one essential correction to my earlier email (I accidentally wrote
"coherence"):
"if a discussion on entanglement
thought experiments (like Schrödinger's cat) does not address the notion of
*decoherence*, one can quite safely ignore it as outdated"
Enqvist's point is rather easy to understand: e.g. Schrödinger's cat cannot
maintain a quantum state because it interacts with the universe all the
time via heat radiation etc (I suppose some interactions could be minimized
in an experiment, but not all, for an object as large as a cat). There is
no need for a conscious observer as decoherence takes care of the wave
function.
I apologize the mistake; I didn't mean to distinguish entaglement from
coherence. OTOH this was a happy mistake as I'm learning more from John's
further discussion.