Chapter 04 · A Theory of Everything
A Theory of Everything
Can all forces and particles be unified?
We have two theories that each work brilliantly in their domain: quantum mechanics for the small, general relativity for the large. They're mathematically incompatible. These are the attempts to resolve that.
Families (6)
- FrontierTwistor TheoryPenrose's program: spacetime is derived from a deeper complex-geometric substrate called twistor space.4 variants
- FrontierAsymptotic SafetyA quantum theory of gravity in its own right, no strings or supersymmetry needed. Gravity is asymptotically safe at the Planck scale: couplings approach a non-trivial fixed point, the theory stays predictive, and the same framework predicts the Higgs mass conditionally.5 variants
- FrontierString TheoryParticles as vibrating strings in 10 or 11 dimensions, with five mathematically consistent superstring theories unified by an 11D parent. Dominant unification candidate for four decades; the empirical contact problem and the landscape problem remain open.5 variants
- FrontierNon-Commutative GeometryReplace spacetime points with an algebra of functions that do not commute, and the Standard Model plus general relativity emerge as two faces of one geometric object. A spectral triple encodes both physics and geometry in a single compact structure.4 variants
- SpeculativeBeneath the Standard ModelFamiliar physics emerges from a deeper substrate; quantum theory and gravity are not the foundation.2 variants1 vote
- FringeWolfram Physics ProjectSimple rewriting rules on abstract hypergraphs produce spacetime, matter, and quantum mechanics from a common discrete substrate. Space is a graph, time is computation, and physical laws emerge from causal invariance.3 variants
Bridged from other chapters (5)
These variants live in their own chapters but also answer this chapter's question.
Ch.03Loop Quantum GravityFrontier
Canonical / Spin-Foam Loop Quantum Gravity
Spacetime is woven from a network of quantum geometric atoms. Area and volume have minimum sizes set by the Planck scale.
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Ch.03Emergent Spacetime & GravityFrontier
Holographic Spacetime
A higher-dimensional spacetime with gravity is exactly described by a lower-dimensional quantum theory on its boundary. Geometry emerges from entanglement.
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Ch.03Causal Dynamical TriangulationFrontier
Foundational CDT Program
Build spacetime out of four-dimensional simplices glued along a strict causal ordering. Sum over every such gluing on a computer. The geometry that emerges is the prediction of quantum gravity.
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Ch.01Eternal InflationStrongly supported
String Theory Landscape
String theory permits ~10⁵⁰⁰ different vacuum states. Each bubble lands in a different one.
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Ch.06Black Hole Information ParadoxFrontier
ER = EPR
Maldacena and Susskind's 2013 conjecture that every entangled pair of particles is connected by a wormhole. Applied to the firewall paradox, the entanglement between late Hawking radiation and the interior IS the geometric continuation across the horizon, so no firewall is needed.
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Ch. 4 · what readers find most compelling, 1 vote cast
Early days, votes still coming in.
1 votes cast
- ★ 01Beneath the Standard Model1vote
- 02Beneath the Standard Model0votes
- 03String Theory0votes
- 04String Theory0votes
- 05String Theory0votes