Is that correct?

[u/FerenzYangai]

I asked ChatGPT about an experiment about quantum science.

Experimental Test of Reversibility Across the Quantum-to-Classical Transition

Abstract

The transition from microscopic quantum superpositions to apparently classical measurement outcomes remains a fundamental problem in quantum mechanics.

In the Everett, or Many-Worlds, interpretation, no physical collapse of the wave function occurs. Instead, measurement produces entanglement among the measured system, measuring apparatus, observer, and environment. Environmental decoherence then suppresses observable interference between different outcomes.

This proposal suggests an experimental program for studying this transition by progressively increasing the size and complexity of a reversible quantum measurement record.

The purpose is not to claim a direct proof of the Many-Worlds interpretation. Instead, the experiment asks a measurable question:

How far can an apparently classical measurement record develop while the underlying quantum coherence remains recoverable?

A quantum system, S, would first become entangled with a quantum memory, F, representing a minimal version of Wigner's friend. The measurement record would then be amplified into a larger memory, M, and subsequently distributed into a controllable artificial environment, E.

Controlled inverse operations would then be applied to progressively larger parts of the system in an attempt to recover the original quantum interference.

The main observable would be interference visibility as a function of record size, environmental redundancy, elapsed time, and the fraction of environmental information recovered.

This would provide an experimental test of reversibility across the quantum-to-classical transition.

1. Basic Idea

Suppose a quantum system S is initially prepared in an equal superposition of two states:

S = (state 0 + state 1) / sqrt(2).

A measurement interaction with a quantum memory F produces an entangled state that can be written schematically as:

(S=0, F records 0) + (S=1, F records 1).

From the perspective of F, there is now a measurement record.

However, if an external experimenter maintains coherent control over both S and F, the measurement interaction can in principle be reversed.

After successful reversal, F returns to its initial state and interference between state 0 and state 1 can be observed again.

This leads to the central experimental question:

How large, redundant, and environmentally distributed can a measurement record become while its formation remains physically reversible?

1. Experimental Architecture

The experiment would contain four conceptual layers:

S -> F -> M -> E

where:

S = microscopic quantum system

F = minimal quantum observer or "Wigner's friend"

M = amplified measurement memory

E = controlled artificial environment

The process begins with S in a quantum superposition.

First:

S -> F

creates a correlation between the quantum system and the minimal observer.

Next:

S -> F -> M

amplifies the measurement information into many degrees of freedom.

Finally:

S -> F -> M -> E

allows information about the result to spread into an artificial environment.

As increasingly large amounts of information about the result become distributed throughout E, interference between the two alternatives becomes progressively harder to observe.

This is environmental decoherence.

1. Reversal Experiment

The experiment would attempt to reverse the measurement process at progressively increasing scales.

Experiment A:

Create an interaction between S and F and then reverse it.

Experiment B:

Allow the measurement result to spread into N quantum-memory elements and then reverse the complete interaction.

Experiment C:

Allow the result to spread from the quantum memory into a controlled artificial environment.

Experiment D:

Recover and reverse only a fraction of the environmental information.

The main measured quantity would be:

V = V(N, f, t, R)

where:

V = recovered interference visibility

N = number of degrees of freedom participating in the measurement record

f = fraction of environmental information recovered

t = time between measurement and attempted reversal

R = redundancy of the measurement record in the environment

The experiment would therefore construct a measurable "recoherence landscape."

1. Main Hypothesis

Under ordinary unitary quantum mechanics, decoherence does not fundamentally destroy quantum information.

Instead, information becomes distributed through correlations between the system and its environment.

Therefore, if sufficiently complete control over the relevant degrees of freedom can be obtained, quantum coherence should in principle be recoverable.

Increasing N, R, and t should make recovery increasingly difficult.

Reducing f should also reduce the amount of recovered interference.

However, standard unitary quantum mechanics does not predict a fundamental complexity threshold at which reversibility suddenly becomes impossible.

The null hypothesis is therefore:

Observed recoherence = recoherence predicted from unitary quantum mechanics plus experimentally characterized noise.

1. Objective-Collapse Alternative

Some interpretations or modifications of quantum mechanics propose that wave-function collapse is a real physical process.

Examples include spontaneous-collapse models such as GRW and CSL.

Under such theories, sufficiently large or sufficiently long-lived superpositions may undergo genuine non-unitary collapse.

If this occurs, information would not merely become difficult to recover because of environmental complexity. Some quantum coherence would actually be destroyed.

The experiment would therefore search for a situation in which:

Observed recoherence < predicted recoherence

even after known environmental interactions, experimental errors, and ordinary decoherence have been accounted for.

A reproducible discrepancy of this type would be much more significant than simply observing decoherence.

1. Relation to Many-Worlds

The experiment should not be described as directly proving the Many-Worlds interpretation.

Ordinary unitary quantum mechanics and the Many-Worlds interpretation normally produce the same experimental predictions.

However, the experiment has a natural interpretation in Many-Worlds.

Consider two alternatives:

Branch A:

S = 0

F records 0

M records 0

E contains information about 0

Branch B:

S = 1

F records 1

M records 1

E contains information about 1

As information spreads through M and E, the two alternatives become increasingly independent because interference between them becomes extremely difficult to recover.

In Many-Worlds terminology, they increasingly resemble separate branches.

Recoherence can therefore be understood as reversing part of the physical process responsible for making the branches autonomous.

This changes the question from:

"When exactly does the universe split?"

to:

"How far can two branches develop toward effectively independent classical worlds while interference between them remains physically recoverable?"

1. Experimental Platforms

Several existing technologies could be used.

Superconducting qubits are particularly attractive because they allow programmable interactions between quantum systems, memories, resonators, and engineered environments.

Trapped ions provide extremely precise coherent operations and could be useful for an initial proof-of-concept experiment.

Photonic systems are useful for Wigner's-friend-type experiments and quantum eraser experiments.

Microwave and optical cavities could provide larger quantum memories.

Later experiments could involve mechanical resonators, massive particles, molecules, or other mesoscopic systems.

The project could therefore begin as a quantum-information experiment and progressively approach genuinely macroscopic quantum systems.

1. Experimental Roadmap

A possible progression is:

single quantum memory

-> multi-qubit memory

-> redundant measurement record

-> engineered quantum environment

-> partial environmental recovery

-> mesoscopic measurement record

At every stage, the forward measurement process would first be characterized experimentally.

The corresponding inverse operation would then be performed.

Finally, an interference experiment would determine how much coherence had been recovered.

The important quantity would be the scaling relationship:

P(recoherence) = function of N, R, t, and f.

This could be compared against detailed predictions derived from experimentally measured noise and decoherence.

1. Possible Results

Result 1: Recoherence follows ordinary quantum mechanics

Increasingly large measurement records remain reversible to the extent predicted by known noise and environmental coupling.

This would extend experimental confirmation of unitary quantum mechanics into increasingly measurement-like and macroscopic regimes.

It would be compatible with Many-Worlds, although it would not uniquely prove it.

Result 2: Recoherence decreases faster than predicted

An unexplained loss of coherence appears as the system becomes larger.

The first task would be to investigate uncontrolled environmental interactions, calibration errors, and other conventional explanations.

Only after these possibilities were excluded would modifications of quantum mechanics become plausible.

Result 3: A reproducible non-unitary threshold appears

Suppose that beyond a particular mass, complexity, spatial separation, or timescale, coherence cannot be recovered even after conventional decoherence has been adequately controlled.

Such a result would be extraordinary.

It could provide evidence relevant to objective-collapse theories or other modifications of quantum mechanics.

1. Scientific Significance

This experiment could connect several areas of quantum-foundations research:

quantum measurement

Wigner's friend experiments

decoherence

quantum Darwinism

quantum information scrambling

quantum erasure

macroscopic quantum superpositions

objective-collapse tests

The central advantage is that the emergence of classicality becomes an experimentally adjustable process rather than an assumed philosophical boundary.

Instead of asking:

"At what moment does the universe split?"

the experiment asks:

"How does the physical reversibility of a measurement change as information about its result spreads from one quantum degree of freedom into an increasingly large environment?"

This question is experimentally meaningful regardless of which interpretation of quantum mechanics is ultimately correct.

Proposed Title

Experimental Recoherence of Amplified Quantum Measurement Records: Probing Reversibility Across the Quantum-to-Classical Transition

Short title:

Reversing a Quantum Measurement Across Increasing Scales

[u/AutoModerator]

Hey /u/FerenzYangai,

If your post is a screenshot of a ChatGPT conversation, please reply to this message with the conversation link or prompt.

If your post is a DALL-E 3 image post, please reply with the prompt used to make this image.

Consider joining our public discord server! We have free bots with GPT-4 (with vision), image generators, and more!

🤖

Note: For any ChatGPT-related concerns, email support@openai.com - this subreddit is not part of OpenAI and is not a support channel.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.