**Definition: **

The holographic principle is a mathematical principle that the total information contained in a volume of space corresponds to an equal amount of information contained on the boundary of that space. This dependence of information on surface area, rather than volume, is one of the key principles of black hole thermodynamics.

In Brian Greene's 2011 book *The Hidden Reality*, he suggests a tightly-interlocked Holographic Multiverse:

the holographic principle envisions that all we experiencee may be fully and equivalently described as the comings and goings that take place at a thin and remote locus. It says that if we could understand the laws that govern physics on that distant surface, and the way phenomena there link to experience here, we would grasp all there is to know about reality.

The holographic principle was originally developed in 1994 by Dutch Nobel laureate Gerard 't Hooft and (shortly thereafter) by Stanford physicist Leonard Susskind. (Susskind's approach was more directly applicable to string theory, while 't Hooft's was a more general statement of the principle.)

In 1997, this principle was applied by Argentinian physicist Juan Maldacena to develop the anti-de Sitter space/conformal field theory correspondence (AdS/CFT correspondence), which demonstrated a connection between a 5-dimensional anti-de Sitter space (described by string theory) and its boundary, a 4-dimensional space that possesses a conformal field theory (described by a quantum gauge theory).