From: The Information Philosopher
John von Neumann
In his 1932 Mathematical Foundations of Quantum Mechanics (in German, English edition 1955) John von Neumann explained that two fundamentally different processes are going on in quantum mechanics (in a temporal sequence for a given particle - not at the same time).
Process 1. A non-causal process, in which the measured electron winds up randomly in one of the possible physical states (eigenstates) of the measuring apparatus plus electron.
The probability for each eigenstate is given by the square of the coefficients cn of the expansion of the original system state (wave function ψ) in an infinite set of wave functions φ that represent the eigenfunctions of the measuring apparatus plus electron.
cn = < φn | ψ >
This is as close as we get to a description of the motion of the particle aspect of a quantum system. According to von Neumann, the particle simply shows up somewhere as a result of a measurement.
Process 2. A causal process, in which the electron wave function ψ evolves deterministically according to Erwin Schrödinger's equation of motion for the wavelike aspect. This evolution describes the motion of the probability amplitude wave ψ between measurements. The wave function exhibits interference effects. But interference is destroyed if the particle has a definite position or momentum. The particle path itself cannot be observed.
(ih/2π) ∂ψ/∂t = Hψ
Von Neumann claimed there is another major difference between these two processes. Process 1 is thermodynamically irreversible. Process 2 is reversible. This confirms the fundamental connection between quantum mechanics and thermodynamics that is explainable by information physics and the information interpretation of quantum mechanics.
Process 2 is deterministic and information preserving or conserving.
The first of these processes has come to be called the collapse of the wave function.
Examined from the point of view of Unified Absolute Relativity, it makes better sense to reverse the two:
The receiving atom, if now rendered out of equilibrium with its environment, that is with surrounding atoms, becomes an emitting or originating atom, emitting a wavefunction equivalent to the extra energy it had received. So a wavefunction from an originating atom (Process 2) transfers energy to a receiving atom (Process 1) which sets up a wavefunction in the received atom (Process 2) which has become an originating atom.
So Unified Absolute Relativity solves the measurement problem by amalgamating the two factors of the Neuman Process.