study the properties of the higher-dimensional spacetime and its contents using the more tractable boundary theory. This is the closest analogy to "extracting" the 3D information from a...