◈ Holography
Space may be built from entanglement — like a hologram, where a 3D image is encoded on a flat surface. For model universes the evidence is strong; for ours it's an open bet.
The clue from black holes
A black hole's entropy grows with the area of its horizon, not its volume (Bekenstein, Hawking). That suggests the information needed to describe a region of space fits on its boundary. Established as theory, not yet tested by experiment.
The holographic principle
't Hooft (1993) and Susskind (1995) proposed that this is general: the physics inside any region can be described by degrees of freedom on its surface. Speculative as a principle about our universe.
A precise version: AdS/CFT
In 1997 Maldacena found a concrete case: string theory in a model universe with a negative cosmological constant ('anti-de Sitter space') is exactly equivalent to an ordinary quantum theory, without gravity, on its boundary. It has passed thousands of calculational checks but isn't proven, and our universe has a positive cosmological constant. Contested (the duality) · Speculative (for our universe).
Entanglement builds space
Ryu and Takayanagi (2006) found that the entanglement between regions of the boundary equals the area of a surface in the interior. Van Raamsdonk (2010) argued that removing entanglement pulls space apart. And Maldacena and Susskind's 'ER = EPR' (2013) proposes that every entangled pair is joined by a tiny wormhole. Speculative — bold, published, and influential.
And time?
Here holography is quieter. In AdS/CFT the boundary theory still has an ordinary time; how time itself might emerge is much less understood than how space does. Contested Holes H1 and H11.
Why there's no lab for this
There's no honest equation for 'watching space emerge' that runs in a browser — a toy animation would only pretend. So this stays a page, not a simulation.
See it in the labs
Sources: Bekenstein, PRD 7 (1973); 't Hooft (1993); Susskind, J. Math. Phys. 36 (1995); Maldacena, Adv. Theor. Math. Phys. 2 (1998); Ryu & Takayanagi, PRL 96 (2006); Van Raamsdonk, Gen. Rel. Grav. 42 (2010); Maldacena & Susskind, Fortsch. Phys. 61 (2013).