Vilenkin's Tunneling from Nothing
The universe quantum-tunneled from literal nothing, no space, no time, no fields.
Placeholder for a 3D visualisation of Quantum Tunneling Origin. The interactive scene will land in Phase 3. This family represents the 'null answer' to the chapter question: that there was no spacetime, no fields, no 'before' in any coherent sense. Apply quantum mechanics to the origin of the universe itself. The result is a wavefunction over possible universes; ours is the one that emerged. Different variants disagree on the boundary condition.
In one sentence
Vilenkin proposed in 1982 that the universe quantum-tunneled into existence from a state with no space, no time, no fields, literal nothing.
The claim
Vilenkin's proposal is the most ontologically radical. He claims our universe came from literal nothing, not from a quantum vacuum or an empty space. The mathematics treats it like quantum tunneling in particle physics, where a particle passes through an energy barrier it should not classically be able to cross.
A quantum vacuum already has structure: space, fields, laws, a Hilbert space. Vilenkin's "nothing" has none of those. It is the absence of geometry itself. The size of the universe tunnels through a forbidden region from zero to a small inflating sphere, then begins to inflate normally.
The family stance
Either literally nothing (Vilenkin), or a state without a temporal boundary (Hartle-Hawking), or a zero-energy quantum fluctuation (Tryon). All deny that a classical "before" makes sense.
Predictions
- Inflation begins naturally with high probability after tunneling
- Universe is initially small, closed, and de Sitter-like
- No contracting phase before the Bang
Evidence
- Inflation is observationally well-supported
- Math is consistent with quantum cosmology formalism
Counterpoints
- Krauss: still requires quantum laws, so not really nothing
- Hawking & Bousso (1995): catastrophic particle production
- Penrose: ignores Weyl curvature hypothesis
Variants in this family
▸Go deeperTechnical detail with proper terminology
Vilenkin uses the Wheeler-DeWitt equation Ĥψ = 0 in minisuperspace (closed FRW with scale factor a as coordinate). The state of "nothing" corresponds to a = 0.
The scale factor tunnels through the classically forbidden region (a < a_min ~ H⁻¹) to emerge as de Sitter spacetime. Probability amplitude ~ exp(-I_E) where I_E is the Euclidean instanton action.
Boundary condition: "outgoing waves only" at a = 0. This distinguishes the proposal from Hartle-Hawking.
References
- EstablishedVilenkin (1982). Phys. Lett. B 117, 25
- EstablishedVilenkin (1988). Phys. Rev. D 37, 888
- EstablishedHawking & Bousso (1995). Phys. Rev. D 52, 5658
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