  Two categories of results regarding quantum measurements are derived in this
work and applied to the problem of collapse. The first category is concerned
with local and transient features of the entanglement between a macroscopic
measuring system and a measured one. These properties result directly from the
Schr\"odinger equation. They cannot be formulated in terms of observables, do
not affect the wave functions themselves but express their history in an
irreversible way. They carry a specific new kind of local probabilities, which
evolve with a finite velocity under nonlinear wave equations. The second
category of results extends these local properties to the case of a macroscopic
system and its environment. Fluctuations in their interaction are predicted
then and generate a specific incoherence in the quantum state of the system.
These two kinds of effects act together when a macroscopic measuring system
interacts with a measured system and with an environment. Their combination
yields then an explicit and effective mechanism of collapse, with a random
behavior resulting from random incoherence. Born's basic probability rule for
the results of measurements turns out then simply a consequence of quantum
dynamics. Some conjectures still enter into the derivation of these effects,
which one may recognize to look hardly credible at first sight. They fit
however so well together that one proposes a more thorough investigation of
their approach as a promising strategy for a self-contained explanation of
collapse.
