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Schrödinger’s Cat and the Meaning of It All

Frank S. Levin

Published Sep 21, 2017• 0 citations
Publisher

Abstract

Abstract Chapter 15 deals with various unresolved issues, such as how measurements are to be described, whether they induce collapse of linear superpositions, and if so, what the result should be. Another is whether quantum mechanics applies to macroscopic measuring devices, and if not, why not. Some of these issues are addressed via the Schrödinger cat-in-the-box experiment, in particular whether the cat is ever half alive and half dead; analogs of the corresponding Schrödinger-cat state (not involving a cat) have been studied experimentally. For Schrödinger, it was ridiculous to apply quantum mechanics to macroscopic situations, nevertheless, it has been explored by many physicists. Whether measurements induce collapse and whether collapse arises in various formulations/interpretations of quantum mechanics is examined in the context of generic measuring instruments known as pointer devices. Various conclusions have been reached, though consensus has not, despite only one interpretation having been verified experimentally.

DOI
10.1093/oso/9780198808275.003.0016

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Abstract Chapter 15 deals with various unresolved issues, such as how measurements are to be described, whether they induce collapse of linear superpositions, and if so, what the result should be. Another is whether quantum mechanics applies to macroscopic measuring devices, and if not, why not. Some of these issues are addressed via the Schrödinger cat-in-the-box experiment, in particular whether the cat is ever half alive and half dead; analogs of the corresponding Schrödinger-cat state (not involving a cat) have been studied experimentally. For Schrödinger, it was ridiculous to apply quantum mechanics to macroscopic situations, nevertheless, it has been explored by many physicists. Whether measurements induce collapse and whether collapse arises in various formulations/interpretations of quantum mechanics is examined in the context of generic measuring instruments known as pointer devices. Various conclusions have been reached, though consensus has not, despite only one interpretation having been verified experimentally.
This paper reviews and suggests a resolution of the problem of definite outcomes of measurement. This problem, also known as ‘Schrodinger’s cat’, has long posed an apparent paradox because the state resulting from a measurement appears to be a quantum superposition in which the detector is in two macroscopically distinct states (alive and dead in the case of the cat) simultaneously. Many alternative interpretations of the quantum mathematical formalism, and several alternative modifications of the theory, have been proposed to resolve this problem, but no consensus has formed supporting any one of them. Applying standard quantum theory to the measurement state, together with the analysis and results of decades of nonlocality experiments with pairs of entangled systems, this paper shows the entangled measurement state is not a paradoxical macroscopic superposition of states. It is instead a phase-dependent superposition of correlations between states of the subsystems. Thus Schrodinger’s cat is a non-paradoxical ‘macroscopic correlation’ in which one of the two correlated systems happens to be a detector. This insight resolves the problem of definite outcomes but it does not entirely resolve the measurement problem because the entangled state is still reversible.
We reopen Erwin Schrodinger's thought experiment involving a cat in an informationally impenetrable box. A common view is that the cat enters a superposition of alive/dead because of a lack of observation, leading to uncertainty about the state of the cat. We, on the other hand, argue that the cat only enters a superposition if everything about the cat is known prior to the box being closed. The superposition results from a lack of uncertainty inside the box. Rather than interpreting this state of affairs as a live and dead cat interacting with each other, we suggest that the more natural interpretation is that of an inability to precisely position events within spacetime due to the lack of uncertainty. We clarify how stable measurement depends on a diversified portfolio of statistical uncertainty, and how the lack of such uncertainty in Schrodinger's box precludes stabilization.
In his famous thought experiment, Schrodinger(1935) imagined a cat that measures the value of a quantum mechanical observable with its life. Since Schrodinger’s time,no any interpretations or modifications of quantum mechanics have been proposed which gives clear unambiguous answers to the questions posed by Schrodinger’s cat of how long superpositions last and when (or whether) they collapse?In this book appropriate modification of quantum mechanics is proposed.We claim that canonical interpretation of the wave function ψ=с1ψ1+с2ψ2 is correct only when the wave function supports ψ1 and ψ2 essentially overlap. When these ones have separated supports we claim that canonical interpretation of the wave function ψ is no longer valid for a such cat state.Possible solution of the Schrodinger’s cat paradox is considered. We pointed out that the collapsed state of the cat always shows definite and predictable outcomes even if the cat also consists of a superposition:|cat>=с1|alive cat>+с2|death cat>.Using new quantum mechanical formalism the EPRB-paradox is considered.We find that the EPRB-paradox can be resolved by nonprincipal and convenient relaxing of the Einstein’s locality principle.
Schrödinger's cat paradox has persisted for nearly a century as a demonstration of the apparent absurdity of quantum superposition when extended to macroscopic scales. This technical note demonstrates that the paradox dissolves entirely within the CAT'S Theory framework through the triadic invariant Reality = Pattern × Intent × Presence (P × I × Pr). We argue that the cat is neither "both alive and dead" nor the victim of mysterious collapse. Instead, superposition represents a state where Presence (Pr) has not yet instantiated, yielding P × I × 0 = 0 (potential but not actual). Measurement does not "cause" collapse through mysterious observer effects; it provides the Presence component required for actualization. This resolution eliminates the need for Multiple Worlds or hidden variables while maintaining consistency with quantum mechanical predictions.
This paper resolves the problem of definite outcomes, also known as "Schrodinger's cat" and the "problem of wavefunction collapse." It's the problem of understanding how nature goes from a coherent superposition of possible outcomes to a single definite outcome. This "measurement problem" has not to my knowledge been solved. The analysis stems from an insight into entanglement demonstrated in two nonlocality experiments involving pairs of momentum-entangled photons. These show that an entangled state of two subsystems is not a superposition of products of paired states, but instead a superposition of correlations between paired states. The "premeasurement state" is just such a superposition with the proviso that one subsystem is the detector of the other subsystem. This state is not a paradoxical superposition of macroscopic detector states; it is instead a superposition of correlations between detector states and microscopic quantum states. Thus, Schrodinger's cat isn't "smeared" between dead and alive but instead represents a nonlocal superposition of correlations between states of the cat and states of the nucleus: This is what we want. We also critique one previously claimed resolution of the measurement problem and seven previously claimed proofs that the measurement problem is unsolvable.
The entangled Schrodinger cat state obtained immediately upon measurement of a superposed two-state quantum system is often considered paradoxical because it appears to predict two macroscopically different outcomes, such as an alive and dead cat. However, nonlocal interferometry experiments testing momentum-entangled photon pairs over all phases demonstrate that the cat state does not fit this description and is not paradoxical. Both experiment and theory imply that it instead represents a superposition of two nonlocally coherent (i.e. phase-dependent) statistical correlations between its sub-systems. This is not paradoxical. Standard quantum theory rigorously predicts the experimentally-observed outcomes of this state. Neither sub-system is superposed; rather, the correlations between the states of the subsystems are superposed. This resolves the problem of definite outcomes. The nonlocal properties of entanglement then ensure that only one outcome occurs while the other outcome simultaneously does not occur, resolving a problem posed by Einstein in 1927. The single outcome that occurs then triggers an irreversible process leading to macroscopic registration of the outcome. This resolves the quantum measurement problem. Collapse occurs because of entanglement and does not require a special collapse postulate. Collapse is a consequence of standard quantum physics and the irreversible nature of the macroscopic registration.