  It is argued that the Schr\"odinger equation does not yield a correct
description of the quantum-mechanical time evolution of states of isolated
(open) systems featuring events. A precise general law for the time evolution
of states replacing the Schr\"odinger equation is formulated within the
so-called ETH-Approach to Quantum Mechanics. This law eliminates the infamous
"measurement problem." Our general results are illustrated by an analysis of
simple models describing a very heavy atom coupled to the quantized radiation
field in a limit where the speed of light tends to infinity. The discussion of
these models is the main subject of our paper.
