The post-determined block universe

Abstract

A series of reasons to take quantum unitary evolution seriously and explain the projection of the state vector as unitary and not discontinuous are presented, including some from General Relativity. This leads to an interpretation of Quantum Mechanics which is unitary at the level of a single world. I argue that unitary evolution is consistent with both quantum measurements and the apparent classicality at the macroscopic level. This allows us to take the wavefunction as ontic (but holistic), but a global consistency condition has to be introduced to ensure this compatibility. I justify this by appealing to sheaf cohomology on the block universe. As a consequence, Quantum Theory turns out to be consistent with a definite four-dimensional spacetime, even if this may consist of superpositions of different geometries. But the block universe subject to global consistency gains a new flavor, which for an observer experiencing the flow of time appears as "superdeterministic" or "retrocausal", although this does not manifest itself in observations in a way which would allow the violation of causality. However, the block universe view offers another interpretation of this behavior, which makes more sense, and removes the tension with causality. Such a block universe subject to global consistency appears thus as being post-determined. Here "post-determined" means that for an observer the block universe appears as not being completely determined from the beginning, but each new quantum observation eliminates some of the possible block universe solutions consistent with the previous observations. I compare the post-determined block universe with other proposals: the presentist view, the block universe, the splitting block universe, and the growing block universe, and explain how it combines their major advantages in a qualitatively different picture.

43 pages, based on a talk of the author at the Fifth International Conference on the Nature and Ontology of Spacetime, 2018. Quantum Stud.: Math. Found. (2020)

References in corpus (17)

• Experimental quantum teleportation
• A Spin Entanglement Witness for Quantum Gravity
• Gravitationally-induced entanglement between two massive particles is sufficient evidence of quantum effects in gravity
• No extension of quantum theory can have improved predictive power
• On the possibility of laboratory evidence for quantum superposition of geometries
• The quantum mechanics of time travel through post-selected teleportation
• Why Eppley and Hannah's Experiment Isn't
• Measurement Analysis and Quantum Gravity
• Bell's Theorem and Locally-Mediated Reformulations of Quantum Mechanics
• Physics in the Real Universe: Time and Spacetime
• Simple Refutation of the Eppley-Hannah argument
• The Evolving Block Universe and the Meshing Together of Times
• Realism and causality I: Pilot wave and retrocausal models as possible facilitators
• Vacuum fluctuation, micro-cyclic "universes" and the cosmological constant problem
• Revisiting the black hole entropy and the information paradox
• A representation of the wave function on the three-dimensional space
• A $\psi$-Ontology Result without the Cartesian Product Assumption

Cited by in corpus (3)

• The Relation between Wavefunction and 3D Space Implies Many Worlds with Local Beables and Probabilities
• Freedom in the many-worlds interpretation
• Does quantum mechanics require "conspiracy"?