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Ch.01 Before the UniverseQuantum Tunneling Origin

Nothing isn't stable. Eventually it becomes a universe.

Vilenkin's Tunneling from Nothing

The universe quantum-tunneled from literal nothing, no space, no time, no fields.

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§1 · The claim, 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.

§2 · Why it might be true

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.

§2.5 · Evidence

  • Inflation is observationally well-supported
  • Math is consistent with quantum cosmology formalism

§3 · What you'd need to test it

  • begins naturally with high probability after tunneling
  • Universe is initially small, closed, and de Sitter-like
  • No contracting phase before the Bang

§4 · Where it breaks

  • Krauss: still requires quantum laws, so not really nothing
  • Hawking & Bousso (1995): catastrophic particle production
  • Penrose: ignores Weyl curvature hypothesis
Go deeper

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 . 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.

§5 · Who built it, and when(4 sources, 4 established)
Vilenkin's Tunneling from Nothing, Alexander Vilenkin19731982198320241998

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