The holographic universe is the idea that everything inside a region of space can be fully described by information stored on that region's boundary, the way a flat hologram encodes a three-dimensional image. In physics this is the holographic principle, proposed by Gerard 't Hooft in 1993 and developed by Leonard Susskind in 1995; it is a statement about how much information space can contain, not a claim that the world is a projection or an illusion. Popular versions, from Michael Talbot's 1991 book to simulation theory, go further than the physics does, and Billy Carson's Fractal Holographic Universe is his own synthesis within that wider conversation.
It matters because the question sits where three things meet: what reality is made of, whether the mind is part of the description, and whether the ancient claim that the small mirrors the large speaks to modern physics. Separating the established from the conjectural is the only way to take any of it seriously. The [holographic universe topic hub](/topics/holographic-universe) collects the rest of the site's coverage.
Where the holographic idea comes from
The holographic principle grew out of black-hole thermodynamics in the 1970s, not out of holography or mysticism. In 1972 and 1973 Jacob Bekenstein argued that a black hole must carry entropy proportional to the area of its event horizon rather than to its volume. Stephen Hawking's 1974 and 1975 work on black-hole radiation fixed the constant, giving the Bekenstein–Hawking formula: entropy equals one quarter of the horizon area in Planck units.
In ordinary physics entropy scales with volume; for a black hole it grows with the surface, as if the whole interior were accounted for by a thin layer on the horizon. Bekenstein then proposed a bound: no region can hold more information than a black hole of the same size, so the maximum information in any region is set by its boundary area.
The hologram, which stores a three-dimensional scene on a flat plate, was the obvious metaphor. The comparison is exact in one respect, that the information lives in one fewer dimension than the thing described, and loose in every other: nothing in the physics says the world is "really" flat or that anything is projecting it.
What the holographic principle actually says
The holographic principle says that the physics inside any region of space can be described completely by a theory living on that region's boundary, with no more than one bit of information per four Planck areas. 't Hooft stated the idea in a 1993 paper, "Dimensional Reduction in Quantum Gravity." Susskind gave it its name and sharpest form in "The World as a Hologram" in 1995.
Three points keep the principle honest. It is a bound on degrees of freedom, derived from gravity. It is a claim about description, not perception: two equivalent descriptions of the same physics do not make either one an illusion. And it was born from the black-hole information paradox, the argument between Hawking and, on the other side, Susskind and 't Hooft over whether information that falls into a black hole is destroyed. None of it refers to consciousness or observers, and any article claiming physicists have proven the universe is a hologram has left the physics behind.
AdS/CFT: the one case where it has been worked out
The holographic principle became more than a conjecture in 1997, when Juan Maldacena found a concrete example of it. His paper "The Large N Limit of Superconformal Field Theories and Supergravity" proposed the AdS/CFT correspondence: a theory of gravity in a particular curved spacetime, anti-de Sitter space, is exactly equivalent to a quantum field theory without gravity on that spacetime's boundary, in one fewer dimension.
It is among the most cited papers in physics because it translates hard gravitational questions into tractable field-theory ones, and it has held up across thousands of calculations. It is the strongest evidence that holography is a real feature of nature rather than an analogy.
The catch is the setting. Anti-de Sitter space has negative curvature and a boundary at infinity; the universe we observe is expanding and closer to de Sitter space, which has no such convenient boundary. Whether a version exists for a universe like ours is an open problem: holography is exactly true in a toy universe that resembles ours only in part, and most physicists expect some form of it to hold in general.
Has the holographic universe been tested?
No experiment has confirmed that our universe is holographic, and the one direct test so far came back negative. Craig Hogan's Holometer at Fermilab, a pair of laser interferometers, looked for a Planck-scale jitter that one model of holographic spacetime predicted; in 2015 it reported no such noise at the sensitivity reached. That ruled out one model, not the principle, which makes no unique prediction about jitter.
On the cosmological side, a 2017 paper by Niayesh Afshordi, Kostas Skenderis and colleagues in Physical Review Letters argued that certain holographic models of the early universe fit the cosmic microwave background about as well as standard inflation, which is consistency, not confirmation. The state of play is a theoretical result with strong support from AdS/CFT, treated as a serious constraint on quantum gravity, and no observational proof.
Talbot, Bohm and Pribram: the popular holographic universe
The phrase "holographic universe" entered popular culture through Michael Talbot's 1991 book of that name, which drew on two earlier thinkers and went well beyond both. The first was David Bohm, the physicist who proposed in Wholeness and the Implicate Order (1980) that the visible world unfolds from a deeper enfolded level he called the implicate order, with the hologram as his image for how the whole is present in every part. The second was Karl Pribram, the neuroscientist who argued from Languages of the Brain (1971) onward that memory is stored in a distributed, hologram-like way. Talbot combined them into the proposal that the brain is a holographic interpreter of a holographic universe, then extended it to psychic phenomena, near-death experiences and mystical states.
Talbot's book predates 't Hooft and Susskind and is not about the holographic principle. Bohm's implicate order is a philosophical interpretation of quantum mechanics that most physicists do not use; Pribram's holonomic brain theory is a minority position in neuroscience. Both are serious ideas, but they belong to a different lineage from the one that runs from Bekenstein to Maldacena; the shared word "hologram" is the main thing connecting them. The [consciousness topic hub](/topics/consciousness) covers the Bohm and Pribram strand in more depth.
Is the holographic universe the same as simulation theory?
No. The holographic principle says information is stored on boundaries; simulation theory says reality is computed by someone. Both suggest the world as experienced is not the deepest level of description, and there the resemblance ends.
The modern form of simulation theory is Nick Bostrom's 2003 paper "Are You Living in a Computer Simulation?" in Philosophical Quarterly. Bostrom did not claim we are simulated; he argued that one of three statements must be true: civilisations almost never reach the stage where they could run ancestor simulations, those that do almost never choose to, or we are almost certainly living in one. It is a probability argument, not physics.
Holography needs no simulator and no outside; a person can accept one idea and reject the other without contradiction. Where the two genuinely touch is the view that information is fundamental, John Wheeler's "it from bit," and that is the ground on which Carson builds.
What a fractal has to do with it
A fractal is a shape that looks similar at every scale of magnification, and it is the third ingredient in Carson's model alongside holography and consciousness. Benoit Mandelbrot named the concept in The Fractal Geometry of Nature (1982), showing that coastlines, clouds, branching trees, blood vessels and the distribution of galaxies are self-similar over a range of scales.
Self-similarity is a real, well-measured property of many natural systems, but it is not the same thing as holography: a hologram fragment reconstructs the whole image at lower resolution, while a fractal part resembles the whole. Popular writers, Carson among them, treat the two as pointing at one underlying pattern; mainstream physics treats them as separate topics. The idea that the part reflects the whole is also far older than either. It is the central maxim of the Emerald Tablet, which is where Carson enters the story.
Billy Carson's reading
Billy Carson's position, set out in his book Fractal Holographic Universe, is that reality is self-similar across every scale, from the subatomic to the galactic, and that consciousness is not a product of matter but the substrate from which matter and space unfold. In his synthesis the holographic principle, fractal geometry and Bohm's implicate order are three modern descriptions of a structure the Hermetic tradition described first.
The anchor for that claim is the Emerald Tablet, the short Hermetic text whose earliest surviving versions are in Arabic from around the eighth or ninth century. Its best-known line, in Isaac Newton's translation with modernised spelling, reads: "That which is below is like that which is above, and that which is above is like that which is below, to do the miracles of one only thing." Carson, who commented on the text in his Compendium of the Emerald Tablets, reads "as above, so below" as a literal statement about the architecture of the cosmos: a fractal, holographic universe in which every part carries the pattern of the whole. The [Emerald Tablets topic hub](/topics/emerald-tablets) covers the text, its history and Carson's commentary.
Carson goes further than the physics on consciousness. He argues that the observer is essential to the holographic description, drawing on interpretations of quantum mechanics that give measurement a central role; the post on [quantum superposition and its impact on our understanding of reality](/quantum-superposition-and-its-impact-on-our-understanding-of-reality) covers the experiments behind that debate. A more speculative strand, covered in the post on [a quantum theory that argues death is not the end for consciousness](/a-quantum-theory-proves-that-death-is-not-the-end-for-our-consciousness), presents Robert Lanza's biocentrism, the view that consciousness creates the physical world and therefore survives the body. Biocentrism is a philosophical proposal, not a result of quantum physics; the interpretations it relies on are contested, and no experiment shows that consciousness is a quantum field. Carson's model draws on the same intuitions, but the physics does not support the stronger claims.
Framed fairly, Carson's contribution is a synthesis rather than a theory in the scientific sense: a genuine result in quantum gravity, a genuine property of complex systems and a genuine ancient text, proposed as three views of one thing. Its appeal is that it gives the Hermetic maxim a modern vocabulary; its limit is that it cannot be tested the way AdS/CFT can. He presents it as a framework for thinking about reality and the self, and that is how to read it.
Watch, read and go deeper
Carson develops the model at length in Fractal Holographic Universe, the primary source for his position. On 4BK TV, [Carson Codex](/watch/carson-codex) is the show where he works through the links between physics, consciousness and the ancient texts. For the source text behind "as above, so below," start at the [Emerald Tablets hub](/topics/emerald-tablets); for the wider debate on mind and matter, the [consciousness hub](/topics/consciousness) gathers the coverage of Bohm, Pribram and biocentrism. Everything on this subject is indexed at the [holographic universe hub](/topics/holographic-universe).
Frequently asked questions
Is the universe really a hologram?
Not in the sense of a projection. The holographic principle says the information in any region of space is limited by the area of its boundary, and in one special case, AdS/CFT, a gravitational universe is exactly equivalent to a boundary theory. Whether our own universe has such a description is open and untested.
Who came up with the holographic universe theory?
The physics version grew from Bekenstein and Hawking's work on black-hole entropy in the 1970s, was proposed as a principle by Gerard 't Hooft in 1993 and Leonard Susskind in 1995, and was made concrete by Juan Maldacena's AdS/CFT correspondence in 1997. The popular version is Michael Talbot's 1991 book, drawing on David Bohm and Karl Pribram.
What is the difference between the holographic principle and simulation theory?
The holographic principle is a result in quantum gravity about where information lives; simulation theory, in Nick Bostrom's 2003 form, is a probability argument that we may be inside a computation run by an advanced civilisation. The two are independent.
What does "as above, so below" have to do with the holographic universe?
The line comes from the Emerald Tablet, a Hermetic text known from Arabic sources of roughly the eighth or ninth century. Billy Carson reads it as an early description of a fractal, holographic cosmos in which every part carries the pattern of the whole; historians of alchemy read it as a cosmological maxim without a modern physical meaning.
Does the holographic universe prove consciousness survives death?
No. Claims that quantum theory proves consciousness is an immortal field come from Robert Lanza's biocentrism, a philosophical position, not from the holographic principle or any experiment. Billy Carson's model treats consciousness as fundamental, but he presents that as his interpretation; the physics does not settle the question either way.
Sources and further reading
- Gerard 't Hooft, "Dimensional Reduction in Quantum Gravity" (1993)
- Leonard Susskind, "The World as a Hologram," Journal of Mathematical Physics (1995)
- Juan Maldacena, "The Large N Limit of Superconformal Field Theories and Supergravity" (1997)
- David Bohm, Wholeness and the Implicate Order (1980)
- Michael Talbot, The Holographic Universe (1991)
- Nick Bostrom, "Are You Living in a Computer Simulation?", Philosophical Quarterly (2003)
- Benoit Mandelbrot, The Fractal Geometry of Nature (1982)
- Billy Carson, Fractal Holographic Universe and Compendium of the Emerald Tablets
