WEX views entanglement as an aspect of the intrinsic wave nature of matter.  The wave packets of photon A and photon B were produced as a single unified wave packet AB carrying two photon quanta of energy in a bi-modal configuration, with two modes moving away from one another.  When wave packet AB encounters a system that causes it to exchange energy, such as your retina, a quantized particle signature is produced at the point of energy exchange.  Wave packet AB loses one photon quantum to your retina, leaving the residual quantum in photon B′.  Since photon A no longer exists, the entangled connection is split, and photon B′ is left with properties complementary to photon A's particle signature through universal conservation laws.

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Conservation laws constrain the allowed correlations between the two modes of the unified structure.  Entanglement is best understood by viewing entangled wave packets as unified physically real objects rather than as two separate wave packets that were never causally independent systems.  When the unified wave packet exchanges energy at one mode, the properties at the other mode are constrained not because information travels between them, but because the constraint is a structural property of the single object itself.  No usable information is transmitted between the modes, consistent with the no-signaling theorem, and no observer at either location can detect anything unusual until the results are later compared.

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WEX does not claim to restore local causality in the sense ruled out by Bell's theorem; it rejects the premise that the two photons were ever separate locally causal systems to begin with.  WEX's claim is that an entangled correlation is a property of a single physical structure rather than a signal passed between two structures, independent of whether that structure is fully resident in spacetime or possesses connectivity not reducible to spacetime separation.  WEX takes no position on how this structural connectivity relates to relativistic simultaneity, a question that remains open for every realist account treating measurement outcomes as definite, and one WEX inherits rather than resolves.

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The Measurement Problem

The central mystery in quantum physics revolves around the “Measurement Problem” (aka. “Observation Problem”), which involves explaining how quantum scale matter transitions from a distribution of possible properties pre-measurement to a precise set of classical properties post-measurement.  The measurement problem is a direct consequence of a lack of definitions for what constitutes a measurement, a measurement device, and where the boundary lies between the quantum and classical worlds, if such a boundary exists at all.  It is the absence of these definitions that leads directly to the paradoxes of quantum physics such as Schrodinger’s Cat, Wigner’s Friend, and the Frauchiger-Renner paradoxes.  The WEX principle incorporates precise definitions for these three terms plus three additional terms that remain undefined in standard quantum theory, which when combined with the wave packet and particle signature definitions provided earlier, resolves numerous paradoxes that result from definitional ambiguities.

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• Measurement or Observation: The absorption of a quantum system's characteristic quantum of energy which produces a particle signature at the point of energy exchange.

• Measurement Device or Observer: Any system that absorbs a quantum of energy from a quantum system and produces a particle signature at the point of contact.

• Entangling Interaction: Any physical interaction between two wave packets that correlates their subsequent behavior without either wave packet transferring a discrete, characteristic quantum of energy to the other. Consistent with the treatment of entangled photon pairs described previously, the two wave packets are now treated as a unified spatially extended wave packet. Because no discrete quantum of energy is exchanged in forming this correlation, the entangling interaction does not produce a particle signature. The unified wave packet persists until a measurement occurs anywhere within its spatial extent that extracts a quantum of energy, which produces a particle signature at that location while irreversibly producing complementary properties in the remainder of the structure through conservation laws.

• Absorbing Structure: A macroscopic arrangement of densely packed quantum systems, each individually capable of absorbing a quantum of energy, whose combined density and coupling strength make the aggregate probability of an energy exchange event occurring somewhere within the structure near certain. A photon wave packet reaching a detection screen encounters an Absorbing Structure: its spatially extended amplitude forms Entangling Interactions with many constituent atoms simultaneously, and an energy exchange is essentially guaranteed to occur at one of them, with the Born rule governing the probability of each location. This explains why dense matter reliably produces particle signatures while a wave packet encountering sparse matter — a single atom in its path, or a dilute gas — may continue with no exchange occurring at all. Whether the resulting exchange constitutes a Measurement or an Observation is a separate question, determined by whether the structure's presence establishes when and where the exchange occurs. A detection screen placed in a beam's path is an Absorbing Structure functioning as a measurement device; a scintillator array awaiting cosmic rays is an Absorbing Structure functioning as an observer. An Absorbing Structure determines that an exchange occurs, not which constituent system undergoes it, at what moment, or under which of the two definitions it falls.

• Quantum System: The wave function for a quantum system should be written from the perspective of a measurement device or observer. If the system has undergone an entangling interaction with another wave packet, the wave function must describe the full spatial extent of the resulting unified wave packet, not merely the original system in isolation, until a measurement occurs anywhere within that unified structure. Furthermore, a wave function cannot contain a measurement device or observer inside the quantum system it describes.

• No Quantum Boundary: Since the intrinsic nature of matter is wave-like, there is no boundary between the quantum and classical world where quantum dynamics cease to apply.

 

Researchers have demonstrated quantum effects in experiments involving increasingly larger and more complex configurations of matter.  Organic molecules with thousands of atoms have demonstrated the intrinsic wave nature of matter applies at the scale of complex molecules.  Micro-mechanical resonators made from trillions of atoms have demonstrated collective vibrational states that illustrate the intrinsic wave nature of matter at scales that are now visible with microscopes.  Quantum biology has produced evidence of quantum effects operating at the molecular and cellular scale in living organisms, including coherent energy transfer during photosynthesis and in retinal proteins that migratory birds appear to use for magnetic navigation.  This evidence suggests that the assumption that quantum effects cannot occur in macroscopic structures, nor in the wet, warm, and electromagnetically noisy environments of biological organisms, is incorrect.  Environmental interactions more broadly can also strongly suppress observable macroscopic coherence.  Quantum effects are theoretically independent of scale under the WEX principle as a natural consequence of the intrinsic wave nature of matter.

 

As researchers look for quantum effects in ever larger matter structures, the challenge becomes isolating and detecting the energy exchange events occurring between the wave packets that form matter structures against the backdrop of environmental noise.  The WEX principle suggests that wave energy exchange events are constantly occurring in all matter structures and at all scales independent of whether they can be detected by scientific instruments.

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Schrödinger’s Cat and Nested Observer Paradoxes

 

This paradox involves placing a cat in a box with a radioactive atom, Geiger counter, and a vial of poison.  The Geiger counter will detect if the atom decays and is set up to break the vial which releases the poison and kills the cat.  It is unclear in standard quantum theory whether the cat qualifies as an observer nor whether the cat exists on the quantum or classical side of the undefined boundary between the two.  Given the lack of definitions, the paradox emerges when the cat is treated as part of the quantum system with everything else inside the box, resulting in the cat being viewed as existing in a "superposition" of simultaneously alive and dead until the box is opened and the cat’s fate is observed (and hopefully still alive!).​

 

Applying the WEX definitions to this paradox leads to the radioactive atom being the only relevant quantum system that needs to be described by a wave function to model the state of the cat.  The Geiger counter acts as a measurement device which detects whether the atom has released energy.  Neither the Geiger counter, vial, or cat should be included within the wave function.  The Geiger counter is excluded because the WEX definition of a quantum system explicitly excludes measurement devices from the system it observes.  The vial and cat are excluded because they are not involved in energy exchange.  The relevant boundary to define the wave function of the system is the atom alone.  WEX treats the cat as always possessing a definite physical state, while the radioactive atom is the quantum system whose decay probability determines the statistics of that state.

 

More complex versions of the Schrödinger’s Cat paradox involving multiple nested measurement devices and observers (e.g. Wigner’s Friend and Frauchiger-Renner paradoxes) are similarly resolved by recognizing the WEX principle explicitly excludes observers inside quantum systems.  The Frauchiger-Renner paradox leads to the claim that one of the following three core assumptions in the foundations of quantum physics must be incorrect:

 

1. Universality: Quantum theory can be applied to everything, including observers and measurement devices.

2. Consistency: Two physicists performing the same calculations on a quantum system will agree on the resulting statistical predictions of the system.

3. Single Outcomes: Two physicists observing the same measurement of a quantum system will agree on the result.

 

Adopting the WEX definition of a quantum system narrows the scope of the “Universality” definition above by “explicitly excluding” observers and measurement devices rather than “explicitly including” them.  This dissolves the Frauchiger-Renner paradox at its source rather than requiring revision to the other core assumptions.

 

Double Slit Experiment

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The double slit experiment is the most well-known quantum experiment because it directly illustrates the wave nature of matter.  A photon wave packet emitted from a light source will spread out over the region of space between the source and a barrier with two slits.  The wave packet will pass through both slits then begin spreading out as a bi-modal wave packet emerging from the two slits on the other side of the barrier.   As this bi-modal wave packet approaches the screen it will begin to interfere with itself, and when it hits the screen, it transfers its energy to the screen, appearing as a particle signature somewhere on the screen.

 

Successive photon wave packets produce a series of particle signature impacts that are distributed on the screen according to the statistics of a single self-interfering wave packet, resulting in the classic double slit interference pattern on the screen which directly illustrates the wave nature of matter.  This description is consistent with the WEX principle as the wave packets travel through both slits in their intrinsic wave state and appear as particle signatures when they transfer a quantum of energy to the screen.  The detection screen is an Absorbing Structure as defined above, dense enough that a measurement is essentially certain to occur somewhere on its surface, with the Born rule governing where each photon's particle signature appears.