[ExI] Superposition of Vacuum States

[John Clark]

On Wed, Dec 17, 2025 at 5:40 AM BillK via extropy-chat <
extropy-chat at lists.extropy.org> wrote:


>
> *> I asked Gemini AI to review this video.Full discussion here:
> <https://gemini.google.com/share/1a453179c016
> <https://gemini.google.com/share/1a453179c016>>BillK*


I said this to Gemini:

*ME: Could Many Worlds avoid Penrose's objection if time is not fundamental
but is branch-dependent, that is to say there is not one and only one time
that is objectively true, but instead time is observer dependent and there
is no unique time evolution? It seems to me that Penrose is assuming that
spacetime is classical, and I think that probably isn't a very good
assumption. And Penrose insists that time defines energy, but globally in
General Relativity the very concept of energy (and its conservation) is
ambiguous, especially in an expanding or accelerating universe.*

This is how Gemini respond:

*GEMINI:* "Your intuition hits on what is arguably the primary weakness in
Penrose's argument: *his assumption that a superposition of spacetimes must
still be describable within a single, semi-classical framework.*

You are effectively describing the *"Quantum Reference Frame"* or *"Emergent
Time"* solution, which many physicists (including Many Worlds proponents)
use to rebut Penrose.

Here is a breakdown of why your objection works and how it neutralizes
Penrose's "proof."
1. Penrose's "Fatal" Assumption: The Single Clock

Penrose's argument relies on a specific conflict:

   -

   *QM* says a superposition evolves according to a Hamiltonian (Energy).
   -

   *GR* says Energy is defined by the "flow of time" (a timelike Killing
   vector).
   -

   *The Trap:* If Branch A has a mass *here*, and Branch B has a mass
   *there*, they curve spacetime differently. Therefore, "Time" flows at
   different rates in each branch.
   -

   *Penrose's Conclusion:* Because you cannot map "Time A" to "Time B"
   perfectly (there is no unique *pointwise identification* of the two
   spacetimes), you cannot define a single Hamiltonian for the whole system.
   The energy becomes "uncertain," and he argues this uncertainty (ΔE)
   forces the system to decay (collapse) in time t≈ℏ/ΔE.

2. The Many Worlds / "Branch-Dependent Time" Rebuttal

Your counter-argument is that *there is no need for a "global" Hamiltonian*
that governs both branches simultaneously from the "outside."

In the Many Worlds Interpretation (MWI), or in modern "Quantum Reference
Frame" theory:

   -

   *Time is Internal:* Time is not a background stage; it is a correlation
   between a clock and a system *within* a branch.
   -

   *No Global Conflict:* Branch A has its own internal clock and metric.
   Branch B has *its* own internal clock and metric.
   -

   *The "Superposition" is Abstract:* The total universal wavefunction
   typically satisfies the *Wheeler-DeWitt equation* (HΨ=0), which is
   static. Time only "happens" *inside* the branches relative to observers.
   -

   *Why this saves MWI:* Since the branches don't need to agree on a
   "global time" to exist, the fact that their clocks run at different rates
   is irrelevant. They simply decohere (separate) and evolve independently.
   The "phase difference" that Penrose claims is fatal just becomes a relative
   phase between valid, non-interacting worlds.

3. Energy Ambiguity in GR

You are also correct that Penrose glosses over the ambiguity of energy in
GR.

   -

   In General Relativity, energy is not always well-defined locally (it
   requires a "timelike Killing vector," which doesn't exist in generic, messy
   spacetimes).
   -

   Penrose tries to fix this by looking at the "gravitational self-energy
   difference" in the Newtonian limit, but critics argue this is a
*semi-classical
   approximation*. He is trying to force Quantum Mechanics to obey a
   classical geometric rule (unique spacetime structure) which likely breaks
   down at the quantum level.

Summary

Penrose's proof works *only if you assume there is one single, objective
"spacetime"* in which the superposition must live. If you accept the Many
Worlds view—that the universe splits into independent spacetimes, each with
its own valid definition of time and energy—his logical contradiction
disappears.

One video that touches on this specific tension (that Gravity might not
need to be quantized in the way Penrose thinks) is from Sabine
Hossenfelder, who discusses Penrose's specific collapse theory.

Penrose's Cyclic Universe & Conformal Cyclic Cosmology
<https://www.google.com/search?q=https://www.youtube.com/watch%3Fv%3D34d7285tO_k>

I selected this video because it discusses Roger Penrose's specific views
on cosmology and the unique way he treats entropy and singularities,
providing context for why he believes standard Quantum Mechanics is
incomplete."

*By the way, the Hossenfelder link Gemini gave doesn't work, at least not
for me.*

* John K Clark*
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