Three serious answers to a question that should not have an answer.
A Heresy in Good Standing
I recently watched a video in which a physicist says, with the calm of a man reading a grocery list, that spacetime is probably not fundamental. The stage on which everything happens turns out to be a painted backdrop. The floor is not the floor.
The reasonable reaction is to assume the speaker has been at the edibles. Spacetime is the one thing we never doubt. Distance feels real because you can stub your toe on it. Time feels real because it keeps stealing your afternoons. Telling a person that these are emergent, downstream, secondary, sounds like telling them that water is, on reflection, optional.
And yet this is now close to the mainstream opinion among the people who do the hard arithmetic. The question that occupies the field is no longer whether spacetime is fundamental. It is what spacetime emerges from. Three programs lead, and they are worth knowing, because each one quietly dismantles an assumption you have carried since childhood. (Full disclosure before we start. I paint pictures and write books for a living, and am a guest in the house of physics, wiping my feet at the door.)
The Universe as a Web of Knowing
The first answer goes by an unlovely name, the holographic principle, and it begins with an observation about information. Gerard ‘t Hooft and Leonard Susskind noticed in the early nineties that the amount of information you can pack into a region of space scales with the area of its surface, rather than the volume inside. Reality keeps its books on the boundary, like a shop that records sales at the door and ignores the stockroom.
In 1997 Juan Maldacena turned the metaphor into mathematics. He showed that a universe with gravity can be perfectly described by a quantum theory living on its lower-dimensional edge, with no gravity in the description at all. Two pictures, one truth. The interior and its boundary say the same thing in different alphabets.
Then came the sentence that should keep you up at night. In 2010 Mark Van Raamsdonk asked what happens if you take the boundary theory and slowly reduce the quantum entanglement between its two halves. The answer, worked out in the equations, is that the interior geometry stretches, thins, and finally tears. Remove the correlation, and the distance grows. Cut it entirely, and the two regions no longer share a spacetime to be far apart in.
Distance is a measure of how much two things fail to know each other.
Shinsei Ryu and Tadashi Takayanagi sharpened this, linking the area of a surface to the entropy of entanglement across it. Maldacena and Susskind pushed it further with a conjecture of almost indecent elegance, that a wormhole joining two black holes and a pair of entangled particles might be the very same thing, glimpsed from two angles. The slogan the field adopted, borrowing from John Wheeler, is “it from qubit.” Geometry is not the stage. Geometry is the running tally of relationships, and where the relationships are dense the cosmos feels near, and where they thin it feels far.
One honest caution, since this essay would like to survive a skeptic. The exact version of this duality lives in a universe shaped differently from ours, curved the wrong way, and nobody has yet made the dictionary work cleanly for the expanding cosmos we actually inhabit. The principle is firm. The application to home is unfinished business.
The Shape Before the Story
The second answer is stranger, and it arrives wearing a name that sounds like a rejected Transformer, the amplituhedron. In 2013 Nima Arkani-Hamed and Jaroslav Trnka found that certain calculations of how particles interact, calculations that normally crawl through pages of spacetime bookkeeping, can be done instead by computing the volume of a single geometric object. This object lives in an abstract mathematical space. It contains no time. It contains no notion of “here” and “there.” It is just a shape.
Here is the part that rearranges the furniture in your skull. The familiar rules, that causes precede effects locally, that probabilities behave themselves, do not get fed into the shape as assumptions. They come out of it, as consequences of the shape’s geometry. Locality and time look less like the bedrock of reality and more like the way a certain crystal happens to catch the light.
The universe may be a shape before it is ever a story.
If that is right, then time is not a river we are floating down. Time is how the shape appears when you are standing inside it, the same way a cathedral seems to unfold corridor by corridor only because you cannot occupy all of it at once. The caveat, again offered freely, is that this machinery currently works for an idealized theory, a clean cousin of the real thing. The dirty, glorious Standard Model of our world has not yet been folded into a polytope. Still, the proof of principle stands, and it is humbling. A shape can dream a spacetime.
The Order Underneath the Smoothness
The third answer is the oldest and the most stubborn, and it says the smoothness is a lie of scale. Look closely enough and spacetime is grainy, made of discrete pieces, the way a photograph dissolves into dots when you press your nose to it.
Causal set theory, proposed in 1987 by Bombelli, Lee, Meyer, and Sorkin, takes this to its austere conclusion. Reality at bottom is a discrete set of events with nothing but a notion of before and after connecting them. Rafael Sorkin compressed the entire program into a phrase fit for carving over a doorway, “order plus number equals geometry.” Give the universe a list of which events come before which, count them, and space and time precipitate out like salt from a drying sea.
Loop quantum gravity, descended from Roger Penrose’s spin networks and carried forward by Carlo Rovelli and Lee Smolin, quantizes the fabric directly. Area and volume come in smallest possible units, and what we call space is a vast web of relations, a network whose nodes do not sit anywhere because the network is the where. The matrix models of the late nineties grow dimensions out of the arithmetic of large grids of numbers. Wheeler dreamed of all this in advance and gave it a name, pregeometry, law without law, the hope that geometry bubbles up from something logically prior to it.
The common confession across this family is plain. Relation comes first. Extension is the echo. The “where” and the “when” are tidy summaries we drape over a churning lattice of priority and connection.
What the Three Have in Common
Notice the family resemblance. Entanglement weaves space from correlation. The amplituhedron derives space from a timeless shape. The discrete models grow space from raw order. Three different alphabets, one sentence underneath them all.
Reality is relationship first and scenery second.
The thing we trusted most, the empty stage, turns out to be the most derivative thing in the building. The void is doing the work. It was always doing the work. The geometry we mistook for the floor is the residue of countless tiny relations, correlations, orderings, foldings, each one referring to the others, the whole structure curling back to define itself with no outside to lean on.
This is recursion in the exact sense, a system that produces its own ground by referring to itself across scales. And it is precisely the territory my books have been mapping, in a different and older language, for five volumes.
The Codex of the Outer Realms
The Codex of the Outer Realms treats the so-called outer gods of public-domain weird fiction not as monsters under the bed, but as contemplative instruments, frameworks for thinking about exactly the questions the physicists are now forced to ask. The parallels are uncomfortably tidy.
Chaos Unveiled reads Azathoth as the blind computation beneath appearance, the substrate that generates structure without intending any of it. That is the entanglement and the matrix churn, mindless, ceaseless, and somehow the author of every geometry. The Screaming Cipher of Nyarlathotep takes information and encoding as its subject, which is the holographic confession in liturgical dress, the message written on the boundary that the interior only thinks it authored. The Gate That Opens Into Itself places Yog-Sothoth at the threshold that is coextensive with all thresholds, relation without location, which is the amplituhedron’s timeless totality wearing a stranger mask. The Pallid Doctrine of Hastur works through self-similarity and law understood as turbulence slowed, the fractal order that the discrete theories find when they look beneath the smooth. And The Heretical Shape of the Universe, the convergence volume, makes the claim outright. The cosmos has a shape prior to its story, and the shape refers to itself, endlessly, with no edge to stand outside of.
None of this is an attempt to dress physics in robes and call it scripture. The physics stands on its own and owes the books nothing. The point runs the other direction. A contemplative tradition built honestly on real esoteric sources, Pseudo-Dionysius and the apophatic mystics, Ibn Arabi, the Kabbalists, the Kashmir Shaivites, kept arriving at the same austere intuition that the equations are now circling. That the ground is not solid. That the one is prior to the many. That awareness aware of its own awareness is the closest the language gets.
The void was never empty, it only looked empty to creatures who mistook the backdrop for the bedrock. The floor is not the floor. Walk carefully. The whole cathedral is humming, and it has been humming the entire time, waiting for someone to press an ear to the stone and listen for the order underneath.
Select Sources
‘t Hooft, Gerard. “Dimensional Reduction in Quantum Gravity.” 1993.
Susskind, Leonard. “The World as a Hologram.” Journal of Mathematical Physics, 1995.
Maldacena, Juan. “The Large N Limit of Superconformal Field Theories and Supergravity.” 1997.
Ryu, Shinsei, and Tadashi Takayanagi. “Holographic Derivation of Entanglement Entropy from AdS/CFT.” 2006.
Van Raamsdonk, Mark. “Building Up Spacetime with Quantum Entanglement.” 2010.
Maldacena, Juan, and Leonard Susskind. “Cool Horizons for Entangled Black Holes.” 2013.
Arkani-Hamed, Nima, and Jaroslav Trnka. “The Amplituhedron.” 2013.
Bombelli, Luca, Joohan Lee, David Meyer, and Rafael Sorkin. “Space-Time as a Causal Set.” Physical Review Letters, 1987.
Rovelli, Carlo, and Lee Smolin. “Discreteness of Area and Volume in Quantum Gravity.” 1995.
Banks, Tom, Willy Fischler, Stephen Shenker, and Leonard Susskind. “M Theory as a Matrix Model: A Conjecture.” 1997.
Wheeler, John Archibald. “Information, Physics, Quantum: The Search for Links.” 1990.
Penrose, Roger. “Angular Momentum: An Approach to Combinatorial Space-Time.” 1971.
Smolin, Lee. Time Reborn. Houghton Mifflin Harcourt, 2013.