Interesting,

There have been quite a few theories that the answer is yes, and that truly, as the old saw goes 'a watched teapot never boils'.

See also http://arxivblog.com/?p=370

It's mostly interesting though for what it says about ψ(a,b,c,d .....) , to wit many-variable wavefunctions, and it furthermore gibes with other results acquired independently, so I'd be extremely interested if anyone could falsify a yes answer to the question.

The answer: Yes, of course! Its a wonderful goal for students to proof it mathematically with Clifford algebra. Last Clifford meeting in Weimar we discussed this matter with much red wine the last night of the meeting

I would like to revisit this question if I may.

Off line, some physicists aver that the QZE does not apply to macroscopic systems.

My take is that as long as the wave function of an ensemble of variables can be properly defined, and that wave function satisfies Schrödinger's equation, and none of the constituent variables has undergone decoherence, then the QZE does apply to that ensemble as well, however macroscopic it may happen to be.

In other words, if the QZE applied to one particle systems only , then the very definition of the wave function of a collective ensemble would have to be redefined, and there would be a fundamental, qualitative difference between Ψ(a) and Ψ(a, b, c, d....)

What is your view?